Hemispheric asymmetry for selective attention.
Brain Res Cogn Brain Res
; 9(1): 85-90, 2000 Jan.
Article
em En
| MEDLINE
| ID: mdl-10666560
ABSTRACT
A letter-identification task, previously demonstrated to show activation of the pulvinar nucleus of the thalamus with fluodeoxyglucose position emission tomography, was administered to 20 normal volunteers. The letter to be detected could appear alone as a big stimulus or as a small one stimulus surrounded by flanking letters. To test for a hemispheric specialization for filtering processes, the stimuli were displayed horizontally, either in the left or in the right hemifield, or vertically, either above or below the fixation point. In addition, to study the effect of cognitive processes on selective attention resources, we varied the feedback conditions, by delivering or not delivering a blue flash in cases of misses or mistakes. The results show a significant interaction between the type of stimulus (alone or surrounded by flankers) and the hemifield of presentation (left or right) only in the condition where the subjects were presented stimuli horizontally without any feedback. In this condition, reaction times (RTs) were shorter in the left hemifield than in the right hemifield for single stimuli, whereas for stimuli surrounded by flankers, the opposite pattern was observed, that is, shorter RT in the right hemifield than in the left one. The present findings suggest a hemispheric specialization for selective attention, in particular at the subcortical level.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Atenção
/
Córtex Visual
/
Pulvinar
/
Dominância Cerebral
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Brain Res Cogn Brain Res
Assunto da revista:
CEREBRO
/
PSICOLOGIA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
França