An involvement of dopamine in higher order choice mechanisms in the monkey.

Low doses of amphetamine induce choice perseveration in an object discrimination task under conditions where such perseveration either increases or decreases the number of rewards obtained as compared to chance performance. Neither stereotyped motor actions nor repetitive choice of position contributed to this effect which could be blocked by pre-treatment with the neuroleptic haloperidol. These results demonstrate that higher order choice mechanisms may involve dopamine systems in the primate.