Representation of angles embedded within contour stimuli in area V2 of macaque monkeys
Representation of angles embedded within contour stimuli in area V2 of macaque monkeys
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DOI：
10.1523/jneurosci.4364-03.2004
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发表时间：
2004-03-31
影响因子：
5.3
通讯作者：
Komatsu, H
中科院分区：
文献类型：
--
作者：
Ito, M;Komatsu, H
嵌入在轮廓中的角度和连接点是表示物体形状的重要特征。为了研究提取这些特征的神经元基础，我们在两只猕猴执行注视任务时进行了细胞外记录。角度刺激是两条大于经典感受野（CRFs）大小的直线半线的组合。每条线从crf的中心向外沿12个方向中的1个方向绘制，使刺激穿过crf并在crf的中心形成角度。在V2区浅层记录的114个神经元中，91个神经元对这些角度刺激表现出选择性反应。其中，41个神经元（36.0%）对60度到150度之间的广角表现出选择性反应，这与对直线或锐角（30度）的反应不同。大约四分之一的神经元对特定角度的反应是高度选择性的。当我们测试相同神经元对单个半线的选择性时，首选方向或多或少与最佳角度刺激的一个或两个组成部分一致。这些结果表明，神经元的选择性既取决于两个成分的组合，也取决于对单个成分的反应。角度选择性V2神经元不太可能是特定的角度检测器，因为它们对最佳角度的响应幅度与对最佳半线的响应幅度难以区分。我们建议从区域V2开始提取嵌入在轮廓刺激中的角度信息。
Angles and junctions embedded within contours are important features to represent the shape of objects. To study the neuronal basis to extract these features, we conducted extracellular recordings while two macaque monkeys performed a fixation task. Angle stimuli were the combination of two straight half-lines larger than the size of the classical receptive fields (CRFs). Each line was drawn from the center to outside the CRFs in 1 of 12 directions, so that the stimuli passed through the CRFs and formed angles at the center of the CRFs. Of 114 neurons recorded from the superficial layer of area V2, 91 neurons showed selective responses to these angle stimuli. Of these, 41 neurons (36.0%) showed selective responses to wide angles between 60degrees and 150degrees that were distinct from responses to straight lines or sharp angles (30degrees). Responses were highly selective to a particular angle in approximately one-fourth of neurons. When we tested the selectivity of the same neurons to individual half-lines, the preferred direction was more or less consistent with one or two components of the optimal angle stimuli. These results suggest that the selectivity of the neurons depends on both the combination of two components and the responses to individual components. Angle-selective V2 neurons are unlikely to be specific angle detectors, because the magnitude of their responses to the optimal angle was indistinguishable from that to the optimal half-lines. We suggest that the extraction of information of angles embedded within contour stimuli may start in area V2.