Goltz Herbert C, DeSouza Joseph F X, Menon Ravi S, Tweed Douglas B, Vilis Tutis
CIHR Group on Action and Perception, University of Western Ontario, London N6A 5C1, Canada.
Neuron. 2003 Jul 31;39(3):569-76. doi: 10.1016/s0896-6273(03)00460-4.
When we move our eyes, why does the world look stable even as its image flows across our retinas, and why do afterimages, which are stationary on the retinas, appear to move? Current theories say this is because we perceive motion by summation: if an object slips across the retina at r degrees/s while the eye turns at e degrees/s, the object's perceived velocity in space should be r + e. We show that activity in MT+, the visual-motion complex in human cortex, does reflect a mix of r and e rather than r alone. But we show also that, for optimal perception, r and e should not summate; rather, the signals coding e interact multiplicatively with the spatial gradient of illumination.
当我们移动眼睛时，为什么即使世界的图像在我们的视网膜上流动，我们看到的世界看起来却是稳定的？还有，为什么静止在视网膜上的后像看起来却在移动？当前的理论认为，这是因为我们通过累加来感知运动：如果一个物体以r度/秒的速度在视网膜上滑动，同时眼睛以e度/秒的速度转动，那么该物体在空间中的感知速度应该是r + e。我们发现，人类大脑皮层视觉运动复合体MT+中的活动确实反映了r和e的混合，而不仅仅是r。但我们也发现，为了实现最佳感知，r和e不应累加；相反，编码e的信号与光照的空间梯度进行乘法交互。
