Acquisition and extinction of conditioned suppression under two training procedures

Eight male albino rats acquired conditioned suppression under either predictable (Estes & Skinner, 1941) or random (Rescorla, 1968) procedures. The random procedure led to more generalized suppression (non-CS suppression) and greater resistance to extinction. In addition, the pattern of responding during the CS differed: the predictable group produced negatively accelerated cumulative records during early extinction trials; the random group produced positively accelerated cumulative records.