Spatial overlap of ON and OFF subregions and its relation to response modulation ratio in macaque primary visual cortex
Spatial overlap of ON and OFF subregions and its relation to response modulation ratio in macaque primary visual cortex
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DOI：
10.1152/jn.00668.2004
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发表时间：
2005-02-01
影响因子：
2.5
通讯作者：
Ringach, DL
中科院分区：
文献类型：
--
作者：
Mata, ML;Ringach, DL
研究了猕猴初级视皮层ON和OFF亚区的空间重叠及其与反应调制比（F1/F0）的关系。ON和OFF子区域的空间图通过与亮点和暗点的动态噪声图案的反向相关来获得。两个空间地图，ON和OFF，通过互相关的尖峰序列与刺激中的亮点和黑点的位置分别产生。采用了若干措施来评估各次区域之间的重叠程度。在神经元的子集中，我们还计算了响应于漂移正弦光栅的F-1/F-0比。所有重叠测量值与F-1/F-0比值之间均存在显著相关性。考虑的大多数重叠指数和F-1/F-0测量具有双峰分布。与此相反，开和关子区域之间的距离归一化的大小是单峰的。令人惊讶的是，一个简单的模型，加性结合ON和OFF子区域与空间分离从单峰分布，可以很容易地解释数据。这些分析阐明了猕猴初级视皮层的子区域重叠和F-1/F-0\比值之间的关系，一个简单的模型为重叠指数的双峰分布和归一化距离的单峰分布的共存提供了一个简洁的解释。
We studied the spatial overlap of ON and OFF subregions in macaque primary visual cortex and its relation to the response modulation ratio ( the F-1/F-0 ratio). Spatial maps of ON and OFF subregions were obtained by reverse correlation with a dynamic noise pattern of bright and dark spots. Two spatial maps, ON and OFF, were produced by cross-correlating the spike train with the location of bright and dark spots in the stimulus respectively. Several measures were used to assess the degree of overlap between subregions. In a subset of neurons, we also computed the F-1/F-0 ratio in response to drifting sinusoidal gratings. Significant correlations were found among all the overlap measures and the F-1/F-0 ratio. Most overlap indices considered, and the F-1/F-0 measure, had bimodal distributions. In contrast, the distance between on and off subregions normalized by their size was unimodal. Surprisingly, a simple model that additively combines ON and OFF subregions with spatial separations drawn from a unimodal distribution, can readily explain the data. These analyses clarify the relationship between subregion overlap and the F-1/F-0\ ratio in macaque primary visual cortex, and a simple model provides a parsimonious explanation for the co-existence of bimodal distributions of overlap indices and a unimodal distribution of the normalized distance.