Temporal discrimination of visual stimuli in pigeons

Abstract

Characteristics of the discrimination of brief visual stimuli were examined in three pigeons by a psychophysical procedure. In a two-choice discrimination task, the difference between the duration to be compared and the standard duration, which yielded 75% correct choice responses, was determined as the difference threshold for each of four standard durations ranging from .25 to 1.0 sec by a variant of the up-down method. It was found that the difference threshold was roughly proportional to the standard duration: Weber's law provided a reasonable approximation. The value of the Weber fraction was about .25, which is in accord with the results of discrimination experiments with longer durations in pigeons. © 1986 Psychonomic Society, Inc.