William F. Dougherty, PsyD

301 W. Grove St. Clarks Summit, PA Tel: 570-207-1529

What is Biofeedback?


Screenshot Example-followed by detailed information. 

Biofeedback is a method for learned control of physiological responses of the body. These responses can be either in the voluntary system, such as skeletal musculature, or in the involuntary, or autonomic nervous system, such as heart rate, vascular responses (frequently indirectly measured as temperature), and sympathetic discharges (measured by the electrical skin response).

The experimental data to support the feasibility of such learned controls first appeared in the 1950s with the work of psychologists such as Neal E. Miller. They increased in the 1960s, mostly through animal studies, although some experiments with humans were also performed. Next came a joint endeavor between experimental psychology and physiology. It became clear that certain dramatic gains could be achieved by using psychological techniques on patients with medical problems. Autonomic and disease specificity and the patient's psychological state must be considered before treatment can begin. For example, learning to relax certain muscles may be somewhat useful in many disorders but may not be the most effective treatment. An anxious patient with tachycardia (rapid heartbeat) benefits much more by learning to slow his or her heart rate rather then by relaxing muscles.

Biofeedback can be used to control certain biological responses that cause health problems, such as headaches, chronically taut muscles from accidents or sports injuries, asthma, high blood pressure, and heart arrhythmias. It is often used instead of, or as a complement to, drugs in pain control.

The training methods are relatively simple, although they require complex and precise instrumentation. After the desired mode of treatment has been determined for a given disorder, the patient is connected to a computer or an equivalent instrument by a polygraph, and the response is presented back to the patient in either a binary or an analog fashion. In the binary approach, a threshold is set, and whenever the patient crosses that threshold, a light or music indicates that the patient is succeeding. In the analog approach the patient monitors the actual numbers in electrical units that represent bodily states such as heart rate, temperature, or vasculature. The two techniques can be combined. Initially the criteria are made easy by the therapist, and as the patient succeeds, the task is made more difficult. Ultimately the patient should become his or her own therapist and eventually control specific body functions without the use of instrumentation.


Simply put, biofeedback is a means for gaining control of our body processes to increase relaxation, relieve pain, and develop healthier, more comfortable life patterns.

Biofeedback gives us information about ourselves by means of external instruments. Using a thermometer to take our temperature is a common kind of biofeedback. Clinical biofeedback follows the same principle, using specialized instruments to monitor various physiological processes as they occur. Moving graphs on a computer screen and audio tones that go up and down "reflect" changes as they occur in the body system being measured.

Biofeedback training familiarizes us with the activity in our various body systems so we may learn to control this activity to relieve stress and improve health. Trying to change physiological activity without biofeedback is like playing darts while blindfolded--we can't see whether we are hitting the mark or not. Biofeedback lets us know when we are changing our physiologies in the desired direction.

Biofeedback is not a treatment. Rather, biofeedback training is an educational process for learning specialized mind/body skills. Learning to recognize physiological responses and alter them is not unlike learning how to play the piano or tennis--it requires practice. Through practice, we become familiar with our own unique psychophysiological patterns and responses to stress, and learn to control them rather than having them control us.

In his book, Biofeedback: A Practitioner's Guide, Mark Schwartz defines biofeedback as "(1) a group of therapeutic procedures that (2) utilizes electronic or electromechanical instruments (3) to accurately measure, process, and 'feed back' to persons (4) information with reinforcing properties (5) about their neuromuscular and autonomic activity, both normal and abnormal, (6) in the form of analog or binary, auditory and/or visual feedback signals. (7) Best achieved with a competent biofeedback professional, (8) the objectives are to help persons develop greater awareness and voluntary control over their physiological processes that are otherwise outside awareness and/or under less voluntary control, (9) by first controlling the external signal, (10) and then by the use of internal psychophysiological cues."

In a typical biofeedback session, the client is seated in a comfortable chair and hooked up to the biofeedback instrument with sensors attached to the surface of the skin at various locations on the body (usually the shoulders, fingers, back, and head). Electrical impulses from these locations are recorded and reflected on a computer monitor in the form of graphs or other visual displays such as mandalas. Additionally, the client may receive auditory feedback reflecting increases and decreases in body system activity in the form of higher and lower musical tones.

Before beginning training, the client's baseline measures in the various modalities are recorded without feedback, to give the clinician a picture of his or her overall psychophysiological state.  This comprehensive evaluation generally takes 32 minutes, during which readings are taken for 5 minutes with eyes closed, 5 minutes with eyes open, 15 minutes of discussion, and 7 minutes of eyes closed self-soothing. The clinician then chooses to begin training by focusing on the most appropriate physiological system, as indicated in the initial evaluation. The client may be directed to pay particular attention to one physiology, while information on the other body systems is monitored by the clinician. While the client is observing the activity of a particular system onscreen, audio feedback in the form of musical tones is also being presented, reflecting activity in the same system or a different one.

