Pointing in visual periphery: is DF's dorsal stream intact?

Hesse C, Ball K, Schenk T (2014)

Publication Type: Journal article

Publication year: 2014

Journal

PLoS ONE Public Library of Science

Book Volume: 9

Pages Range: e91420

Journal Issue: 3

DOI: 10.1371/journal.pone.0091420

Abstract

Observations of the visual form agnosic patient DF have been highly influential in establishing the hypothesis that separate processing streams deal with vision for perception (ventral stream) and vision for action (dorsal stream). In this context, DF's preserved ability to perform visually-guided actions has been contrasted with the selective impairment of visuomotor performance in optic ataxia patients suffering from damage to dorsal stream areas. However, the recent finding that DF shows a thinning of the grey matter in the dorsal stream regions of both hemispheres in combination with the observation that her right-handed movements are impaired when they are performed in visual periphery has opened up the possibility that patient DF may potentially also be suffering from optic ataxia. If lesions to the posterior parietal cortex (dorsal stream) are bilateral, pointing and reaching deficits should be observed in both visual hemifields and for both hands when targets are viewed in visual periphery. Here, we tested DF's visuomotor performance when pointing with her left and her right hand toward targets presented in the left and the right visual field at three different visual eccentricities. Our results indicate that DF shows large and consistent impairments in all conditions. These findings imply that DF's dorsal stream atrophies are functionally relevant and hence challenge the idea that patient DF's seemingly normal visuomotor behaviour can be attributed to her intact dorsal stream. Instead, DF seems to be a patient who suffers from combined ventral and dorsal stream damage meaning that a new account is needed to explain why she shows such remarkably normal visuomotor behaviour in a number of tasks and conditions.

Authors with CRIS profile

Thomas Schenk Professur für kognitive Neurologie

Involved external institutions

Durham University GB United Kingdom (GB) University of Aberdeen GB United Kingdom (GB)

How to cite

APA:

Hesse, C., Ball, K., & Schenk, T. (2014). Pointing in visual periphery: is DF's dorsal stream intact? PLoS ONE, 9(3), e91420. https://dx.doi.org/10.1371/journal.pone.0091420

MLA:

Hesse, Constanze, Keira Ball, and Thomas Schenk. "Pointing in visual periphery: is DF's dorsal stream intact?" PLoS ONE 9.3 (2014): e91420.

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