title: Distinct Computational Principles Govern Multisensory Integration in Primary Sensory and Association Cortices.
abstract: Human observers typically integrate sensory signals in a statistically optimal fashion into a coherent percept by weighting them in proportion to their reliabilities. An emerging debate in neuroscience is to which extent multisensory integration emerges already in primary sensory areas or is deferred to higher-order association areas. This fMRI study used multivariate pattern decoding to characterize the computational principles that define how auditory and visual signals are integrated into spatial representations across the cortical hierarchy. Our results reveal small multisensory influences that were limited to a spatial window of integration in primary sensory areas. By contrast, parietal cortices integrated signals weighted by their sensory reliabilities and task relevance in line with behavioral performance and principles of statistical optimality. Intriguingly, audiovisual integration in parietal cortices was attenuated for large spatial disparities when signals were unlikely to originate from a common source. Our results demonstrate that multisensory interactions in primary and association cortices are governed by distinct computational principles. In primary visual cortices, spatial disparity controlled the influence of non-visual signals on the formation of spatial representations, whereas in parietal cortices, it determined the influence of task-irrelevant signals. Critically, only parietal cortices integrated signals weighted by their bottom-up reliabilities and top-down task relevance into multisensory spatial priority maps to guide spatial orienting.
authors: Max Planck Institute for Biological Cybernetics, Spemannstrasse 38, 72076 Tübingen, Germany; Department of Psychiatry and Psychotherapy, University of Tübingen, Calwerstrasse 14, 72076 Tübingen, Germany. Electronic address: tim.rohe@tuebingen.mpg.de.
authors: Tim
authors: T
authors: Rohe
authors: Max Planck Institute for Biological Cybernetics, Spemannstrasse 38, 72076 Tübingen, Germany; Centre for Computational Neuroscience and Cognitive Robotics, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. Electronic address: u.noppeney@bham.ac.uk.
authors: Uta
authors: U
authors: Noppeney
mesh_terms: D000328:Adult; D001307:Auditory Perception; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000502:physiology*; D013028:Space Perception; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception; D055815:Young Adult