View source for Biofeedback

{{Short description|Gaining awareness of biological processes}}
{{Infobox medical intervention
|  Name        = Biofeedback
|  Image       = Biofeedback en.svg
|  Alt         = A person is connected to a computer with sensors, receiving information from the sensors via visual and sound information produced by the computer.
|  Caption     = A diagram showing the feedback loop between person, sensor, and processor to help provide biofeedback training
|  ICD10       = {{ICD10PCS|GZC|G/Z/C}}
|  ICD9        = {{ICD9|94.39}}
|  MeshID      = D001676
|  MedlinePlus = 002241
|  OtherCodes  = 
}}
[[File:Biofeedback training program for post-traumatic stress symptoms.jpg|thumb|Biofeedback device for treating [[posttraumatic stress disorder]]]]

'''Biofeedback''' is the technique of gaining greater [[awareness]] of many [[physiology|physiological]] functions of one's own body by using [[Electronics|electronic]] or other instruments, and with a [[goal]] of being able to [[Manipulation (psychology)|manipulate]] the body's systems at will. [[Human]]s conduct biofeedback naturally all the time, at varied levels of [[consciousness]] and intentionality. Biofeedback and the biofeedback loop can also be thought of as [[Emotional self-regulation|self-regulation]].<ref>{{cite book | last1 = Durand | first1 = Vincent Mark | last2 = Barlow | first2 = David | name-list-style = vanc |title=Abnormal psychology: an integrative approach |publisher=Wadsworth Cengage Learning |location=Belmont, CA |year=2009 |pages= [https://books.google.com/books?id=Mo_q4zFVNo4C&pg=PA331 331] |isbn=978-0-495-09556-9 }}</ref><ref name = AAPB>{{cite news|publisher=[[Association for Applied Psychophysiology and Biofeedback]]|title=What is Biofeedback|url=http://www.aapb.org/i4a/pages/index.cfm?pageid=1|others=(See bottom of page.)|date=18 May 2008|access-date=2015-03-05}}</ref>  Some of the processes that can be controlled include [[Electroencephalography|brainwaves]], [[muscle tone]], [[skin conductance]], [[heart rate]] and [[pain]] perception.<ref>{{cite journal |author-link=Christopher deCharms |author3-link=Gary H. Glover | vauthors = deCharms RC, Maeda F, Glover GH, Ludlow D, Pauly JM, Soneji D, Gabrieli JD, Mackey SC | display-authors = 6 | title = Control over brain activation and pain learned by using real-time functional MRI | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 51 | pages = 18626–31 | date = December 2005 | pmid = 16352728 | pmc = 1311906 | doi = 10.1073/pnas.0505210102 | bibcode = 2005PNAS..10218626D | doi-access = free }}</ref>

Biofeedback may be used to improve [[health]], performance, and the physiological changes that often occur in conjunction with changes to [[thought]]s, [[emotion]]s, and [[behavior]]. Recently, [[technologies]] have provided assistance with intentional biofeedback.  Eventually, these changes may be maintained without the use of extra equipment, for no equipment is necessarily required to practice biofeedback.<ref name = AAPB/>

[[Meta-analysis]] of different biofeedback treatments have shown some benefit in the treatment of [[headache]]s and [[migraine]]s and [[Attention deficit hyperactivity disorder|ADHD]], though most of the studies in these meta-analyses did not make comparisons with alternative treatments.<ref name="ncbi.nlm.nih.gov">Nestoriuc Y, Martin A. Efficacy of biofeedback for migraine: a meta-analysis. 2007. In: Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK73546/</ref><ref name="Efficacy of biofeedback for migrain">{{cite journal | vauthors = Nestoriuc Y, Martin A | title = Efficacy of biofeedback for migraine: a meta-analysis | journal = Pain | volume = 128 | issue = 1–2 | pages = 111–27 | date = March 2007 | pmid = 17084028 | doi = 10.1016/j.pain.2006.09.007 | s2cid = 23351902 }}</ref><ref name="Biofeedback treatment for headache">{{cite journal | vauthors = Nestoriuc Y, Martin A, Rief W, Andrasik F | title = Biofeedback treatment for headache disorders: a comprehensive efficacy review | journal = Applied Psychophysiology and Biofeedback | volume = 33 | issue = 3 | pages = 125–40 | date = September 2008 | pmid = 18726688 | doi = 10.1007/s10484-008-9060-3 | s2cid = 29122354 }}</ref>

==Information coded biofeedback==
'''Information coded biofeedback''' is an evolving form and methodology in the field of biofeedback.  Its uses may be applied in the areas of health, wellness and awareness.  Biofeedback has its modern conventional roots in the early 1970s.<ref name="ReferenceB">{{cite book|last1=Brown|first1=Barbara B | name-list-style = vanc |title=New mind, new body: Bio-feedback; new directions for the mind|url=https://archive.org/details/newmindnewbody00barb|url-access=registration|date=January 1, 1975|publisher=Bantam Books |isbn=9780553128741 }}</ref><ref>{{cite book|last1=Karlins|first1=Marvins | name-list-style = vanc |title=Biofeedback|date=January 1, 1973|publisher=Warner Paperback Library |isbn=978-0446760188}}</ref>

Over the years, biofeedback as a discipline and a technology has continued to mature and express new versions of the method with novel interpretations in areas utilizing the [[Electromyography|electromyograph]], electrodermograph, [[electroencephalograph]] and [[electrocardiogram]] among others.
The concept of biofeedback is based on the fact that a wide variety of ongoing intrinsic natural functions of the organism occur at a level of awareness generally called the "unconscious".<ref name="ReferenceB"/>  The biofeedback process is designed to interface with select aspects of these "unconscious" processes.

The definition reads:
Biofeedback is a process that enables an individual to learn how to change physiological activity for the purposes of improving health and performance. Precise instruments measure physiological activity such as brainwaves, heart function, breathing, muscle activity, and skin temperature. These instruments rapidly and accurately feed back information to the user. The presentation of this information—often in conjunction with changes in thinking, emotions, and behavior—supports desired physiological changes. Over time, these changes can endure without continued use of an instrument.<ref name="AAPB" />

A more simple definition could be:
Biofeedback is the process of gaining greater awareness of many physiological functions primarily using instruments that provide information on the activity of those same systems, with a goal of being able to manipulate them at will.<ref>{{cite book |last1=Durand |first1=Vincent Mark|last2=Barlow |first2= David| name-list-style = vanc |title=Abnormal psychology: an integrative approach|date=2009|location=Belmont, CA: Wadsworth Cengage Learning|isbn=978-0-495-09556-9|page=331}}</ref> (Emphasis{{Which|date=January 2023}} added by author.)

In both of these definitions, a cardinal feature of the concept is the association of the "will" with the result of a new cognitive "learning" skill.<ref>{{cite journal|last1=Brown|first1=Barbara B | name-list-style = vanc |title=Biological Awareness as a State of Consciousness|journal=Journal of Altered States of Consciousness|date=1975|volume=2|issue=1–14}}</ref> Some examine this concept and do not necessarily ascribe it simply to a willful acquisition of a new learned skill but also extend the dynamics into the realms of a behavioristic conditioning.<ref>{{cite journal|last1=Dupuis|first1=Garnet| name-list-style = vanc |title=The Unconscious and Its Role in Biofeedback Processes|journal=Center of International Studies|date=November 29, 2001}}</ref><ref>{{cite journal| vauthors = Sherlin LH, Arns M, Lubar J, Heinrich H, Kerson C, Strehl U, Sterman MB | title = Neurofeedback and Basic Learning Theory: Implications for Research and Practice. | journal = Journal of Neurotherapy | date = October 2011 | volume = 15 | issue = 4 | pages = 292–304 | doi = 10.1080/10874208.2011.623089 | doi-access = free }}</ref>  Behaviorism contends that it is possible to change the actions and functions of an organism by exposing it to a number of conditions or influences.  Key to the concept is not only that the functions are unconscious but that conditioning processes themselves may be unconscious to the organism.<ref>{{cite book| vauthors = Skinner BF |title=About Behaviorism|date=1974|publisher=Knopf Doubleday Publishing |isbn=978-0-394-71618-3}}</ref>  Information coded biofeedback relies primarily on the behavior conditioning aspect of biofeedback in promoting significant changes in the functioning of the organism.

The principle of information is both complex and, in part, controversial. The term itself is derived from the Latin verb {{Lang|la|informare}} which means literally 'to bring into form or shape'.  The meaning of ''information'' is largely affected by the context of usage.  Probably the simplest and perhaps most insightful definition of ''information'' was given by Gregory Bateson—"Information is news of change" or another as "the difference that makes a difference".<ref>{{cite book|last1=Bateson|first1=Gregory| name-list-style = vanc |title=Form, Substance, and Difference, in Steps to an Ecology of Mind|publisher=University of Chicago Press|date=1972}}</ref>   Information may also be thought of as "any type of pattern that influences the formation or transformation of other patterns".<ref>{{cite book|last1=Claude|first1=Shannon| name-list-style = vanc |title=The Mathematical Theory of Communication|date=1949|bibcode=1949mtc..book.....S }}</ref>  Recognizing the inherent [[complexity]] of an organism, information coded biofeedback applies algorithmic calculations in a [[stochastic]] approach to identify significant probabilities in a limited set of possibilities.

==Sensor modalities==

===Electromyograph===
[[File:Muscle Whistler with EMG surface electrodes (1971).jpg|thumb|The "Muscle Whistler", shown here with surface EMG electrodes, was an early biofeedback device developed by [[Harry Garland]] and [[Roger Melen]] in 1971.<ref>{{Cite journal | journal = Popular Electronics | title = Build the Muscle Whistler | last1 = Garland | first1 = Harry | last2 = Melen | first2 = Roger | name-list-style = vanc | volume = 35 | issue = 5 | pages = 60–62 | year = 1971 }}</ref><ref name="Whistler"/>]]
An [[electromyograph]] ([[Electromyography|EMG]]) uses surface electrodes to detect muscle action potentials from underlying skeletal muscles that initiate muscle contraction. Clinicians record the surface electromyogram (SEMG) using one or more active electrodes that are placed over a target muscle and a reference electrode that is placed within six inches of either active. The SEMG is measured in [[microvolt]]s (millionths of a volt).<ref>{{cite book | vauthors = Tassinary LG, Cacioppo JT, Vanman EJ | date = 2007 | chapter = The skeletomotor system: Surface electromyography. | veditors = Cacioppo JT, Tassinary LG, Berntson GG | title = Handbook of psychophysiology | edition = 3rd | location = New York | publisher = Cambridge University Press }}</ref><ref>{{cite book | vauthors = Florimond V | date = 2009 | title = Basics of surface electromyography applied to physical rehabilitation and biomechanics | location = Montreal | publisher = Thought Technology Ltd. }}</ref>

In addition to surface electrodes, clinicians may also insert wires or needles intramuscularly to record an EMG signal. While this is more painful and often costly, the signal is more reliable since surface electrodes pick up cross talk from nearby muscles.  The use of surface electrodes is also limited to superficial muscles, making the intramuscular approach beneficial to access signals from deeper muscles. The electrical activity picked up by the electrodes is recorded and displayed in the same fashion as the surface electrodes.<ref>{{cite web|title=Electromyography (EMG)|url=http://www.hopkinsmedicine.org/healthlibrary/test_procedures/neurological/electromyography_emg_92,P07656/|work=Johns Hopkins Medicine|access-date=2014-03-18}}</ref> Prior to placing surface electrodes, the skin is normally shaved, cleaned and exfoliated to get the best signal. Raw EMG signals resemble noise (electrical signal not coming from the muscle of interest) and the voltage fluctuates; therefore, they are processed normally in three ways: rectification, filtering, and integration. This processing allows for a unified signal that is then able to be compared to other signals using the same processing techniques.

Biofeedback therapists use EMG biofeedback when treating [[anxiety]] and [[worry]], [[chronic pain]], computer-related disorder, [[essential hypertension]], headache (migraine, mixed headache, and [[tension-type headache]]), [[low back pain]], [[physical rehabilitation]] ([[cerebral palsy]], incomplete spinal cord lesions, and [[stroke]]), [[temporomandibular joint dysfunction]] (TMD), [[torticollis]], and [[fecal incontinence]], [[urinary incontinence]], and [[pelvic pain]].<ref>{{cite book | vauthors = Peper E, Gibney KH | year = 2006 | title = Muscle biofeedback at the computer: A manual to prevent repetitive strain injury (RSI) by taking the guesswork out of assessment, monitoring, and training | location = Amersfoort, The Netherlands | publisher = BFE | url = http://www.aapb.org/tl_files/AAPB/files/biof_35_2_biofeedback.pdf | archive-url = https://web.archive.org/web/20101019023511/http://aapb.org/tl_files/AAPB/files/biof_35_2_biofeedback.pdf | archive-date = 2010-10-19 }}</ref><ref name = Yucha2008>{{cite book | vauthors = Yucha C, Montgomery D | year = 2008 | title = Evidence-based practice in biofeedback and neurofeedback | location =Wheat Ridge, CO | publisher = AAPB | url = http://www.isnr.org/uploads/EvidenceBasedYuchaMontgomeryW.pdf | archive-url = https://web.archive.org/web/20101009135554/http://isnr.org/uploads/EvidenceBasedYuchaMontgomeryW.pdf | archive-date = 2010-10-09 }}</ref> Physical therapists have also used EMG biofeedback for evaluating muscle activation and providing feedback for their patients.<ref name="Whistler">{{cite journal | vauthors = Forward E | title = Patient evaluation with an audio electromyogram monitor: "The Muscle Whistler" | journal = Physical Therapy | volume = 52 | issue = 4 | pages = 402–3 | date = April 1972 | pmid = 5012359 | doi = 10.1093/ptj/52.4.402 }}</ref>

===Feedback thermometer===
A feedback thermometer detects skin temperature with a [[thermistor]] (a temperature-sensitive resistor) that is usually attached to a finger or toe and measured in degrees Celsius or Fahrenheit. Skin temperature mainly reflects [[arteriole]] diameter. Hand-warming and hand-cooling are produced by separate mechanisms, and their regulation involves different skills.<ref name="Andreassi, J. L. 2007">{{cite book | vauthors = Andreassi JL | date = 2007 | title = Psychophysiology: Human behavior and physiological response | edition = 5th | location = Hillsdale, NJ | publisher = Lawrence Erlbaum and Associates, Inc }}</ref> Hand-warming involves arteriole [[vasodilation]] produced by a beta-2 adrenergic hormonal mechanism.<ref>{{cite journal | vauthors = Cohen RA, Coffman JD | title = Beta-adrenergic vasodilator mechanism in the finger | journal = Circulation Research | volume = 49 | issue = 5 | pages = 1196–201 | date = November 1981 | pmid = 6117377 | doi = 10.1161/01.res.49.5.1196 | doi-access = free }}</ref> Hand-cooling involves arteriole [[vasoconstriction]] produced by the increased firing of [[Sympathetic nervous system|sympathetic]] [[C-fiber]]s.<ref>{{cite journal | vauthors = Freedman RR, Sabharwal SC, Ianni P, Desai N, Wenig P, Mayes M | title = Nonneural beta-adrenergic vasodilating mechanism in temperature biofeedback | journal = Psychosomatic Medicine | volume = 50 | issue = 4 | pages = 394–401 | year = 1988 | pmid = 2842815 | doi = 10.1097/00006842-198807000-00007 | s2cid = 24316214 }}</ref>

Biofeedback therapists use temperature biofeedback when treating chronic pain, [[edema]], headache (migraine and tension-type headache), essential hypertension, [[Raynaud's phenomenon|Raynaud's disease]], anxiety, and [[Stress (biology)|stress]].<ref name = Yucha2008/>

===Electrodermograph===
An electrodermograph (EDG) measures skin electrical activity directly (skin conductance and skin potential) and indirectly (skin resistance) using electrodes placed over the digits or hand and wrist. Orienting responses to unexpected stimuli, arousal and worry, and cognitive activity can increase [[eccrine]] sweat gland activity, increasing the conductivity of the skin for electric current.<ref name="Andreassi, J. L. 2007"/>
 
