Analysis of pathways mediating preserved vision after striate cortex lesions.

Published

Journal Article

This study investigated the neural substrates of preserved visual functioning in a patient with homonymous hemianopsia and Riddoch syndrome after a posterior cerebral artery stroke affecting the primary visual cortex (area V1). The limited visual abilities of this patient included above-chance verbal reports of movement and color change as well as discrimination of movement direction in the hemianopic field. Functional magnetic resonance imaging showed that motion and color-change stimuli presented to the hemianopic field produced activation in several extrastriate areas of the lesioned hemisphere that were defined using retinotopic mapping. Magnetoencephalographic recordings indicated that evoked activity occurred earlier in the higher-tier visual areas V4/V8 and V5 than in the lower-tier areas V2/V3 adjacent to the lesion. In addition, the functional magnetic resonance imaging analysis showed an increased functional connectivity between areas V4/V8 and V5 of the lesioned hemisphere in comparison with the same areas in the intact hemisphere during the presentation of color changes. These results suggest that visual perception after the V1 lesion in Riddoch syndrome is mediated by subcortical pathways that bypass V1 and project first to higher-tier visual areas V5 and V4/V8 and subsequently to lower-tier areas V2/V3.

Full Text

Duke Authors

Cited Authors

  • Schoenfeld, MA; Noesselt, T; Poggel, D; Tempelmann, C; Hopf, J-M; Woldorff, MG; Heinze, H-J; Hillyard, SA

Published Date

  • December 2002

Published In

Volume / Issue

  • 52 / 6

Start / End Page

  • 814 - 824

PubMed ID

  • 12447936

Pubmed Central ID

  • 12447936

Electronic International Standard Serial Number (EISSN)

  • 1531-8249

International Standard Serial Number (ISSN)

  • 0364-5134

Digital Object Identifier (DOI)

  • 10.1002/ana.10394

Language

  • eng