Effects of anticholinergics on serial-probe recognition accuracy of rhesus macaques (Macaca mulatta).

Potential deleterious behavioral effects of the anticholinergics biperiden and scopolamine were examined via the performance of rhesus monkeys on a serial-probe recognition (SPR) procedure. On each trial, six unique stimuli (list items) were presented sequentially followed by a choice phase. In the choice phase, two stimuli were presented, a standard or 'default' stimulus (a white rectangle) and a 'probe' stimulus that differed with each choice trial.