In ''skin conductance'', an electrodermograph imposes an imperceptible current across the skin and measures how easily it travels through the skin. When anxiety raises the level of sweat in a sweat duct, conductance increases. Skin conductance is measured in microsiemens (millionths of a [[siemens (unit)|siemens]]). In ''skin potential'', a therapist places an active electrode over an active site (e.g., the palmar surface of the hand) and a reference electrode over a relatively inactive site (e.g., forearm). Skin potential is the voltage that develops between eccrine sweat glands and internal tissues and is measured in millivolts (thousandths of a volt). In ''skin resistance'', also called [[galvanic skin response]] (GSR), an electrodermograph imposes a current across the skin and measures the amount of opposition it encounters. Skin resistance is measured in kΩ (thousands of ohms).<ref>{{cite book | vauthors = Dawson ME, Schell AM, Filion DL | date = 2007 | chapter = The electrodermal system. | veditors = Cacioppo JT, Tassinary LG, Berntson GG | title = Handbook of psychophysiology | edition = 3rd | location = New York | publisher = Cambridge University Press }}</ref>

Biofeedback therapists use electrodermal biofeedback when treating [[anxiety disorders]], [[hyperhidrosis]] (excessive sweating), and stress.<ref name = Yucha2008/><ref>{{cite book | vauthors = Moss D | date = 2003 | chapter = The anxiety disorders. | veditors = Moss D, McGrady A, Davies T, Wickramasekera I | title = Handbook of mind-body medicine in primary care | pages = 359–375 | location = Thousand Oaks, CA | publisher = Sage }}</ref> Electrodermal biofeedback is used as an adjunct to psychotherapy to increase client awareness of their emotions.<ref name="Toomim, M. 1975">{{cite journal | vauthors = Toomim MK, Toomim H | year = 1975 | title = GSR biofeedback in psychotherapy: Some clinical observations | journal = Psychotherapy: Theory, Research & Practice | volume = 12 | issue = 1| pages = 33–8 | doi = 10.1037/h0086402 }}</ref><ref>{{cite journal | vauthors = Moss D | year = 2005 | title = Psychophysiological psychotherapy: The use of biofeedback, biological monitoring, and stress management principles in psychotherapy | journal = Psychophysiology Today  | volume = 2 | issue = 1| pages = 14–18 }}</ref> In addition, electrodermal measures have long served as one of the central tools in [[polygraphy]] ([[lie detection]]) because they reflect changes in anxiety or emotional activation.<ref>{{cite journal | vauthors = Pennebaker JW, Chew CH | title = Behavioral inhibition and electrodermal activity during deception | journal = Journal of Personality and Social Psychology | volume = 49 | issue = 5 | pages = 1427–33 | date = November 1985 | pmid = 4078683 | doi = 10.1037/0022-3514.49.5.1427 }}</ref>

===Electroencephalograph===
An [[electroencephalograph]] (EEG) measures the electrical activation of the brain from scalp sites located over the human cortex.  The EEG shows the amplitude of electrical activity at each cortical site, the amplitude and relative power of various wave forms at each site, and the degree to which each cortical site fires in conjunction with other cortical sites (coherence and symmetry).<ref>{{cite book | vauthors = Kropotov JD | date = 2009 | title = Quantitative EEG, event-related potentials and neurotherapy. | location = San Diego, CA | publisher = Academic Press }}</ref>

The EEG uses precious metal electrodes to detect a voltage between at least two electrodes located on the scalp. The EEG records both excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) that largely occur in dendrites in pyramidal cells located in macrocolumns, several millimeters in diameter, in the upper cortical layers. [[Neurofeedback]] monitors both slow and fast cortical potentials.<ref name="Thompson, M. 2003">{{cite book | vauthors = Thompson M, Thompson L | date = 2003 | title = The biofeedback book: An introduction to basic concepts in applied psychophysiology. | location = Wheat Ridge, CO | publisher = Association for Applied Psychophysiology and Biofeedback }}</ref>

Slow cortical potentials are gradual changes in the membrane potentials of cortical dendrites that last from 300 ms to several seconds. These potentials include the [[contingent negative variation]] (CNV), [[readiness potential]], [[movement-related potentials]] (MRPs), and [[P300 (neuroscience)|P300]] and [[N400 (neuroscience)|N400]] potentials.<ref name="Stern, R. M. 2001">{{cite book | vauthors = Stern RM, Ray WJ, Quigley KS | date = 2001 | title = Psychophysiological recording | url = https://archive.org/details/psychophysiologi00robe | url-access = registration | edition = 2nd | location = New York | publisher = Oxford University Press }}</ref>

Fast cortical potentials range from 0.5&nbsp;Hz to 100&nbsp;Hz.<ref>{{cite book | vauthors = LaVaque TJ | date = 2003 | chapter = Neurofeedback, Neurotherapy, and quantitative EEG | veditors = Moss D, McGrady A, Davies T, Wickramasekera I | title = Handbook of mind-body medicine for primary care | pages = 123–136 | location = Thousand Oaks, CA | publisher = Sage }}</ref> The main frequency ranges include delta, theta, alpha, the sensorimotor rhythm, low beta, high beta, and gamma. The thresholds or boundaries defining the frequency ranges vary considerably among professionals. Fast cortical potentials can be described by their predominant frequencies, but also by whether they are synchronous or asynchronous wave forms. Synchronous wave forms occur at regular periodic intervals, whereas asynchronous wave forms are irregular.<ref name="Thompson, M. 2003"/>

The synchronous [[delta rhythm]] ranges from 0.5 to 3.5&nbsp;Hz. Delta is the dominant frequency from ages 1 to 2, and is associated in adults with deep sleep, critical for memory, cognition, sleep maintenance, and mental health. Disorders that disrupt sleep such as insomnia, traumatic brain injury, obstructive sleep apnea, and other neuropsychiatric conditions are also associated with the delta rhythm.<ref>{{Cite journal |last1=Uygun |first1=David S. |last2=Basheer |first2=Radhika |date=2022-10-01 |title=Circuits and components of delta wave regulation |journal=Brain Research Bulletin |volume=188 |pages=223–232 |doi=10.1016/j.brainresbull.2022.06.006 |issn=1873-2747 |pmc=9680038 |pmid=35738502}}</ref>

The synchronous [[theta rhythm]] ranges from 4 to 7&nbsp;Hz. Theta is the dominant frequency in healthy young children and is associated with drowsiness or starting to sleep, REM sleep, hypnagogic imagery (intense imagery experienced before the onset of sleep), hypnosis, attention, and processing of cognitive and perceptual information.

The synchronous [[alpha rhythm]] ranges from 8 to 13&nbsp;Hz and is defined by its waveform and not by its frequency. Alpha activity can be observed in about 75% of awake, relaxed individuals and is replaced by low-amplitude desynchronized beta activity during movement, complex problem-solving, and visual focusing. This phenomenon is called alpha blocking.

The synchronous [[sensorimotor rhythm]] (SMR) ranges from 12 to 15&nbsp;Hz and is located over the sensorimotor cortex (central sulcus). The sensorimotor rhythm is associated with the inhibition of movement and reduced muscle tone.

The [[beta rhythm]] consists of asynchronous waves and can be divided into low beta and high beta ranges (13–21&nbsp;Hz and 20–32&nbsp;Hz). Low beta is associated with activation and focused thinking. High beta is associated with anxiety, [[hypervigilance]], [[panic]], peak performance, and [[worry]].

EEG activity from 36 to 44&nbsp;Hz is also referred to as gamma. Gamma activity is associated with perception of meaning and meditative awareness.<ref name="Thompson, M. 2003"/><ref>{{cite book | vauthors = Steriade M | date =  2005 | chapter = Cellular substrates of brain rhythms. | veditors = Niedermeyer E, Lopes da Silva F | title = Electroencephalography: Basic principles, clinical applications, and related fields | edition = 5th | location = Philadelphia | publisher = Lippincott Williams & Wilkins }}</ref><ref name="Shaffer">{{cite book | vauthors = Shaffer F, Moss D | date = 2006 | chapter = Biofeedback | veditors = Yuan CS, Bieber EJ, Bauer BA | title = Textbook of complementary and alternative medicine | edition = 2nd | pages = 291–312 | location = Abingdon, Oxfordshire, UK | publisher = Informa Healthcare }}</ref>

Neurotherapists use EEG biofeedback when treating [[Substance use disorder|addiction]], [[attention deficit hyperactivity disorder]] (ADHD), [[learning disability]], anxiety disorders (including [[worry]], [[obsessive-compulsive disorder]] and posttraumatic stress disorder), [[Major depressive disorder|depression]], migraine, and [[generalized seizures]].<ref name = Yucha2008/><ref>{{cite book | vauthors = Budzynski TH, Budzynski HK, Evans JR, Abarbanel A | date = 2009 | title = Introduction to quantitative EEG and neurofeedback | edition = 2nd | location = Burlington, MA | publisher = Academic Press }}</ref>

===Photoplethysmograph===
[[File:EmWave2, powering up.jpg|thumb|180px|upright|An ''emWave2'' photoplethysmograph for monitoring heart rate variability]]

[[File:Photoplethysmograph - Biofeedback HRV with ear sensor.jpg|thumb|180px|upright| ''Stone'' computer-based photoplethysmograph with ear sensor]]

A [[photoplethysmograph]] (PPG) measures the relative blood flow through a digit using a photoplethysmographic (PPG) sensor attached by a Velcro band to the fingers or to the temple to monitor the [[Superficial temporal artery|temporal artery]]. An infrared light source is transmitted through or reflected off the tissue, detected by a [[phototransistor]], and quantified in arbitrary units. Less light is absorbed when blood flow is greater, increasing the intensity of light reaching the sensor.<ref name="Combatalade, D. 2009">Combatalade, D. (2009). ''Basics of heart rate variability applied to psychophysiology''. Montreal, Canada: Thought Technology Ltd.</ref>

A photoplethysmograph can measure blood volume pulse (BVP), which is the phasic change in blood volume with each heartbeat, heart rate, and [[heart rate variability]] (HRV), which consists of beat-to-beat differences in intervals between successive heartbeats.<ref name="Lehrer, P. M. 2007 P. M">{{cite book | vauthors = Lehrer PM | date = 2007 | chapter = Biofeedback training to increase heart rate variability. | veditors = Lehrer PM, Woolfolk RM, Sime WE | title = Principles and practice of stress management | edition = 3rd | location = New York | publisher = The Guilford Press }}</ref><ref>{{cite journal | vauthors = Peper E, Harvey R, Lin IM, Tylova H, Moss D | year = 2007 | title = Is there more to blood volume pulse than heart rate variability, respiratory sinus arrhythmia, and cardio-respiratory synchrony? | journal = Biofeedback | volume = 35 | issue = 2| pages = 54–61 }}</ref>

A photoplethysmograph can provide useful feedback when temperature feedback shows minimal change. This is because the PPG sensor is more sensitive than a thermistor to minute blood flow changes.<ref name="Shaffer" />  Biofeedback therapists can use a photoplethysmograph to supplement temperature biofeedback when treating chronic pain, edema, headache (migraine and tension-type headache), essential hypertension, Raynaud's disease, anxiety, and stress.<ref name = Yucha2008/>

===Electrocardiogram===
The [[electrocardiogram]] (ECG) uses electrodes placed on the torso, wrists, or legs, to measure the electrical activity of the heart and measures the [[interbeat interval]] (distances between successive [[R-wave]] peaks in the [[QRS complex]]). The interbeat interval, divided into 60 seconds, determines the heart rate at that moment. The statistical variability of that interbeat interval is what we call heart rate variability.<ref>{{cite book | vauthors = Berntson GG, Quigley KS, Lozano D | date = 2007 | chapter = Cardiovascular psychophysiology. | veditors = Cacioppo JT, Tassinary LG, Berntson GG | title = Handbook of psychophysiology | edition = 3rd | location = New York | publisher = Cambridge University Press }}</ref> The ECG method is more accurate than the PPG method in measuring heart rate variability.<ref name="Combatalade, D. 2009"/><ref name=":0">{{cite journal | author = Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology | title = Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology | journal = Circulation | volume = 93 | issue = 5 | pages = 1043–65 | date = March 1996 | pmid = 8598068 | doi = 10.1161/01.cir.93.5.1043 }}</ref>

Biofeedback therapists use [[heart rate variability]] (HRV) biofeedback when treating [[asthma]],<ref>{{cite journal | vauthors = Lehrer PM, Vaschillo E, Vaschillo B, Lu SE, Scardella A, Siddique M, Habib RH | title = Biofeedback treatment for asthma | journal = Chest | volume = 126 | issue = 2 | pages = 352–61 | date = August 2004 | pmid = 15302717 | doi = 10.1378/chest.126.2.352 }}</ref> [[COPD]],<ref>{{cite journal | vauthors = Giardino ND, Chan L, Borson S | title = Combined heart rate variability and pulse oximetry biofeedback for chronic obstructive pulmonary disease: preliminary findings | journal = Applied Psychophysiology and Biofeedback | volume = 29 | issue = 2 | pages = 121–33 | date = June 2004 | pmid = 15208975 | doi = 10.1023/B:APBI.0000026638.64386.89 | s2cid = 21774729 }}</ref> depression,<ref name="Preliminary results of an open labe">{{cite journal | vauthors = Karavidas MK, Lehrer PM, Vaschillo E, Vaschillo B, Marin H, Buyske S, Malinovsky I, Radvanski D, Hassett A | display-authors = 6 | title = Preliminary results of an open label study of heart rate variability biofeedback for the treatment of major depression | journal = Applied Psychophysiology and Biofeedback | volume = 32 | issue = 1 | pages = 19–30 | date = March 2007 | pmid = 17333315 | doi = 10.1007/s10484-006-9029-z | s2cid = 31614375 }}</ref> anxiety,<ref>{{cite journal | vauthors = Trousselard M, Canini F, Claverie D, Cungi C, Putois B, Franck N | title = Cardiac Coherence Training to Reduce Anxiety in Remitted Schizophrenia, a Pilot Study | journal = Applied Psychophysiology and Biofeedback | volume = 41 | issue = 1 | pages = 61–9 | date = March 2016 | pmid = 26346569 | pmc = 4749648 | doi = 10.1007/s10484-015-9312-y }}</ref> [[fibromyalgia]],<ref>{{cite journal | vauthors = Hassett AL, Radvanski DC, Vaschillo EG, Vaschillo B, Sigal LH, Karavidas MK, Buyske S, Lehrer PM | display-authors = 6 | title = A pilot study of the efficacy of heart rate variability (HRV) biofeedback in patients with fibromyalgia | journal = Applied Psychophysiology and Biofeedback | volume = 32 | issue = 1 | pages = 1–10 | date = March 2007 | pmid = 17219062 | doi = 10.1007/s10484-006-9028-0 | s2cid = 17033799 }}</ref> [[heart disease]],<ref>{{cite journal | vauthors = Cowan MJ, Pike KC, Budzynski HK | title = Psychosocial nursing therapy following sudden cardiac arrest: impact on two-year survival | journal = Nursing Research | volume = 50 | issue = 2 | pages = 68–76 | year = 2001 | pmid = 11302295 | doi = 10.1097/00006199-200103000-00002 }}</ref> and unexplained [[abdominal pain]].<ref>{{cite journal | vauthors = Humphreys PA, Gevirtz RN | title = Treatment of recurrent abdominal pain: components analysis of four treatment protocols | journal = Journal of Pediatric Gastroenterology and Nutrition | volume = 31 | issue = 1 | pages = 47–51 | date = July 2000 | pmid = 10896070 | doi = 10.1097/00005176-200007000-00011 | doi-access = free }}</ref> Research shows that HRV biofeedback can also be used to improve physiological and psychological wellbeing in healthy individuals.<ref name = "Barrios-Choplin_1997">{{cite journal | vauthors = Barrios-Choplin BO, McCraty RO, Cryer B |date=July 1997 |title=An inner quality approach to reducing stress and improving physical and emotional wellbeing at work|journal=Stress Medicine |volume=13 |issue=3 |pages=193–201 |doi=10.1002/(sici)1099-1700(199707)13:3<193::aid-smi744>3.0.co;2-i }}</ref>

HRV data from both polyplethysmographs and electrocardiograms are analyzed via mathematical transformations such as the commonly used [[fast Fourier transform]] (FFT).<ref name=":0" /> The FFT splits the HRV data into a [[Spectral density|power spectrum]], revealing the waveform's constituent frequencies.<ref name="Combatalade, D. 2009" /> Among those constituent frequencies, high-frequency (HF) and low-frequency (LF) components are defined as above and below .15&nbsp;Hz, respectively. As a rule of thumb, the LF component of HRV represents sympathetic activity, and the HF component represents parasympathetic activity. The two main components are often represented as a LF/HF ratio and used to express sympathovagal balance.<ref name="Combatalade, D. 2009" /> Some researchers consider a third, medium-frequency (MF) component from .08&nbsp;Hz to .15&nbsp;Hz, which has been shown to increase in power during times of appreciation.<ref>{{cite journal | vauthors = McCraty R, Atkinson M, Tiller WA, Rein G, Watkins AD | title = The effects of emotions on short-term power spectrum analysis of heart rate variability | journal = The American Journal of Cardiology | volume = 76 | issue = 14 | pages = 1089–93 | date = November 1995 | pmid = 7484873 | doi = 10.1016/s0002-9149(99)80309-9 }}</ref>

