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Publications

Journal Article Preprint Epublish

PubMed: 40462954 DOI: 10.1101/2025.05.13.653501

Layer-specific spatiotemporal dynamics of feedforward and feedback in human visual object perception.

bioRxiv

Authors: Tony Carricarte, Siying Xie, Johannes Singer, Robert Trampel, Laurentius Huber, Nikolaus Weiskopf, Radoslaw M Cichy

Affiliations

  • Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany. Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany. Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, 10117 Berlin, Germany.
  • Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany.
  • Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany.
  • Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany.
  • Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, 10117 Berlin, Germany.
  • Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Universität Leipzig, 04103 Leipzig, Germany.
  • Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR London, United Kingdom.
  • Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, 10117 Berlin, Germany.

Abstract

Visual object perception is mediated by information flow between regions of the ventral visual stream along feedforward and feedback anatomical connections. However, feedforward and feedback signals during naturalistic vision are rapid and overlapping, complicating their identification and precise functional specification. Here we recorded human layer-specific fMRI responses to naturalistic object images in early visual cortex (EVC) and lateral occipital complex (LOC) to isolate feedforward and feedback information signals spatially by their cortical layer specific termination pattern. We combined these layer-specific fMRI responses with electroencephalography (EEG) responses for the same images to segregate feedforward and feedback signals in both time and space. Feedforward signals emerge early in the middle layers of EVC and LOC, followed by feedback signals in the superficial layer of both regions, and the deep layer of EVC. Comparing the identified dynamics in LOC to a visual deep neural network (DNN), revealed that early feedforward signals in LOC encode medium complexity features, whereas later feedback signals increase the representational format to high complexity features. Together this specifies the spatiotemporal dynamics and functional role of feedforward and feedback information flow mediating visual object perception.

MeSH

Feedback, Perception