Yang Jiale, Kanazawa So, Yamaguchi Masami K, Kuriki Ichiro
Department of Psychology, Chuo University, 742-1 Higashi-Nakano, Hachioji, Tokyo 192-0393, Japan;
Department of Psychology, Japan Women's University, 1-1-1 Nishi-Ikuta, Tama, Kawasaki, Kanagawa 214-8565, Japan;
Proc Natl Acad Sci U S A. 2016 Mar 1;113(9):2370-5. doi: 10.1073/pnas.1512044113. Epub 2016 Feb 8.
Perceptual color space is continuous; however, we tend to divide it into only a small number of categories. It is unclear whether categorical color perception is obtained solely through the development of the visual system or whether it is affected by language acquisition. To address this issue, we recruited prelinguistic infants (5- to 7-mo-olds) to measure changes in brain activity in relation to categorical color differences by using near-infrared spectroscopy (NIRS). We presented two sets of geometric figures to infants: One set altered in color between green and blue, and the other set altered between two different shades of green. We found a significant increase in hemodynamic responses during the between-category alternations, but not during the within-category alternations. These differences in hemodynamic response based on categorical relationship were observed only in the bilateral occipitotemporal regions, and not in the occipital region. We confirmed that categorical color differences yield behavioral differences in infants. We also observed comparable hemodynamic responses to categorical color differences in adults. The present study provided the first evidence, to our knowledge, that colors of different categories are represented differently in the visual cortex of prelinguistic infants, which implies that color categories may develop independently before language acquisition.
感知颜色空间是连续的;然而,我们倾向于将其仅划分为少数几个类别。尚不清楚分类颜色感知是仅通过视觉系统的发育获得的,还是受语言习得的影响。为了解决这个问题,我们招募了前语言期婴儿(5至7个月大),使用近红外光谱(NIRS)来测量与分类颜色差异相关的大脑活动变化。我们向婴儿展示了两组几何图形:一组在绿色和蓝色之间变化颜色,另一组在两种不同深浅的绿色之间变化。我们发现在类别间交替期间血液动力学反应显著增加,但在类别内交替期间没有增加。基于分类关系的这些血液动力学反应差异仅在双侧枕颞区域观察到,而在枕叶区域未观察到。我们证实分类颜色差异在婴儿中产生行为差异。我们还在成年人中观察到了对分类颜色差异的类似血液动力学反应。据我们所知,本研究首次提供了证据,表明不同类别的颜色在语言前婴儿的视觉皮层中表现不同,这意味着颜色类别可能在语言习得之前就独立发展了。