===Pneumograph===
A [[pneumograph]] or respiratory strain gauge uses a flexible sensor band that is placed around the chest, abdomen, or both. The strain gauge method can provide feedback about the relative expansion/contraction of the chest and abdomen, and can measure [[respiratory rate]] (the number of breaths per minute).<ref name="Stern, R. M. 2001"/> Clinicians can use a pneumograph to detect and correct dysfunctional breathing patterns and behaviors. Dysfunctional breathing patterns include [[clavicular breathing]] (breathing that primarily relies on the [[external intercostals]] and the [[accessory muscles of respiration]] to inflate the lungs), reverse breathing (breathing where the abdomen expands during exhalation and contracts during inhalation), and [[thoracic breathing]] (shallow breathing that primarily relies on the external intercostals to inflate the lungs). Dysfunctional breathing behaviors include [[apnea]] (suspension of breathing), gasping, sighing, and wheezing.<ref name="Peper, E. 2008">{{cite book | vauthors = Peper E, Tylova H, Gibney KH, Harvey R, Combatalade D | date = 2008 | title = Biofeedback mastery: An experiential teaching and self-training manual | location = Wheat Ridge, CO | publisher = Association for Applied Psychophysiology and Biofeedback }}</ref>

A pneumograph is often used in conjunction with an [[electrocardiograph]] (ECG) or photoplethysmograph (PPG) in heart rate variability (HRV) training.<ref name="Lehrer, P. M. 2007 P. M"/><ref>{{cite journal | vauthors = Lehrer PM, Vaschillo E, Vaschillo B | title = Resonant frequency biofeedback training to increase cardiac variability: rationale and manual for training | journal = Applied Psychophysiology and Biofeedback | volume = 25 | issue = 3 | pages = 177–91 | date = September 2000 | pmid = 10999236 | doi = 10.1023/A:1009554825745 | s2cid = 163754 }}</ref>

Biofeedback therapists use pneumograph biofeedback with patients diagnosed with anxiety disorders, asthma, chronic pulmonary obstructive disorder (COPD), essential hypertension, [[panic attacks]], and stress.<ref name = Yucha2008/><ref name="Fried, R. 1987">{{cite journal | vauthors = Fried R | date = 1987 | title = The hyperventilation syndrome: Research and clinical treatment | journal = Journal of Neurology, Neurosurgery, and Psychiatry | volume = 51 | issue = 12 | pages = 1600–1 | location = Baltimore | publisher = Johns Hopkins University Press | doi = 10.1136/jnnp.51.12.1600-b | pmid = 3146617 | pmc = 1032792 }}</ref>

===Capnometer===
A [[capnometer]] or [[capnograph]] uses an infrared detector to measure end-tidal {{chem|CO|2}} (the partial pressure of carbon dioxide in expired air at the end of expiration) exhaled through the nostril into a latex tube. The average value of end-tidal {{chem|CO|2}} for a resting adult is 5% ({{convert|36|torr|kPa|abbr=on|disp=or}}). A capnometer is a sensitive index of the quality of patient breathing. Shallow, rapid, and effortful breathing lowers {{chem|CO|2}}, while deep, slow, effortless breathing increases it.<ref name="Peper, E. 2008"/>

Biofeedback therapists use capnometric biofeedback to supplement respiratory strain gauge biofeedback with patients diagnosed with anxiety disorders, asthma, chronic pulmonary obstructive disorder (COPD), essential hypertension, panic attacks, and stress.<ref name = Yucha2008/><ref name="Fried, R. 1987"/><ref>{{cite book | vauthors = Fried R | date = 1993 | title = The psychology and physiology of breathing | location = New York | publisher = Plenum Press }}</ref>

===Rheoencephalograph===

[[Rheoencephalography]] (REG), or brain blood flow biofeedback, is a biofeedback technique of a conscious control of blood flow. An electronic device called a [[rheoencephalograph]] [from Greek {{lang|grc-Latn|rheos}} 'stream, anything flowing', from {{lang|grc-Latn|rhein}} 'to flow'] is utilized in brain blood flow biofeedback. Electrodes are attached to the skin at certain points on the head and permit the device to measure continuously the electrical conductivity of the tissues of structures located between the electrodes. The brain blood flow technique is based on non-invasive method of measuring bio-impedance. Changes in bio-impedance are generated by blood volume and blood flow and registered by a rheographic device.<ref>{{cite conference | vauthors = Tokarev VE | title = A Rheoencephalogram (REG) Variability System Based on ISKRA-226 Personal Computer | conference = Institute for Complex Problem of Hygiene Healthcare Conference | location = Novokuznetsk, Russia | date = 1989 | pages = 115–116 }}</ref> The pulsative bio-impedance changes directly reflect the total blood flow of the deep structures of brain due to high frequency impedance measurements.<ref>{{cite conference | vauthors = Tokarev VE | title = Regulatory Mechanisms of Physiological Systems During REG Biofeedback | conference = 25th Annual Meeting of Association of Applied Psychophysiology and Biofeedback | location = Atlanta, USA | date =  1994 }}</ref>

===Hemoencephalography===
[[Hemoencephalography]] or HEG biofeedback is a functional [[infrared]] imaging technique. As its name describes, it measures the differences in the color of light reflected back through the scalp based on the relative amount of oxygenated and unoxygenated blood in the brain. Research continues to determine its reliability, validity, and clinical applicability. HEG is used to treat [[ADHD]] and migraine, and for research.<ref>{{cite book | vauthors = Toomim H, Carmen J | chapter = Homoencephalography: Photon-based blood flow neurofeedback. | veditors = Budzynski TH, Budzynski HK, Evans JR, Abarbanel A | date = 2009 | title = Introduction to quantitative EEG and neurofeedback | edition = 2nd | location = Burlington, MA | publisher = Academic Press }}</ref>

=== Pressure ===
Pressure can be monitored as a patient performs exercises while resting against an air-filled cushion.<ref>{{Cite web|url=http://www.sportstek.net/pressure_biofeedback.htm|title=Chattanooga Stabilizer Pressure Biofeeedback}}</ref>  This is pertinent to [[physiotherapy]]. Alternatively, the patient may actively grip or press against an air-filled cushion of custom shape.<ref>[http://pressureairbiofeedback.com/index.html pab®, Pressure Air Biofeedback]</ref>

==Applications==

===Urinary incontinence===
Mowrer detailed the use of a bedwetting alarm that sounds when children urinate while asleep. This simple biofeedback device can quickly teach children to wake up when their bladders are full and to contract the urinary sphincter and relax the detrusor muscle, preventing further urine release. Through classical conditioning, sensory feedback from a full bladder replaces the alarm and allows children to continue sleeping without urinating.<ref>{{cite book | vauthors = Mowrer OH | date = 1960 | title = Learning theory and behavior | url = https://archive.org/details/learningtheorybe00mowr | location = New York | publisher = Wiley }}</ref>

[[Arnold Kegel|Kegel]] developed the perineometer in 1947 to treat urinary incontinence (urine leakage) in women whose pelvic floor muscles are weakened during pregnancy and childbirth. The perineometer, which is inserted into the vagina to monitor pelvic floor muscle contraction, satisfies all the requirements of a biofeedback device and enhances the effectiveness of popular Kegel exercises.<ref>{{cite conference | vauthors = Perry JD, Talcott LB | date = 1989 | title = The Kegel Perineometer: Biofeedback Twenty Years Before Its Time. A "Special Historical Paper." | conference = Proceedings of the 20th Annual Meeting of the Association for Applied Psychophysiology and Biofeedback | location = San Diego, CA | pages = 169–172 }}</ref> Contradicting this, a 2023 [[Systematic review|Systematic Review]] of the literature including eight studies found the scientific evidence to compare pelvic floor muscle training for urinary and anal incontinence after childbirth with and without biofeedback is considered insufficient.<ref>{{Cite journal |last1=Höder |first1=Amanda |last2=Stenbeck |first2=Josefin |last3=Fernando |first3=Mia |last4=Lange |first4=Elvira |date=2023-11-18 |title=Pelvic floor muscle training with biofeedback or feedback from a physiotherapist for urinary and anal incontinence after childbirth - a systematic review |journal=BMC Women's Health |volume=23 |issue=1 |pages=618 |doi=10.1186/s12905-023-02765-7 |doi-access=free |issn=1472-6874 |pmid=37980530|pmc=10657595 }}</ref>

In 1992, the United States Agency for Health Care Policy and Research recommended biofeedback as a first-line treatment for adult urinary incontinence.<ref>{{cite journal | vauthors = Busby-Whitehead J, Johnson T, Clarke MK | title = Re: Biofeedback for the treatment of stress and urge incontinence | journal = The Journal of Urology | volume = 156 | issue = 2 Pt 1 | pages = 483 | date = August 1996 | pmid = 8683712 | doi = 10.1016/S0022-5347(01)65896-8 }}</ref>

In 2019, the National Institute for Health and Care Excellence recommended against the routine use of use biofeedback in managing urinary incontinence in women who can actively contract the pelvic floor. It may be considered though,  to aid motivation and adherence to therapy.<ref name="Clinical Excellence 2019">Urinary incontinence and pelvic organ prolapse in women: management. National Institute for Health and Clinical Excellence. NICE guideline [NG123]. Published date: 02 April 2019, Last updated: 24 June 2019</ref>

===Fecal incontinence, constipation and anismus===
Biofeedback is a treatment for [[anismus]] (paradoxical contraction of puborectalis during defecation). This therapy directly evolved from the investigation [[anorectal manometry]] where a probe that can record pressure is placed in the anal canal. Biofeedback therapy is also a commonly used and researched therapy for fecal incontinence, but the benefits are uncertain.<ref name="Norton 2012">{{cite journal | vauthors = Norton C, Cody JD | title = Biofeedback and/or sphincter exercises for the treatment of faecal incontinence in adults | journal = The Cochrane Database of Systematic Reviews | volume = 2012 | issue = 7 | pages = CD002111 | date = July 2012 | pmid = 22786479 | doi = 10.1002/14651858.CD002111.pub3 | pmc = 11365095 }}</ref> Biofeedback therapy varies in the way it is delivered. It is also unknown if one type has benefits over another.<ref name="Norton 2012" /> The aims have been described as to enhance either the rectoanal inhibitory reflex (RAIR), rectal sensitivity (by discrimination of progressively smaller volumes of a rectal balloon and promptly contracting the [[external anal sphincter]] (EAS)), or the strength and endurance of the EAS contraction. Three general types of biofeedback have been described, though they are not mutually exclusive, with many protocols combining these elements.<ref name="Norton 2012" /> Similarly there is variance of the length of both the individual sessions and the overall length of the training, and if home exercises are performed in addition and how. In rectal sensitivity training, a balloon is placed in the rectum, and is gradually distended until there is a sensation of rectal filling. Successively smaller volume reinflations of the balloon aim to help the person detect rectal distension at a lower threshold, giving more time to contract the EAS and prevent incontinence, or to journey to the toilet. Alternatively, in those with urge incontinence/ rectal hypersensitivity, training is aimed at teaching the person to tolerate progressively larger volumes. Strength training may involve electromyography (EMG) skin electrodes, manometric pressures, intra-anal EMG, or [[endoanal ultrasound]]. One of these measures are used to relay the muscular activity or anal canal pressure during anal sphincter exercise. Performance and progress can be monitored in this manner. Co-ordination training involves the placing of 3 balloons, in the rectum and in the upper and lower anal canal. The rectal balloon is inflated to trigger the RAIR, an event often followed by incontinence. Co-ordination training aims to teach voluntary contraction of EAS when the RAIR occurs (i.e. when there is rectal distension).<ref name="Norton 2012" />

There is some research that shows the effects of biofeedback on irritable bowel syndrome. However, there may be some adverse effects when using these devices.<ref>{{Cite journal|last1=Goldenberg|first1=Joshua Z|last2=Brignall|first2=Matthew|last3=Hamilton|first3=Michelle|last4=Beardsley|first4=Jennifer|last5=Batson|first5=Richard D|last6=Hawrelak|first6=Jason|last7=Lichtenstein|first7=Brad|last8=Johnston|first8=Bradley C|date=2019-11-12|editor-last=Cochrane IBD Group|title=Biofeedback for treatment of irritable bowel syndrome|journal=Cochrane Database of Systematic Reviews|volume=2019|issue=11|language=en|doi=10.1002/14651858.CD012530.pub2|pmc=6848969|pmid=31713856}}</ref>

In 2010 and 2017, the National Institute for Health and Care Excellence recommended against the use of biofeedback in managing constipation in children.<ref name="Clinical Excellence 2010">Constipation in children and young people: diagnosis and management. National Institute for Health and Clinical Excellence. Clinical guideline [CG99]. Published date: 26 May 2010, Last updated: 13 July 2017</ref>

===EEG===
{{Main|Electroencephalography|Neurofeedback}}
[[Richard Caton|Caton]] recorded spontaneous electrical potentials from the exposed cortical surface of monkeys and rabbits, and was the first to measure event-related potentials (EEG responses to stimuli) in 1875.<ref>{{cite journal | vauthors = Caton R | year = 1875 | title = The electric currents of the brain | journal = British Medical Journal | volume = 2 | page = 278 }}</ref>

[[Nikolay Danilevsky|Danilevsky]] published ''Investigations in the Physiology of the Brain'', which explored the relationship between the EEG and states of consciousness in 1877.<ref name="Brazier, M. A. B. 1959">{{cite journal | vauthors = Brazier MA | title = The EEG in epilepsy. A historical note | journal = Epilepsia | volume = 1 | issue = 1–5 | pages = 328–36 | date = June 1960 | pmid = 13804067 | doi = 10.1111/j.1528-1157.1959.tb04270.x | s2cid = 1245463 }}</ref>

[[Adolf Beck (physiologist)|Beck]] published studies of spontaneous electrical potentials detected from the brains of dogs and rabbits, and was the first to document alpha blocking, where light alters rhythmic oscillations, in 1890.<ref>{{cite journal | vauthors = Coenen AM, Zajachkivsky O, Bilski R | year = 1998 | title = Scientific priority of A. Beck in the neuro-physiology | journal = Experimental and Clinical Physiology and Biochemistry | volume = 1 | pages = 105–109 }}</ref>

[[Charles Scott Sherrington|Sherrington]] introduced the terms [[neuron]] and [[synapse]] and published the ''Integrative Action of the Nervous System'' in 1906.<ref>{{cite book | vauthors = Sherrington CS | date = 1906 | title = The integrative action of the nervous system | url = https://archive.org/details/integrativeacti00shergoog | location = New Haven, CT | publisher = Yale University Press }}</ref>

[[Vladimir Pravdich-Neminsky|Pravdich-Neminsky]] photographed the EEG and event related potentials from dogs, demonstrated a 12–14&nbsp;Hz rhythm that slowed during asphyxiation, and introduced the term electrocerebrogram in 1912.<ref>{{cite journal | vauthors = Pravdich-Neminsky VV | year = 1913 | title = Ein Versuch der Registrierung der elektrischen Gehirnerscheinungen | journal = Zentralblatt für Physiologie | volume = 27 | pages = 951–960 }}</ref>

[[Alexander Forbes (physiologist)|Forbes]] reported the replacement of the string galvanometer with a vacuum tube to amplify the EEG in 1920. The vacuum tube became the de facto standard by 1936.<ref>{{cite journal | vauthors = Forbes A, Mann DW | year = 1924 | title = A revolving mirror for use with the string galvanometer | journal = J. Opt. Soc. Am. A | volume = 8 | issue = 6| pages = 807–816 | bibcode = 1924JOSA....8..807F | doi = 10.1364/JOSA.8.000807 }}</ref>

