Moshe Feldenkrais on Internal Inhibition

“In normal life, activity is never confined to one and the same motor cell in the cortex. In exceptional circumstances, when such concentration of activity is called for, there is an immediate fall of reactivity. It is Pavlov’s contention that to prevent complete exhaustion of a cell or a small group of cells on which activity is thus focused, an inhibitory process comes into being which reduces the reactivity of the cells concerned. The spreading of this inhibitory state to the surrounding cells is what we call sleep.” (Body and Mature Behavior, p. 30)

“Before dealing with this phenomenon it is necessary to acquaint ourselves with delayed and trace reflexes. The sound stimulus and food-giving can be done simultaneously. In this case the conditioned reflex is called simultaneous. If the food is given a few seconds later, the reflex is called delayed. If a long time, say, several minutes is allowed to elapse before the food is given, the established reflex is called trace reflex. Delayed reflexes take longer to establish than simultaneous ones, and trace reflexes longer than delayed; their stability decreases with increasing difficulty of establishment.

“If the food is given before the conditioned stimulus is applied, nothing happens at all unless the interval is very short indeed.

“Now if the stimulus alone of a trace reflex is frequently applied, salivation decreases gradually and stops altogether. The dog becomes drowsy in the lengthy intervals. Sleep, after Pavlov, is a generalized internal inhibition. Inhibitions just like the positive reflexes, are initially vague, diffuse or generalized. Discrimination sets in later.” (Body and Mature Behavior, p. 46)