RESPONSES OF NEURONS IN MACAQUE MT TO STOCHASTIC MOTION SIGNALS
RESPONSES OF NEURONS IN MACAQUE MT TO STOCHASTIC MOTION SIGNALS
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DOI：
10.1017/s0952523800010269
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发表时间：
1993-11-01
影响因子：
1.9
通讯作者：
MOVSHON, JA
中科院分区：
文献类型：
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作者：
BRITTEN, KH;SHADLEN, MN;MOVSHON, JA
动态随机点刺激已被广泛用于探索运动加工的中枢机制。我们测量了警觉猴MT区神经元的反应，同时改变了运动信号的强度和方向。运动的强度由时空相关点的比例控制，我们称之为刺激的相关性。对于许多MT细胞，响应随刺激相关性近似线性变化。当它们发生时，非线性同样可能被正向或负向加速。我们还探讨了这些细胞的响应幅度和响应方差之间的关系，并发现，在一般协议与其他调查人员，这种关系符合幂律指数略大于1。细胞放电的变化几乎不受我们随机显示中固有的试验间波动的影响，因此很可能是神经起源。这些随机运动刺激的线性响应预测的简单，低层次的运动模型，结合传感器具有相对较宽的空间和时间频率调谐。
Dynamic random-dot stimuli have been widely used to explore central mechanisms of motion processing. We have measured the responses of neurons in area MT of the alert monkey while we varied the strength and direction of the motion signal in such displays. The strength of motion is controlled by the proportion of spatiotemporally correlated dots, which we term the correlation of the stimulus. For many MT cells, responses varied approximately linearly with stimulus correlation. When they occurred, nonlinearities were equally likely to be either positively or negatively accelerated. We also explored the relationship between response magnitude and response variance for these cells and found, in general agreement with other investigators, that this relationship conforms to a power law with an exponent slightly greater than 1. The variance of the cells' discharge is little influenced by the trial-to-trial fluctuations inherent in our stochastic display, and is therefore likely to be of neural origin. Linear responses to these stochastic motion stimuli are predicted by simple, low-level motion models incorporating sensors having relatively broad spatial and temporal frequency tuning.