Nature and interaction of signals from the receptive field center and surround in macaque V1 neurons
Nature and interaction of signals from the receptive field center and surround in macaque V1 neurons
复制标题
DOI：
10.1152/jn.00692.2001
复制
发表时间：
2002-11-01
影响因子：
2.5
通讯作者：
Movshon, JA
中科院分区：
文献类型：
--
作者：
Cavanaugh, JR;Bair, W;Movshon, JA
信息被整合到整个视野中，将局部特征转化为全局感知。我们现在知道，V1神经元提供更多的空间整合比原来认为由于其非经典抑制环境的存在。为了理解视觉皮层的空间整合，我们研究了中心和周围对神经元反应的影响的性质和程度。我们使用漂移正弦光栅在圆形和环形孔径估计的大小的感受野的兴奋中心和抑制周围。我们使用的组合内和外的感受野的刺激，探索的性质，周围的感受野中心的相对和绝对的对比度的函数的刺激在两个地区的影响。我们的结论是，最好的相互作用被解释为一个分裂的调制响应增益的信号从周围。然后，我们开发了一个感受野模型的基础上的信号从高斯形中心和环绕机制的比例。我们表明，这个模型可以很好地解释感受野大小的变化与对比度，我们和其他人已经观察到的和对比度适应状态的大小变化。该模型实现了这一成功的简单变化的相对增益的两个组成部分的机制的感受野。因此，这个模型提供了一个简约的解释各种现象，涉及明显的感受野大小的变化，并占这些现象纯粹的两个感受野机制，本身不改变大小。我们使用的范围内的中心机制在我们的模型作为一个指标的空间范围内的中央兴奋部分的感受野。我们比较了该中心的范围内V1的水平连接的测量，并确定水平皮质内连接的程度匹配的感受野中心机制。对抑制性环境的输入可以部分地来自于来自较高区域的反馈信号。
Information is integrated across the visual field to transform local features into a global percept. We now know that V1 neurons provide more spatial integration than originally thought due to the existence of their nonclassical inhibitory surrounds. To understand spatial integration in the visual cortex, we have studied the nature and extent of center and surround influences on neuronal response. We used drifting sinusoidal gratings in circular and annular apertures to estimate the sizes of the receptive field's excitatory center and suppressive surround. We used combinations of stimuli inside and outside the receptive field to explore the nature of the surround influence on the receptive field center as a function of the relative and absolute contrast of stimuli in the two regions. We conclude that the interaction is best explained as a divisive modulation of response gain by signals from the surround. We then develop a receptive field model based on the ratio of signals from Gaussian-shaped center and surround mechanisms. We show that this model can account well for the variations in receptive field size with contrast that we and others have observed and for variations in size with the state of contrast adaptation. The model achieves this success by simple variations in the relative gain of the two component mechanisms of the receptive field. This model thus offers a parsimonious explanation of a variety of phenomena involving changes in apparent receptive field size and accounts for these phenomena purely in terms of two receptive field mechanisms that do not themselves change in size. We used the extent of the center mechanism in our model as an indicator of the spatial extent of the central excitatory portion of the receptive field. We compared the extent of the center to measurements of horizontal connections within V1 and determined that horizontal intracortical connections are well matched in extent to the receptive field center mechanism. Input to the suppressive surround may come in part from feedback signals from higher areas.