A Brief History of Biofeedback
Bio-information comes in many forms, transmitted through your skin, muscles, organs, and nervous tissue. It is something that you and I rely on every moment of our lives, aiding us in movement, balance, and navigation of our environment, as well as mediating our interaction with others. Over the last 100 years, technologies have evolved that allow us to do even more with these natural, organic processes. This article focuses on such technology. Popular biofeedback methods include use of tools that measure heart-rate and heart rate variability, skin-conductance, skin temperature, and respiration, as well as technologies that scan the brain and other bodily processes that are otherwise invisible to the naked eye (see Moss & Shaffer, 2016, for a comprehensive list)
The science of biofeedback is based on a continuously evolving recognition that the human body is complex. The human body is not a physical lump the way that a rock is, even though both can occasionally be found lying perfectly motionless on weekend afternoons. The human body comprises countless processes that are always in flux, making adjustments in response to changes in the environment and bodily position. This complexity was not always taken for granted by biologists. Indeed, biofeedback technology would not have made any sense in the 19thcentury. That is until a few key breakthrough studies in human biology took place, such as the work of German neurologist Kurt Goldstein (1878–1965).
Before 1900, and to some extent still today, modern biology was based on the physics of Isaac Newton (1643–1727) and his assumption that the human body operates like a machine. In a machine, every part has its function, and these functions may be added together to accomplish more complicated functions. The machine metaphor of human biology might compare the heart which pumps blood to the fuel pump in an automobile’s gas tank. To be sure, both parts have their job to do. But the heart is far more sophisticated than a fuel pump, and by extension, the body is far more sophisticated than a machine. The pace of the heartbeat is making tiny changes moment to moment, and in response to changes in the environment — even changes that you do not realize. A loud noise initiates an increased heart rate even before you are consciously aware of the sound. Think of all the heart-rate changes that might occur throughout a routine drive through the city: listening to music, witnessing a near-miss collision, or glancing worriedly at your speedometer when passing a police officer. Each of these events initiate minor shifts in heart-rate. All of this is to say nothing of your gastrointestinal system, thermoregulation, digestion, and cognitive focus, each with their own moment-by-moment changes. Fortunately for us, many biologists throughout the early 20thcentury realized that there was more going on in the human body than mechanical operations.
Our bodies are not simply reactive the way that parts in a machine are: a spark plug fires in response to an ignition switch which responds to the turning of key cylinder which responds to the key you are turning with your hand (or, increasingly, the button you are depressing on your key fob), and so on down the line of causality. Our bodies, by comparison, are inter-active.The bodily response to the environment is reciprocal. One clear example of this should drive this difference home, although it is not one you might expect.
Remember the “patellar tendon reflex”? This is the routine medical examination procedure where the doctor bangs on the relaxed knee of the patient’s leg which dangles off the side of the examining bed. By striking the relaxed patellar tendon, the patient’s quadriceps contract and “whoop” up the foot goes. A blow to the tendon causes the muscular contraction. While this seems like a mechanical a-causes-b chain-reaction type of event, careful inspection of the human person demonstrates that there is more to this than meets the eye. Kurt Goldstein (2000), the neurologist mentioned above, explains it more carefully: “The ‘patellar reflex,’ for example, has proved to be by no means invariably constant in the same individual. It varies, depending, among other things, on the position of the limb, on the behavior of the rest of the organism, and on whether or not attention is paid to it. […] A certain kind of attention diminishes the response, another kind exaggerates it” and so on (Goldstein, 2000, pp. 70–71).
The British Zoologist William Homan Thorpe described similar processes in the animals he observed. Namely, that “organisms absorb and store information, change their behavior as a result of that information, and all but the very lowest forms of animals (and perhaps these too) have special organs for detecting, sorting, and organizing this information” (1977, p. 3). Throughout the middle of the 20thcentury, the paradigm in biology shifts from one of body-as-machine to body-as-process.
