Prehension and perception of size in left visual neglect

R D McIntosh, C L Pritchard, H C Dijkerman, A D Milner, R C Roberts

Research output: Contribution to journalArticlepeer-review

Abstract

Right hemisphere damaged patients with and without left visual neglect, and age-matched controls had objects of various sizes presented within left or right body hemispace. Subjects were asked to estimate the objects' sizes or to reach out and grasp them, in order to assess visual size processing in perceptual-experiential and action-based contexts respectively. No impairments of size processing were detected in the prehension performance of the neglect patients but a generalised slowing of movement was observed, associated with an extended deceleration phase. Additionally both patient groups reached maximum grip aperture relatively later in the movement than did controls. For the estimation task it was predicted that the left visual neglect group would systematically underestimate the sizes of objects presented within left hemispace but no such abnormalities were observed. Possible reasons for this unexpected null finding are discussed.

Original languageEnglish
Pages (from-to)315
Number of pages13
JournalBehavioural Neurology
Volume13
Issue number1-2
Publication statusPublished - 2001

Keywords

  • visual neglect
  • hemimicropsia
  • perception
  • prehension
  • size distortion
  • RIGHT-HEMISPHERE LESIONS
  • DIRECTED ARM MOVEMENTS
  • UNILATERAL NEGLECT
  • DIRECTIONAL HYPOKINESIA
  • VISUOSPATIAL NEGLECT
  • HEMISPATIAL NEGLECT
  • DISTORTION
  • SPACE
  • HAND
  • HEMIMICROPSIA

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