The Consistency of Crossmodal Synchrony Perception Across the Visual, Auditory, and Tactile Senses

Abstract

Crossmodal judgments of relative timing commonly yield a nonzero point of subjective simultaneity (PSS). Here, we test whether subjective simultaneity is coherent across all pairwise combinations of the visual, auditory, and tactile modalities. To this end, we examine PSS estimates for transitivity: If Stimulus A has to be presented x ms before Stimulus B to result in subjective simultaneity, and B y ms before C, then A and C should appear simultaneous when A precedes C by z ms, where z = x + y. We obtained PSS estimates via 2 different timing judgment tasks—temporal order judgments (TOJs) and synchrony judgments (SJs)—thus allowing us to examine the relationship between TOJ and SJ. We find that (a) SJ estimates do not violate transitivity, and that (b) TOJ and SJ data are linearly related. Together, these findings suggest that both TOJ and SJ access the same perceptual representation of simultaneity and that this representation is globally coherent across the tested modalities. Furthermore, we find that (b) TOJ estimates are intransitive. This is consistent with the proposal that while the perceptual representation of simultaneity is coherent, relative timing judgments that access this representation can at times be incoherent with each other because of postperceptual response biases.