Biofeedback is the technique of gaining greater awareness of many physiological functions of one's own body by using electronic or other instruments, and with a goal of being able to manipulate the body's systems at will. Humans conduct biofeedback naturally all the time, at varied levels of consciousness and intentionality. Biofeedback and the biofeedback loop can also be thought of as self-regulation. Some of the processes that can be controlled include brainwaves, muscle tone, skin conductance, heart rate and pain perceptio
Biofeedback may be used to improve health, performance, and the physiological changes that often occur in conjunction with changes to thoughts, emotions, 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.
Meta-analysis of different biofeedback treatments have shown some benefit in the treatment of headaches and migraines and ADHD, though most of the studies in these meta-analyses did not make comparisons with alternative treatments.
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.ver 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 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". 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.
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.
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.
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.
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.
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 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".
Information may also be thought of as "any type of pattern that
influences the formation or transformation of other patterns". 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
The "Muscle Whistler", shown here with surface EMG electrodes, was an early biofeedback device developed by Harry Garland and Roger Melen in 1971.
An electromyograph (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 microvolts (millionths of a volt).
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.
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.
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. Hand-warming involves arteriole vasodilation produced by a beta-2 adrenergic hormonal mechanism. Hand-cooling involves arteriole vasoconstriction produced by the increased firing of sympatheticC-fibers.
Biofeedback therapists use temperature biofeedback when treating chronic pain, edema, headache (migraine and tension-type headache), essential hypertension, Raynaud's disease, anxiety, and stress.
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.
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). 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).
Biofeedback therapists use electrodermal biofeedback when treating anxiety disorders, hyperhidrosis (excessive sweating), and stress. Electrodermal biofeedback is used as an adjunct to psychotherapy to increase client awareness of their emotions. 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.
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).
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.
Fast cortical potentials range from 0.5 Hz to 100 Hz.
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.
The synchronous delta rhythm
ranges from 0.5 to 3.5 Hz. Delta is the dominant frequency from ages 1
to 2, and is associated in adults with deep sleep and brain pathology
like trauma and tumors, as well as learning disability.
The synchronous theta rhythm
ranges from 4 to 7 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 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 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 Hz and 20–32 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 Hz is also referred to as gamma. Gamma
activity is associated with perception of meaning and meditative
awareness.
An emWave2 photoplethysmograph for monitoring heart rate variabilityStone 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 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.
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.
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.
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.
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. The ECG method is more accurate than the PPG method in measuring heart rate variability.
Biofeedback therapists use heart rate variability (HRV) biofeedback when treating asthma, COPD, depression, anxiety, fibromyalgia, heart disease, and unexplained abdominal pain.
Research shows that HRV biofeedback can also be used to improve
physiological and psychological wellbeing in healthy individuals.
HRV data from both polyplethysmographs and electrocardiograms are
analyzed via mathematical transformations such as the commonly-used fast Fourier transform (FFT). The FFT splits the HRV data into a power spectrum, revealing the waveform's constituent frequencies.
Among those constituent frequencies, high-frequency (HF) and
low-frequency (LF) components are defined as above and below .15 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.
Some researchers consider a third, medium-frequency (MF) component from
.08 Hz to .15 Hz, which has been shown to increase in power during
times of appreciation.
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).
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.
A pneumograph is often used in conjunction with an electrocardiograph (ECG) or photoplethysmograph (PPG) in heart rate variability (HRV) training.
Biofeedback therapists use pneumograph biofeedback with patients
diagnosed with anxiety disorders, asthma, chronic pulmonary obstructive
disorder (COPD), essential hypertension, panic attacks, and stress.
Capnometer
A capnometer or capnograph uses an infrared detector to measure end-tidal 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 CO 2
for a resting adult is 5% (36 Torr or 4.8 kPa). A capnometer is a
sensitive index of the quality of patient breathing. Shallow, rapid, and
effortful breathing lowers CO 2, while deep, slow, effortless breathing increases it.
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.
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 rheos 'stream, anything flowing', from 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.
The pulsative bio-impedance changes directly reflect the total blood
flow of the deep structures of brain due to high frequency impedance
measurements.
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.
Pressure
Pressure can be monitored as a patient performs exercises while resting against an air-filled cushion. This is pertinent to physiotherapy. Alternatively, the patient may actively grip or press against an air-filled cushion of custom shape.
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.
