The spatial precision of contextual feedback signals in human V1

Petro, L. S. , Smith, F. W., Abbatecola, C. and Muckli, L. (2023) The spatial precision of contextual feedback signals in human V1. Biology, 12(7), 1022. (doi: 10.3390/biology12071022) (PMID:37508451) (PMCID:PMC10376409)

Abstract

Neurons in the primary visual cortex (V1) receive sensory inputs that describe small, local regions of the visual scene and cortical feedback inputs from higher visual areas processing the global scene context. Investigating the spatial precision of this visual contextual modulation will contribute to our understanding of the functional role of cortical feedback inputs in perceptual computations. We used human functional magnetic resonance imaging (fMRI) to test the spatial precision of contextual feedback inputs to V1 during natural scene processing. We measured brain activity patterns in the stimulated regions of V1 and in regions that we blocked from direct feedforward input, receiving information only from non-feedforward (i.e., feedback and lateral) inputs. We measured the spatial precision of contextual feedback signals by generalising brain activity patterns across parametrically spatially displaced versions of identical images using an MVPA cross-classification approach. We found that fMRI activity patterns in cortical feedback signals predicted our scene-specific features in V1 with a precision of approximately 4 degrees. The stimulated regions of V1 carried more precise scene information than non-stimulated regions; however, these regions also contained information patterns that generalised up to 4 degrees. This result shows that contextual signals relating to the global scene are similarly fed back to V1 when feedforward inputs are either present or absent. Our results are in line with contextual feedback signals from extrastriate areas to V1, describing global scene information and contributing to perceptual computations such as the hierarchical representation of feature boundaries within natural scenes.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Smith, Dr Fraser and Abbatecola, Dr Clement and Petro, Dr Lucy and Muckli, Professor Lars
• Authors: Petro, L. S., Smith, F. W., Abbatecola, C., and Muckli, L.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Biology
• Publisher: MDPI
• ISSN: 2079-7737
• ISSN (Online): 2079-7737
• Published Online: 20 July 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Biology 12(7): 1022
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
307180		Human Brain Project SGA_3	Lars Muckli	European Commission (EC)	945539	SPN - Centre for Cognitive Neuroimaging (CCNi)
311400		Layer-specific cortical feedback dynamics - Human Ultra-High Resolution functional Brain Imaging for Predictive Brain Functions	Lars Muckli	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/V010956/1	SPN - Centre for Cognitive Neuroimaging (CCNi)