[[Hans Berger|Berger]] (1924) published the first human EEG data. He recorded electrical potentials from his son Klaus's scalp. At first he believed that he had discovered the physical mechanism for telepathy but was disappointed that the electromagnetic variations disappear only millimeters away from the skull. (He did continue to believe in telepathy throughout his life, however, having had a particularly confirming event regarding his sister). He viewed the EEG as analogous to the ECG and introduced the term {{Lang|de|elektenkephalogram}}. He believed that the EEG had diagnostic and therapeutic promise in measuring the impact of clinical interventions. Berger showed that these potentials were not due to scalp muscle contractions. He first identified the alpha rhythm, which he called the Berger rhythm, and later identified the beta rhythm and [[sleep spindles]]. He demonstrated that alterations in consciousness are associated with changes in the EEG and associated the beta rhythm with alertness. He described interictal activity (EEG potentials between seizures) and recorded a partial complex seizure in 1933. Finally, he performed the first QEEG, which is the measurement of the signal strength of EEG frequencies.<ref>{{cite journal | vauthors = Berger H | year = 1920 | title = Ueber das elektroenkephalogramm des menschen | journal = Archiv für Psychiatrie und Nervenkrankheiten | volume = 87 | pages = 527–570 | doi = 10.1007/BF01797193 | s2cid = 10835361 | hdl = 11858/00-001M-0000-002A-5DE0-7 | hdl-access = free }}</ref>

[[Edgar Adrian, 1st Baron Adrian|Adrian]] and [[Bryan Harold Cabot Matthews|Matthews]] confirmed Berger's findings in 1934 by recording their own EEGs using a cathode-ray oscilloscope. Their demonstration of EEG recording at the 1935 Physiological Society meetings in England caused its widespread acceptance. Adrian used himself as a subject and demonstrated the phenomenon of alpha blocking, where opening his eyes suppressed alpha rhythms.<ref>{{cite journal | vauthors = Adrian ED, Mathews BH | year = 1934 | title = The Berger rhythm | journal = Brain | volume = 57 | issue = 4| pages = 355–385 | doi = 10.1093/brain/57.4.355 }}</ref>

[[Frederic A. Gibbs|Gibbs]], [[Hallowell Davis|Davis]], and [[William Gordon Lennox|Lennox]] inaugurated clinical electroencephalography in 1935 by identifying abnormal EEG rhythms associated with epilepsy, including [[interictal]] spike waves and 3&nbsp;Hz activity in [[absence seizures]].<ref name="Brazier, M. A. B. 1959"/>

[[Frédéric Bremer|Bremer]] used the EEG to show how sensory signals affect vigilance in 1935.<ref>{{cite journal | vauthors = Bremer F | year = 1935 | title = Cerveau isole et physiologie du sommeil | journal = Com. Ren. Soc. Bio. | volume = 118 | pages = 1235–1241 }}</ref>

[[William Grey Walter|Walter]] (1937, 1953) named the [[delta waves]] and [[theta waves]], and the contingent negative variation (CNV), a slow cortical potential that may reflect expectancy, motivation, intention to act, or attention. He located an [[occipital lobe]] source for alpha waves and demonstrated that delta waves can help locate brain lesions like tumors. He improved Berger's electroencephalograph and pioneered EEG topography.<ref>{{cite journal | vauthors = Bladin PF | title = W. Grey Walter, pioneer in the electroencephalogram, robotics, cybernetics, artificial intelligence | journal = Journal of Clinical Neuroscience | volume = 13 | issue = 2 | pages = 170–7 | date = February 2006 | pmid = 16455257 | doi = 10.1016/j.jocn.2005.04.010 | s2cid = 9994415 }}</ref>

Kleitman has been recognized as the "Father of American sleep research" for his seminal work in the regulation of sleep-wake cycles, [[circadian rhythms]], the sleep patterns of different age groups, and the effects of [[sleep deprivation]]. He discovered the phenomenon of [[rapid eye movement sleep|rapid eye movement]] (REM) sleep with his graduate student Aserinsky in 1953.<ref>{{cite journal | vauthors = Kleitman N | title = Patterns of dreaming | journal = Scientific American | volume = 203 | issue = 5 | pages = 82–8 | date = November 1960 | pmid = 13756738 | doi = 10.1038/scientificamerican1160-82 | bibcode = 1960SciAm.203e..82K }}</ref>

Dement, another of Kleitman's students, described the EEG architecture and phenomenology of sleep stages and the transitions between them in 1955, associated REM sleep with dreaming in 1957, and documented sleep cycles in another species, cats, in 1958, which stimulated basic sleep research. He established the Stanford University Sleep Research Center in 1970.<ref>{{cite book | vauthors = Dement W | date = 2000 | title = The promise of Sleep: A pioneer in sleep medicine explores the vital connection between health, happiness, and a good night's sleep | location = New York | publisher = Random House }}</ref>

Andersen and Andersson (1968) proposed that thalamic pacemakers project synchronous alpha rhythms to the [[Cerebral cortex|cortex]] via thalamocortical circuits.<ref>{{cite book | vauthors = Andersen P, Andersson S | date = 1968 | title = A physiological basis of the alpha rhythm | location = New York | publisher = Appleton-Century-Crofts }}</ref>

Kamiya (1968) demonstrated that the alpha rhythm in humans could be [[operant]]ly conditioned. He published an influential article in ''Psychology Today'' that summarized research that showed that subjects could learn to discriminate when alpha was present or absent, and that they could use feedback to shift the dominant alpha frequency about 1&nbsp;Hz. Almost half of his subjects reported experiencing a pleasant "alpha state" characterized as an "alert calmness." These reports may have contributed to the perception of alpha biofeedback as a shortcut to a meditative state. He also studied the EEG correlates of meditative states.<ref>{{cite book | vauthors = Kamiya J | date = 1969 | chapter = [[Operant]] control of the EEG alpha rhythm. | veditors = Tart C | title = Altered states of consciousness | location = NY | publisher =  Wiley }}</ref>

Brown (1970) demonstrated the clinical use of alpha-theta biofeedback. In research designed to identify the subjective states associated with EEG rhythms, she trained subjects to increase the abundance of alpha, beta, and theta activity using visual feedback and recorded their subjective experiences when the amplitude of these frequency bands increased. She also helped popularize biofeedback by publishing a series of books, including ''New Mind, New body'' (1974) and ''Stress and the Art of Biofeedback'' (1977).<ref>{{cite book | vauthors = Brown B | date = 1974 | title = New mind, new body | url = https://archive.org/details/newmindnewbody0000unse | url-access = registration | location = New York | publisher = Harper & Row | isbn = 9780060105495 }}</ref><ref>{{cite book | vauthors = Brown B | date = 1977 | title = Stress and the art of biofeedback | location = New York | publisher = Harper & Row }}</ref><ref>{{cite book | vauthors = Brown B | date = 1980 | title = Supermind: The ultimate energy | location = New York | publisher = Harper & Row }}</ref>

Mulholland and Peper (1971) showed that occipital alpha increases with eyes open and not focused, and is disrupted by visual focusing; a rediscovery of alpha blocking.<ref>{{cite journal | vauthors = Mulholland TB, Peper E | title = Occipital alpha and accommodative vergence, pursuit tracking, and fast eye movements | journal = Psychophysiology | volume = 8 | issue = 5 | pages = 556–75 | date = September 1971 | pmid = 5116820 | doi = 10.1111/j.1469-8986.1971.tb00491.x }}</ref>

Green and Green (1986) investigated voluntary control of internal states by individuals like Swami Rama and American Indian medicine man Rolling Thunder both in India and at the [[Menninger Foundation]]. They brought portable biofeedback equipment to India and monitored practitioners as they demonstrated self-regulation. A film containing footage from their investigations was released as ''Biofeedback: The Yoga of the West'' (1974). They developed alpha-theta training at the Menninger Foundation from the 1960s to the 1990s. They hypothesized that theta states allow access to unconscious memories and increase the impact of prepared images or suggestions. Their alpha-theta research fostered Peniston's development of an alpha-theta addiction protocol.<ref name="Green, E. 1977">{{cite book | vauthors = Green E, Green A | date = 1977 | title = Beyond biofeedback | location = San Francisco | publisher = Delacorte Press }}</ref>

Sterman (1972) showed that cats and human subjects could be operantly trained to increase the amplitude of the sensorimotor rhythm (SMR) recorded from the sensorimotor cortex. He demonstrated that SMR production protects cats against drug-induced generalized seizures (tonic-clonic seizures involving loss of consciousness) and reduces the frequency of seizures in humans diagnosed with [[epilepsy]]. He found that his SMR protocol, which uses visual and auditory EEG biofeedback, normalizes their EEGs (SMR increases while theta and beta decrease toward normal values) even during sleep. Sterman also co-developed the Sterman-Kaiser (SKIL) QEEG database.<ref>{{cite journal | vauthors = Sterman MB | title = Neurophysiologic and clinical studies of sensorimotor EEG biofeedback training: some effects on epilepsy | journal = Seminars in Psychiatry | volume = 5 | issue = 4 | pages = 507–25 | date = November 1973 | pmid = 4770578 }}</ref>

Birbaumer and colleagues (1981) have studied feedback of slow cortical potentials since the late 1970s. They have demonstrated that subjects can learn to control these DC potentials and have studied the efficacy of slow cortical potential biofeedback in treating ADHD, epilepsy, migraine, and schizophrenia.<ref>{{cite journal | vauthors = Birbaumer N, Elbert T, Lutzenberger W, Rockstroh B, Schwarz J | title = EEG and slow cortical potentials in anticipation of mental tasks with different hemispheric involvement | journal = Biological Psychology | volume = 13 | pages = 251–60 | date = December 1981 | pmid = 7342994 | doi = 10.1016/0301-0511(81)90040-5 | s2cid = 43281624 }}</ref>

Lubar (1989) studied SMR biofeedback to treat attention disorders and epilepsy in collaboration with Sterman. He demonstrated that SMR training can improve attention and academic performance in children diagnosed with Attention Deficit Disorder with Hyperactivity (ADHD). He documented the importance of theta-to-beta ratios in ADHD and developed theta suppression-beta enhancement protocols to decrease these ratios and improve student performance.<ref>{{cite book | vauthors = Lubar JF | date = 1989 | chapter = Electroencephalographic biofeedback and neurological applications. | veditors = Basmajian JV | title = Biofeedback: Principles and practice for clinicians | edition = 3rd | pages = 67–90 | location = Baltimore | publisher = Williams and Wilkins }}</ref>  The Neuropsychiatric EEG-Based Assessment Aid (NEBA) System, a device used to measure the Theta-to-Beta ratio, was approved as a tool to assist in diagnosis of ADHD on July 15, 2013.<ref>{{cite press release |title= FDA permits marketing of first brain wave test to help assess children and teens for ADHD |url= https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm360811.htm |archive-url= https://web.archive.org/web/20130718090543/http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm360811.htm |url-status= dead |archive-date= July 18, 2013 |date= 2013-07-15 |publisher= Food and Drug Administration |access-date= 2013-09-18}}</ref> A 2019 Systematic Review studied the use of Qualitative EEG's as a biomarker for diagnosing ADHD and other child psychiatric disorders as compared to and showed higher theta/beta ratio in ADHD vs healthy controls.<ref>{{Cite journal |last1=McVoy |first1=Molly |last2=Lytle |first2=Sarah |last3=Fulchiero |first3=Erin |last4=Aebi |first4=Michelle E. |last5=Adeleye |first5=Olunfunke |last6=Sajatovic |first6=Martha |date=9 July 2019 |title=A systematic review of quantitative EEG as a possible biomarker in child psychiatric disorders |url=https://pubmed.ncbi.nlm.nih.gov/31300243/ |journal=Psychiatry Research |volume=279 |pages=331–344 |doi=10.1016/j.psychres.2019.07.004 |issn=1872-7123 |pmid=31300243}}</ref>

===Electrodermal system===
Feré demonstrated the exosomatic method of recording of skin electrical activity by passing a small current through the skin in 1888.<ref>{{cite journal | vauthors = Féré C | title = Note sur les modifications de la tension électrique dans le corps humain. | journal = Comptes Rendus des Séances de la Société de Biologie | date = January 1888 | volume = 5 | pages = 28–33 }}</ref>

Tarchanoff used the endosomatic method by recording the difference in skin electrical potential from points on the skin surface in 1889; no external current was applied.<ref>{{cite journal | vauthors = Tarchanoff J | year = 1890 | title = Uber die galvanischen Erscheinungen an der Haut des Menschen bei Relzung der Sinnesorgane und bei verschiedenen Formen der psychischen Tatigkeit | journal = Arch. Ges. Physiol. | volume = 46 | pages = 46–55 | doi = 10.1007/BF01789520 | s2cid = 2839053 }}</ref>

[[Jung]] employed the [[galvanometer]], which used the exosomatic method, in 1907 to study unconscious emotions in word-association experiments.<ref>{{cite journal | vauthors = Peterson F, Jung CG | year = 1907 | title = Psycho-physical investigations with the galvanometer and pneumograph in normal and insane individuals | journal = Brain | volume = 30 | issue = 2| pages = 153–218 | doi = 10.1093/brain/30.2.153 |hdl=11858/00-001M-0000-002C-1710-9 | hdl-access = free }}</ref>

Marjorie and [[Neurofeedback|Hershel Toomim]] (1975) published a landmark article about the use of GSR biofeedback in psychotherapy.<ref name="Toomim, M. 1975"/>

Meyer and Reich discussed similar material in a British publication.<ref name=Meyer&Reich>{{cite journal | vauthors = Meyer V, Reich B | title = Anxiety management--the marriage of physiological and cognitive variables | journal = Behaviour Research and Therapy | volume = 16 | issue = 3 | pages = 177–82 | date = June 1978 | pmid = 358963 | doi = 10.1016/0005-7967(78)90064-5 }}</ref>

===Musculoskeletal system===
[[Edmund Jacobson|Jacobson]] (1930) developed hardware to measure EMG voltages over time, showed that cognitive activity (like imagery) affects EMG levels, introduced the deep relaxation method [[Progressive muscle relaxation|Progressive Relaxation]], and wrote ''Progressive Relaxation'' (1929) and ''You Must Relax'' (1934). He prescribed daily Progressive Relaxation practice to treat diverse psychophysiological disorders like hypertension.<ref>{{cite book | vauthors = Jacobson E | date = 1938 | title = Progressive relaxation | location = Chicago | publisher = University of Chicago Press }}</ref>

Several researchers showed that human subjects could learn precise control of individual motor units (motor neurons and the muscle fibers they control). [[Lindsley]] (1935) found that relaxed subjects could suppress motor unit firing without biofeedback training.<ref>{{cite journal | vauthors = Lindsley DB | year = 1935 | title = Characteristics of single motor unit responses in human muscle during various degrees of contraction | journal = American Journal of Physiology | volume = 113 | pages = 88–89 }}</ref>

Harrison and Mortensen (1962) trained subjects using visual and auditory EMG biofeedback to control individual motor units in the tibialis anterior muscle of the leg.<ref>{{cite journal | vauthors = Harrison VF, Mortensen OA | title = Identification and voluntary control of single motor unit activity in the tibialis anterior muscle | journal = The Anatomical Record | volume = 144 | issue = 2 | pages = 109–16 | date = October 1962 | pmid = 13953011 | doi = 10.1002/ar.1091440205 | s2cid = 35757088 }}</ref>

Basmajian (1963) instructed subjects using unfiltered auditory EMG biofeedback to control separate motor units in the abductor pollicis muscle of the thumb in his Single Motor Unit Training (SMUT) studies. His best subjects coordinated several motor units to produce drum rolls. Basmajian demonstrated practical applications for neuromuscular rehabilitation, [[pain management]], and headache treatment.<ref>{{cite book | vauthors = Basmajian JV | date = 1967 | title = Muscles alive: Their functions revealed by electromyography | url = https://archive.org/details/musclesalivetheie2basm | url-access = registration | location = Baltimore | publisher = Williams and Wilkins }}</ref>

Marinacci (1960) applied EMG biofeedback to neuromuscular disorders (where [[proprioception]] is disrupted) including Bell Palsy (one-sided facial paralysis), [[polio]], and stroke.<ref>{{cite journal | vauthors = Marinacci AA | year = 1960 | title = Lower motor neuron disorders superimposed on the residuals of poliomyelitis. Value of the electromyogram in differential diagnosis | journal = Bulletin of the Los Angeles Neurological Society | volume = 25 | pages = 18–27 | pmid = 14421110 }}</ref>

