کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10465989 925747 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Oblique spatial shifts of subjective visual straight ahead orientation in quadrantic visual field defects
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب رفتاری
پیش نمایش صفحه اول مقاله
Oblique spatial shifts of subjective visual straight ahead orientation in quadrantic visual field defects
چکیده انگلیسی
Patients with postchiasmatic visual field defects often show a contralesional bias towards the scotoma in line bisection or when indicating their visual subjective straight ahead (VSSA). Recent evidence suggests a retinotopic misrepresentation of visual space in patients with homonymous quadrantanopia (HQ). We therefore assessed in the present study whether patients with HQ show an oblique shift of their VSSA towards their scotoma, in addition to the known bias in horizontal line bisection. Moreover, we examined whether eccentric fixation contributes to this shift. To this purpose, 15 non-neglecting stroke patients with HQ and 15 matched healthy control subjects were assessed in horizontal line bisection and in the horizontal and vertical dimension of their VSSA. Additionally, perimetric blind spot mapping was performed. Eight out of nine patients with left quadranopia showed the typical leftsided, horizontal line bisection error, while only one out of seven patients with rightsided quadranopia showed a rightsided shift. Normal subjects showed a non-significant leftward shift in line bisection (pseudoneglect). All 15 patients with HQ showed a large oblique shift of their VSSA towards the blind quadrants, while normal subjects showed no systematic left-rightward shift, but a small downward shift of the VSSA. The position of the blind spot was normal in all testable eyes of patients and control subjects, thus excluding eccentric fixation or cyclorotation of the eyes. In conclusion, our study reveals a hitherto unreported oblique spatial shift of subjective visual body orientation towards the blind quadrants in non-neglecting patients with quadranopia.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuropsychologia - Volume 48, Issue 11, September 2010, Pages 3205-3210
نویسندگان
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