Hotson J R, Anand S
Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA.
Neuropsychologia. 1999 Feb;37(2):169-79. doi: 10.1016/s0028-3932(98)00091-8.
An extrastriate visual area near the human temporo parieto occipital junction (TPO) may selectively mediate motion processing, while contributing little to the perception of color or form. This TPO area may be the human analogue of the monkey middle temporal (MT or V5) and medial superior temporal (MST) extrastriate visual areas. The selectivity of the effect of transcranial magnetic stimulation (TMS) on motion processing was unknown, as was the timecourse of occipital to TPO motion processing. In the first experiment, unilateral TMS was delivered over TPO 50-250 ms after the onset of a random dot motion discrimination display that was presented in the right or left hemifield. TMS reduced the correct discrimination of motion direction only when it was delivered in a discrete time window 100-175 ms following the onset of the display. TMS did not significantly affect hemifield spatial acuity in the same time window. In the second experiment, bilateral TMS delivered over occipital cortex also degraded the discrimination of motion-defined form (MDF) in a discrete time window following the onset of a display presented foveally. Bilateral focal TMS delivered over TPO disrupted the discrimination of MDF in a time window beginning 20-40 ms later than the effect of TMS delivered over occipital cortex. Bilateral focal TMS delivered over TPO also degraded the discrimination of color-defined form, motion direction and color. TMS can trace the timing of visual processing from occipital to extrastriate visual areas.
人类颞顶枕交界区（TPO）附近的一个纹外视觉区域可能选择性地介导运动处理，而对颜色或形状的感知贡献很小。这个TPO区域可能相当于猴子的颞中（MT或V5）和颞上内侧（MST）纹外视觉区域。经颅磁刺激（TMS）对运动处理影响的选择性尚不清楚，枕叶到TPO运动处理的时间进程也是如此。在第一个实验中，在随机点运动辨别显示出现在右半视野或左半视野后50 - 250毫秒，对TPO进行单侧TMS。只有当TMS在显示开始后100 - 175毫秒的离散时间窗口内施加时，才会降低运动方向的正确辨别。在同一时间窗口内，TMS对半视野空间敏锐度没有显著影响。在第二个实验中，对枕叶皮质进行双侧TMS也会在中央凹呈现的显示开始后的离散时间窗口内降低对运动定义形状（MDF）的辨别。对TPO进行双侧局灶性TMS在比枕叶皮质施加TMS的效应晚20 - 40毫秒开始的时间窗口内破坏了MDF的辨别。对TPO进行双侧局灶性TMS也降低了对颜色定义形状、运动方向和颜色的辨别。TMS可以追踪从枕叶到纹外视觉区域的视觉处理时间。
