Infant temporal contrast sensitivity functions (tCSFs) mature earlier for luminance than for chromatic stimuli: evidence for precocious magnocellular development?
Infant temporal contrast sensitivity functions (tCSFs) mature earlier for luminance than for chromatic stimuli: evidence for precocious magnocellular development?
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DOI：
10.1016/s0042-6989(99)00020-6
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发表时间：
1999-09-01
期刊：
影响因子：
1.8
通讯作者：
Lia, B
中科院分区：
文献类型：
--
作者：
Dobkins, KR;Anderson, CM;Lia, B
为了研究亮度和色度时间对比敏感度函数（tCSF）的发展，我们从3个月和4个月大的婴儿中获得了色度和亮度对比度阈值，并将其与先前获得的成人函数进行了比较。刺激是0.27 cyc/deg的移动正弦光栅，以五种时间频率之一呈现：1.0、2.1、4.2、9.4或19 Hz（对应速度：3.8、7.7、15、34、69 deg/s）。先前的研究，包括我们自己的研究，已经表明成人tCSF对于亮度刺激是带通的（峰值在5-10 Hz），而对于彩色刺激是低通的（灵敏度在>2 Hz时下降），并且当根据视锥对比度绘制时，这两个函数在4-5 Hz附近相互交叉。在本研究中，我们发现，在3个月和4个月大的亮度tCSF的形状和峰值出现非常相似的成人。相比之下，婴儿的彩色tCSF明显不同于成人。与我们先前的报告（Dobkins，K。R.，Lia，B.，& Teller，D. Y.（1997年）。Vision Research，37（19），2699-2716），3个月大的儿童的色功能相当平坦，缺乏成人功能的急剧的高时间频率下降特征。此外，亮度tCSF在3个月大的升高以上的彩色tCSF，这两个功能不表现出成人样的时间频率测试范围内的交叉。到4个月大时，彩色对比敏感度的实质性发展发生在最低的时间频率。虽然还不成熟，但4个月大的彩色tCSF已经开始采用更像成年人的形状。此外，与成人相似，4个月大婴儿的亮度和色度tCSF在5 Hz附近相互交叉。在成人中，认为大细胞（M）和小细胞（P）途径分别是带通亮度和低通色度tCSF的基础（例如Lee，B. B.，Pokorny，J.，史密斯，弗吉尼亚州，马丁，公共关系，& Valberg，A.（1990年）。Journal of the Optical Society of America（a），7（12），2223-2236）。基于成人的心理生理和神经反应之间的这种对应关系，我们的研究结果表明，相对缓慢的发展，在婴儿的彩色tCSF可能反映了不成熟的彩色反应在P通路和/或依赖于源于M通路的彩色反应。(C)1999爱思唯尔科技有限公司。保留所有权利。
In order to investigate the development of luminance and chromatic temporal contrast sensitivity functions (tCSFs), we obtained chromatic and luminance contrast thresholds from individual 3- and 4-month old infants, and compared them to previously obtained functions in adults. Stimuli were moving sinusoidal gratings of 0.27 cyc/deg, presented at one of five temporal frequencies: 1.0, 2.1, 4.2, 9.4 or 19 Hz (corresponding speeds: 3.8, 7.7, 15, 34, 69 deg/s). Previous studies, including our own, have shown that adult tCSFs are bandpass for luminance stimuli (peaking at 5-10 Hz), yet lowpass for chromatic stimuli (sensitivity falling at >2 Hz), and that the two functions cross one another near 4-5 Hz when plotted in terms of cone contrast. In the present study, we find that the shapes and peaks of the luminance tCSF in both 3- and 4-months-olds appear quite similar to those of adults. By contrast, chromatic tCSFs in infants are markedly different from those of adults. In agreement with our earlier report (Dobkins, K. R., Lia, B., & Teller, D. Y. (1997). Vision Research, 37(19), 2699-2716), the chromatic function in 3-month-olds is rather flat, lacking the sharp high temporal frequency fall-off characteristic of the adult function. In addition, the luminance tCSF in 3-month-olds is elevated above the chromatic tCSF, and the two functions do not exhibit an adult-like cross-over within the range of temporal frequencies tested. By 4 months of age, substantial development of chromatic contrast sensitivity takes place at the lowest temporal frequencies. Although still immature, the 4-month-old chromatic tCSF has begun to adopt a more adult-like shape. In addition, similar to adults, luminance and chromatic tCSFs in 4-month-olds cross one another near 5 Hz. In adults, magnocellular (M) and parvocellular (P) pathways are thought to underlie the bandpass luminance and lowpass chromatic tCSF, respectively (e.g. Lee, B. B., Pokorny, J., Smith, V. C., Martin, P. R., & Valberg, A. (1990). Journal of the Optical Society of America (a), 7(12), 2223-2236). Based on this correspondence between psychophysical and neural responses in adults, our results suggest that the relatively slow development of the chromatic tCSF in infants may reflect immature chromatic responses in the P pathway and/or reliance on chromatic responses originating in the M pathway. (C) 1999 Elsevier Science Ltd. All rights reserved.