Spatiotemporal architecture of cortical multisensory interactions: New insights into old rules

Abstract

Event Abstract Back to Event Spatiotemporal architecture of cortical multisensory interactions: New insights into old rules Mark Wallace1, 2, 3* 1 Vanderbilt University, Department of Hearing & Speech Sciences, United States 2 Vanderbilt University, Department of Psychology, United States 3 Vanderbilt University, Vanderbilt Kennedy Center, United States Neurons that receive convergent input from multiple sensory modalities are found at virtually all levels of the neuraxis. Rather than simply serving as passive filters, these multisensory neurons actively transform their different sensory inputs to give rise to responses that often differ dramatically from the individual unisensory responses (or their simple summation). Such changes in neural encoding have been suggested to form the substrate for the behavioral and perceptual alterations that can be observed under multisensory conditions. Prior work has established that both the sign (i.e., enhancement vs. depression) and magnitude of the interaction that results from a multisensory combination is critically dependent on the spatial and temporal relationship of the paired stimuli, as well as on their relative effectiveness in eliciting a response. However, despite the profound insights that they offer, recent work has shown that the spatial, temporal and inverse effectiveness “principles” of multisensory integration often fail to predict or capture the complete interactive profile of the neuron under study. Recent observations from our laboratory have suggested that a solution to this problem may lie in the receptive field architecture of multisensory neurons, and in the way that space, time and effectiveness interact to shape the resultant multisensory interaction. Single-unit recordings from individual multisensory neurons in both the brainstem (i.e., the superior colliculus) and cortex (i.e., the anterior ectosylvian sulcus) of the cat have revealed a complex and heterogeneous spatial architecture to the receptive fields of multisensory neurons, often with areas of robust response being surrounded by areas of weak response. Furthermore, this heterogeneity can be shared across different sensory modalities (e.g., similar visual and auditory spatial receptive fields [SRFs]), or it can differ dramatically between these modalities. Perhaps most importantly, because of its effects on the magnitude of the unisensory responses, SRF heterogeneity appeared to be a major determinant of the resultant multisensory interaction. For example, pairings at locations of minimal efficiacy resulted in large superadditive interactions, whereas those at more effective locations gave rise to additive or subadditive interactions. Such a result makes the provocative suggestion that space matters in multisensory interactions only as a result of its effects on the vigor of the evoked responses. Furthermore, when examined in the temporal dimension, the creation of spatiotemporal receptive fields (STRFs) for subcortical and cortical multisensory neurons illustrate a previously unrecognized dynamism to multisensory interactions that can dramatically alter both the latency and duration of the evoked discharges. Taken together, these results reveal a previously unexplored level of complexity to multisensory processes that is likely to provide important insights into the transformation and encoding of multisensory information and its role in guiding behavior and shaping perception. Supported by NIH MH63861 and the Vanderbilt Kennedy Center Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Oral Presentation Topic: Symposium 3: Neural basis of multisensory integration Citation: Wallace M (2008). Spatiotemporal architecture of cortical multisensory interactions: New insights into old rules. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.021 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Nov 2008; Published Online: 27 Nov 2008. * Correspondence: Mark Wallace, Vanderbilt University, Department of Hearing & Speech Sciences, Nashville,TN, United States, mark.wallace@vanderbilt.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mark Wallace Google Mark Wallace Google Scholar Mark Wallace PubMed Mark Wallace Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. 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