Spectral properties of V4 neurons in the macaque
Spectral properties of V4 neurons in the macaque
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DOI：
10.1523/jneurosci.10-10-03369.1990
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发表时间：
1990-10
期刊：
影响因子：
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通讯作者：
Stanley J. Scheinl;R. Desimone
中科院分区：
文献类型：
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作者：
Stanley J. Scheinl;R. Desimone
用窄带和宽带彩色光定量研究了5只猕猴V_4区129个细胞的光谱特性。绝大多数细胞在其感受野内表现出一定程度的波长敏感性。72%的细胞的光谱响应曲线中的主峰的半带宽小于50 nm;这些细胞的平均半带宽为27 nm，与小细胞背外侧膝状体核（dLGN）中的颜色对手神经节细胞和细胞的半带宽相似。对比度反应函数表明，这些细胞的窄光谱调谐来自视锥细胞与对手的相互作用.从感受野大小的比较，我们认为，一个典型的V4神经元的总和输入，最终来自几千个神经节或小细胞dLGN细胞。尽管它们对波长敏感，但大多数V4细胞的特性不符合一些简单的“颜色选择性”分类标准。首先，很少有细胞表现出明显的迹象，颜色的兼容性，即，对抑制或关闭激发光谱对手的波长。第二，V4中约30%的细胞具有双峰的光谱响应曲线。(The这些第二峰的波长分布几乎与主峰的波长分布相同，并且峰波长的组合是相当随机的。第三，大多数细胞对白色光有反应;总体而言，对白色光的反应约为对最佳窄带或宽带彩色光的反应的60%。同样，大多数V4细胞对我们提供的所有或几乎所有不同的宽带彩色光至少有一个小的反应。因此，给定的V4细胞很可能对自然场景中的大多数彩色或白色表面做出反应。这些组合的响应特性可能解释了广泛不同的百分比的“颜色”的细胞在以前的研究报告的V4。我们在V4中发现的最不寻常的光谱特性是在大多数细胞的“经典感受野”之外有一个大的光谱敏感的环境。虽然周围刺激本身不会引起任何反应，但周围刺激可以完全抑制对感受野中最佳颜色刺激的反应。一般来说，感受场激发和环绕抑制的最佳波长相同或接近相同。因此，可以在V4中计算“颜色对比度”。在某些情况下，周围的对比波长会导致对感受场刺激的反应适度增强。（400字处截断摘要）
Spectral properties of 129 cells in the V4 area of 5 macaque monkeys were studied quantitatively with narrow-band and broad-band colored lights. The large majority of cells exhibited some degree of wavelength sensitivity within their receptive fields. The half-bandwidth of the primary peak in the spectral-response curve was less than 50 nm for 72% of the cells; the mean half-bandwidth of these cells, 27 nm, is similar to that found for color-opponent ganglion cells and cells in the parvocellular dorsal lateral geniculate nucleus (dLGN). Contrast- response functions indicated that the narrow spectral tuning of these cells derived from cone opponent interactions. From comparison of receptive-field sizes, we suggest that a typical V4 neuron sums inputs that ultimately derive from several thousand ganglion or parvocellular dLGN cells. In spite of their wavelength sensitivity, most V4 cells had properties that would not fit some simple criteria for classification as “color selective.” First, few cells showed overt signs of color opponency, namely, on-inhibition or off-excitation to spectrally opponent wavelengths. Second, about 30% of the cells in V4 had spectral- response curves with 2 peaks. (The wavelength distribution of these second peaks was almost identical to that of primary peaks, and combinations of peak wavelengths were fairly random.) Third, most cells responded to white light; overall, the response to white light was about 60% of that to the best narrow-band or broad-band colored light. Similarly, most V4 cells gave at least a small response to all or nearly all of the different broad-band colored lights we presented. Therefore, a given V4 cell is very likely to respond to most of the colored or white surfaces in natural scenes. These combinations of response properties probably explain the widely divergent percentages of “color” cells reported in previous studies of V4. The most unusual spectral property we found in V4 was a large, spectrally sensitive surround outside the “classical receptive field” of most cells. Although stimulation of the surround by itself did not cause any response, surround stimulation could completely suppress the response to even the optimally colored stimulus in the receptive field. In general, the optimal wavelengths for receptive-field excitation and surround suppression were the same or nearly so. Thus, “color contrast” may be computed in V4. In some cases, contrasting wavelengths in the surround caused moderate enhancement of response to a receptive-field stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)