"While Marinacci used EMG to treat neuromuscular disorders, his colleagues used the EMG only for diagnosis. They were unable to recognize its potential as a teaching tool even when the evidence stared them in the face! Many electromyographers who performed nerve conduction studies used visual and auditory feedback to reduce interference when a patient recruited too many motor units. Even though they used EMG biofeedback to guide the patient to relax so that clean diagnostic EMG tests could be recorded, they were unable to envision EMG biofeedback treatment of motor disorders."<ref>{{cite journal | vauthors = Peper E, Shaffer F | title = Biofeedback history: An alternative view. | journal = Biofeedback | date = Winter 2010| volume = 38 | issue = 4 | pages = 142–147 | doi = 10.5298/1081-5937-38.4.03 | s2cid = 143535178 }}</ref>

Whatmore and Kohli (1968) introduced the concept of dysponesis (misplaced effort) to explain how functional disorders (where body activity is disturbed) develop. Bracing your shoulders when you hear a loud sound illustrates dysponesis, since this action does not protect against injury.<ref>{{cite journal | vauthors = Whatmore GB, Kohi DR | title = Dysponesis: a neurophysiologic factor in functional disorders | journal = Behavioral Science | volume = 13 | issue = 2 | pages = 102–24 | date = March 1968 | pmid = 4231964 | doi = 10.1002/bs.3830130203 }}</ref> These clinicians applied EMG biofeedback to diverse functional problems like headache and hypertension. They reported case follow-ups ranging from 6 to 21 years. This was long compared with typical 0–24 month follow-ups in the clinical literature. Their data showed that skill in controlling misplaced efforts was positively related to clinical improvement. Last, they wrote ''The Pathophysiology and Treatment of Functional Disorders'' (1974) that outlined their treatment of functional disorders.<ref>{{cite book | vauthors = Whatmore G, Kohli D | date = 1974 | title = The physiopathology and treatment of functional disorders | location = New York | publisher = Grune & Stratton }}</ref>

Wolf (1983) integrated EMG biofeedback into physical therapy to treat stroke patients and conducted landmark stroke outcome studies.<ref>{{cite journal | vauthors = Wolf SL | title = Electromyographic biofeedback applications to stroke patients. A critical review | journal = Physical Therapy | volume = 63 | issue = 9 | pages = 1448–59 | date = September 1983 | pmid = 6351119 | doi = 10.1093/ptj/63.9.1448 }}</ref>

Peper (1997) applied SEMG to the workplace, studied the ergonomics of computer use, and promoted "healthy computing."<ref>{{cite book | vauthors = Shumay D, Peper E | date = 1997 | chapter = Healthy computing: A comprehensive group training approach using biofeedback. | veditors = Salvendy G, Smith MJ, Koubek RJ | title = Design of computing systems: Cognitive considerations | location = New York | publisher = Elsevier }}</ref>

Taub (1999, 2006) demonstrated the clinical efficacy of [[constraint-induced movement therapy]] (CIMT) for the treatment of spinal cord-injured and stroke patients.<ref>{{cite journal | vauthors = Taub E, Uswatte G, Pidikiti R | title = Constraint-Induced Movement Therapy: a new family of techniques with broad application to physical rehabilitation--a clinical review | journal = Journal of Rehabilitation Research and Development | volume = 36 | issue = 3 | pages = 237–51 | date = July 1999 | pmid = 10659807 }}</ref><ref>{{cite journal | vauthors = Taub E, Uswatte G, King DK, Morris D, Crago JE, Chatterjee A | title = A placebo-controlled trial of constraint-induced movement therapy for upper extremity after stroke | journal = Stroke | volume = 37 | issue = 4 | pages = 1045–9 | date = April 2006 | pmid = 16514097 | doi = 10.1161/01.STR.0000206463.66461.97 | doi-access = free }}</ref>

===Cardiovascular system===
Shearn (1962) operantly trained human subjects to increase their heart rates by 5 beats-per-minute to avoid electric shock.<ref name="Shearn 1962">{{cite journal | vauthors = Shearn DW | title = Operant conditioning of heart rate | journal = Science | volume = 137 | issue = 3529 | pages = 530–1 | date = August 1962 | pmid = 13911531 | doi = 10.1126/science.137.3529.530 | bibcode = 1962Sci...137..530S | s2cid = 27576691 }}</ref> In contrast to Shearn's slight heart rate increases, [[Swami Rama]] used yoga to produce atrial flutter at an average 306 beats per minute before a Menninger Foundation audience. This briefly stopped his heart's pumping of blood and silenced his pulse.<ref name="Green, E. 1977"/>

Engel and Chism (1967) operantly trained subjects to decrease, increase, and then decrease their heart rates (this was analogous to ON-OFF-ON EEG training). He then used this approach to teach patients to control their rate of [[premature ventricular contractions]] (PVCs), where the ventricles contract too soon. Engel conceptualized this training protocol as illness onset training, since patients were taught to produce and then suppress a symptom.<ref>{{cite journal | vauthors = Engel BT, Chism RA | title = Operant conditioning of heart rate speeding | journal = Psychophysiology | volume = 3 | issue = 4 | pages = 418–26 | date = April 1967 | pmid = 6041674 | doi = 10.1111/j.1469-8986.1967.tb02728.x }}</ref> Peper has similarly taught asthmatics who wheeze to better control their breathing.<ref>{{cite book | vauthors = Peper E, Ancoli S, Quinn M | date = 1979 | title = Mind/Body integration: Essential readings in biofeedback | location = New York | publisher = Plenum Press }}</ref>

Schwartz (1971, 1972) examined whether specific patterns of cardiovascular activity are easier to learn than others due to biological constraints. He examined the constraints on learning integrated (two autonomic responses change in the same direction) and differentiated (two autonomic responses change inversely) patterns of [[blood pressure]] and heart rate change.<ref>{{cite journal | vauthors = Schwartz GE, Shapiro D, Tursky B | title = Learned control of cardiovascular integration in man through operant conditioning | journal = Psychosomatic Medicine | volume = 33 | issue = 1 | pages = 57–62 | year = 1971 | pmid = 5100734 | doi = 10.1097/00006842-197101000-00004 | s2cid = 38435459 }}</ref>

Schultz and Luthe (1969) developed [[Autogenic Training]], which is a deep relaxation exercise derived from hypnosis. This procedure combines passive volition with imagery in a series of three treatment procedures (standard Autogenic exercises, Autogenic neutralization, and Autogenic meditation). Clinicians at the Menninger Foundation coupled an abbreviated list of standard exercises with thermal biofeedback to create autogenic biofeedback.<ref>{{cite book | vauthors = Schultz JH, Luthe W | date = 1969 | title = Autogenic therapy: Autogenic methods. | location = New York | publisher = Grune & Stratton }}</ref> Luthe (1973) also published a series of six volumes titled ''Autogenic therapy''.<ref>{{cite book | vauthors = Luthe W | date = 1973 | title = Autogenic therapy: Treatment with autogenic neutralization | location = New York | publisher = Grune & Stratton }}</ref>

Fahrion and colleagues (1986) reported on an 18–26 session treatment program for hypertensive patients. The Menninger program combined breathing modification, autogenic biofeedback for the hands and feet, and frontal EMG training. The authors reported that 89% of their medication patients discontinued or reduced medication by one-half while significantly lowering blood pressure. While this study did not include a double-blind control, the outcome rate was impressive.<ref>{{cite journal | vauthors = Fahrion S, Norris P, Green A, Green E, Snarr C | title = Biobehavioral treatment of essential hypertension: a group outcome study | journal = Biofeedback and Self-Regulation | volume = 11 | issue = 4 | pages = 257–77 | date = December 1986 | pmid = 3607093 | doi = 10.1007/BF01000163 | s2cid = 35235128 }}</ref>

Freedman and colleagues (1991) demonstrated that hand-warming and hand-cooling are produced by different mechanisms. The primary hand-warming mechanism is [[beta-adrenergic]] (hormonal), while the main hand-cooling mechanism is alpha-adrenergic and involves sympathetic C-fibers. This contradicts the traditional view that finger blood flow is controlled exclusively by sympathetic C-fibers. The traditional model asserts that, when firing is slow, hands warm; when firing is rapid, hands cool. Freedman and colleagues' studies support the view that hand-warming and hand-cooling represent entirely different skills.<ref>{{cite journal | vauthors = Freedman RR, Keegan D, Migály P, Galloway MP, Mayes M | title = Plasma catecholamines during behavioral treatments for Raynaud's disease | journal = Psychosomatic Medicine | volume = 53 | issue = 4 | pages = 433–9 | year = 1991 | pmid = 1924655 | doi = 10.1097/00006842-199107000-00008 | s2cid = 41125990 }}</ref>

Vaschillo and colleagues (1983) published the first studies of heart rate variability (HRV) biofeedback with [[cosmonauts]] and treated patients diagnosed with psychiatric and psychophysiological disorders.<ref>{{cite journal | vauthors = Vashchillo EG, Zingerman AM, Konstantinov MA, Menitskii DN | year = 1983 | title = Research of the resonance characteristics for the cardiovascular system | journal = Human Physiology | volume = 9 | pages = 257–265 }}</ref><ref>{{cite journal | vauthors = Chernigovskaya NV, Vaschillo EG, Petrash VV, Rusanovsky VV | year = 1990 | title = Voluntary regulation of the heart rate as a method of functioning condition correction in neurotics | journal = Human Physiology | volume = 16 | pages = 58–64 }}</ref> Lehrer collaborated with Smetankin and Potapova in treating pediatric asthma patients<ref>{{cite journal | vauthors = Lehrer P, Smetankin A, Potapova T | title = Respiratory sinus arrhythmia biofeedback therapy for asthma: a report of 20 unmedicated pediatric cases using the Smetankin method | journal = Applied Psychophysiology and Biofeedback | volume = 25 | issue = 3 | pages = 193–200 | date = September 2000 | pmid = 10999237 | doi = 10.1023/A:1009506909815 | s2cid = 25390678 }}</ref> and published influential articles on HRV asthma treatment in the medical journal ''Chest''.<ref>{{cite journal | vauthors = Lehrer P, Vaschillo E, Lu SE, Eckberg D, Vaschillo B, Scardella A, Habib R | title = Heart rate variability biofeedback: effects of age on heart rate variability, baroreflex gain, and asthma | journal = Chest | volume = 129 | issue = 2 | pages = 278–84 | date = February 2006 | pmid = 16478842 | doi = 10.1378/chest.129.2.278 }}</ref> The most direct effect of HRV biofeedback is on the baroreflex, a homeostatic reflex that helps control blood pressure fluctuations.<ref>{{cite journal | vauthors = Vaschillo E, Lehrer P, Rishe N, Konstantinov M | title = Heart rate variability biofeedback as a method for assessing baroreflex function: a preliminary study of resonance in the cardiovascular system | journal = Applied Psychophysiology and Biofeedback | volume = 27 | issue = 1 | pages = 1–27 | date = March 2002 | pmid = 12001882 | doi = 10.1023/a:1014587304314 | s2cid = 14307928 }}</ref> When blood pressure goes up, the baroreflex makes heart rate go down. The opposite happens when blood pressure goes down. Because it takes about 5 seconds for blood pressure to change after changes in heart rate (think of different amounts of blood flowing through the same sized tube), the baroreflex produces a rhythm in heart rate with a period of about 10 seconds. Another rhythm in heart rate is caused by respiration (respiratory sinus arrhythmia), such that heart rate rises during inhalation and falls during exhalation. During HRV biofeedback, these two reflexes stimulate each other, stimulating resonance properties of the cardiovascular system caused by the inherent rhythm in the baroreflex,<ref name="Vaschillo_2006">{{cite journal | vauthors = Vaschillo EG, Vaschillo B, Lehrer PM | title = Characteristics of resonance in heart rate variability stimulated by biofeedback | journal = Applied Psychophysiology and Biofeedback | volume = 31 | issue = 2 | pages = 129–42 | date = June 2006 | pmid = 16838124 | doi = 10.1007/s10484-006-9009-3 | s2cid = 2451332 }}</ref> and thus causing very big oscillations in heart rate and large-amplitude stimulation of the baroreflex.<ref>{{cite journal | vauthors = Lehrer PM, Vaschillo E, Vaschillo B, Lu SE, Eckberg DL, Edelberg R, Shih WJ, Lin Y, Kuusela TA, Tahvanainen KU, Hamer RM | display-authors = 6 | title = Heart rate variability biofeedback increases baroreflex gain and peak expiratory flow | journal = Psychosomatic Medicine | volume = 65 | issue = 5 | pages = 796–805 | year = 2003 | pmid = 14508023 | doi = 10.1097/01.psy.0000089200.81962.19 | s2cid = 5741194 }}</ref> Thus HRV biofeedback exercises the baroreflex, and strengthens it. This apparently has the effect of modulating autonomic reactivity to stimulation. Because the baroreflex is controlled through brain stem mechanisms that communicate directly with the insula and amygdala, which control emotion, HRV biofeedback also appears to modulate emotional reactivity, and to help people with anxiety, stress, and depression<ref name="Preliminary results of an open labe"/><ref>{{cite journal | vauthors = Zucker TL, Samuelson KW, Muench F, Greenberg MA, Gevirtz RN | title = The effects of respiratory sinus arrhythmia biofeedback on heart rate variability and posttraumatic stress disorder symptoms: a pilot study | journal = Applied Psychophysiology and Biofeedback | volume = 34 | issue = 2 | pages = 135–43 | date = June 2009 | pmid = 19396540 | doi = 10.1007/s10484-009-9085-2 | citeseerx = 10.1.1.623.5683 | s2cid = 1579288 }}</ref><ref>{{cite journal | vauthors = Lehrer PM, Gevirtz R | title = Heart rate variability biofeedback: how and why does it work? | journal = Frontiers in Psychology | volume = 5 | pages = 756 | year = 2014 | pmid = 25101026 | pmc = 4104929 | doi = 10.3389/fpsyg.2014.00756 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Kudo N, Shinohara H, Kodama H | title = Heart rate variability biofeedback intervention for reduction of psychological stress during the early postpartum period | journal = Applied Psychophysiology and Biofeedback | volume = 39 | issue = 3–4 | pages = 203–11 | date = December 2014 | pmid = 25239433 | pmc = 4220117 | doi = 10.1007/s10484-014-9259-4 }}</ref><ref>{{cite journal | vauthors = Henriques G, Keffer S, Abrahamson C, Horst SJ | title = Exploring the effectiveness of a computer-based heart rate variability biofeedback program in reducing anxiety in college students | journal = Applied Psychophysiology and Biofeedback | volume = 36 | issue = 2 | pages = 101–12 | date = June 2011 | pmid = 21533678 | doi = 10.1007/s10484-011-9151-4 | s2cid = 13266430 }}</ref>

Emotions are intimately linked to heart health, which is linked to physical and mental health. In general, good mental<ref name="ReferenceC">{{cite journal | vauthors = Thayer JF, Hansen AL, Saus-Rose E, Johnsen BH | title = Heart rate variability, prefrontal neural function, and cognitive performance: the neurovisceral integration perspective on self-regulation, adaptation, and health | journal = Annals of Behavioral Medicine | volume = 37 | issue = 2 | pages = 141–53 | date = April 2009 | pmid = 19424767 | doi = 10.1007/s12160-009-9101-z | s2cid = 3677295 | doi-access = free }}</ref><ref>{{cite journal | vauthors = McCraty R, Atkinson M, Tomasino D, Bradley RT | title = The Coherent Heart Heart-Brain Interactions, Psychophysiological Coherence, and the Emergence of System-Wide Order. | journal = Integral Review | date = December 2009 | volume = 5 | issue = 2 | pages = 41–46 | url = http://www.integral-review.org/issues/vol_5_no_2_mccraty_et_al_the_coherent_heart.pdf }}</ref> and physical<ref>{{cite journal| vauthors = McCraty R, Atkinson M, Tomasino D, Bradley RT |title=The Coherent Heart|journal=Integral Review|date=2009|volume=5|issue=2|pages=22–26}}</ref> health are correlated with positive emotions and high heart rate variability (HRV) modulated by mostly high frequencies. High HRV has been correlated with increased executive functioning skills such as memory and reaction time.<ref name="ReferenceC"/>  Biofeedback that increased HRV and shifted power toward HF (high-frequencies) has been shown to lower blood pressure.<ref name = "Barrios-Choplin_1997" />

