The perception of temporal order: Fundamental issues and a general model

Abstract

How do people judge the order of two nearly simultaneous stimuli, such as a light and a tone? We consider this question in the context of a general independent-channels model that incorporates most existing models of order perception as special cases, and which has been implicitly assumed when temporal-order judgments are used to study perceptual latency. In the model, a "decision function" converts a difference in central "arrival times" of two sensory signals into an order judgment. The psychometric function for order is regarded as a distribution function, and can be represented additively in terms of the central arrival latencies and the decision function. Various distinct decision functions correspond to various previously proposed mechanisms involving a "perceptual moment," attention switching, a threshold for arrival-time dif- ferences, and so forth (Section II). One test of the model is to compare reaction-time measurements with order judgments (Section III). Discrepancies can be understood by an analysis of the concept of perceptual latency that recognizes the internal response to a pulse as being spread out in time (Section IV).