ORCID Profile
0000-0003-0197-7545
Current Organisation
University of Rochester
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Publisher: Cold Spring Harbor Laboratory
Date: 18-02-2021
DOI: 10.1101/2021.02.16.431524
Abstract: The visual pathways that guide actions do not necessarily mediate conscious perception. Patients with primary visual cortex (V1) damage lose conscious perception but often retain unconscious abilities (e.g. blindsight). Here, we asked if saccade accuracy and post-saccadic following responses (PFRs) that automatically track target motion upon saccade landing are retained when conscious perception is lost. We contrasted these behaviors in the blind and intact-fields of 11 chronic V1-stroke patients, and in 8 visually-intact controls. Saccade accuracy was relatively normal in all cases. Stroke patients also had normal PFR in their intact-fields, but no PFR in their blind-fields. Thus, V1 damage did not spare the unconscious visual processing necessary for automatic, post-saccadic smooth eye movements. Importantly, visual training that recovered motion perception in the blind-field did not restore the PFR, suggesting a clear dissociation between pathways mediating perceptual restoration and automatic actions in the V1-damaged visual system.
Publisher: Wiley
Date: 20-02-2017
DOI: 10.1002/DNEU.22467
Abstract: The common marmoset has attracted increasing interest as a model for visual neuroscience. A measurement of fundamental importance to ensure the validity of visual studies is spatial acuity. The marmoset has excellent acuity that has been reported at the fovea to be nearly half that of the human (Ordy and Samorajski []: Vision Res 8:1205-1225), a value that is consistent with them having similar photoreceptor densities combined with their smaller eye size (Troilo et al. []: Vision Res 33:1301-1310). Of interest, the marmoset exhibits a higher proportion of cones than rods in peripheral vision than human or macaque, which in principle could endow them with better peripheral acuity depending on how those signals are pooled in subsequent processing. Here, we introduce a simple behavioral paradigm to measure acuity and then test how acuity in the marmoset scales with eccentricity. We trained subjects to fixate a central point and detect a peripheral Gabor by making a saccade to its location. First, we found that accurate assessment of acuity required correction for myopia in all adult subjects. This is an important point because marmosets raised in laboratory conditions often have mild to severe myopia (Graham and Judge []: Vision Res 39:177-187), a finding that we confirm, and that would limit their utility for studies of vision if uncorrected. With corrected vision, we found that their acuity scales with eccentricity similar to that of humans and macaques, having roughly half the value of the human and with no clear departure for higher acuity in the periphery. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 300-313, 2017.
Publisher: eLife Sciences Publications, Ltd
Date: 03-05-2022
Publisher: eLife Sciences Publications, Ltd
Date: 22-06-2022
DOI: 10.7554/ELIFE.67573
Abstract: The visual pathways that guide actions do not necessarily mediate conscious perception. Patients with primary visual cortex (V1) damage lose conscious perception but often retain unconscious abilities (e.g. blindsight). Here, we asked if saccade accuracy and post-saccadic following responses (PFRs) that automatically track target motion upon saccade landing are retained when conscious perception is lost. We contrasted these behaviors in the blind and intact fields of 11 chronic V1-stroke patients, and in 8 visually intact controls. Saccade accuracy was relatively normal in all cases. Stroke patients also had normal PFR in their intact fields, but no PFR in their blind fields. Thus, V1 damage did not spare the unconscious visual processing necessary for automatic, post-saccadic smooth eye movements. Importantly, visual training that recovered motion perception in the blind field did not restore the PFR, suggesting a clear dissociation between pathways mediating perceptual restoration and automatic actions in the V1-damaged visual system.
Location: United States of America
No related grants have been discovered for Jude Mitchell.