کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9197833 1188876 2005 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Control networks and hemispheric asymmetries in parietal cortex during attentional orienting in different spatial reference frames
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب شناختی
پیش نمایش صفحه اول مقاله
Control networks and hemispheric asymmetries in parietal cortex during attentional orienting in different spatial reference frames
چکیده انگلیسی
Neuropsychological research has consistently demonstrated that spatial attention can be anchored in one of several coordinate systems, including those defined with respect to an observer (viewer-centered), to the gravitational vector (environment-centered), or to individual objects (object-centered). In the present study, we used hemodynamic correlates of brain function to investigate the neural systems that mediate attentional control in two competing reference frames. Healthy volunteers were cued to locations defined in either viewer-centered or object-centered space to discriminate the shape of visual targets subsequently presented at the cued locations. Brain responses to attention-directing cues were quantified using event-related functional magnetic resonance imaging. A fronto-parietal control network was activated by attention-directing cues in both reference frames. Voluntary shifts of attention produced increased neural activity bilaterally in several cortical regions including the intraparietal sulcus, anterior cingulate cortex, and the frontal eye fields. Of special interest was the observation of hemispheric asymmetries in parietal cortex; there was significantly greater activity in left parietal cortex than in the right, but this asymmetry was more pronounced for object-centered shifts of attention, relative to viewer-centered shifts of attention. Measures of behavioral performance did not differ significantly between the two reference frames. We conclude that a largely overlapping, bilateral, cortical network mediates our ability to orient spatial attention in multiple coordinate systems, and that the left intraparietal sulcus plays an additional role for orienting in object-centered space. These results provide neuroimaging support for related claims based on findings of deficits in object-based orienting in patients with left parietal lesions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NeuroImage - Volume 25, Issue 3, 15 April 2005, Pages 668-683
نویسندگان
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