Contrast sensitivity: a fundamental limit to vision restoration after V1 damage.

Autor:	Yang J; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Saionz EL; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Cavanaugh MR; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Fahrenthold BK; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Melnick MD; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Tadin D; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Briggs F; Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642.; Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627.; Center for Visual Science, University of Rochester, Rochester, New York 14627., Carrasco M; Department of Psychology and Center for Neural Science, New York University, NY, NY 10003., Huxlin KR; Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642.; Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642.; Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627.; Center for Visual Science, University of Rochester, Rochester, New York 14627.
Jazyk:	angličtina
Zdroj:	MedRxiv : the preprint server for health sciences [medRxiv] 2023 Sep 02. Date of Electronic Publication: 2023 Sep 02.
DOI:	10.1101/2023.08.31.23294827
Abstrakt:	Stroke damage to the primary visual cortex (V1) causes severe visual deficits, which benefit from perceptual retraining. However, whereas training with high-contrast stimuli can locally restore orientation and direction discrimination abilities at trained locations, it only partially restores luminance contrast sensitivity (CS). Recent work revealed that high-contrast discrimination abilities may be preserved in the blind field of some patients early after stroke. Here, we asked if CS for orientation and direction discrimination is similarly preserved inside the blind field, to what extent, and whether it could benefit from a visual training intervention. Thirteen subacute (<3 months post-V1-stroke) and 12 chronic (>6 months post-V1-stroke) participants were pre-tested, then trained to discriminate either orientation or motion direction of Gabor patches of progressively lower contrasts. At baseline, more subacute than chronic participants could correctly discriminate the orientation of high-contrast Gabors in their blind field, but all failed to perform this task at lower contrasts, even when 10Hz flicker or motion direction were added. Training improved CS in a greater portion of subacute than chronic participants, but no-one attained normal CS, even when stimuli contained flicker or motion. We conclude that, unlike the near-complete training-induced restoration of high-contrast orientation and direction discrimination, there is limited capacity for restoring CS after V1 damage in adulthood. Our results suggest that CS involves different neural substrates and computations than those required for orientation and direction discrimination in V1-damaged visual systems. Competing Interests: Conflict of interest statement: Krystel R. Huxlin, inventor on US Patent No. 7,549,743. All others: none.
Databáze:	MEDLINE
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