A comparative study of shape representation in macaque visual areas V2 and V4
A comparative study of shape representation in macaque visual areas V2 and V4
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DOI：
10.1093/cercor/bhl020
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发表时间：
2007-05-01
期刊：
影响因子：
3.7
通讯作者：
Van Essen, David C.
中科院分区：
文献类型：
--
作者：
Hegde, Jay;Van Essen, David C.
我们比较了纹外视区V2和V4的形状表征方面，这两个区域都涉及形状加工，属于不同的层次。我们记录了清醒的，固定的猴子匹配组的轮廓和光栅刺激的低或中等复杂性的细胞的反应。这些包括简单的刺激（酒吧和正弦曲线）和更复杂的刺激（角度，交叉点，弧，和非笛卡尔光栅），所有缩放到感受野大小。每个区域内的细胞的响应基本上由测试的每个形状特征调制，许多响应测量在区域之间具有实质性重叠。我们的分析揭示了许多明确的和可靠的差异方面的有效性，并响应调制，各种形状的特点。在V2和V4中，光栅刺激平均比轮廓刺激更有效，但在V4中差异更明显。作为一个群体，V4通过一些形状特征（包括简单形状特征）显示出更大的反应调节，V2通过许多其他形状特征（包括复杂形状特征）显示出更大的反应调节。从区域V1的记录证明了复杂的形状选择性，在一些细胞和相对温和的人口差异相比，V2。总之，通过该分析揭示的2维形状特征的表示在3个区域中变化很大。但令人惊讶的是，我们的分析所揭示的差异，无论是单独的还是集体的，都与解剖层次的逐步组织不平行。跨层级的视觉形状表示的共性可能反映了在多个空间尺度上生成复杂形状表示所使用的神经回路的复制。
We compared aspects of shape representation in extrastriate visual areas V2 and V4, which are both implicated in shape processing and belong to different hierarchical levels. We recorded responses of cells in awake, fixating monkeys to matched sets of contour and grating stimuli of low or intermediate complexity. These included simple stimuli (bars and sinusoids) and more complex stimuli (angles, intersections, arcs, and non-Cartesian gratings), all scaled to receptive field size. The responses of cells within each area were substantially modulated by each shape characteristic tested, with substantial overlap between areas by many response measures. Our analyses revealed many clear and reliable differences between areas in terms of the effectiveness of, and response modulation by, various shape characteristics. Grating stimuli were on average more effective than contour stimuli in V2 and V4, but the difference was more pronounced in V4. As a population, V4 showed greater response modulation by some shape characteristics (including simple shape characteristics) and V2 showed greater response modulation by many others (including complex shape characteristics). Recordings from area V1 demonstrated complex shape selectivity in some cells and relatively modest population differences in comparison with V2. Altogether, the representation of 2-dimensional shape characteristics revealed by this analysis varies substantially among the 3 areas. But surprisingly, the differences revealed by our analyses, individually or collectively, do not parallel the stepwise organization of the anatomical hierarchy. Commonalities of visual shape representation across hierarchical levels may reflect the replication of neural circuits used in generating complex shape representations at multiple spatial scales.