Every individual exhibits a unique set of characteristic psychophysiological patterns that reflect the various accommodations to stress that he or she has made over the years. The goal of biofeedback training is to gain self-regulatory skills with which to adjust the activity in various systems to optimal levels for the task at hand.  Clinically, I have found that clients have greater success when they train toward a specific range of activity in each modality that research has found to be both possible and desirable, rather than simply training to reduce activity. We call these ranges the goal zones.

Biofeedback Modalities

Many physiological processes can be monitored for biofeedback applications. Some of the more common ones are:


Temperature is measured by sensors placed on the ring fingers. The temperature modality indicates the contraction or relaxation of the smooth muscles surrounding the blood vessels, which determine how much blood reaches the fingertips. When these muscles are contracted (tense), the temperature is cooler because less blood reaches the fingers. We experience this coldness in our hands when we are stressed--for example, when going to a job interview and shaking hands with a prospective boss. It is not uncommon for people's temperature readings to be as low as 70 to 80 degrees Fahrenheit, nor is it uncommon to see a difference of five or ten degrees between right and left hand measures. The brain is organized so that right hemisphere is associated with activity in the left side of the body, and the left hemisphere is associated with activity in the right side of the body. Some clinicians believe that when one hand is significantly colder than the other, this represents an imbalance in the activity of the right and left hemispheres of the brain.

Clinically, the goal of training is to achieve a balance between right and left hand temperatures in the range between 94 and 98 degrees Fahrenheit.


Muscle activity is measured by the EMG (electromyograph), which detects the electrical activity occurring within certain muscles, typically the trapezius (shoulder) and anterior temporalis (jaw and scalp) muscles. Muscle tension indicates stress; for example, it is common for people to react to the stress of anger by clenching their teeth and generally tensing up.

To measure EMG, the skin is cleaned and adhesive sensors with a conductive gel are attached to the shoulder muscles.  Clinically, the jaw and scalp sensors placed on the outer forehead are small silver discs held in place by an elastic headband. Muscle activity is measured in microvolts, and it is not uncommon for levels to range from 5 to 40 microvolts.

The goal of training is to quiet muscle activity to a range between .5 and 2.5 microvolts.


Electrodermal activity (EDA) is measured in two ways: BSR (basal skin response) is a measure of the average activity of the eccrine (sweat) glands, and GSR (galvanic skin response) is a measure of the phasic activity (the high and low points) of eccrine gland activity. Most people are familiar with having cold, clammy hands under stressful circumstances, such as meeting new people or having to perform before an audience. The coldness comes from constriction of the smooth muscles surrounding the blood vessels (measured by Temp), while the dampness is caused by eccrine gland activity. The eccrine glands secrete a salty solution in response to emotional and stress stimuli, and this salty solution conducts electricity.

BSR sensors are attached with elastic bands to the first and second fingers of the right hand. It is not unusual for people to measure between 150 and 500 kilohms without training.

The goal of training is to reduce eccrine gland activity to the range between 800 and 1200 kilohms.

Heart Rate:

Heart rate is measured in beats per minute. Faster heart rates are often caused by stress; for example, our hearts may race and pound when we are afraid. Other kinds of stress, such as depression, may result in lower heart rates.

To measure heart rate, the inside wrists are cleaned and three silver sensors with conductive gel are slipped under elastic wrist bands. Heart rate can also be measured at the fingertips.  The goal of training is to achieve a heart rate between 56 and 66 beats per minute.


Respiration is measured in breaths per minute, typically by a strain gauge worn around the chest.  This is measured by the same sensors that are used to measure shoulder muscle activity. Our respiration becomes faster, shallower and uneven when we are stressed, for example, when we gasp in surprise or feel short of breath when frightened. It is not unusual for people to have a breath rate of between 16 and 30 per minute prior to training.

The goal of training is to reduce breath rate to 8 to 12 breaths per minute.


Brain waves are measured by the electroencephalograph (EEG). EEG is comprised of several bandwidths: Theta (4-7 Hz), Alpha (8-12 Hz), Beta (13-20 Hz), Gamma (21+). The overall purpose of EEG training is to develop range of motion among bandwidths, so that the client knows what each bandwidth feels like and how to use each state for its characteristic benefits. Speaking very generally, beta and gamma are useful for directed activity and getting things done; alpha is useful in situations where relaxed vigilance is called for (such as meditation); and theta is useful for creative, day-dreamy generation of imagery (theta is sometimes called the gateway to the unconscious).