This shift in biological theory brings us to an important point of scientific history. As scientists began to grow comfortable with the idea that the human body is a dynamic and interactive process, their ideas about what it means to be a person also began to expand. Indeed, it is at this point that we begin to see biology, biophysics, psychology, computer science, integrative medicine, and philosophy merge together in a unique way. I outline some of these mergers in a recent book (Whitehead, 2018).
The Fundamentals of Biofeedback
You and I rely on a host of bodily processes in order to accomplish simple tasks such as balancing or standing upright. There are, of course, the many muscles in the legs, hips, and core, as well as a nervous system feedback loops called the afferent and efferent pathways. These feedback loops are paired with perceptual and vestibular feedback loops. The impact that visual perception has for balance can be found in the dizzying carnival game where one must balance on a bridge while the walls spin around you. By watching a toddler attempt to stand or walk, you will be reminded that these feedback loops are not easily mastered. It takes many months for the infant to simply hold her head erect perpendicularly without it wobbling about. We eventually become so accustomed to using these biological feedback loops to accomplish our routines that they begin to fade into the background. They are always there, something we are reminded of whenever a certain blood-alcohol level or spell of vertigo results in the sense that the room is spinning.
Feedback of this sort is not limited to internal bio- and neurological processes. We also learn to interpret information from our environment, integrating it into our awareness of ourselves in space. When driving a new car for the first time, the placement of the mirrors, the responsiveness of the brake pedal, and the location of the clutch friction point each take a bit of getting used to. You might, for example, have to depress the brake pedal all the way to the floor before the brake pad system responds. The first time you approach a stop sign you might have the experience that you are not slowing down as quickly as you should and end up pushing the pedal to the floor, screeching to a jolting halt. After interacting with and integrating this feedback loop a few times, you begin to operate through it with less and less conscious attention, and eventually ignore it completely. In this manner, the car becomes an extension of you.
Important feedback is transmitted internally (through the body) and externally (through interaction with the environment). The clinical procedure of biofeedback combines these two by first externalizing a bit of internal feedback and amplifying it through a piece of technology before reintroducing it back to the person so that it can be re-integrated. For example, your brain produces varying wavelength patterns while you sleep. These wave-patterns can be measured by an electroencephalography (EEG) machine. Brain waves emitted during sleep can indicate periods of restlessness during the night or periods of deep/shallow sleep, and they can be useful in diagnosing sleep problems. This biological information is only available to us once externalized and amplified by an EEG. With this new feedback loop, the available information can be reintegrated into a patient’s sleep habits and a new, perhaps more restful, sleep habit can be developed.
Fortunately, you and I don’t need to hook a dozen electrodes to our scalp in order to benefit from biofeedback technology. Heart rate levels, which fluctuate throughout the day, can convey valuable information about levels of stress, anxiety, and relaxation. Your current heart rate, which can be detected by more and more accessories including watches and rings, can indicate autonomic nervous system arousal, which is important to understand for mental and physical health and wellness.
Conclusion: Integrating Biofeedback into Daily Life
The many processes of your body have one thing in common: each are in service to the continuation of the process of you(whatever that might be today). On the one hand, you areyour body, so these processes must continue, for example, for your cells to receive the nourishment they need. But on the other hand, you are also a person — partner, friend, business person, mother/father, volunteer, student, professional, etc., and these biological systems are also in service to these identities. When any of these identities is altered, such as getting a promotion or being fired from a job, you experience an immediate physiological sensation (such as the peculiar sensation of having blood evacuate your stomach when you learn that s/he likes you back). After all, it is not some body of which you are in possession; you areyour body. This also means that your personality is not merely a consequence of biology and genetic predisposition. The relationship between biology and personality is more dynamic and reciprocal than that.
Like our biological systems, our personalities are also dynamic, flexible, and capable of change. Personality psychologist Martin Seligman (2006) built his positive psychology fame around his discovery that the personality trait of optimism/pessimism was not something you were born with, but something that could, to some extent, be developed through certain cognitive and behavioral practices.
If you are interested in learning more about biofeedback research, I recommend following the work of clinical psychologist Donald Mossbiofe, who heads a biofeedback laboratory at Saybrook University in San Francisco, CA.