On the other hand, LF (low-frequency) power in the heart is associated with sympathetic vagal activity, which is known to increase the risk of heart attack.<ref>{{cite journal | vauthors = Lown B, DeSilva RA | title = Roles of psychologic stress and autonomic nervous system changes in provocation of ventricular premature complexes | journal = The American Journal of Cardiology | volume = 41 | issue = 6 | pages = 979–85 | date = May 1978 | pmid = 665521 | doi = 10.1016/0002-9149(78)90850-0 }}</ref>
LF-dominated HRV power spectra are also directly associated with higher mortality rates in healthy individuals,<ref>{{cite journal | vauthors = Tsuji H, Larson MG, Venditti FJ, Manders ES, Evans JC, Feldman CL, Levy D | title = Impact of reduced heart rate variability on risk for cardiac events. The Framingham Heart Study | journal = Circulation | volume = 94 | issue = 11 | pages = 2850–5 | date = December 1996 | pmid = 8941112 | doi = 10.1161/01.CIR.94.11.2850 }}</ref><ref>{{cite journal | vauthors = Tsuji H, Venditti FJ, Manders ES, Evans JC, Larson MG, Feldman CL, Levy D | title = Reduced heart rate variability and mortality risk in an elderly cohort. The Framingham Heart Study | journal = Circulation | volume = 90 | issue = 2 | pages = 878–83 | date = August 1994 | pmid = 8044959 | doi = 10.1161/01.CIR.90.2.878 | doi-access = free }}</ref> and among individuals with mood disorders.<ref>{{cite journal | vauthors = Kemp AH, Quintana DS | title = The relationship between mental and physical health: insights from the study of heart rate variability | journal = International Journal of Psychophysiology | volume = 89 | issue = 3 | pages = 288–96 | date = September 2013 | pmid = 23797149 | doi = 10.1016/j.ijpsycho.2013.06.018 | s2cid = 27558660 }}</ref>
Anger and frustration increase the LF range of HRV.<ref name="ReferenceE">{{cite journal | vauthors = McCraty R, Atkinson M, Tiller WA, Rein G, Watkins AD | title = The effects of emotions on short-term power spectrum analysis of heart rate variability | journal = The American Journal of Cardiology | volume = 76 | issue = 14 | pages = 1089–93 | date = November 1995 | pmid = 7484873 | doi = 10.1016/S0002-9149(99)80309-9 }}</ref> Other studies have shown anger to increase the risk of heart attack,.<ref>{{cite journal | vauthors = Mittleman MA, Maclure M, Sherwood JB, Mulry RP, Tofler GH, Jacobs SC, Friedman R, Benson H, Muller JE | display-authors = 6 | title = Triggering of acute myocardial infarction onset by episodes of anger. Determinants of Myocardial Infarction Onset Study Investigators | journal = Circulation | volume = 92 | issue = 7 | pages = 1720–5 | date = October 1995 | pmid = 7671353 | doi = 10.1161/01.cir.92.7.1720 }}</ref>

Because emotions have such an impact on cardiac function, which cascades to numerous other biological processes, emotional regulation techniques are able to effect practical, psychophysiological change.<ref name="Barrios-Choplin_1997"/>
McCraty et al. discovered that feelings of gratitude increased HRV and moved its power spectrum toward the MF (mid-frequency) and HF (high-frequency) ranges, while decreasing LF (low-frequency) power.<ref name="ReferenceE"/>

Other techniques that have been claimed to increase HRV include strenuous aerobic exercise,<ref>{{cite journal | vauthors = Boutcher SH, Park Y, Dunn SL, Boutcher YN | title = The relationship between cardiac autonomic function and maximal oxygen uptake response to high-intensity intermittent-exercise training | journal = Journal of Sports Sciences | volume = 31 | issue = 9 | pages = 1024–9 | date = May 2013 | pmid = 23362808 | doi = 10.1080/02640414.2012.762984 | s2cid = 43718273 }}</ref> and meditation.<ref>{{cite journal | vauthors = Krygier JR, Heathers JA, Shahrestani S, Abbott M, Gross JJ, Kemp AH | title = Mindfulness meditation, well-being, and heart rate variability: a preliminary investigation into the impact of intensive Vipassana meditation | journal = International Journal of Psychophysiology | volume = 89 | issue = 3 | pages = 305–13 | date = September 2013 | pmid = 23797150 | doi = 10.1016/j.ijpsycho.2013.06.017 | s2cid = 12471642 }}</ref>

===Pain===
In 2021, the National Institute for Health and Care Excellence recommended against the use of biofeedback in managing chronic pain in adults.<ref name="ReferenceD">Chronic pain (primary and secondary) in over 16s: assessment of all chronic pain and management of chronic primary pain. National Institute for Health and Clinical Excellence. NICE guideline [NG193]. Published date: 07 April 2021</ref>

====Chronic back pain====
Newton-John, Spense, and Schotte (1994) compared the effectiveness of Cognitive Behavior Therapy (CBT) and Electromyographic Biofeedback (EMG-Biofeedback) for 44 participants with chronic low back pain. Newton-John et al. (1994) split the participants into two groups, then measured the intensity of pain, the participants' perceived disability, and depression before treatment, after treatment and again six months later. Newton-John et al.(1994) found no significant differences between the group which received CBT and the group which received EMG-Biofeedback. This seems to indicate that biofeedback is as effective as CBT in chronic low back pain. Comparing the results of the groups before treatment and after treatment, indicates that EMG-Biofeedback reduced pain, disability, and depression as much as by half.<ref>{{cite journal | vauthors = Newton-John TR, Spence SH, Schotte D | title = Cognitive-behavioural therapy versus EMG biofeedback in the treatment of chronic low back pain | journal = Behaviour Research and Therapy | volume = 33 | issue = 6 | pages = 691–7 | date = July 1995 | pmid = 7654161 | doi = 10.1016/0005-7967(95)00008-l }}</ref>

====Muscle pain====
Budzynski and Stoyva (1969) showed that EMG biofeedback could reduce [[frontalis muscle]] (forehead) contraction.<ref>{{cite journal | vauthors = Budzynski TH, Stoyva JM | title = An instrument for producing deep muscle relaxation by means of analog information feedback | journal = Journal of Applied Behavior Analysis | volume = 2 | issue = 4 | pages = 231–7 | year = 1969 | pmid = 16795225 | pmc = 1311072 | doi = 10.1901/jaba.1969.2-231 }}</ref> They demonstrated in 1973 that analog (proportional) and binary (ON or OFF) visual EMG biofeedback were equally helpful in lowering masseter SEMG levels.<ref>{{cite journal | vauthors = Bydyznski T, Stoyva J | title = An electromyographic feedback technique for teaching voluntary relaxation of the masseter muscle | journal = Journal of Dental Research | volume = 52 | issue = 1 | pages = 116–9 | year = 1973 | pmid = 4509482 | doi = 10.1177/00220345730520010201 | s2cid = 34753419 }}</ref>
McNulty, Gevirtz, Hubbard, and Berkoff (1994) proposed that [[sympathetic nervous system]] innervation of [[muscle spindles]] underlies [[trigger points]].<ref>{{cite journal | vauthors = McNulty WH, Gevirtz RN, Hubbard DR, Berkoff GM | title = Needle electromyographic evaluation of trigger point response to a psychological stressor | journal = Psychophysiology | volume = 31 | issue = 3 | pages = 313–6 | date = May 1994 | pmid = 8008795 | doi = 10.1111/j.1469-8986.1994.tb02220.x }}</ref>

====Tension headache====
Budzynski, Stoyva, Adler, and Mullaney (1973) reported that auditory frontalis EMG biofeedback combined with home relaxation practice lowered tension headache frequency and frontalis EMG levels. A control group that received noncontingent (false) auditory feedback did not improve. This study helped make the frontalis muscle the placement-of-choice in EMG assessment and treatment of headache and other psychophysiological disorders.<ref>Budzynski, T. H., Stoyva, J. M., Adler, C. S., & Mullaney, D. EMG biofeedback and tension headache: A controlled-outcome study. ''Psychosomatic Medicine'', 35,  484-496.</ref>

====Migraine====
Sargent, Green, and Walters (1972, 1973) demonstrated that hand-warming could abort migraines and that autogenic biofeedback training could reduce headache activity. The early Menninger migraine studies, although methodologically weak (no pretreatment baselines, control groups, or random assignment to conditions), strongly influenced migraine treatment.<ref>{{cite journal | vauthors = Sargent JD, Green EE, Walters ED | title = The use of autogenic feedback training in a pilot study of migraine and tension headaches | journal = Headache | volume = 12 | issue = 3 | pages = 120–4 | date = October 1972 | pmid = 5075461 | doi = 10.1111/j.1526-4610.1972.hed1203120.x | s2cid = 36834854 }}</ref><ref>{{cite journal | vauthors = Sargent JD, Walters ED, Green EE | title = Psychosomatic self-regulation of migraine headaches | journal = Seminars in Psychiatry | volume = 5 | issue = 4 | pages = 415–28 | date = November 1973 | pmid = 4770571 }}</ref>
A 2013 review classified biofeedback among the techniques that might be of benefit in the management of chronic migraine.<ref name="Evans 2013">{{cite journal | vauthors = Evans RW | title = A rational approach to the management of chronic migraine | journal = Headache | volume = 53 | issue = 1 | pages = 168–176 | date = January 2013 | pmid = 23293866 | doi = 10.1111/head.12014 | s2cid = 20018343 }}</ref>{{Primary source inline|date=January 2013}} More recent studies have demonstrated the efficacy of biofeedback training in reducing frequency of migraines when compared to other non-medical interventions, like relaxation training.<ref>{{Cite journal |title=Behavioral Interventions for Migraine Prevention |url=https://effectivehealthcare.ahrq.gov/products/behavioral-interventions-migraine-prevention/research |access-date=2025-03-03 |website=effectivehealthcare.ahrq.gov |date=2024 |language=en |doi=10.23970/ahrqepccer270 |last1=Treadwell |first1=Jonathan R. |last2=Tsou |first2=Amy Y. |last3=Rouse |first3=Benjamin |last4=Ivlev |first4=Ilya |last5=Fricke |first5=Julie |last6=Buse |first6=Dawn |last7=Powers |first7=Scott W. |last8=Minen |first8=Mia |last9=Szperka |first9=Christina L. |last10=Mull |first10=Nikhil K. |pmid=39471258 |url-access=subscription }}</ref> 

====Phantom-limb pain====
Flor (2002) trained amputees to detect the location and frequency of shocks delivered to their stumps, which resulted in an expansion of corresponding cortical regions and significant reduction of their phantom limb pain.<ref>{{cite journal | vauthors = Flor H | title = Phantom-limb pain: characteristics, causes, and treatment | journal = The Lancet. Neurology | volume = 1 | issue = 3 | pages = 182–9 | date = July 2002 | pmid = 12849487 | doi = 10.1016/S1474-4422(02)00074-1 | s2cid = 16941466 }}</ref>

===Financial decision-making===
Financial traders use biofeedback as a tool for regulating their level of emotional arousal in order to make better financial decisions. The technology company [[Philips]] and the Dutch bank [[ABN AMRO]] developed a biofeedback device for retail investors based on a galvanic skin response sensor.<ref>{{cite conference | vauthors = Djajadiningrat T, Geurts L, Munniksma PR, Christiaansen G, de Bont J | date = 2009 | title = Rationalizer: An emotion mirror for online traders. | conference = Proceedings of the 5th International Workshop on Design and Semantics of Form and Movement | location = Taipei, Taiwan | pages = 39–48 }}</ref> Astor et al. (2013) developed a biofeedback based [[serious game]] in which financial decision makers can learn how to effectively regulate their emotions using heart rate measurements.<ref>{{cite journal |vauthors=Astor PJ, Adam MT, Jerčić P, Schaaff K, Weinhardt C | year = 2013 | title = Integrating biosignals into information systems: A NeuroIS tool for improving emotion regulation | journal = [[Journal of Management Information Systems]] | volume = 30 | issue = 3 | pages = 247–277 | doi = 10.2753/MIS0742-1222300309 | s2cid = 42644671 }}</ref>

===Stress reduction===
A randomized study by Sutarto et al. assessed the effect of resonant breathing biofeedback (recognize and control involuntary heart rate variability) among manufacturing operators; depression, anxiety and stress significantly decreased.<ref name="Sutarto2012">{{cite journal | vauthors = Sutarto AP, Wahab MN, Zin NM | title = Resonant breathing biofeedback training for stress reduction among manufacturing operators | journal = International Journal of Occupational Safety and Ergonomics | volume = 18 | issue = 4 | pages = 549–61 | year = 2012 | pmid = 23294659 | doi = 10.1080/10803548.2012.11076959 | doi-access = free }}</ref>{{Primary source inline|date=January 2013}} Heart rate variability data can be analyzed with deep neural networks to accurately predict stress levels.<ref>{{Cite journal| vauthors = Al-Jebrni AH, Chwyl B, Wang XY, Wong A, Saab BJ |date= May 2020 |title=AI-enabled remote and objective quantification of stress at scale |journal=Biomedical Signal Processing and Control |language=en |volume=59 |pages=101929 |doi=10.1016/j.bspc.2020.101929 |doi-access=free }}</ref> This technology is utilized in a mobile app in combination with mindfulness techniques to effectively promote stress reduction.<ref>{{cite journal | vauthors = Walsh KM, Saab BJ, Farb NA | title = Effects of a Mindfulness Meditation App on Subjective Well-Being: Active Randomized Controlled Trial and Experience Sampling Study | journal = JMIR Mental Health | volume = 6 | issue = 1 | pages = e10844 | date = January 2019 | pmid = 30622094 | pmc = 6329416 | doi = 10.2196/10844 | doi-access = free }}</ref>

=== Anxiety management ===

A [[Meta-analysis|meta analysis]] by the ''University of Cambridge'' compiles previous studies on biofeedback being used in the management and control of anxiety. In this article the previous studies are evaluated for validity and relevance into how they attribute to the effectiveness of biofeedback being used in tandem with other forms of therapy to produce reduced and manageable anxiety. This analysis concluded that the use of biofeedback in the form of [[Heart rate variability|HRV]] monitoring produced self reported large reduction of anxiety as a consistent finding in the studies that were a part of the meta analysis.<ref>{{Cite journal|last1=Goessl|first1=V. C.|last2=Curtiss|first2=J. E.|last3=Hofmann|first3=S. G.|date=November 2017|title=The effect of heart rate variability biofeedback training on stress and anxiety: a meta-analysis|url=https://www.cambridge.org/core/product/identifier/S0033291717001003/type/journal_article|journal=Psychological Medicine|language=en|volume=47|issue=15|pages=2578–2586|doi=10.1017/S0033291717001003|pmid=28478782|s2cid=4710497|issn=0033-2917|hdl=2144/26911|hdl-access=free}}</ref>

==Clinical effectiveness==

===Research===
Moss, LeVaque, and Hammond (2004) observed that "Biofeedback and neurofeedback seem to offer the kind of evidence-based practice that the healthcare establishment is demanding."<ref>{{cite book | veditors = Geyman JP, Deyon RA, Ramsey SD | date = 2000 | title = Evidence-based clinical practice: Concepts and approach | location = Boston | publisher = Butterworth-Heinemann }}</ref><ref>{{cite book | vauthors = Sackett DL, Straus SE, Richardson WS, Rosenberg W, Haynes RB | title = Evidence-based medicine: How to practice and teach EBM | year = 2000 | url = https://archive.org/details/evidencebasedmed00davi | url-access = registration | location = Edinburgh, New York | publisher = Churchill Livingstone | isbn = 9780443062407 }}</ref> "From the beginning biofeedback developed as a research-based approach emerging directly from laboratory research on psychophysiology and behavior therapy. The ties of biofeedback/neurofeedback to the biomedical paradigm and to research are stronger than is the case for many other behavioral interventions" (p.&nbsp;151).<ref>{{cite journal | vauthors = Moss DE, LaVaque TJ, Hammond D | year = 2004 | title = Introduction to White Papers Series series—Guest editorial | journal = Applied Psychophysiology and Biofeedback | volume = 29 | issue = 3| pages = 151–152 | doi = 10.1023/B:APBI.0000039305.13608.37 | s2cid = 145631046 }}</ref>

The Association for Applied Psychophysiology and Biofeedback (AAPB) and the International Society for Neurofeedback and Research (ISNR) have collaborated in validating and rating treatment protocols to address questions about the clinical efficacy of biofeedback and neurofeedback applications, like ADHD and headache. In 2001, Donald Moss, then president of the Association for Applied Psychophysiology and Biofeedback, and Jay Gunkelman, president of the International Society for Neurofeedback and Research, appointed a task force to establish standards for the efficacy of biofeedback and neurofeedback.

