Adaptive shape processing in primary visual cortex
Adaptive shape processing in primary visual cortex
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DOI：
10.1073/pnas.1105855108
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发表时间：
2011-06-14
影响因子：
11.1
通讯作者：
Gilbert, Charles D.
中科院分区：
文献类型：
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作者：
McManus, Justin N. J.;Li, Wu;Gilbert, Charles D.
从复杂的感官输入中获取意义的能力需要在空间和时间上整合信息，以及塑造这种整合的认知机制。我们研究了初级视觉皮层 (V1) 中的这些过程，其中神经元被认为沿着关联场 (AF) 定义的轮廓整合视觉输入。我们从猕猴 V1 的单个细胞中记录了细胞外的情况，以绘制 AF 地图，通过使用优化算法来找到最大限度地激活单个细胞的轮廓。我们将该算法与延迟匹配样本任务相结合，以测试猴子对特定提示形状的期望如何塑造最佳轮廓。我们发现 V1 神经元对复杂形状具有选择性，这一特性此前被认为是较高皮质区域的特性。此外，形状选择性通过感知任务重新编程：在整个网络中，几何选择性的最佳模式在 AF 的不同子集之间转移，交替表示已知在自然场景中占主导地位的不同刺激特征。我们的结果提出了皮质功能的一般模型，其中水平连接提供了广泛的潜在关联领域，而自上而下的输入动态地门控这些连接以任务切换网络的功能。
The ability to derive meaning from complex sensory input requires the integration of information over space and time, as well as cognitive mechanisms to shape that integration. We studied these processes in the primary visual cortex (V1), where neurons are thought to integrate visual inputs along contours defined by an association field (AF). We recorded extracellularly from single cells in macaque V1 to map the AF, by using an optimization algorithm to find the contours that maximally activated individual cells. We combined the algorithm with a delayed-match-to-sample task, to test how the optimal contours might be molded by the monkey's expectation for particular cue shapes. We found that V1 neurons were selective for complex shapes, a property previously ascribed to higher cortical areas. Furthermore, the shape selectivity was reprogrammed by perceptual task: Over the whole network, the optimal modes of geometric selectivity shifted between distinct subsets of the AF, alternately representing different stimulus features known to predominate in natural scenes. Our results suggest a general model of cortical function, whereby horizontal connections provide a broad domain of potential associations, and top-down inputs dynamically gate these linkages to task switch the function of a network.