Basics of Biofeedback Tools for Self-Regulation
Biofeedback is a system designed to enhance self-awareness and self-regulation. Biofeedback uses physiological measurements such as skin temperature, respiration, heart rate, muscle tension, and skin conductance, which are recorded and then ‘fed back’ for interpretation and adjustment. In the case of neurofeedback, this measurement takes place for the electrical signals of the brain, as recordings are made and then interpreted.
If we use the broadest definition of biofeedback, we can trace its early origins back thousands of years to the practices of meditation and yoga. Patanjali’s Yoga Sutras outline a system of relating to the mind, body and the phenomenal world prior to outlining the postural sequences (asana) or breath control (pranayama) that many of us have come to associate with modern yoga. More recently, in the late 18th century physician Luigi Galvani was a pioneer in electrophysiology, discovering that muscles twitched when receiving a current. In the early 20th century the psychiatrist Carl Jung employed Galvanic Skin Response (GSR) measures during some of his evaluations. By the 1920’s the psychiatrist Hans Berger invented the electroencephalograph (EEG) to measure the electrical activity of the brain.
In the 1960’s biofeedback emerged as a discipline with organized clinical applications such as for treatment of migraine headaches at the Menninger Clinic. By this time, there was a model for understanding that the human autonomic nervous system (which controls heart rate, respiration, temperature and sweat) responds ‘automatically,’ meaning that it is often outside our conscious awareness. The autonomic nervous system includes the sympathetic, parasympathetic and enteric (gastrointestinal) nervous systems.
Of particular importance to biofeedback is the relationship between the sympathetic and parasympathetic nervous systems. While the sympathetic nervous system is responsible for the ‘fight, flight, freeze’ response, the parasympathetic system is responsible for our ‘rest and digest’ response. It may be helpful to use the analogy of the sympathetic system as an accelerator, and the parasympathetic system as a brake, although there are exceptions to this dichotomy. Most importantly, much of what we do in our daily lives entails a balance between these two systems for optimal functioning. Ideally there is some equilibrium in our ability to mobilize, energize and also calm or slow down depending upon our needs and circumstances.
As of 2007, biofeedback was formally defined by the Applied Psychophysiology and Biofeedback (AAPB), Biofeedback Certification International Alliance (BCIA) and the International Society for Neurofeedback and Research (ISNR) as:
“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 brain waves, 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 psychological changes. Over time, these changes can endure without continued use of an instrument.”
As noted above, the modalities for biofeedback assessment and training may include respiration (breath), heart rate, heart rate variability (HRV), muscle tension (SEMG), skin conductance (SC; sweat gland activity), skin temperature, and in the case of neurofeedback, electrical signals from the brain using electroencephalograpy (EEG). Each of these modalities provides its own data and applications, depending upon the presenting symptoms and concerns of the client.
Heart rate variability, known as HRV, is a statistic that represents the variation in the time interval between our heartbeats. We now know that healthy hearts have a high degree of variability. What’s more, this statistic is negatively correlated with age, meaning that the HRV metrics decrease as we get older. There is a complex relationship between the fibers of the sympathetic and parasympathetic nervous systems behind the HRV metrics. For some clients, one of the aims of biofeedback may be to increase HRV to optimize health. HRV is decreased by age, poor sleep, stress and chronic illness. While it is beyond the scope of this blog to present all the details, advanced statistical analyses have transformed our ability to interpret HRV heart rate data.
Since the 1990’s, there has been a surge of research regarding the physical and psychological correlates of heart rate variability (HRV), because it turns out to be a robust indicator of health. HRV training has been shown to decrease symptoms of anxiety, depression, and also to improve outcomes for people with asthma, hypertension and migraines. Research has also shown that HRV training improves emotion regulation, sustained attention, situational awareness and memory retrieval.
The overarching goals of biofeedback treatment and training are to improve awareness, which includes cognitive, physiological and emotional processes. Once a baseline of awareness is established, it aims at improving the self-regulation of physiology, via heart rate, heart rate variability, respiration, temperature, muscle tension and/or skin conductance, depending upon specific client goals. The broader goal is to generate long-term improvement by using these skills in everyday life without the help of the equipment in the clinician’s office. For some the purpose of biofeedback will be to improve their current state of health, while others look for performance optimization in their profession or sport.
References
Billman, G. (2011). Heart Rate Variability- A Historical Perspective. Front.Physiol.
2: 86.
Khazan, I. (2013). The Clinical Handbook of Biofeedback. London, UK: Wiley-Blackwell.
Patanjali. Yoga: Discipline of Freedom (1995), Translated by Barbara Stoller Miller. University of California Press, Ltd. London, England.
