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Titolo:
Maintaining and shifting attention within left or right hemifield
Autore:
Vandenberghe, R; Duncan, J; Arnell, KM; Bishop, SJ; Herrod, NJ; Owen, AM; Minhas, PS; Dupont, P; Pickard, JD; Orban, GA;
Indirizzi:
Katholieke Univ Leuven, Neuro & Psychofysiol Lab, Louvain, Belgium Katholieke Univ Leuven Louvain Belgium ychofysiol Lab, Louvain, Belgium Univ Cambridge, MRC, Cognit & Brain Sci Unit, Cambridge, England Univ Cambridge Cambridge England t & Brain Sci Unit, Cambridge, England Wolfson Brain Imaging Ctr, Cambridge, England Wolfson Brain Imaging Ctr Cambridge England ing Ctr, Cambridge, England Univ Hosp Gasthuisberg, Dept Nucl Med, B-3000 Louvain, Belgium Univ Hosp Gasthuisberg Louvain Belgium B-3000 d, B-3000 Louvain, Belgium
Titolo Testata:
CEREBRAL CORTEX
fascicolo: 7, volume: 10, anno: 2000,
pagine: 706 - 713
SICI:
1047-3211(200007)10:7<706:MASAWL>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
POSITRON EMISSION TOMOGRAPHY; VISUAL-SPATIAL ATTENTION; SELECTIVE ATTENTION; ORIENTATION DISCRIMINATION; VISUOSPATIAL ATTENTION; SUSTAINED ATTENTION; BRAIN ACTIVITY; PARIETAL; PET; NEGLECT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
32
Recensione:
Indirizzi per estratti:
Indirizzo: Vandenberghe, R Northwestern Univ, Sch Med, Cognit Neurol & Alzheimers DisCtr, 320 E Super St Suite 11-461, Chicago, IL 60611 USA Northwestern Univ 320 E Super St Suite 11-461 Chicago IL USA 60611
Citazione:
R. Vandenberghe et al., "Maintaining and shifting attention within left or right hemifield", CEREB CORT, 10(7), 2000, pp. 706-713

Abstract

Positron emission tomography (PET) was used to examine two questions: (i) which structures of the intact human brain change their activity with the direction of attention to left or right visual field; and (ii) how does activity in these structures, and in parietal cortex in particular, depend on the frequency of attentional shifts? Subjects were required to discriminate the orientation of peripheral gratings. The two main experimental variableswere the attended hemifield (left or right) and the proportion of trials requiring a shift within that hemifield (20% or 80%). A detection control condition was also included. Behaviourally, subjects were less accurate and significantly slower when a trial required a shift than when it did not. Ventral and lateral occipital areas showed significantly higher blood flow levels contralateral to the direction of attention. Replicating previous work,there was also a significant main effect of the direction of attention in left lateral prefrontal cortex blood flow levels were higher during leftward attention in comparison both to baseline and to rightward attention. Thisleft frontal effect reached significance in single subjects in whom several activation sites could be distinguished within left middle and inferior frontal gyrus. Right and left parietal cortex were activated during both left- and right-field attention conditions, with a tendency for higher activity levels when attention was directed contralaterally. Contrary to the experimental hypothesis, however, parietal regions were not activated differentially by high versus low numbers of attentional shifts. The current experiment confirms that left frontal convexity is sensitive to manipulations of the direction of visuospatial attention. The results do not indicate a specific role of parietal cortex in attentional shifting.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/01/20 alle ore 08:11:17