Hierarchical stimuli and hemispheric specialization: Two case studies

M. R. Polster, Steven Z Rapcsak

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Local versus global visual processing was examined in two patients with massive unilateral left hemisphere lesions using a directed attention task involving hierarchical stimuli. Previous studies found an impressive global advantage in patients with posterior left hemisphere lesions on similar tasks. In addition, whereas patients with left inferior parietal lobule (IPL) lesions showed the global interference on local processing that is typically observed in normals, patients with lesions centered on the superior temporal gyrus (STG) demonstrated no interference. Paradoxically, our two patients who had complete destruction of both the left IPL and STG regions showed an overall local advantage due to local interference on global processing. We propose that following extensive left hemisphere damage, the isolated right hemisphere may be able to perform efficiently the type of processing usually ascribed to the left hemisphere (i.e., local). However, at least under certain conditions, this apparent functional plasticity seems to occur at the expense of the type of processing normally associated with the right hemisphere (i.e., global).

Original languageEnglish (US)
Pages (from-to)487-497
Number of pages11
JournalCortex
Volume30
Issue number3
StatePublished - 1994
Externally publishedYes

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Cerebral Dominance
Temporal Lobe
Parietal Lobe

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Hierarchical stimuli and hemispheric specialization : Two case studies. / Polster, M. R.; Rapcsak, Steven Z.

In: Cortex, Vol. 30, No. 3, 1994, p. 487-497.

Research output: Contribution to journalArticle

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