Brain wave measurements are recorded through silver discs placed at four locations: center forehead, right forehead, the base of the scalp to the right of center (occipital 1), and the base of the scalp to the left of center (occipital 2).

Unlike some of the body measures, EEG is a very complex phenomenon. Clinicians have dedicated years of research exploring and interpreting EEG data to establish a unique training protocol called BioIntegration, which complements and enhances body measure training.

Amplitude density is an exciting measure that reflects the activity of the brain as it occurs, revealing both how much activity is occurring and how often it occurs in each bandwidth. Amplitude density is measured in microvolts per second.

Standard EEG measurement includes measurement of right and left brain activity.

Brain waves respond to subtle psychophysiological conditions, such as whether the eyes are open or closed, whether or not we are speaking, and the content of our thoughts.  EEG training generally aims first at reducing activity in the 13-35 Hz bandwidth (beta-gamma). This bandwidth typically characterizes our waking state and often accompanies unnecessary tension we habitually carry in our bodies. When a client becomes familiar with how this bandwidth feels, he or she can recognize it and move out of it to accomplish certain goals, for example, to relax.

When the client has learned to reduce activity in the beta and gamma bandwidths (13-35 Hz), training is continued to enhance the production of alpha activity. When the client has learned how to generate increased alpha activity, training moves on to encourage the client's ability to generate theta waves.

Other biofeedback modalities include electrogastrography (EGG) to measure stomach functions; strain gauges to monitor penile erections; and moisture sensors to indicate bladder incontinence.

It is advantageous for clients to receive feedback in many modalities at once, even if the practitioner chooses to address a specific condition by working primarily with one modality (e.g., using Temperature training as a means of reducing migraine headaches). Multimodal training recognizes that the human being is a complex whole, whose various systems are constantly interacting in an effort to achieve a point of homeostasis (balance). When a client receives information about several psychophysiological systems during training, he or she can develop an understanding of the interrelationships that support his or her usual psychophysiological state and has more choices in terms of self-regulation skills.

Indications for Training

Clinical biofeedback is used successfully in the following applications:

  • Anxiety disorders
  • Mild depression
  • Epilepsy
  • Headaches
  • Concentration improvement for education and meditation
  • Control of brain waves for spiritual development and inner tranquillity
  • Musculoskeletal disorders involving chronic muscle tension
  • Relaxation therapies
  • Stress management techniques
  • Neuromuscular re-education of gait mechanics
  • Chronic pain syndromes
  • High blood pressure
  • Asthma
  • Circulatory problems such as Raynaud's Disease
  • Temporomandibular joint syndrome (TMJ), jaw pain and dysfunction
  • Bruxism (teeth grinding, often at night)
  • Urinary incontinence (bedwetting, nocturnal enuresis, leaky bladder)
  • Fecal incontinence
  • Attention Deficit Disorder (ADHD)

Although biofeedback training may focus specifically on one psychophysiological system as a means of addressing a particular presenting complaint, clients are soon reminded of the holistic nature of the human organism as they observe that changes made within one system create changes in all other systems, to greater or lesser degrees. It is a mistake to think of biofeedback training in any one modality as the hammer that pounds the nail of a certain problem, leaving the rest of the structure unaffected. As clients discover the interrelationships that exist between psychophysiological systems, they learn to create a "mix" that addresses their presenting complaints and shows them a path out of habitual patterns of consciousness and behavior, facilitating personal and evolutionary development. We call this "BioIntegration"--the process by which an individual, through multimodality training, links internal and external life events such that he or she is able to make more real-time choices instead of being unconsciously dominated by habitual patterns.

Thus, biofeedback training has long-range implications that go beyond the notion of "fixing what ails you." While the training is certainly beneficial for a wide range of complaints and provides relief from and mastery over many conditions in a gentle and completely noninvasive way without the use of drugs, it inevitably does more than that. It awakens the realization that we have the power to make lasting changes in our bodies and minds, and the accompanying opportunity to direct these changes for life-enhancing benefits.


When we speak of neurotechnology, we refer to those devices and techniques capable of producing changes in the electrical activity of the user's brain. When these occur, we may experience deep, stress-relieving relaxation, increased receptivity to information (with the ability to process and recall it), and automatic changes in dysfunctional thoughts, feelings, and behaviors. With any luck, we may enter a creative reverie with fertile ideas and solutions to problems. Some people use the technology to improve their ability to learn and remember, some to center and establish a base of tranquillity in a stressful world, and others for entertainment. We think of these products as accelerators of change.

