کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9197754 1188871 2005 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Asymmetric modulation of human visual cortex activity during 10° lateral gaze (fMRI study)
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب شناختی
پیش نمایش صفحه اول مقاله
Asymmetric modulation of human visual cortex activity during 10° lateral gaze (fMRI study)
چکیده انگلیسی
We used BOLD fMRI to study the differential effects of the direction of gaze on the visual and the ocular motor systems. Fixation of a target straight ahead was compared to fixation of a target 10° to the right and 10° to the left from gaze straight ahead, and to eyes open in complete darkness in thirteen healthy volunteers. While retinotopic coordinates remained the same in all fixation conditions, the fixation target shifted with respect to a head-centered frame of reference. During lateral fixation, deactivations in higher-order visual areas (one ventral cluster in the lingual and fusiform gyri and one dorsal cluster in the postero-superior cuneus) and, as a trend, activations in early visual cortical areas were found predominantly in the hemisphere contralateral to the fixation target. We propose that visual processing is performed predominantly in the hemisphere contralateral to gaze direction, even during small gaze shifts into one visual hemifield. The excitability of visual neurons may be modulated depending on eye position to construct a head-centered frame of reference from a retinotopic input, thus allowing perceptual stability of space during eye movements. A further finding was that BOLD signal increases in fronto-parietal ocular motor and attentional structures were more pronounced during lateral than central fixation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NeuroImage - Volume 28, Issue 1, 15 October 2005, Pages 4-13
نویسندگان
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