Further Test of the Deprivation Trace Hypothesis

Abstract

32 rats were used to test the deprivation-trace hypothesis of O'Kelly and Heyer (1951). In a 2 × 2 × 2 factorial design the following variables were manipulated: delay between saline injection and bar-press testing, 30 min. vs 240 min., presence or absence of food during the delay period, and schedule of reinforcement, VI-¼ min. vs VI-1 min. The only significant differences were the main effects of schedule and delay. The prediction was supported, but alternative interpretations not requiring the hypothesis were offered.