EFFECTS OF REPEATED ADMINISTRATION OF AMPHETAMINE ON BEHAVIORAL VIGILANCE - EVIDENCE FOR SENSITIZED ATTENTIONAL IMPAIRMENTS

The effects of repeated intermittent administration of amphetamine (1, 2, 3 mg/kg, IP) on the performance of rats in a task designed to asse ss sustained attention were tested. A substantial increase in the numb er of false alarms (i.e., ''claims'' for hits in nonsignal trials) was observed following subsequent administrations of amphetamine. This ef fect could not be accounted for by drug-induced side or position biase s, switching behavior or stereotypy. The effects of repeated amphetami ne may model some of the cognitive processes which mediate the attribu tion of incentive salience to stimuli associated with repeated psychos timulant administration and the development of psychostimulant-induced psychotic symptoms.