Linking neural representation to function in stereoscopic depth perception: Roles of the middle temporal area in coarse versus fine disparity discrimination
Linking neural representation to function in stereoscopic depth perception: Roles of the middle temporal area in coarse versus fine disparity discrimination
复制标题
DOI：
10.1523/jneurosci.5435-05.2006
复制
发表时间：
2006-06-21
影响因子：
5.3
通讯作者：
DeAngelis, Gregory C.
中科院分区：
文献类型：
--
作者：
Uka, Takanori;DeAngelis, Gregory C.
对双眼视差具有选择性的神经元形成了立体深度感知的神经基质，并且存在于灵长类动物视觉皮层的多个区域中。据推测，视差的多种表示形式的存在是为了服务于不同的功能，但不同视觉区域对深度感知的具体贡献仍然知之甚少。我们通过比较中颞（MT）区域对两个深度辨别任务的表现的贡献来研究这个问题：“粗略”任务涉及在存在噪声的情况下区分绝对差异，而“精细”任务涉及在不存在噪声的情况下区分两个刺激之间相对差异的非常小的差异。在精细任务中，我们发现 MT 的电微刺激不会影响感知决策，尽管许多个体 MT 神经元具有足够的敏感性来解释行为表现。相比之下，同一记录位点的微刺激确实会影响粗略任务中的深度感知。我们假设这些结果可能是由于 MT 神经元不代表相对差异信号这一事实来解释的，而相对差异信号被认为对于精细任务至关重要。这一假设得到了单单元记录的支持，该记录显示 MT 神经元在类似于精细任务中使用的刺激配置中发出绝对而非相对的差异信号。这项工作在机器翻译中差异的神经表征与该区域对深度感知的功能贡献之间建立了联系。
Neurons selective for binocular disparity form the neural substrate for stereoscopic depth perception and are found in several areas of primate visual cortex. Presumably, multiple representations of disparity exist to serve different functions, but the specific contributions of different visual areas to depth perception remain poorly understood. We examine this issue by comparing the contributions of the middle temporal (MT) area to performance of two depth discrimination tasks: a "coarse" task that involves discrimination between absolute disparities in the presence of noise, and a "fine" task that involves discrimination of very small differences in relative disparity between two stimuli in the absence of noise. In the fine task, we find that electrical microstimulation of MT does not affect perceptual decisions, although many individual MT neurons have sufficient sensitivity to account for behavioral performance. In contrast, microstimulation at the same recording sites does bias depth percepts in the coarse task. We hypothesized that these results may be explained by the fact that MT neurons do not represent relative disparity signals that are thought to be essential for the fine task. This hypothesis was supported by single-unit recordings that show that MT neurons signal absolute, but not relative, disparities in a stimulus configuration similar to that used in the fine task. This work establishes a link between the neural representation of disparity in MT and the functional contributions of this area to depth perception.