Schwartz Greg, Taylor Sam, Fisher Clark, Harris Rob, Berry Michael J
Department of Molecular Biology, Princeton University, Princeton, NJ 08542, USA.
Neuron. 2007 Sep 20;55(6):958-69. doi: 10.1016/j.neuron.2007.07.042.
We show that when a moving object suddenly reverses direction, there is a brief, synchronous burst of firing within a population of retinal ganglion cells. This burst can be driven by either the leading or trailing edge of the object. The latency is constant for movement at different speeds, objects of different size, and bright versus dark contrasts. The same ganglion cells that signal a motion reversal also respond to smooth motion. We show that the brain can build a pure reversal detector using only a linear filter that reads out synchrony from a group of ganglion cells. These results indicate that not only can the retina anticipate the location of a smoothly moving object, but that it can also signal violations in its own prediction. We show that the reversal response cannot be explained by models of the classical receptive field and suggest that nonlinear receptive field subunits may be responsible.
我们发现，当一个移动的物体突然改变方向时，一群视网膜神经节细胞会出现短暂的同步放电。这种放电可以由物体的前缘或后缘驱动。对于不同速度的运动、不同大小的物体以及亮暗对比度，潜伏期是恒定的。发出运动反转信号的相同神经节细胞也对平滑运动做出反应。我们表明，大脑可以仅使用一个线性滤波器构建一个纯反转探测器，该滤波器从一组神经节细胞中读取同步性。这些结果表明，视网膜不仅可以预测平滑移动物体的位置，还可以发出自身预测中的异常信号。我们表明，反转反应不能用经典感受野模型来解释，并提出非线性感受野亚基可能是原因所在。