The Task Force document was published in 2002,<ref name="LaVaque, T. J. 2002">{{cite journal | author = Association for Applied Psychophysiology and Biofeedback | title = Template for developing guidelines for the evaluation of the clinical efficacy of psychophysiological interventions | journal = Applied Psychophysiology and Biofeedback | volume = 27 | issue = 4 | pages = 273–81 | date = December 2002 | pmid = 12557455 | pmc = 2779403 | doi = 10.1023/A:1021061318355 }}</ref> and a series of white papers followed, reviewing the efficacy of a series of disorders.<ref>{{cite journal | vauthors = Moss DE, LaVaque TJ, Hammond D | year = 2004 | title = Introduction to White Papers Series series -- Guest editorial | journal = Applied Psychophysiology and Biofeedback | volume = 29 | issue = 3| pages = 151–152 | doi = 10.1023/B:APBI.0000039305.13608.37 | s2cid = 145631046 }}</ref> The white papers established the efficacy of biofeedback for functional anorectal disorders,<ref>{{cite journal | vauthors = Palsson OS, Heymen S, Whitehead WE | title = Biofeedback treatment for functional anorectal disorders: a comprehensive efficacy review | journal = Applied Psychophysiology and Biofeedback | volume = 29 | issue = 3 | pages = 153–74 | date = September 2004 | pmid = 15497616 | doi = 10.1023/B:APBI.0000039055.18609.64 | citeseerx = 10.1.1.458.3576 | s2cid = 11430280 }}</ref> [[attention deficit disorder]],<ref>{{cite journal | vauthors = Monastra VJ, Lynn S, Linden M, Lubar JF, Gruzelier J, LaVaque TJ | title = Electroencephalographic biofeedback in the treatment of attention-deficit/hyperactivity disorder | journal = Applied Psychophysiology and Biofeedback | volume = 30 | issue = 2 | pages = 95–114 | date = June 2005 | pmid = 16013783 | doi = 10.1007/s10484-005-4305-x | citeseerx = 10.1.1.527.1668 | s2cid = 9183254 }}</ref> facial pain and temporomandibular joint dysfunction,<ref>{{cite journal | vauthors = Crider A, Glaros AG, Gevirtz RN | title = Efficacy of biofeedback-based treatments for temporomandibular disorders | journal = Applied Psychophysiology and Biofeedback | volume = 30 | issue = 4 | pages = 333–45 | date = December 2005 | pmid = 16385422 | doi = 10.1007/s10484-005-8420-5 | s2cid = 9714081 }}</ref> [[hypertension]],<ref>{{cite journal | vauthors = Linden W, Moseley JV | title = The efficacy of behavioral treatments for hypertension | journal = Applied Psychophysiology and Biofeedback | volume = 31 | issue = 1 | pages = 51–63 | date = March 2006 | pmid = 16565886 | doi = 10.1007/s10484-006-9004-8 | s2cid = 35953369 }}</ref> urinary incontinence,<ref>{{cite journal | vauthors = Glazer HI, Laine CD | title = Pelvic floor muscle biofeedback in the treatment of urinary incontinence: a literature review | journal = Applied Psychophysiology and Biofeedback | volume = 31 | issue = 3 | pages = 187–201 | date = September 2006 | pmid = 16983505 | doi = 10.1007/s10484-006-9010-x | s2cid = 34541641 }}</ref> [[Raynaud's phenomenon]],<ref>{{cite journal | vauthors = Karavidas MK, Tsai PS, Yucha C, McGrady A, Lehrer PM | title = Thermal biofeedback for primary Raynaud's phenomenon: a review of the literature | journal = Applied Psychophysiology and Biofeedback | volume = 31 | issue = 3 | pages = 203–16 | date = September 2006 | pmid = 17016765 | doi = 10.1007/s10484-006-9018-2 | s2cid = 12514778 }}</ref> [[substance abuse]],<ref>{{cite journal | vauthors = Sokhadze TM, Cannon RL, Trudeau DL | title = EEG biofeedback as a treatment for substance use disorders: review, rating of efficacy, and recommendations for further research | journal = Applied Psychophysiology and Biofeedback | volume = 33 | issue = 1 | pages = 1–28 | date = March 2008 | pmid = 18214670 | pmc = 2259255 | doi = 10.1007/s10484-007-9047-5 }}</ref> and headache.<ref name="Biofeedback treatment for headache"/>

A broader review was published<ref>{{cite book | vauthors = Yucha C, Gilbert C | date = 2004 | title = Evidence-based practice in biofeedback and neurofeedback | location = Wheat Ridge, CO | publisher = Association for Applied Psychophysiology and Biofeedback }}</ref> and later updated,<ref name = Yucha2008/> applying the same efficacy standards to the entire range of medical and psychological disorders. The 2008 edition reviewed the efficacy of biofeedback for over 40 clinical disorders, ranging from alcoholism/substance abuse to [[vulvar vestibulitis]]. The ratings for each disorder depend on the nature of research studies available on each disorder, ranging from anecdotal reports to [[double blind]] studies with a [[control group]]. Thus, a lower rating may reflect the lack of research rather than the ineffectiveness of biofeedback for the problem.

The randomized trial by Dehli et al. compared if the injection of a bulking agent in the anal canal was superior to sphincter training with biofeedback to treat fecal incontinence. Both methods lead to an improvement of FI, but comparisons of [[Fecal incontinence#Severity scales|St Mark's scores]] between the groups showed no differences in effect between treatments.<ref name="Dehli2013">{{cite journal | vauthors = Dehli T, Stordahl A, Vatten LJ, Romundstad PR, Mevik K, Sahlin Y, Lindsetmo RO, Vonen B | display-authors = 6 | title = Sphincter training or anal injections of dextranomer for treatment of anal incontinence: a randomized trial | journal = Scandinavian Journal of Gastroenterology | volume = 48 | issue = 3 | pages = 302–10 | date = March 2013 | pmid = 23298304 | doi = 10.3109/00365521.2012.758770 | s2cid = 13111762 }}</ref>

Following their reviews, the National Institute for Health and Care Excellence have recommended against the use of biofeedback in the treatment of constipation in children, urinary incontinence in women, and chronic pain.<ref name="Clinical Excellence 2010"/><ref name="Clinical Excellence 2019"/><ref name="ReferenceD"/>

===Efficacy===
Yucha and Montgomery's (2008) ratings are listed for the five levels of efficacy recommended by a joint Task Force and adopted by the Boards of Directors of the Association for Applied Psychophysiology (AAPB) and the International Society for Neuronal Regulation (ISNR).<ref name="LaVaque, T. J. 2002"/> From weakest to strongest, these levels include: not empirically supported, possibly efficacious, probably efficacious, efficacious, and efficacious and specific.

Level 1: '''Not empirically supported.''' This designation includes applications supported by anecdotal reports and/or case studies in non-peer-reviewed venues. Yucha and Montgomery (2008) assigned eating disorders, immune function, [[spinal cord injury]], and [[syncope (medicine)|syncope]] to this category.<ref name = Yucha2008/>

Level 2: '''Possibly efficacious.''' This designation requires at least one study of sufficient statistical power with well-identified outcome measures but lacking randomized assignment to a control condition internal to the study. Yucha and Montgomery (2008) assigned asthma, [[autism]], [[Bell palsy]], cerebral palsy, COPD, [[coronary artery disease]], [[cystic fibrosis]], depression, [[erectile dysfunction]], fibromyalgia, hand dystonia, [[irritable bowel syndrome]], [[PTSD]], [[repetitive strain injury]], [[respiratory failure]], stroke, [[tinnitus]], and urinary incontinence in children to this category.<ref name = Yucha2008/>

Level 3: '''Probably efficacious.''' This designation requires multiple observational studies, clinical studies, waitlist-controlled studies, and within subject and intrasubject replication studies that demonstrate efficacy. Yucha and Montgomery (2008) assigned [[alcoholism]] and substance abuse, [[arthritis]], [[diabetes mellitus]], fecal disorders in children, fecal incontinence in adults, [[insomnia]], pediatric headache, [[traumatic brain injury]], urinary incontinence in males, and vulvar vestibulitis ([[vulvodynia]]) to this category.<ref name = Yucha2008/>

Level 4: '''Efficacious.''' This designation requires the satisfaction of six criteria:

(a) In a comparison with a no-treatment control group, alternative treatment group, or sham (placebo) control using randomized assignment, the investigational treatment is shown to be statistically significantly superior to the control condition or the investigational treatment is equivalent to a treatment of established efficacy in a study with sufficient power to detect moderate differences.

(b) The studies have been conducted with a population treated for a specific problem, for whom inclusion criteria are delineated in a reliable, operationally defined manner.

(c) The study used valid and clearly specified outcome measures related to the problem being treated.

(d) The data are subjected to appropriate data analysis.

(e) The diagnostic and treatment variables and procedures are clearly defined in a manner that permits replication of the study by independent researchers.

(f) The superiority or equivalence of the investigational treatment has been shown in at least two independent research settings.

Yucha and Montgomery (2008) assigned attention deficit hyperactivity disorder (ADHD), anxiety, chronic pain, epilepsy, [[constipation]] (adult), headache (adult), hypertension, [[motion sickness]], [[Raynaud's disease]], and temporomandibular joint dysfunction to this category.<ref name = Yucha2008/>

Level 5: '''Efficacious and specific.''' The investigational treatment must be shown to be statistically superior to credible sham therapy, pill, or alternative bona fide treatment in at least two independent research settings. Yucha and Montgomery (2008) assigned urinary incontinence (females) to this category.<ref name = Yucha2008/>

===Criticisms===
In a healthcare environment that emphasizes cost containment and evidence-based practice, critics question how these treatments compare with conventional behavioral and medical interventions on efficacy and cost.<ref>{{cite book | vauthors = Moss D, Andrasik F | chapter = Foreword: Evidence-based practice in biofeedback and neurofeedback | veditors = Yucha C, Montgomery D | date = 2008 | title = Evidence-based practice in biofeedback and neurofeedback | edition = 2nd | location = Wheat Ridge, CO | publisher = Association for Applied Psychophysiology and Biofeedback }}</ref> A review of a meta-analysis of biofeedback treatments noted the lack of comparisons with existing treatments in most of the studies included.<ref name="ncbi.nlm.nih.gov"/><ref name="Efficacy of biofeedback for migrain"/>

==Organizations==
The Association for Applied Psychophysiology and Biofeedback (AAPB) is a non-profit scientific and professional society for biofeedback and neurofeedback. The International Society for Neurofeedback and Research (ISNR) is a non-profit scientific and professional society for neurofeedback. The Biofeedback Foundation of Europe (BFE)<ref>{{Cite web|url=http://bfe.org/|title=Biofeedback Federation of Europe – BFE|website=bfe.org}}</ref> sponsors international education, training, and research activities in biofeedback and neurofeedback.<ref name="Peper, E. 2008"/> The Northeast Regional Biofeedback Association (NRBS)<ref>{{Cite web|url=https://nrbs.org/|title=Northeast Region Biofeedback Society – Promoting biofeedback education in the Northeast Region|website=nrbs.org}}</ref> sponsors theme-centered educational conferences, political advocacy for biofeedback friendly legislation, and research activities in biofeedback and neurofeedback in the Northeast regions of the United States. The Southeast Biofeedback and Clinical Neuroscience Association (SBCNA)<ref>{{Cite web |url=http://www.sebiofeedback.org/ |title=Southeast Biofeedback and Clinical Neuroscience Association - Home |access-date=2013-10-14 |archive-date=2013-11-27 |archive-url=https://web.archive.org/web/20131127082612/http://sebiofeedback.org/ |url-status=dead }}</ref> is a non-profit regional organization supporting biofeedback professionals with continuing education, ethics guidelines, and public awareness promoting the efficacy and safety of professional biofeedback. The SBCNA offers an Annual Conference for professional continuing education as well as promoting biofeedback as an adjunct to the allied health professions. The SBCNA was formally the North Carolina Biofeedback Society (NCBS), serving Biofeedback since the 1970s. In 2013, the NCBS reorganized as the SBCNA supporting and representing biofeedback and neurofeedback in the Southeast Region of the United States of America.<ref>{{Cite web|url=http://sebiofeedback.org/about|title=Southeast Biofeedback and Clinical Neuroscience Association - About SBCNA|website=sebiofeedback.org}}</ref>

===Certification===
The Biofeedback Certification International Alliance (formerly the Biofeedback Certification Institute of America) is a non-profit organization that is a member of the [[Institute for Credentialing Excellence]] (ICE). BCIA offers biofeedback certification, neurofeedback (also called EEG biofeedback) certification, and pelvic muscle dysfunction biofeedback. BCIA certifies individuals meeting education and training standards in biofeedback and neurofeedback and progressively recertifies those satisfying continuing education requirements. BCIA certification has been endorsed by the Mayo Clinic,<ref name = value>{{cite journal | vauthors = Neblett R, Shaffer F, Crawford J | year = 2008 | title = What is the value of Biofeedback Certification Institute of America certification? | journal = Biofeedback | volume = 36 | issue = 3| pages = 92–94 }}</ref> the Association for Applied Psychophysiology and Biofeedback (AAPB), the International Society for Neurofeedback and Research (ISNR),<ref name="Peper, E. 2008"/> and the Washington State Legislature.<ref>http://apps.leg.wa.gov/WAC/default.aspx?cite=296-21-280 Washington State Legislature WAC 296-21-280 Biofeedback Rules.</ref>

The BCIA didactic education requirement includes a 48-hour course from a regionally accredited academic institution or a BCIA-approved training program that covers the complete General Biofeedback Blueprint of Knowledge and study of human anatomy and physiology. The General Biofeedback Blueprint of Knowledge areas include: I. Orientation to Biofeedback, II. Stress, Coping, and Illness, III. Psychophysiological Recording, IV. Surface Electromyographic (SEMG) Applications, V. Autonomic Nervous System (ANS) Applications, VI. Electroencephalographic (EEG) Applications, VII. Adjunctive Interventions, and VIII. Professional Conduct.<ref>{{cite book | vauthors = Gevirtz R | date = 2003 | chapter = The behavioral health provider in mind-body medicine. | veditors = Moss D, McGrady A, Davies TC, Wickramasekera I | title = Handbook of mind-body medicine for primary care | location = Thousand Oaks, CA | publisher = Sage Publications, Inc }}</ref>

Applicants may demonstrate their knowledge of human anatomy and physiology by completing a course in human anatomy, human physiology, or human biology provided by a regionally accredited academic institution or a BCIA-approved training program or by successfully completing an Anatomy and Physiology exam covering the organization of the human body and its systems.

