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Titolo:
A parametric fMRI study of overt and covert shifts of visuospatial attention
Autore:
Beauchamp, MS; Petit, L; Ellmore, TM; Ingeholm, J; Haxby, JV;
Indirizzi:
NIMH, Lab Brain & Cognit, Bethesda, MD 20892 USA NIMH Bethesda MD USA 20892 MH, Lab Brain & Cognit, Bethesda, MD 20892 USA Univ Caen, Univ Paris 05, CNRS,CEA,UMR 6095, Grp Imagerie Neurofonct, F-14032 Caen, France Univ Caen Caen France F-14032 Imagerie Neurofonct, F-14032 Caen, France
Titolo Testata:
NEUROIMAGE
fascicolo: 2, volume: 14, anno: 2001,
pagine: 310 - 321
SICI:
1053-8119(200108)14:2<310:APFSOO>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
SACCADIC EYE-MOVEMENTS; HUMAN VISUAL-CORTEX; POSITRON EMISSION TOMOGRAPHY; SURFACE-BASED ANALYSIS; FUNCTIONAL-ANATOMY; MEDIAL WALL; HUMAN BRAIN; ACTIVATION; PURSUIT; SYSTEM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Beauchamp, MS NIMH, Lab Brain & Cognit, Bethesda, MD 20892 USA NIMH Bethesda MD USA 20892 & Cognit, Bethesda, MD 20892 USA
Citazione:
M.S. Beauchamp et al., "A parametric fMRI study of overt and covert shifts of visuospatial attention", NEUROIMAGE, 14(2), 2001, pp. 310-321

Abstract

It has recently been demonstrated that a cortical network of visuospatial and oculomotor control areas is active for covert shifts of spatial attention (shifts of attention without eye movements) as well as for overt shifts of spatial attention (shifts of attention with saccadic eye movements). Studies examining activity in this visuospatial network during attentional shifts at a single rate have given conflicting reports about how the activity differs for overt and covert shifts. To better understand how the network subserves attentional shifts, we performed a parametric study in which subjects made either overt attentional shifts or covert attentional shifts at three different rates (0.2, 1.0, and 2.0 Hz). At every shift rate, both overtand covert shifts of visuospatial attention induced activations in the precentral sulcus, intraparietal sulcus, and lateral occipital cortex that were of greater amplitude for overt than during covert shifting. As the rate of attentional shifts increased, responses in the visuospatial network increased in both overt and covert conditions but this parametric increase was greater during overt shifts. These results confirm that overt and covert attentional shifts are subserved by the same network of areas. Overt shifts ofattention elicit more neural activity than do covert shifts, reflecting additional activity associated with saccade execution. An additional finding concerns the anatomical organization of the visuospatial network. Two distinct activation foci were observed within the precentral sulcus for both overt and covert attentional shifts, corresponding to specific anatomical landmarks. We therefore reappraise the correspondence of these two precentral areas with the frontal eye fields. (C) 2001 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 23:57:45