The Effect of two “Tranquillizers” on Auditory Discrimination and Delayed Response Performance of Monkeys

Five rhesus monkeys were tested on performance of an auditory discrimination and a delayed response test with a sliding scale of increasing difficulty after treatment with (a) 0·2 to 0·5 mgm./kgm. reserpine, (b) 150 mgm./kgm. meprobamate, (c) an equivalent saline injection, and (d) no treatment. Both drug treatments resulted in a severe deficit on the auditory discrimination and no change or improvement in delayed response performance. The auditory deficit was not due simply to an increased latency of response.

It is suggested that these results support the hypothesis that reserpine and meprobamate reduce the utilization of sensory information.