ACUTE EFFECTS OF LSD ON RHESUS-MONKEY OPERANT TEST BATTERY PERFORMANCE

The acute effects of LSD were assessed in rhesus macaques using behavi or in several complex tasks designed to model aspects of time estimati on, short-term memory and attention, motivation, learning, and color a nd position discrimination. The end points monitored included percent task completed, response rate, and accuracy. LSD (0.0003-0.03 mg/kg in travenously) significantly decreased percent task completed and accura cy in the time estimation task at doses less than or equal to 0.003 mg /kg, but did not significantly affect response rate in this task at an y dose tested. Accuracy in the short-term memory task was significantl y decreased at the highest dose tested (0.03 mg/kg), but no other end points were affected in this task. Response rate was decreased in both the motivation and learning tasks at doses (0.01 and 0.003 mg/kg, res pectively) lower than those affecting other end points. In the color a nd position discrimination task, only response rate was affected (0.01 and 0.03 mg/kg). These data demonstrate that in rhesus monkeys, perfo rmance of tasks believed to depend on aspects of time estimation and m otivation are more sensitive to the acute disruptive effects of LSD th an are tasks thought to model learning, short-term memory, and color a nd position discrimination. (C) 1997 Elsevier Science Inc.