Feedback versus an illusion in time

The accuracy of many perceptual comparisons depends greatly on the order in which the to-be-compared stimuli are presented. With comparisons of durations around 300 ms, these presentation-order effects do not diminish, even with extended practice, when feedback about response accuracy is withheld. Providing such feedback greatly diminishes presentation-order effects and coincidentally produces substantial increases in response accuracy. The feedback acts in part through inducing response biases and in part through changes in sensitivity. The contradiction between studies which report time-order errors in duration comparison and those which do not is attributable to differences in the use of information feedback.