Stimulating both eyes with matching stimuli enhances V1 responses

Blake A Mitchell; Kacie Dougherty; Jacob A Westerberg; Brock M Carlson; Loïc Daumail; Alexander Maier; Michele A Cox

doi:10.1016/j.isci.2022.104182

Stimulating both eyes with matching stimuli enhances V1 responses

iScience. 2022 Apr 1;25(5):104182. doi: 10.1016/j.isci.2022.104182. eCollection 2022 May 20.

Authors

Blake A Mitchell¹, Kacie Dougherty², Jacob A Westerberg¹, Brock M Carlson¹, Loïc Daumail¹, Alexander Maier¹, Michele A Cox³

Affiliations

¹ Department of Psychology, Vanderbilt Brain Institute, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37240, USA.
² Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA.
³ Center for Visual Science, University of Rochester, Rochester, NY 14627, USA.

Abstract

Neurons in the primary visual cortex (V1) of primates play a key role in combining monocular inputs to form a binocular response. Although much has been gleaned from studying how V1 responds to discrepant (dichoptic) images, equally important is to understand how V1 responds to concordant (dioptic) images in the two eyes. Here, we investigated the extent to which concordant, balanced, zero-disparity binocular stimulation modifies V1 responses to varying stimulus contrast using intracranial multielectrode arrays. On average, binocular stimuli evoked stronger V1 activity than their monocular counterparts. This binocular facilitation scaled most proportionately with contrast during the initial transient. As V1 responses evolved, additional contrast-mediated dynamics emerged. Specifically, responses exhibited longer maintenance of facilitation for lower contrast and binocular suppression at high contrast. These results suggest that V1 processes concordant stimulation of both eyes in at least two sequential steps: initial response enhancement followed by contrast-dependent control of excitation.

Keywords: Behavioral neuroscience; Biological sciences; Neuroscience.