Biofeedback: Peripheral Nervous System
Neurofeedback: Central Nervous System
Imagine holding a sensitive digital thermometer in your hand. A thermometer so sensitive that you can see it bouncing up and down, apparently by itself. But it is accurate, your hand temperature varies slightly moment to moment.
If you direct your attention to relaxation by loosening any tension in your hand, the blood flow increases. With warm blood flow the temperature goes up. A hand temperature of 94.5º F or above is often associated with general relaxation and a sense of well being.
That is one kind of peripheral biofeedback. A useful skill to be sure, especially when it can be tapped at challenging times. However, peripheral biofeedback is limited. Not everyone can attain the state or acquire the skill, and it does not have a lasting effect. On the other hand, neurofeedback allows you to make enduring improvements in how the central nervous system functions.
Since 1949, biofeedback has involved monitoring and feeding back information about the psycho physiological state. Traditional biofeedback uses peripheral based measures like EDR, TEMP, EMG, BVP, and Respiratory Waveform to monitor and feed back information about the status of these peripheral measures of sympathetic nervous system activity. Clients are trained to become familiar with eliciting these states, which they must consciously remember to do in their day to day lives.
Since 1970, neurofeedback has ascended in value because it monitors and feeds back information about activity in the central nervous system (CNS). The brain is at the center of virtually every self-regulatory loop and process in humans. Monitoring and feeding back information about CNS status results in rapid and robust changes because you are influencing psychophysiology at its core.
The effects of training the central nervous system, radiate throughout the system. However, peripheral training may or may not generalize to influence the more central processes. For instance, many clinicians have used temperature feedback to alleviate migraines. Training the client to increase their peripheral temperature as measured at the fingertip, foot and/or stomach, leads to a decrease in the duration, intensity and frequency of migraines in many clients.
However, it is not easy for most clients to learn this skill, and they must continue to practice the skill outside of the office, or else the training effect is likely to fade away over time. When this happens, migraines can begin to re-emerge. Additionally, there is no clear connection between changes in peripheral temperatures and other, more central changes in the brain.
Neurofeedback, on the other hand, directly trains the functioning of the CNS, which is where migraines occur. Decades of clinical experience consistently show that the training effect maintains and proliferates without conscious practice on the part of the client.
During neurofeedback, the brain receives the information it needs to re-establish its intrinsic healthy chaos, and so does not create migraines. In particular, we have found that training to decrease amplitude in the range of 3-5 Hz and 23-38 Hz bilaterally while simultaneously increasing amplitude at 14 Hz on the right side and 15-18 Hz on the left side, virtually eliminates migraines.
In other words, to experience a migraine the CNS must produce elevated amplitude levels in the 3-5 Hz and 23-28 Hz ranges bilaterally with relatively decreased amplitude levels at 14 Hz on the right and 15-18 Hz on the left.