Hemispheric asymmetries for different components of global/local attention occur in distinct temporo-parietal loci.

Published

Journal Article

Data from brain-damaged and neurologically intact populations indicate hemispheric asymmetries in the temporo-parietal cortex for discriminating an object's global form (e.g. the overall shape of a bicycle) versus its local parts (e.g. the spokes in a bicycle tire). However, it is not yet clear whether such asymmetries reflect processes that (i) bias attention toward upcoming global versus local stimuli and/or (ii) attend/identify global versus local stimuli after they are presented. To investigate these possibilities, we asked sixteen healthy participants to perform a cued global/local attention task while their brain activity was recorded using event-related functional magnetic resonance imaging (fMRI). The results indicated a novel double dissociation. Hemispheric asymmetries for deploying attention toward expected global versus local object features were specific to the intraparietal sulcus (iPs). However, hemispheric asymmetries for identifying global versus local features after they were presented were specific to the inferior parietal lobe/superior temporal gyrus (IPL/STG). This double dissociation provides the first direct evidence that hemispheric asymmetries associated with different components of global/local attention occur in distinct temporo-parietal loci. Furthermore, it parallels an analogous dissociation reported in a recent fMRI study of spatial orienting, suggesting that global/local attention and spatial attention might rely on similar cognitive/neural mechanisms.

Full Text

Duke Authors

Cited Authors

  • Weissman, DH; Woldorff, MG

Published Date

  • June 2005

Published In

Volume / Issue

  • 15 / 6

Start / End Page

  • 870 - 876

PubMed ID

  • 15459080

Pubmed Central ID

  • 15459080

International Standard Serial Number (ISSN)

  • 1047-3211

Digital Object Identifier (DOI)

  • 10.1093/cercor/bhh187

Language

  • eng

Conference Location

  • United States