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. Contradicting this, a 2013 randomized controlled trial found no benefit of adding biofeedback to pelvic floor muscle exercise in stress urinary incontinence. In another randomized controlled trial the addition of biofeedback to the training of pelvic floor muscles
for the treatment of stress urinary incontinence, improved pelvic floor
muscle function, reduced urinary symptoms, and improved of the quality
of life.
In 1992, the United States Agency for Health Care Policy and
Research recommended biofeedback as a first-line treatment for adult
urinary incontinence.
In 2019, the National Institute for Health and Care Excellence
recommended against the routine use of 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.
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. Biofeedback therapy varies in the way it is delivered. It is also unknown if one type has benefits over another.
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.
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).
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.n 2010 and 2017, the National Institute for Health and Care
Excellence recommended against the use of biofeedback in managing
constipation in children.
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.
Danilevsky published Investigations in the Physiology of the Brain, which explored the relationship between the EEG and states of consciousness in 1877.
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.
Sherrington introduced the terms neuron and synapse and published the Integrative Action of the Nervous System in 1906.
Pravdich-Neminsky
photographed the EEG and event related potentials from dogs,
demonstrated a 12–14 Hz rhythm that slowed during asphyxiation, and
introduced the term electrocerebrogram in 1912.
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.
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 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.
Adrian and 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.
Gibbs, Davis, and Lennox inaugurated clinical electroencephalography in 1935 by identifying abnormal EEG rhythms associated with epilepsy, including interictal spike waves and 3 Hz activity in absence seizures.
Bremer used the EEG to show how sensory signals affect vigilance in 1935.
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.
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 (REM) sleep with his graduate student Aserinsky in 1953.
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.
Andersen and Andersson (1968) proposed that thalamic pacemakers project synchronous alpha rhythms to the cortex via thalamocortical circuits.
Kamiya (1968) demonstrated that the alpha rhythm in humans could be operantly 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 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.
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).
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.
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.
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.
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.
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.
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.
However, the field has recently moved away from the measure. This move
has been caused by the general change in the population norms in the
past 20 years (most likely due to the change in the average amount of
sleep in young people).
Electrodermal system
Feré
demonstrated the exosomatic method of recording of skin electrical
activity by passing a small current through the skin in 1888.
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.
Jung employed the galvanometer, which used the exosomatic method, in 1907 to study unconscious emotions in word-association experiments.
Marjorie and Hershel Toomim (1975) published a landmark article about the use of GSR biofeedback in psychotherapy.
Meyer and Reich discussed similar material in a British publication.
Musculoskeletal system
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 Relaxation, and wrote Progressive Relaxation (1929) and You Must Relax (1934). He prescribed daily Progressive Relaxation practice to treat diverse psychophysiological disorders like hypertension.
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.
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.
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.
Marinacci (1960) applied EMG biofeedback to neuromuscular disorders (where proprioception is disrupted) including Bell Palsy (one-sided facial paralysis), polio, and stroke.
"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."
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.
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.
Wolf (1983) integrated EMG biofeedback into physical therapy to
treat stroke patients and conducted landmark stroke outcome studies.
Peper (1997) applied SEMG to the workplace, studied the ergonomics of computer use, and promoted "healthy computing."
Taub (1999, 2006) demonstrated the clinical efficacy of constraint-induced movement therapy (CIMT) for the treatment of spinal cord-injured and stroke patients.
Cardiovascular system
Shearn (1962) operantly trained human subjects to increase their heart rates by 5 beats-per-minute to avoid electric shock. 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.
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. Peper has similarly taught asthmatics who wheeze to better control their breathing.
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.
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. Luthe (1973) also published a series of six volumes titled Autogenic therapy.
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.
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.
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.Lehrer collaborated with Smetankin and Potapova in treating pediatric asthma patients and published influential articles on HRV asthma treatment in the medical journal Chest.
The most direct effect of HRV biofeedback is on the baroreflex, a
homeostatic reflex that helps control blood pressure fluctuations.
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, and thus causing very big oscillations in heart rate and large-amplitude stimulation of the baroreflex.
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.
Emotions are intimately linked to heart health, which is linked to physical and mental health. In general, good mental and physical
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. Biofeedback that increased HRV and shifted power toward HF (high-frequencies) has been shown to lower blood pressure.
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.
LF-dominated HRV power spectra are also directly associated with higher mortality rates in healthy individuals, and among individuals with mood disorders.
Anger and frustration increase the LF range of HRV. Other studies have shown anger to increase the risk of heart attack.
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.
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.
Other techniques that have been claimed to increase HRV include strenuous aerobic exercise, and meditation.
