Perceptual learning shapes multisensory causal inference via two distinct mechanisms.
To accurately represent the environment, our brains must integrate sensory signals from a common source while segregating those from independent sources. A reasonable strategy for performing this task is to restrict integration to cues that coincide in space and time. However, because multisensory signals are subject to differential transmission and processing delays, the brain must retain a degree of tolerance for temporal discrepancies. Recent research suggests that the width of this 'temporal binding window' can be reduced through perceptual learning, however, little is known about the mechanisms underlying these experience-dependent effects. Here, in separate experiments, we measure the temporal and spatial binding windows of human participants before and after training on an audiovisual temporal discrimination task. We show that training leads to two distinct effects on multisensory integration in the form of (i) a specific narrowing of the temporal binding window that does not transfer to spatial binding and (ii) a general reduction in the magnitude of crossmodal interactions across all spatiotemporal disparities. These effects arise naturally from a Bayesian model of causal inference in which learning improves the precision of audiovisual timing estimation, whilst concomitantly decreasing the prior expectation that stimuli emanate from a common source.
Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, College Green, Dublin 2, Ireland.
David P
DP
McGovern
Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, College Green, Dublin 2, Ireland.|École d'Optométrie, Université de Montréal, Montréal, Québec, H3T 1P1, Canada.
Eugenie
E
Roudaia
Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, College Green, Dublin 2, Ireland.
Fiona N
FN
Newell
Visual Neuroscience Group, School of Psychology, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom.
Neil W
NW
Roach
D000293:Adolescent; D000328:Adult; D001307:Auditory Perception; D001499:Bayes Theorem; D005260:Female; D006801:Humans; D007858:Learning; D008297:Male; D011594:Psychometrics; D014796:Visual Perception; D055815:Young Adult