Perceptual learning shapes multisensory causal inference via two distinct mechanisms

McGovern, David P.; Roudaia, Eugenie; Newell, Fiona N.; Roach, Neil W.

Abstract

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.

Citation

McGovern, D. P., Roudaia, E., Newell, F. N., & Roach, N. W. (2016). Perceptual learning shapes multisensory causal inference via two distinct mechanisms. Scientific Reports, 6, Article 24673. https://doi.org/10.1038/srep24673

• Journal Article Type: Article
• Acceptance Date: Apr 4, 2016
• Online Publication Date: Apr 19, 2016
• Publication Date: Apr 19, 2016
• Deposit Date: May 11, 2016
• Publicly Available Date: May 11, 2016
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Article Number: 24673
• DOI: https://doi.org/10.1038/srep24673
• Public URL: https://nottingham-repository.worktribe.com/output/784635
• Publisher URL: http://www.nature.com/articles/srep24673
• Contract Date: May 11, 2016