کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4349176 1615183 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extinction is not a natural consequence of unilateral spatial neglect: Evidence from contrast detection experiments
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Extinction is not a natural consequence of unilateral spatial neglect: Evidence from contrast detection experiments
چکیده انگلیسی

To investigate whether the expression of visual extinction is dependent upon the contralesional low saliency existing in neglect, we tested stroke patients with neglect and extinction, as well as normal controls, on detection of a peripheral Gabor patch, while a competing patch was presented simultaneously on the other side. To compensate for uneven saliency we set the contrast level relative to the detection threshold on each side. Patients showed contralesional extinction even for stimuli set at threshold level. They differed from controls in their sensitivity to changes in relative contrast between sides, showing stronger tendency for extinction and requiring much higher contrast increments in the target patch in order to eliminate extinction. The differences between normal and pathological extinction, shown despite compensation for contralesional perceptual attenuation due to neglect, suggest an additional extinction-specific deficit related to an abnormal interplay between the bilaterally presented stimuli. These findings have important theoretical implications concerning the relationship between neglect and extinction. They demonstrate that the hypothetical ‘attentional gradient’, taken to explain reduced saliency of stimuli in the neglected side, cannot fully account for the phenomenon of extinction.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience Letters - Volume 420, Issue 3, 15 June 2007, Pages 240–244
نویسندگان
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