Pain
In 2021, the
National Institute for Health and Care Excellence recommended against
the use of biofeedback in managing chronic pain in adults.
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.
Muscle pain
Budzynski and Stoyva (1969) showed that EMG biofeedback could reduce frontalis muscle (forehead) contraction.
They demonstrated in 1973 that analog (proportional) and binary (ON or
OFF) visual EMG biofeedback were equally helpful in lowering masseter
SEMG levels.
McNulty, Gevirtz, Hubbard, and Berkoff (1994) proposed that sympathetic nervous system innervation of muscle spindles underlies trigger points.
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.
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.
A 2013 review classified biofeedback among the techniques that might be of benefit in the management of chronic migraine.
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.
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. 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.
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.Heart rate variability data can be analyzed with deep neural networks to accurately predict stress levels. This technology is utilized in a mobile app in combination with mindfulness techniques to effectively promote stress reduction.
Anxiety management
A 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 HRV
monitoring produced self reported large reduction of anxiety as a
consistent finding in the studies that were a part of the meta analysis.
Relaxation
In a study of 18 healthy individuals published in the International Journal of Stress Management
it was established that with the use of biofeedback there were large
improvements in the individuals ability to relax which was translated in
the individuals having improved scores on the Smith Relaxation States
Inventory 3 test which measures mindfulness, energized positive feelings
and basic relaxation.
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."
"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. 151).
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, and a series of white papers followed, reviewing the efficacy of a series of disorders. The white papers established the efficacy of biofeedback for functional anorectal disorders, attention deficit disorder, facial pain and temporomandibular joint dysfunction, hypertension, urinary incontinence, Raynaud's phenomenon, substance abuse, and headache.
A broader review was published and later updated,
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 St Mark's scores between the groups showed no differences in effect between treatments. 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.
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).
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 to this category.
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.
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.
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.
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.
A review of a meta-analysis of biofeedback treatments noted the lack of
comparisons with existing treatments in most of the studies included.
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) sponsors international education, training, and research activities in biofeedback and neurofeedback. The Northeast Regional Biofeedback Association (NRBS)
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)
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.
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,
the Association for Applied Psychophysiology and Biofeedback (AAPB),
the International Society for Neurofeedback and Research (ISNR), and the Washington State Legislature.
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.
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.
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.
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.
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. 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. Alexander Graham Bell attempted to teach the deaf to speak through the use of two devices—the phonautograph, created by Édouard-Léon Scott's, and a 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. After World War II, mathematician Norbert Wiener developed cybernetic theory, that proposed that systems are controlled by monitoring their results. 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. 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
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. In 1974, H.D. Kimmel trained subjects to sweat using the galvanic skin response.
Timeline
1958 – G. Mandler's group studied the process of autonomic feedback and its effects.
1962 – D. Shearn used feedback instead of conditioned stimuli to change heart rate.
1962 – Publication of Muscles Alive by John Basmajian and Carlo De Luca
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'.
1974 – Publication of The Alpha Syllabus: A Handbook of Human EEG Alpha Activity and the first popular book on biofeedback, New Mind, New Body (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
1976 – BRS renamed the Biofeedback Society of America (BSA)
1977 – Publication of Beyond Biofeedback by Elmer and Alyce Green and Biofeedback: Methods and Procedures in Clinical Practice by George Fuller and Stress and The Art of Biofeedback by Barbara B. Brown
1978 – Publication of Biofeedback: A Survey of the Literature by Francine Butler
1979 – Publication of Biofeedback: Principles and Practice for Clinicians by John Basmajian and Mind/Body Integration: Essential Readings in Biofeedback by Erik Peper, Sonia Ancoli, and Michele Quinn
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 and Supermind: The Ultimate Energy by Barbara B. Brown
1984 – Publication of Principles and Practice of Stress Management by Woolfolk and Lehrer and Between Health and Illness: New Notions on Stress and the Nature of Well Being by Barbara B. Brown
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
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
2004 – Publication of Evidence-Based Practice in Biofeedback and Neurofeedback by Carolyn Yucha and Christopher Gilbert
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
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. More information is available at the website of the CNRS French National Center of Neural Research.
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.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.
In 2001, the company Journey to Wild Divine began producing biofeedback hardware and software for the Mac and Windowsoperating systems. 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.
In the mid-1970s, an episode of the television series The Bionic Woman
featured a doctor who could "heal" himself using biofeedback techniques
to communicate to his body and react to stimuli. For example, he could
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 could 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 could 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.
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