Effects of Temporal Distribution on Utility of Temporal Factors in Competitive Audio-Visual Perceived Synchrony

The perception of audio-visual synchrony is affected by both temporal coincidence and stimulus congruency factors. In situations when temporal and stimulus information are not in agreement, the perceiver must rely on the relative informative value of both factors in deciding which of multiple potential binding candidates are most likely to be of a common source to a target. Previous research has shown that, all being equal, participants tend to rely primarily on temporal information, and only take stimulus information into consideration when temporal information is ambiguous. The current research seeks to examine the reliance on temporal vs. stimulus information by altering the degree of useful information available in temporal aspects. By varying the temporal distribution of stimuli, it was possible to either increase or decrease the number of trials on which temporal information is conclusive. Data indicate that when temporal information is less informative (i.e., when more asynchronous stimuli are presented), we become less reliant on using prior knowledge about timing relationships when making synchrony judgements. However, when temporal information is more informative (i.e., when more synchronous stimuli are presented) there is no increase in reliance on this type of information. These findings increase what is known about competitive audiovisual processing, and the fact that temporal information serves as a kind of default stimulus property, which can be decreased by reducing the utility of that information.