Visual field representation and location of visual area V1 in human visual cortex by functional MRI

Human area V1 offers an excellent opportunity to study, using functional MRI, a range of properties in a specific cortical visual area, whose borders are defined objectively and convergently by retinotopic criteria. Previous fMRI studies in V1 retinotopic are typically used central and/or peri-central visual field stimulus. The retinotopic characteristics on human peripheral vision are still not well known. In this study, we developed a new visual presentation system widest view (60 deg of eccentricity). The wide-view visual presentation system was made from nonmagnetic optical fibers and a contact lens, so can use in general clinical fMRI condition and the cost is lower. We used the newly wide view visual presentation system, firstly get a success in the world to identify human primary visual cortex (V1) of the eccentricity 60 deg. And we acquired the areal cortical magnification function for V1 between the 0-60deg eccentricities was Mareal =272/(E+1.44)2. The mean cortical surface area of V1 between the 0-60deg eccentricities was about 2229mm2. Our results have well agreement with the using physiological, patients and anatomical measurements. The analysis indicates that (1) the estimate of scaling factor in linear magnification factors is larger than previous studies which focus on central vision. (2) the estimate of the peripheral factor in dipolar model is too large to make the curve direction of the iso-eccentricity ring's in the periphery be the same as that on the center in V1.