Hemispheric asymmetry for selective attention

Citation
S. Chokron et al., Hemispheric asymmetry for selective attention, COGN BRAIN, 9(1), 2000, pp. 85-90
Citations number
39
Categorie Soggetti
Neurosciences & Behavoir
Journal title
COGNITIVE BRAIN RESEARCH
ISSN journal
09266410 → ACNP
Volume
9
Issue
1
Year of publication
2000
Pages
85 - 90
Database
ISI
SICI code
0926-6410(200001)9:1<85:HAFSA>2.0.ZU;2-6
Abstract
A letter-identification task, previously demonstrated to show activation of the pulvinar nucleus of the thalamus with fluodeoxyglucose position emissi on tomography, was administered to 20 normal volunteers. The letter to be d etected could appear alone as a big stimulus or as a small one stimulus sur rounded by flanking letters. To test for a hemispheric specialization for f iltering processes, the stimuli were displayed horizontally, either in the left or in the right hemifield, or vertically, either above or below the fi xation point. In addition, to study the effect of cognitive processes on se lective attention resources, we varied the feedback conditions, by deliveri ng or not delivering a blue flash in cases of misses or mistakes. The resul ts show a significant interaction between the type of stimulus (alone or su rrounded by flankers) and the hemifield of presentation (left or right) onl y in the condition where the subjects were presented stimuli horizontally w ithout any feedback, In this condition, reaction times (RTs) were shorter i n the left hemifield than in the right hemifield for single stimuli, wherea s for stimuli surrounded by flankers, the opposite pattern was observed, th at is, shorter RT in the right hemifield than in the left one. The present findings suggest a hemispheric specialization for selective attention, in p articular at the subcortical level. (C) 2000 Elsevier Science B.V. All righ ts reserved.