Tootell R B, Hadjikhani N K, Vanduffel W, Liu A K, Mendola J D, Sereno M I, Dale A M
Nuclear Magnetic Resonance Center, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA.
Proc Natl Acad Sci U S A. 1998 Feb 3;95(3):811-7. doi: 10.1073/pnas.95.3.811.
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. The retinotopy in V1 (also known as primary visual cortex, striate cortex, or Brodmann's area 17) was defined in each subject by using both stationary and phase-encoded polar coordinate stimuli. Data from V1 and neighboring retinotopic areas were displayed on flattened cortical maps. In additional tests we revealed the paired cortical representations of the monocular "blind spot." We also activated area V1 preferentially (relative to other extrastriate areas) by presenting radial gratings alternating between 6% and 100% contrast. Finally, we showed evidence for orientation selectivity in V1 by measuring transient functional MRI increases produced at the change in response to gratings of differing orientations. By systematically varying the orientations presented, we were able to measure the bandwidth of the orientation "transients" (45 degrees).
人类V1区为使用功能磁共振成像（functional MRI）研究特定皮质视觉区域的一系列特性提供了绝佳机会，该区域的边界由视网膜拓扑标准客观且一致地定义。通过使用静态和相位编码极坐标刺激，在每个受试者中定义了V1区（也称为初级视觉皮层、纹状皮层或布罗德曼17区）的视网膜拓扑结构。来自V1区和相邻视网膜拓扑区域的数据显示在扁平化的皮质图谱上。在额外的测试中，我们揭示了单眼“盲点”的配对皮质表征。我们还通过呈现对比度在6%和100%之间交替变化的径向光栅，优先激活了V1区（相对于其他纹外区域）。最后，我们通过测量对不同方向光栅的反应变化时产生的瞬时功能磁共振成像增加，证明了V1区存在方向选择性。通过系统地改变呈现的方向，我们能够测量方向“瞬变”的带宽（45度）。
