THE EFFECTS OF NUMBER OF TRIALS AND INTERSESSION INTERVAL ON CLASSICAL DISCRIMINATION CONDITIONING OF THE HEART RATE AND EYEBLINK RESPONSE OF THE RABBIT

A 3 by 3 factorial experiment was conducted to determine the effect of the number of trials per session (24, 48 and 96 trials) and the intersession interval (24, 48 and 96 hour) on the classical discrimination conditioning of tJ1e HR and EB response of the rabbit. Thirty-six Ss, randomly assigned to 1 of 9 groups of the 4 Ss each, received either 12, 24, or 48 trials with the CS+ and either 12, 24 or 48 trials with the CS-. All Ss received 1 day of adaptation followed by classical discrimination conditioning until they reached an CD criterion of 85% responding to CS+ and less than 20% responding to CS-. The results of the study indicated that: a) the rate of acquisition of the EB CRs is an inverse function of the number of trials per session during the first 384 acquisition trials; b) the acquisition of the EB CRs over sessions is directly related to the number of trials per session; c) the effect of the intersession interval on the HR and EB CRs seems nonsignificant; d) the lowest HR responding occurred in the 96 trials/session group.