Woelders Tom, Didikoglu Altug, Bickerstaff Lucien, Brown Timothy M, Lucas Robert J
Division of Neuroscience, School of Biological Sciences, Faculty of Biology Medicine and Health, Centre for Biological Timing, University of Manchester, Manchester, UK.
Department of Neuroscience, Izmir Institute of Technology, Gulbahce, Urla, Izmir, Turkey.
Sleep. 2025 Feb 10;48(2). doi: 10.1093/sleep/zsae289.
Melanopsin-expressing retinal ganglion cells, which provide light information to time sleep and entrain circadian clocks, also influence perceived brightness raising the possibility that psychophysical paradigms could be used to explore the origins and implications of variability in melanopic sensitivity. We aimed to develop accessible psychophysical tests of melanopic vision and relate outcomes with a pupillometric measure of melanopsin function (post-illumination pupil response) and prior light exposure.
Individually calibrated pairs of isoluminant stimuli differing in melanopic radiance from a four primary source were presented sequentially with superimposed random color offsets in a two alternative forced choice brightness preference paradigm to 41 naïve adult participants with personal light exposure data for the prior 7 days and post-illumination pupil response measures defined by comparing maintained pupil constriction for luminance matched "red" vs "blue" pulses.
Across participants we observed the expected tendency to report positive melanopsin contrast stimuli as "brighter" (one-tailed t-test p < 0.001), but with substantial inter-individual variability in both sensitivity (melanopsin contrast at criterion preference p = 0.75) and amplitude (preference at maximum melanopic contrast). There was little correlation between these psychophysical outcomes and post-illumination pupil response magnitude, or between either psychophysical or post-illumination pupil response measures and light history metrics (pairwise Pearson correlation coefficients -0.5> < 0.5). Random forest machine learning failed to satisfactorily predict outcome for either psychophysical or post-illumination pupil response measures based upon these inputs.
Our findings reveal that estimates of melanopic function provided by perceptual and pupillometric paradigms can be largely independent of one another and of recent history of light exposure.
表达黑视蛋白的视网膜神经节细胞可提供光信息以调节睡眠和校准生物钟，同时也会影响感知亮度，这使得心理物理学范式有可能用于探索黑素视敏度变异性的起源及影响。我们旨在开发可用于黑素视觉的心理物理学测试，并将测试结果与黑素视蛋白功能的瞳孔测量指标（光照后瞳孔反应）及先前的光照暴露情况相关联。
以两个交替的强制选择亮度偏好范式，向41名未经过训练的成年参与者依次呈现由四种主要光源产生的黑素辐射不同的单独校准的等亮度刺激对，并叠加随机颜色偏移。这些参与者提供了前7天的个人光照暴露数据以及通过比较亮度匹配的“红色”与“蓝色”脉冲的持续瞳孔收缩来定义的光照后瞳孔反应测量值。
在所有参与者中，我们观察到预期的趋势，即将正性黑视蛋白对比刺激报告为“更亮”（单尾t检验p<0.001），但在敏感性（标准偏好下的黑视蛋白对比度p=0.75）和幅度（最大黑素对比度下的偏好）方面个体间存在很大差异。这些心理物理学结果与光照后瞳孔反应幅度之间几乎没有相关性，心理物理学测量或光照后瞳孔反应测量与光照历史指标之间也没有相关性（成对皮尔逊相关系数-0.5><0.5）。基于这些输入，随机森林机器学习未能令人满意地预测心理物理学测量或光照后瞳孔反应测量的结果。
我们的研究结果表明，感知范式和瞳孔测量范式所提供的黑素视蛋白功能估计在很大程度上可能相互独立，且与近期光照暴露历史无关。
