Albright T D, Desimone R, Gross C G
J Neurophysiol. 1984 Jan;51(1):16-31. doi: 10.1152/jn.1984.51.1.16.
We recorded from single neurons in visual area MT of the macaque in order to examine the spatial distribution of its directionally selective cells. The animals were paralyzed and anesthetized with nitrous oxide. All MT neurons (n = 614) responded better to moving stimuli than to stationary stimuli. For 55% of the neurons, responses to moving stimuli were independent of stimulus color, shape, length, or orientation. For the remaining cells, stimulus length affected the response magnitude and tuning bandwidth but not the preferred direction. MT neurons were divided into four categories on the basis of their sensitivity to moving stimuli: 60% responded exclusively to one direction of motion, 24% responded best to one direction with a weaker response in the opposite direction, 8% responded equally well to two opposite directions of motion, and 8% responded equally well to all directions of motion. The direction preferences of successively sampled cells on a penetration either changed by small increments or occasionally by approximately 180 degrees. Thus, there is a systematic representation of direction of motion. The representation of axis of motion, i.e., the orientation of the path along which a stimulus moves, is more continuous than the representation of direction of motion. There was a systematic relationship between penetration angle and rate of change of preferred axis of motion, indicating that cells with a similar axis of motion preference are arranged in vertical columns. Furthermore, axis of motion columns appear to exist in the form of continuous slabs in area MT. The size of these slabs is such that 180 degrees of axis of motion are represented in 400-500 micron of cortex. There was also a systematic relationship between penetration angle and frequency of 180 degrees reversals, indicating that cells with a similar direction of motion preference are also organized in vertical columns and cells with opposite direction preferences are located in adjacent columns within a single axis of motion column. Just as in macaque striate cortex where approximately 500 micron of cortex contain the mechanism for the local analysis of stimulus orientation, so in MT approximately 500 micron of cortex contain the mechanism for the local analysis of stimulus motion.
我们记录了猕猴视觉区域MT中单个神经元的活动，以研究其方向选择性细胞的空间分布。动物被一氧化二氮麻痹并麻醉。所有MT神经元（n = 614）对移动刺激的反应比对静止刺激的反应更好。对于55%的神经元，对移动刺激的反应与刺激颜色、形状、长度或方向无关。对于其余细胞，刺激长度影响反应幅度和调谐带宽，但不影响偏好方向。MT神经元根据其对移动刺激的敏感性分为四类：60%仅对一个运动方向有反应，24%对一个方向反应最佳，对相反方向反应较弱，8%对两个相反运动方向反应相同，8%对所有运动方向反应相同。在一次穿刺中连续采样的细胞的方向偏好要么以小增量变化，要么偶尔变化约180度。因此，存在运动方向的系统表征。运动轴的表征，即刺激移动路径的方向，比运动方向的表征更连续。穿刺角度与偏好运动轴的变化率之间存在系统关系，表明具有相似运动轴偏好的细胞排列在垂直柱中。此外，运动轴柱似乎以连续板层的形式存在于MT区域。这些板层的大小使得在400 - 500微米的皮层中代表180度的运动轴。穿刺角度与180度反转频率之间也存在系统关系，表明具有相似运动方向偏好的细胞也排列在垂直柱中，而具有相反方向偏好的细胞位于单个运动轴柱内的相邻柱中。就像猕猴纹状皮层中约500微米的皮层包含用于局部分析刺激方向的机制一样，在MT中约500微米的皮层包含用于局部分析刺激运动的机制。
