Marijuana influenced changes in GSR activation peaking during paired-associate learning

Abstract

Activation Peaking (AP) referes to a patterned physiological response occuring during learning. Marijuana has been found to interface with both paired-associate learning and phasic GSR activity. Therefore, a study was performed to assess the effects of marijuana intoxication on paired-associate learning and concomitant GSR AP. Two marijuana usage categories were employed - light and heavy usage Ss. Within each category four groups were run in a design to test state-dependent effects. Each S was seen twice a seven-day inter-session interval. The groups were P-P, P-M, M-M and M-P with P = placebo and M = 14 mg † 2 THC . At each session S learned a nine-word paired-associate list to a criterion of one correct recitation, and then received 100 percent overlearning. No usage or group differences were found in level of basal conductance, except lights showed habituation over sessions and heavies did not. Magnitude of phasic GSR activation, aligned for AP, was significantly reduced for both heavy usage and marijuana intoxicated Ss. Also, only on placebo days was an AP effect evident. The results were discussed in terms of marijuana's effect on learning and physiology with emphasis on possible mechanisms of action.