The effect of amphetamine on delayed response performance in the monkey.

The effect of amphetamine on discrete-trial, visual discrimination where response was permitted simultaneously with stimulus presentations or 0, 1, or 3 sec after stimulus presentation, was assessed in the marmoset. An interaction between dose and delay was observed comprising significantly impaired performance after amphetamine under conditions of longer delay. Results are interpreted in terms of loss of response inhibition and increased distraction and are compared with frontal lobe function in the primate.