Grill-Spector K, Kushnir T, Edelman S, Itzchak Y, Malach R
Weizmann Institute of Science, Rehovot, Israel.
Neuron. 1998 Jul;21(1):191-202. doi: 10.1016/s0896-6273(00)80526-7.
The extent to which primary visual cues such as motion or luminance are segregated in different cortical areas is a subject of controversy. To address this issue, we examined cortical activation in the human occipital lobe using functional magnetic resonance imaging (fMRI) while subjects performed a fixed visual task, object recognition, using three different primary visual cues: motion, texture, or luminance contrast. In the first experiment, a region located on the lateral aspect of the occipital lobe (LO complex) was preferentially activated in all 11 subjects both by luminance and motion-defined object silhouettes compared to full-field moving and stationary noise (ratios, 2.00+/-0.19 and 1.86+/-0.65, respectively). In the second experiment, all subjects showed enhanced activation in the LO complex to objects defined both by luminance and texture contrast compared to full-field texture patterns (ratios, 1.43+/-0.08 and 1.32+/-0.08, respectively). An additional smaller dorsal focus that exhibited convergence of object-related cues appeared to correspond to area V3a or a region slightly anterior to it. These results show convergence of visual cues in LO and provide strong evidence for its role in object processing.
诸如运动或亮度等主要视觉线索在不同皮质区域的分离程度是一个存在争议的话题。为了解决这个问题，我们在受试者执行固定视觉任务（物体识别）时，使用功能磁共振成像（fMRI）检查了人类枕叶的皮质激活情况，该任务使用了三种不同的主要视觉线索：运动、纹理或亮度对比度。在第一个实验中，与全场移动和静止噪声相比，枕叶外侧区域（LO复合体）在所有11名受试者中均被亮度和运动定义的物体轮廓优先激活（比率分别为2.00±0.19和1.86±0.65）。在第二个实验中，与全场纹理模式相比，所有受试者在LO复合体中对由亮度和纹理对比度定义的物体均表现出增强的激活（比率分别为1.43±0.08和1.32±0.08）。一个额外的较小的背侧焦点，表现出与物体相关线索的汇聚，似乎对应于V3a区域或其稍前方的一个区域。这些结果显示了LO中视觉线索的汇聚，并为其在物体处理中的作用提供了有力证据。
