Timing and classifying brief acoustic stimuli by songbirds and humans

The durations of animals' brief vocalizations provide conspecifics with imp ortant recognition cues. In the present experiments, zebra finches and huma ns (trained musicians) were rewarded for responding after S+ (standard) aud itory signals from 56 to 663 ms and not for responding after shorter or lon ger S- (comparison) durations from 10 to 3684 ms. With either a single stan dard (Experiment 1) or multiple standards (Experiment 2), both zebra finche s and humans timed brief signals to about the same level of accuracy. The r esults were in qualitative agreement with predictions from scalar timing th eory and its connectionist implementation in both experiments. The connecti onist model provides a good quantitative account of temporal gradients with a single standard (Experiment 1) but not with multiple standards (Experime nt 2).