Biofeedback's early history
Many of our body's systems just do their job without us thinking about them. The cells of our body and our internal organs just "do what they do". Our heart continues to beat, and our internal organs keep us alive with the whole miraculous thing orchestrated somehow down to the cellular level.
Science long ago labelled those parts of our nervous system that silently do their job without our conscious intervention the "autonomic nervous system" (ANS). Of course alongside the ANS we have the somatic aspects of the nervous system that are in our conscious control and we can often sense the interplay of these two sides of the body's peripheral nervous system.
As late as the 1950's scientists resisted the idea that it was even possible to have an conscious control or influence over the ANS. Biological processes such as heart rate, blood pressure regulation and skin temperature were assumed to be under the control of the ANS. Within the following decade that paradigm started to shift as we learned that we could actually influence the ANS - that thoughts were "things" that could indeed influence both our physiological and psychological states.
As long ago as 1875 science discovered that mental activity resulted in fluctuations in the brain's electrical activity. By 1920 Hans Berger recorded the first electroencephalograph (EEG signals) on the human scalp and observed how thinking and alertness affected the patterns of change he saw in the EEG signal. He believed that observable patterns in the EEG could reflect clinical disorders and in fact many neurofeedback practitioners today work with protocols that have this as a foundation.
Other scientists focused on the peripheral nervous system and observed the body's biological signals. For example, Carl Jung was one of a number of people who looked at the Galvanic Skin Response (GSR) - a measure of the electrical conductivity of the skin. The idea was to observe the link between pyschological and physiological states. He noted that he could detect changes in the GSR when patients were asked for a reaction to certain words in a word association test.
As we all know, we can have words that carry an emotional "sting" by being associated with personal and perhaps significant life events. By looking at the GSR he was able to get insight into how the body was actually responding to particular thoughts. Today we know that GSR or Electrodermal Activity (EDA) is very sensitive to activation of the sympathetic branch of the ANS - when we are responding to a stressor the electrical resistance of our skin changes.
By the 1960's research proved that subjects could influence ANS functions via a process termed operant conditioning. Biofeedback's foundations were then secure.
In 1963 John Basmajian developed the principles of electromyography (EMG) and learned that even a signle motor unit starting in the motor cortex of the brain and extending down to the thumb could come under conscious control. Although this was not a practical application of biofeedback at the time because it used needle electrodes and an invasive approach, it did effectively demonstrate the mind-body connection at work.
In a future article we will peak at the evolution of biofeedback into clinical practice.