Every thought, feeling, sensation, and level of awareness has a corresponding brain wave pattern. If an individual wants to improve attention and focus, for example, they need to learn to control their brain waves. Until now, that meant lots of hard work practicing some form of non-assisted biofeedback control with little guarantee of success. Fortunately, the way to attain more performance, improved memory, and a reduction in stress/frustration has arrived.


Auditory Visual Stimulation or AVS biofeedback equipment, comes in a number of forms and flavors. The most well-known and effective measure the brain's electrical activity and then pulse lights and sounds to control that activity. Such devices, through flickering lights and precisely controlled rhythmic tones, stimulate and synchronize the hemispheres of the brain while entraining the brain wave frequencies into desirable states of consciousness. The study of these brainwave patterns, the summation of the brain's electrical activity, as represented by electroencephalography EEG), has led scientists to the discovery that different brainwave patterns are associated with different states of awareness.

Four main brainwave patterns have been recognized:

Beta Waves          13 - 30 Hz          Alert state
Alpha Waves          8 - 12 Hz          Relaxed wakefulness
Theta Waves          4 - 7 Hz           Reverie, imagery
Delta Waves         .5 - 3 Hz           Deep sleep

In the '30s, researchers found that repetitive light stimulation (strobing) caused brain waves to follow and pulse at the same frequency. This frequency following response (entrainment) forms the foundation for many of the effects of the auditory visual stimulation. AVS units have lights in glasses that pulse at predetermined frequencies, generally from 1 to 40 cycles per second (Hz).

If you select a session with a target frequency in the low alpha or theta range, you should feel a change in awareness within a few minutes. Many people report a floating feeling. Your attention may start to wander as your thoughts become less linear and logical. Perhaps you may find yourself in a lucid dream complete with sights, sounds and feelings. Some people, auditory types, often hear words in the pulsed sounds. This indicates theta activity and heightened creativity. Because your sense of time changes during the session, it may seem as if you have slept. Usually you will feel a definite difference between your state before the session and how you feel during the session.

Most programs start out in the beta frequency range (13-40 Hz.) and gradually slow (ramp) to the target range. The initial phase may seem frenetic, but these frequencies come closest to the brain's when starting. This closeness makes entrainment possible. Starting out a session in theta, for instance, would make it difficult for a beta dominant brain to synch up. This initial phase passes quickly as the pulsing slows. Some users may not find the first sessions very entraining. This happens when a person remains analytical, excited at the novelty of the experience or resistant to letting go. Letting go of control stimulates the production of alpha and theta rhythms. In the beginning, most users will benefit from simply "going with the flow" even if that includes losing awareness.


These rhythms affect the body/mind profoundly with lasting effects even without the user's conscious participation. Many users will notice immediate, spontaneous changes in their attitudes and behavior. Others may need to have regular sessions for a number of weeks before the desired results appear. Once the balancing, stress-reducing, and attention and focus effects of the AVS biofeedback become engrained, the training remains useful for enhancing self-esteem, creativity boosting, and accelerated learning.

With the relief of tension/stress/resistance in the body/mind, the user becomes receptive to information from "inside" and "outside" essential to fundamental change. Spoken words during certain L/S session will embed in deep layers of the user's consciousness to change thoughts, feelings and behavior automatically. The clinicianÂ’s digitally mastered voice has an amazing effect when combined with an individually developed AVS biofeedback program.  Statistically, 72 percent of individuals receiving biofeedback are helped significantly; 20 percent moderately; and 8 percent marginally.

By stimulating balanced, abundant neurotransmitter production, expanding neural pathways, and programming desirable, ecologically sound behaviors, AVS biofeedback can enhance physical healing and homeostasis, intellectual performance (creativity/IQ attentional flexibility), and greatly improved sense of well-being long after the session.

The state of deep rest and hemispheric balance possible with AVS technology can rejuvenate the body/mind and have lasting effects in every area of one's life.  To understand how this technology works, individuals are encouraged to schedule an initial session with a clinician who is trained and certified in biofeedback applications. The first session generally will include gathering a complete history and reviewing school or medical records.  A sample introductory session will be provided and the individual will experience the results.  For additional information regarding AVS biofeedback, or to schedule an appointment please call Bill Dougherty directly at 570-480-6140 for a personal response. 

Bibliography: Benjamin, John V., Biofeedback (1989); Carroll, Douglas, Biofeedback in Practice (1984); Green, Elmer and Alyce, Beyond Biofeedback (1989); Hatch, J. P., et al., eds., Biofeedback: Studies in Clinical Efficacy (1987); Jones, Marcer, Donald, Biofeedback and Related Therapies in Clinical Practice (1986); Richter-Heinrich, E., and Miller, N. E., Biofeedback (1982).


Information provided on the site is meant to complement and not replace any advice or information from a health professional. Page updated on June 10, 2016.