Peterzell D H, Teller D Y
Department of Psychology, University of Washington, Scattle 98195-1525, USA.
Vision Res. 1996 Oct;36(19):3077-85. doi: 10.1016/0042-6989(96)00061-2.
The number and nature of spatial channels tuned to low spatial frequencies in photopic vision was examined by measuring individual differences in the contrast sensitivity functions (CSFs) of seven visually normal adults. Stationary, 51 cd/m2, low spatial frequency sinusoidal gratings between 0.27 and 2.16 c/deg were used as stimuli. Correlational and factor analyses revealed that the set of CSFs contained only one statistical source of individual variability at spatial frequencies below 1 c/deg (tuned to a peak of about 0.8 c/deg), and a second source above 1 c/deg (tuned to about 1.4 c/deg). The sources ("factor-channels") mapped well onto the two coarsest spatial frequency channels from some existing computational models. The analysis was applied also to earlier data from 4-, 6- and 8-month-old infants, in which two sources of variability have been found below 1 c/deg [Peterzell, D. H., Werner, J. S. & Kaplan, P. S. (1995). Vision Research, 35, 961-980]. The combined results are consistent with the hypothesis that in photopic vision of the neonate, there are two channels with peak sensitivities below 1 c/deg, and that these channels shift their tuning from lower to higher spatial frequencies by about a factor of four during development.
通过测量7名视力正常成年人的对比敏感度函数（CSF）中的个体差异，研究了明视觉中调谐到低空间频率的空间通道的数量和性质。使用51 cd/m²的固定低空间频率正弦光栅，空间频率在0.27至2.16 c/deg之间作为刺激。相关分析和因子分析表明，在低于1 c/deg的空间频率下（调谐到约0.8 c/deg的峰值），CSF集合仅包含一个个体变异性的统计来源，而在高于1 c/deg的空间频率下（调谐到约1.4 c/deg）存在第二个来源。这些来源（“因子通道”）与一些现有计算模型中两个最粗的空间频率通道很好地对应。该分析还应用于4个月、6个月和8个月大婴儿的早期数据，在这些数据中，在低于1 c/deg的频率下发现了两个变异性来源[Peterzell, D. H., Werner, J. S. & Kaplan, P. S. (1995). Vision Research, 35, 961 - 980]。综合结果与以下假设一致：在新生儿的明视觉中，有两个峰值敏感度低于1 c/deg的通道，并且这些通道在发育过程中其调谐从较低空间频率转移到较高空间频率，幅度约为四倍。
