NONVOLITIONAL BIOFEEDBACK THERAPY.

A procedure known as the nonvolitional biofeedback system is developed and reported which obviates the need for active cooperation of the patient. In the procedure, the scalp-derived EEG is filtered and one of the filtered components is made use of to drive a filament lamp after suitable phase shift. Normally, filtered alpha rhythm is selected, and, on providing photic alpha feedback to a subject, his scalp alpha activity increases to maximum. Statistically significant increase in power spectrum of EEG in the alpha band and increase in latency of midlatency auditory evoked potentials were observed in control subjects. The procedure is presently in use for the management of some psychosomatic disorders.