کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9197791 | 1188872 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Multifocal fMRI mapping of visual cortical areas
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب شناختی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Multifocal fMRI mapping of visual cortical areas Multifocal fMRI mapping of visual cortical areas](/preview/png/9197791.png)
چکیده انگلیسی
The multifocal mapping of electroretinograms and visual evoked potentials has established an important role in both basic research and in diagnostic procedures. We have developed a multifocal mapping method for fMRI, which allows detailed analysis of multiple local visual field representations in the cortex with excellent spatial resolution. Visual field was divided into 60 regions in a dartboard configuration, scaled according to the human magnification factor. Within blocks of 7 s, half of the regions were stimulated with checkerboard patterns contrast reversing at 8 reversals per second, while the other half remained inactive at uniform luminance. The subset of active regions changed with each 7-s block, according to an orthogonal design. Functional MRI was done with a 3-T GE Signa and analyzed with SPM2. A general linear model was fitted producing activation maps for each of the 60 regions, and local signal changes were quantified from V1. These activation maps were next assigned to 3D surface models of the cortical sheet, and then unfolded, using the Brain à la Carte software package. Phase-encoded retinotopic analysis of conventional design served as qualitative comparison data. With multifocal fMRI, all regions were mapped with good signal-to-noise ratio in V1, and subsets of regions showed activation in V2 and V3. This method allows rapid and direct exploration of multiple local visual responses, and is thus able to give complementary information to phase encoded mapping of retinotopic areas.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NeuroImage - Volume 27, Issue 1, 1 August 2005, Pages 95-105
Journal: NeuroImage - Volume 27, Issue 1, 1 August 2005, Pages 95-105
نویسندگان
S. Vanni, L. Henriksson, A.C. James,