Effects of benactyzine on an equilibrium and multiple response task in rhesus monkeys.

Five Macaca mulatta were tested for performance changes following exposure to benactyzine HCl (intramuscular) at four doses ranging from 0.054 mg/kg to 1.7 mg/kg. Subjects simultaneously operated a primate equilibrium platform and responded to a multiple alternative reaction task. Performance on both the continuous and discrete tasks were progressively degraded as benactyzine dose increased. At the higher doses it appeared that they concentrated their efforts on one of the tasks while neglecting the other. Thus, performance on one task might be normal and at the same time performance on another task would be degraded.