Applicants must also document practical skills training that includes 20 contact hours supervised by a BCIA-approved mentor designed to them teach how to apply clinical biofeedback skills through self-regulation training, 50 patient/client sessions, and case conference presentations. Distance learning allows applicants to complete didactic course work over the internet. Distance mentoring trains candidates from their residence or office.<ref>{{cite journal | vauthors = De Bease C | year = 2007 | title = Biofeedback Certification Institute of America certification: Building skills without walls | journal = Biofeedback | volume = 35 | issue = 2| pages = 48–49 }}</ref> They must recertify every 4 years, complete 55 hours of continuing education during each review period or complete the written exam, and attest that their license/credential (or their supervisor's license/credential) has not been suspended, investigated, or revoked.<ref name="ReferenceA">{{cite book | vauthors = Shaffer F, Schwartz MS | chapter = Entering the field and assuring competence. | veditors = Schwartz MS, Andrasik F | title = Biofeedback: A practitioner's guide | date = March 2017 | edition = 4th | location = New York | publisher = The Guilford Press | isbn = 978-1-4625-3194-3 }}</ref>

==History==
[[Claude Bernard]] proposed in 1865 that the body strives to maintain a steady state in the internal environment ([[milieu intérieur]]), introducing the concept of [[homeostasis]].<ref>{{cite book | vauthors = Bernard C |author-link=Claude Bernard |title=An Introduction to the study of experimental medicine |publisher=Dover |location=Mineola, N.Y |year=1957 |orig-year=First published 1865 |isbn=978-0-486-20400-0 |url-access=registration |url=https://archive.org/details/introductiontost00clau }}</ref>  In 1885, J.R. Tarchanoff showed that voluntary control of heart rate could be fairly direct (cortical-autonomic) and did not depend on "cheating" by altering breathing rate.<ref>{{cite journal | vauthors = Tarchanoff JR | year = 1885 | title = [Voluntary acceleration of the heart beat in man] | journal = Pflügers Archiv für die gesamte Physiologie | volume =35|  pages = 109–135 | doi = 10.1007/BF01612726| s2cid = 11910652 | url = https://zenodo.org/record/1917559 }}</ref> In 1901, J. H. Bair studied voluntary control of the retrahens aurem muscle that wiggles the [[ear]], discovering that subjects learned this skill by inhibiting interfering muscles and demonstrating that skeletal muscles are self-regulated.<ref>{{cite journal | doi = 10.1037/h0074157 | vauthors = Bair JH | year = 1901 | title = Development of voluntary control | url = http://bjp.rcpsych.org/cgi/pdf_extract/48/200/158 | journal = Psychological Review | volume = 8 | pages = 474–510 | issue = 5| hdl = 2027/mdp.39015070189314 | url-access = subscription }}</ref> [[Alexander Graham Bell]] attempted to teach the deaf to speak through the use of two devices—the [[phonautograph]], created by [[Édouard-Léon Scott de Martinville|Édouard-Léon Scott's]], and a [[Pressure measurement|manometric flame]].  The former translated sound vibrations into tracings on smoked glass to show their acoustic waveforms, while the latter allowed sound to be displayed as patterns of light.<ref>{{cite book | vauthors = Bruce RC |title=Bell: Alexander Graham Bell and the conquest of solitude |publisher=Cornell University Press |location=Ithaca, N.Y |year=1990 |isbn=978-0-8014-9691-2 }}</ref>  After [[World War II]], mathematician [[Norbert Wiener]] developed [[Cybernetics|cybernetic theory]], that proposed that systems are controlled by monitoring their results.<ref>{{cite book | last = Wiener | first = Norbert | name-list-style = vanc |title=Cybernetics Or Control And Communication In The Animal And The Machine |publisher=Kessinger Publishing, LLC |year=2007 |isbn=978-1-4325-9444-2 }}</ref> The participants at the landmark 1969 conference at the Surfrider Inn in Santa Monica coined the term ''biofeedback'' from Wiener's [[feedback]].  The conference resulted in the founding of the Bio-Feedback Research Society, which permitted normally isolated researchers to contact and collaborate with each other, as well as popularizing the term ''biofeedback''.<ref>{{cite book | vauthors = Moss D |title=Humanistic and transpersonal psychology: a historical and biographical sourcebook |publisher= [[Greenwood Publishing Group|Greenwood Press]] |location=Westport, Conn |year=1999 |isbn=978-0-313-29158-6 | chapter = Biofeedback, mind-body medicine, and the higher limits of human nature}}</ref>  The work of [[B.F. Skinner]] led researchers to apply [[operant conditioning]] to biofeedback, decide which responses could be voluntarily controlled and which could not. In the first experimental demonstration of biofeedback, Shearn<ref>169</ref> used these procedures with heart rate. The effects of the perception of autonomic nervous system activity was initially explored by [[George Mandler]]'s group in 1958. In 1965, Maia Lisina combined classical and operant conditioning to train subjects to change blood vessel diameter, eliciting and displaying reflexive blood flow changes to teach subjects how to voluntarily control the temperature of their skin.<ref>{{cite book | vauthors = Lisina MI | year = 1965 | chapter = The role of orientation in the transformation of involuntary reactions into voluntary ones | veditors = Voronin IG, Leontiev AN, Luria AR, Sokolov EN, Vinogradova OB | title = Orienting reflex and exploratory behavior | pages = 339–44 | location = Washington, DC | publisher = American Institute of Biological Studies }}</ref> In 1974, H.D. Kimmel trained subjects to sweat using the galvanic skin response.<ref>{{cite journal | vauthors = Kimmel HD | title = Instrumental conditioning of autonomically mediated responses in human beings | journal = The American Psychologist | volume = 29 | issue = 5 | pages = 325–35 | date = May 1974 | pmid = 4847492 | doi = 10.1037/h0037621 }}</ref>

===Timeline===
1958 – G. Mandler's group studied the process of autonomic feedback and its effects.<ref name="Autonomic feedback: the perception">{{cite journal | vauthors = Mandler G, Mandler JM, Uviller ET | title = Autonomic feedback: the perception of autonomic activity | journal = Journal of Abnormal Psychology | volume = 56 | issue = 3 | pages = 367–73 | date = May 1958 | pmid = 13538604 | doi = 10.1037/h0048083 }}</ref>

1962 – D. Shearn used feedback instead of conditioned stimuli to change heart rate.<ref name="Shearn 1962" />

1962 – Publication of ''Muscles Alive'' by John Basmajian and Carlo De Luca<ref>{{cite book | vauthors = Basmajian JB, De Luca CJ | title = Muscles Alive: Their Functions Revealed by Electromyography | publisher = Williams & Wilkins | location = Baltimore | date = 1962 }}</ref>

1968 – Annual Veteran's Administration research meeting in Denver that brought together several biofeedback researchers

1969 – April: Conference on Altered States of Consciousness, Council Grove, KS; October: formation and first meeting of the Biofeedback Research Society (BRS), Surfrider Inn, Santa Monica, CA; co-founder Barbara B. Brown becomes the society's first president

1972 – Review and analysis of early biofeedback studies by D. Shearn in the 'Handbook of Psychophysiology'.<ref>{{cite book | vauthors = Shearn DW | chapter = Operant analysis in psychophysiology | veditors = Greenfield NS, Sternbach RA | title = Handbook of Psychophysiology | publisher = Holt, Rinehart and Winston | location = New York | date = 1972 }}</ref>

1974 – Publication of ''The Alpha Syllabus: A Handbook of Human EEG Alpha Activity''<ref>{{cite book | vauthors = Brown BB | title = The Alpha Syllabus: A Handbook of Human EEG Alpha Activity | url = https://archive.org/details/alphasyllabushan0000unse | url-access = registration | publisher = Charles C. Thomas Publisher, Ltd. | location = Springfield, IL | date = 1974 }}</ref> and the first popular book on biofeedback, ''New Mind, New Body''<ref>{{cite book | vauthors = Brown BB | title = New Mind, New Body: Bio-feedback&nbsp;— New Directions for the Mind | publisher = Harper & Row | location = New York | date = 1974 }}</ref> (December), both by Barbara B. Brown

1975 – American Association of Biofeedback Clinicians founded; publication of ''The Biofeedback Syllabus: A Handbook for the Psychophysiologic Study of Biofeedback'' by Barbara B. Brown<ref>{{cite book | vauthors = Brown BB | title = The Biofeedback Syllabus: A Handbook for the Psychophysiologic Study of Biofeedback | publisher = Charles C. Thomas Publisher, Ltd. | location = Springfield, IL | date = 1975 }}</ref>

1976 – BRS renamed the Biofeedback Society of America (BSA)

1977 – Publication of ''Beyond Biofeedback'' by Elmer and Alyce Green<ref name="Green, E. 1977"/> and ''Biofeedback: Methods and Procedures in Clinical Practice'' by George Fuller<ref>{{cite book | vauthors = Fuller GD | title = Biofeedback: Methods and Procedures in Clinical Practice | publisher = Biofeedback Institute of San Francisco | location = San Francisco | date = 1977 }}</ref> and ''Stress and The Art of Biofeedback'' by Barbara B. Brown<ref>{{cite book | vauthors = Brown BB | title = Stress and The Art of Biofeedback | publisher = Harper & Row | location = New York | date = 1977 }}</ref>

1978 – Publication of ''Biofeedback: A Survey of the Literature'' by Francine Butler<ref>{{cite book | vauthors = Butler F | title = Biofeedback: A survey of the literature | url = https://archive.org/details/biofeedbacksurve0000butl | url-access = registration | publisher = IFI/Plenum Data Company | location = New York | date = 1978 | isbn = 9780306651731 }}</ref>

1979 – Publication of ''Biofeedback: Principles and Practice for Clinicians'' by John Basmajian<ref>{{cite book | vauthors = Basmajian JV | date = 1979 | title = Biofeedback: Principles and practice for clinicians | url = https://archive.org/details/biofeedbackprinc0000unse | url-access = registration | location = Baltimore | publisher = Williams & Wilkins }}</ref> and ''Mind/Body Integration: Essential Readings in Biofeedback'' by Erik Peper, Sonia Ancoli, and Michele Quinn<ref>{{cite book | vauthors = Peper E, Ancoli S, Quinn M | title = Mind/Body integration: Essential Readings in Biofeedback | publisher = Plenum Press | location = New York | date = 1979 }}</ref>

1980 – First national certification examination in biofeedback offered by the Biofeedback Certification Institute of America (BCIA); publication of ''Biofeedback: Clinical Applications in Behavioral Medicine'' by David Olton and Aaron Noonberg<ref>{{cite book | vauthors = Olton DS, Noonberg AR | title = Biofeedback: Clinical Applications in Behavioral Medicine | url = https://archive.org/details/biofeedbackclini00olto | url-access = registration | publisher = Prentice-Hall, Inc. | location = Englewood Cliffs, NJ | date = 1980 | isbn = 9780130763150 }}</ref> and ''Supermind: The Ultimate Energy'' by Barbara B. Brown<ref>{{cite book | vauthors = Brown BB | title = Supermind: The Ultimate Energy | publisher = Harper & Row | location = New York | date = 1980 }}</ref>

1984 – Publication of ''Principles and Practice of Stress Management'' by Woolfolk and Lehrer<ref>{{cite book | vauthors = Woolfolk RL, Lehrer PM | title = Principles and practice of stress management | publisher = The Guilford Press | location = New York | date = 1984 }}</ref> and ''Between Health and Illness: New Notions on Stress and the Nature of Well Being'' by Barbara B. Brown<ref>{{cite book | vauthors = Brown BB | title = Between Health and Illness: New Notions on Stress and the Nature of Well Being | url = https://archive.org/details/betweenhealthill0000brow | url-access = registration | publisher = Houghton Mifflin | location = New York | date = 1984 | isbn = 9780395346341 }}</ref>

1984 - Publication of ''The Biofeedback Way To Starve Stress'', by Mark Golin in Prevention Magazine 1984

1987 – Publication of ''Biofeedback: A Practitioner's Guide'' by Mark Schwartz<ref>{{cite book | veditors = Schwartz M | title = Biofeedback: A practitioner's guide | publisher = The Guilford Press | location = New York | date = 1987 }}</ref>

1989 – BSA renamed the Association for Applied Psychophysiology and Biofeedback

1991 – First national certification examination in stress management offered by BCIA

1994 – Brain Wave and EMG sections established within AAPB

1995 – Society for the Study of Neuronal Regulation (SSNR) founded

1996 – Biofeedback Foundation of Europe (BFE) established

1999 – SSNR renamed the Society for Neuronal Regulation (SNR)

2002 – SNR renamed the International Society for Neuronal Regulation (ISNR)

2003 – Publication of ''The Neurofeedback Book'' by Thompson and Thompson<ref>{{cite book | vauthors = Thompson M, Thompson L | title = The neurofeedback book: An introduction to basic concepts in applied psychophysiology | publisher = The Association for Applied Psychophysiology and Biofeedback | location = Wheat Ridge, CO | date =  2003 }}</ref>

2004 – Publication of ''Evidence-Based Practice in Biofeedback and Neurofeedback'' by Carolyn Yucha and Christopher Gilbert<ref>{{cite book | vauthors = Yucha C, Gilbert C | chapter = Evidence-based practice in biofeedback and neurofeedback | title = The Association for Applied Psychophysiology and Biofeedback | location = Wheat Ridge, CO | date = 2004 }}</ref>

2006 – ISNR renamed the International Society for Neurofeedback and Research (ISNR)

2008 – Biofeedback Neurofeedback Alliance formed to pool the resources of the AAPB, BCIA, and ISNR on joint initiatives

2008 – Biofeedback Alliance and Nomenclature Task Force define biofeedback

2009 – The International Society for Neurofeedback & Research defines neurofeedback<ref>{{cite book | title = Biofeedback tutor | publisher = Biosource Software | location = Kirksville, MO | date = 2010 }}</ref>

2010 – Biofeedback Certification Institute of America renamed the Biofeedback Certification International Alliance (BCIA)

==In popular culture==
* Biofeedback data and biofeedback technology are used by Massimiliano Peretti in a contemporary art environment, the [[Amigdalae]] project.  This project explores the way in which emotional reactions filter and distort human [[perception]] and observation.  During the performance, biofeedback medical technology, such as the [[EEG]], [[body temperature]] variations, heart rate, and galvanic responses, are used to analyze an audience's emotions while they watch the video art.  Using these signals, the music changes so that the consequent sound environment simultaneously mirrors and influences the viewer's [[emotional state]].<ref>{{cite web|url=http://www.kontinuita.com/ |title=under changes |publisher=Kontinuita.com |access-date=2012-01-09}}</ref><ref>{{cite web |url=http://www.scope-art.com/index.php?option=com_content&task=view&id=102&Itemid=206 |title=Scope New York Home |publisher=Scope-art.com |access-date=2012-01-09 |archive-url=https://web.archive.org/web/20071012145912/http://www.scope-art.com/index.php?option=com_content&task=view&id=102&Itemid=206 |archive-date=2007-10-12 |url-status=dead }}</ref>  More information is available at the website of the CNRS French National Center of Neural Research.<ref>{{Cite web | url=http://cogimage.dsi.cnrs.fr/seminaires/resumes/resume_amygdalae_2005.htm | title=Cogimage Cnrs Upr640}}</ref>
* Charles Wehrenberg implemented ''competitive-relaxation'' as a gaming paradigm with the ''Will Ball Games'' circa 1973. In the first bio-mechanical versions, comparative GSR inputs monitored each player's relaxation response and moved the ''Will Ball'' across a playing field appropriately using stepper motors.[[Image:WillBall table.png|thumb|WillBall gaming table 1973]] In 1984, Wehrenberg programmed the ''Will Ball'' games for Apple II computers. The ''Will Ball'' game itself is described as pure ''competitive-relaxation''; ''Brain Ball'' is a duel between one player's left- and right-brain hemispheres; ''Mood Ball'' is an obstacle-based game; ''Psycho Dice'' is a psycho-kinetic game.<ref>{{cite book | first = Charles | last = Wehrenberg | name-list-style = vanc | title = Will Ball | publisher = Solo Zone | location = San Francisco | date = 1995–2001 | isbn = 1-886163-02-2 }}</ref> 
* In 2001, the company [[Journey to Wild Divine]] began producing biofeedback hardware and software for the [[Mac (computer)|Mac]] and [[Microsoft Windows|Windows]] [[operating system]]s. Third-party and open-source software and games are also available for the Wild Divine hardware. ''[[Tetris 64]]'' makes use of biofeedback to adjust the speed of the tetris puzzle game.
* [[David Rosenboom]] has worked to develop musical instruments that would respond to mental and physiological commands. Playing these instruments can be learned through a process of biofeedback.
* An episode of the television series ''The Bionic Woman'' features a doctor who can "heal" himself using biofeedback techniques to communicate to his body and react to stimuli. For example, he can exhibit "super" powers, such as walking on hot coals by feeling the heat on the sole of his feet and then convincing his body to react by sending large quantities of perspiration to compensate. He can also convince his body to deliver extremely high levels of adrenalin to provide more energy to allow him to run faster and jump higher. When injured, he can slow his heart rate to reduce blood pressure, send extra platelets to aid in clotting a wound, and direct white blood cells to an area to attack infection.
* In the science-fiction book ''Quantum Lens'' by Douglas E. Richards, bio-feedback is used to enhance certain abilities to detect quantum effects that give the user special powers.

== See also ==
{{Portal|Science}}
* [[Direct visual feedback]]
* [[Journey to Wild Divine]], a biofeedback-based, multi-sensor, game-like software package
* [[Polygraph]], uses exact same sensors as biofeedback devices

==Footnotes==
{{reflist}}

== External links ==
*{{Commons category-inline}}
*[http://www.aapb.org/ Association for Applied Psychophysiology and Biofeedback (AAPB)]
*[http://www.bcia.org/ Biofeedback Certification Institute of America (BCIA)]
*[http://www.bfe.org/ Biofeedback Foundation of Europe (BFE)]
*[http://www.dgbfb.de/ Deutsche Gesellschaft für Biofeedback e.V. (DGBfb e.V.)]
*[http://www.isnr.org/ International Society for Neurofeedback & Research (ISNR)]
{{Psychotherapy}}
{{Meditation}}

{{Authority control}}

[[Category:Biofeedback| ]]
[[Category:Physiology]]
[[Category:Mind–body interventions]]
[[Category:Devices to alter consciousness]]
[[Category:Feedback]]