Motion streaks provide a spatial code for motion direction
Motion streaks provide a spatial code for motion direction
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DOI：
10.1038/21886
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发表时间：
1999-07-01
期刊：
影响因子：
64.8
通讯作者：
Geisler, WS
中科院分区：
文献类型：
--
作者：
Geisler, WS
尽管灵长类动物初级视觉皮层（V1）中的许多神经元具有方向选择性（1），但它们提供了关于刺激运动方向的模糊信息（2，3），有证据表明视觉系统解决这种模糊性的方法之一是通过计算，从V1神经元的反应，在两个或更多个空间方向上的速度分量，然后组合这些速度分量（2-9）。在这里，我考虑另一种确定运动方向的潜在神经机制。当局部图像特征移动得足够快时，由于视觉系统中的时间积分，它应该在空间中变得模糊，从而产生一个空间信号，即“运动条纹”，该信号指向运动的方向。这里报道的方向掩蔽和适应实验表明，这些运动方向的空间信号存在于人类视觉系统中的特征速度超过约1特征宽度每100 ms。计算机模拟表明，这种心理物理发现与V1神经元的已知响应特性一致，并且这些空间信号，当适当处理时，足以确定自然图像中的运动方向。
Although many neurons in the primary visual cortex (V1) of primates are direction selective(1), they provide ambiguous information about the direction of motion of a stimulus(2,3), There is evidence that one of the ways in which the visual system resolves this ambiguity is by computing, from the responses of V1 neurons, velocity components in two or more spatial orientations and then combining these velocity components(2-9). Here I consider another potential neural mechanism for determining motion direction. When a localized image feature moves fast enough, it should become smeared in space owing to temporal integration in the visual system, creating a spatial signal-a 'motion streak'-oriented in the direction of the motion. The orientation masking and adaptation experiments reported here show that these spatial signals for motion direction exist in the human visual system for feature speeds above about 1 feature width per 100 ms. Computer simulations show that this psychophysical finding is consistent with the known response properties of V1 neurons, and that these spatial signals, when appropriately processed, are sufficient to determine motion direction in natural images.