Biofeedback, quite simply is a technique which takes a measurement of the body, and provides a result.
A scale can be said to be a biofeedback device that measures weight; a thermometer one that measures body temperature. We can measure factors of the body electric such as the voltage of the firing brain cells, the amperage of the heart muscle contractions, the voltage of the muscles and the resistance to the flow of electricity of the skin.
We can measure the oscillations of these factors and as seen by the EEG, ECG, EMG and GSR. The same technological theories that brought us biofeedback in the 1960’s, have also brought devices like the CAT Scan, MRI, TENS, ultra-sound, and many other sophisticated technologies to our healthcare systems.
The information measured with a biofeedback device is then “fed-back” to the client, informing them of various physiological parameters and stress responses within the body, and educating them about the need to retrain their body’s stress responses, balance the body electric, make lifestyle changes or learn to control physiological reactions, in order to achieve improved relaxation and better health overall.
Biofeedback utilizes electro-dermal sensors to measure Galvanic Skin Resistance (GSR), also referred to as Electro-Dermal Response (EDR). GSR measures mild electrical impulses on the surface of our skin, which change due to moisture. The moisture of the skin changes according to the body’s degree of stress and/or relaxation. There is a direct relationship between sympathetic nervous activity and emotional arousal. GSR is so sensitive it can even measure fluctuations in emotional states; think about the lie detector, for example.
Biofeedback instruments measure muscle activity, skin temperature, electrodermal activity (sweat gland activity), respiration, heart rate, heart rate variability, blood pressure, brain electrical activity and blood flow. There are many types of biofeedback: GSR, EEG, CAT scan, MRI, etc. These technologies are able to capture the bodies’ analog electrical signals and translate those signals into meaningful information through complex algorithmic software that a technician can then decipher.