Mechanisms of motivation in avoidance behavior.

The mechanisms involved in avoidance behavior are discussed. It is assumed that the conditioned stimulus (CS) activates the memory pattern of associations related to the former applications of the unconditioned stimulus (US) and, as a result, produces an undesirable sensory state. This activates another memory pattern of associations related to the avoidance response and the postponement of the US. The performance of the avoidance response discontinues the CS, resulting in inactivation of the first memory pattern; this leads to a removal of the undesirable sensations, i.e., to an improvement in the sensory state. It is suggested that avoidance behavior obeys the same general rules which apply to approach (appetitive) behavior. In both approach and avoidance behavior the instrumental response provides a desirable sensory change (due to obtaining of the desired US in approach behavior and the postponement of the undesired US together with the discontinuation of CS in avoidance behavior). In 'both cases the response gradually extinguishes when its performance no longer provides the sensory "better-being".