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.

Intermittent reinforcement and salt arousal of thirst in rats

“…The motivational properties of NaCI injections have been studied by Beck and Carter (1965), Wayner et al (1970), Winer (1971), and others. Leverpress response rates on both CRF (continuous) and short FR (fixed-ratio) schedules increase with increasing concentrations of NaCl and then decrease at high concentrations (Stricker, 1968; Wayner et al, 1970).…”

“…However, the influence of NaCI-induced thirst on behavior under nonregulatory-type schedules (e.g., variable interval or VI) is unclear. Beck and Carter (1965) showed that NaCI injections could apparently induce leverpressing for VI water reinforcement in sated rats previously trained to press for water. Increased response rates following longer delays after NaCl injections suggested that the NaCl was, in fact, motivating the previously learned behavior.…”