The Role of the Central Nervous System Cholinergic Mechanisms in Behavior and Learning

The principal purpose of this study was to investigate the possible differential effects of LSD as a function of procedural variations in performance of delayed response tasks. In general, LSD was found to impair delayed response performance in the monkey. From the standpoint of dose-effect relationships, the results suggest a positive correlation between magnitude of dose and extent of functional impairment. A tendency toward rapidly developing tolerance was observed. A 'placebo effect' in response to the control agent (sterile water) was encountered in a significant number of monkeys.