Perceptually bistable three-dimensional figures evoke high choice probabilities in cortical area
Perceptually bistable three-dimensional figures evoke high choice probabilities in cortical area
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DOI：
10.1523/jneurosci.21-13-04809.2001
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发表时间：
2001-07-01
影响因子：
5.3
通讯作者：
Parker, AJ
中科院分区：
文献类型：
--
作者：
Dodd, JV;Krug, K;Parker, AJ
灵长类动物中颞区（MT）的深度知觉的作用进行了研究，考虑到审判的神经元活动和深度感觉之间的相关性。一组移动的随机点描绘了一个围绕其主轴旋转的圆柱体。在这种由运动产生结构的刺激中，旋转的方向是模糊的，由此产生的光感受经历自发的波动。刺激可以通过增加双眼视差而变得清晰。我们训练猴子在一组刺激中报告旋转方向，其中一个刺激的视差为零。MT区的许多视差选择性神经元对由视差定义的旋转方向具有选择性。在重复呈现模糊（零视差）刺激时，神经元放电和报告的旋转方向之间存在相关性，如布拉德利等人（1998）所发现的。使用选择概率对该效应进行量化（Britten等人，1996）使我们能够证明这种相关性不能用眼球运动、行为偏差或对空间位置的注意力来解释。因此，MT神经元似乎参与了感知决策过程。平均选择概率（0.67）基本上大于在方向辨别任务中MT神经元所报道的平均选择概率（Britten等人，1996年）。这意味着MT神经元对这两项任务做出了不同的贡献。对于深度任务，要么使用的神经元池较小，要么池中神经元之间的相关性较大。
The role of the primate middle temporal area (MT) in depth perception was examined by considering the trial-to-trial correlations between neuronal activity and reported depth sensations. A set of moving random dots portrayed a cylinder rotating about its principal axis. In this structure-from-motion stimulus, the direction of rotation is ambiguous and the resulting percept undergoes spontaneous fluctuations. The stimulus can be rendered unambiguous by the addition of binocular disparities. We trained monkeys to report the direction of rotation in a set of these stimuli, one of which had zero disparity. Many disparity-selective neurons in area MT are selective for the direction of rotation defined by disparity. Across repeated presentations of the ambiguous (zero-disparity) stimulus, there was a correlation between neuronal firing and the reported direction of rotation, as found by Bradley et al. (1998). Quantification of this effect using choice probabilities (Britten et al., 1996) allowed us to demonstrate that the correlation cannot be explained by eye movements, behavioral biases, or attention to spatial location. MT neurons therefore appear to be involved in the perceptual decision process. The mean choice probability (0.67) was substantially larger than that reported for MT neurons in a direction discrimination task (Britten et al., 1996). This implies that MT neurons make a different contribution to the two tasks. For the depth task, either the pool of neurons used is smaller or the correlation between neurons in the pool is larger.