Functional measurements of human ventral occipital cortex: retinotopy and colour
Functional measurements of human ventral occipital cortex: retinotopy and colour
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DOI：
10.1098/rstb.2002.1108
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发表时间：
2002-08-29
影响因子：
6.3
通讯作者：
Wandell, BA
中科院分区：
文献类型：
--
作者：
Wade, AR;Brewer, AA;Wandell, BA
人类的色觉起源于视锥细胞，其空间密度在中央凹处达到峰值，并向周边迅速下降。出于这个原因，人们期望在那些支持颜色感知的皮质位置中找到大量富含视锥细胞的中央凹。人类枕叶皮层包含几个不同的中心凹表征，其中至少有两个延伸到腹侧表面：该区域被认为对色觉至关重要。为了更多地了解这些腹侧信号，我们使用功能磁共振成像来识别腹侧表面的视野图和颜色响应度。我们在V3腹侧附近的4cm(2)区域找到了完整对侧半视野的视觉图，该图的中心凹表示与V1/2/3区域的表示相汇合。此外，在位于汇合的 V1/2/3 中心凹表征前方 3-5 cm 的腹侧表面上存在明显的中心凹表征。该组织与区域 V8 的定义不一致，该定义假设存在与 V3v 相邻的四分之一场表示。对亮度匹配的彩色和非彩色图案的反应比较表明，对彩色刺激的活动增加，从 V1 区域开始，延伸到新的半视野表示，并进一步延伸到腹侧枕叶的前部。
Human colour vision originates in the cone photoreceptors, whose spatial density peaks in the fovea and declines rapidly into the periphery. For this reason, one expects to find a large representation of the cone-rich fovea in those cortical locations that support colour perception. Human occipital cortex contains several distinct foveal representations including at least two that extend onto the ventral surface: a region thought to be critical for colour vision. To learn more about these ventral signals, we used functional magnetic resonance imaging to identify visual field maps and colour responsivity on the ventral surface. We found a visual map of the complete contralateral hemifield in a 4 cm(2) region adjacent to ventral V3,the foveal representation of this map is confluent with that of areas V1/2/3. Additionally, a distinct foveal representation is present on the ventral surface situated 3-5 cm anterior from the confluent V1/2/3 foveal representations. This organization is not consistent with the definition of area V8, which assumes the presence of a quarter field representation adjacent to V3v. Comparisons of responses to luminance-matched coloured and achromatic patterns show increased activity to the coloured stimuli beginning in area V1 and extending through the new hemifield representation and further anterior in the ventral occipital lobe.