IMPACT OF D-AMPHETAMINE ON TEMPORAL ESTIMATION IN PIGEONS TESTED WITHA PRODUCTION PROCEDURE

The influence of d-amphetamine on timing in pigeons was examined with a production procedure. Birds were trained with a fixed time schedule in which food reinforcement was contingent on the first response made after a duration signal had appeared for 30 s. Probe tests involved tr ials in which the duration signal was extended to 90 s and reinforceme nt was omitted. In Experiment 1, 2.0 mg/kg d-amphetamine shifted peak responding to a duration shorter than that found with saline. In Exper iment 2, the dose-response function for this drug effect was examined. A 0.3-mg/kg dose of d-amphetamine had no impact on performance, but a 1.0-mg/kg dose shifted the peak duration significantly relative to sa line; a 2.0-mg/kg dose shifted the function even more. These results c omplement previous findings with rats tested with the peak procedure a nd pigeons tested with a discrimination procedure. (C) 1997 Elsevier S cience Inc.