Department of Psychology, University of Nevada, Reno, NV, USA.
Proc Biol Sci. 2010 Jun 22;277(1689):1817-25. doi: 10.1098/rspb.2009.1832. Epub 2010 Feb 10.
The spectral sensitivity of the visual system varies markedly between the fovea and surrounding periphery owing in part to the rapid fall in macular pigment density with eccentricity. We examined how colour appearance changes between the fovea and near periphery (8 degrees) by measuring achromatic loci and the loci of unique and binary hues. Chosen colours remained much more similar at the two locations than predicted by the change in spectral sensitivity. Compensation for white may reflect long-term gain changes within the cones that equate sensitivity for the local average stimulus in the fovea and periphery. However, adjusting only to the average stimulus cannot correct for all of the effects of a spectral sensitivity change, and predicts differences in colour percepts between the fovea and periphery that were not observed. The similarities in hue percepts at 0 and 8 degrees thus suggest that additional processes help compensate colour appearance to maintain constancy in the near periphery. We model the results of previous studies to show that similar adjustments are implied by age-related changes in lens pigment, and to show that these adjustments are consistent with previous measurements of peripheral colour appearance based on hue cancellation.
由于黄斑色素密度随离轴距离的迅速下降，视觉系统的光谱灵敏度在中央凹和周围周边之间有显著差异。我们通过测量消色点和独特色及混合色的位置，研究了中央凹和近周边（8 度）之间的颜色外观如何变化。与光谱灵敏度变化所预测的相比，所选颜色在两个位置之间仍然更为相似。对白色的补偿可能反映了锥体细胞内长期增益的变化，使中央凹和周边局部平均刺激的灵敏度相等。然而，仅进行平均刺激的调整并不能纠正光谱灵敏度变化的所有影响，也不能预测在中央凹和周边之间观察到的颜色感知差异。因此，在 0 度和 8 度时色调感知的相似性表明，其他过程有助于补偿颜色外观，以保持近周边的恒定性。我们模拟先前研究的结果表明，晶状体色素的年龄相关性变化暗示了类似的调整，并且这些调整与基于色调消除的先前周边颜色外观测量结果一致。
