GIGA-Cyclotron Research Centre-In Vivo Imaging, University of Liège, Liège, Belgium.
Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, The Netherlands.
J Sleep Res. 2024 Aug;33(4):e14101. doi: 10.1111/jsr.14101. Epub 2023 Nov 16.
Light has many non-image-forming functions including modulation of pupil size and stimulation of alertness and cognition. Part of these non-image-forming effects may be mediated by the brainstem locus coeruleus. The processing of sensory inputs can be associated with a transient pupil dilation that is likely driven in part by the phasic activity of the locus coeruleus. In the present study, we aimed to characterise the task-evoked pupil response associated with auditory inputs under different light levels and across two cognitive tasks. We continuously monitored the pupil of 20 young healthy participants (mean [SD] 24.05 [4.0] years; 14 women) whilst they completed an attentional and an emotional auditory task whilst exposed to repeated 30-40-s blocks of light interleaved with darkness periods. Blocks could either consist of monochromatic orange light (0.16 melanopic equivalent daylight illuminance (EDI) lux) or blue-enriched white light of three different levels [37, 92, 190 melanopic EDI lux; 6500 K]. For the analysis, 15 and then 14 participants were included in the attentional and emotional tasks, respectively. Generalised linear mixed models showed a significant main effect of light level on the task-evoked pupil responses triggered by the attentional and emotional tasks (p ≤ 0.0001). The impact of light was different for the target versus non-target stimulus of the attentional task but was not different for the emotional and neutral stimulus of the emotional task. There is a smaller sustained pupil size during brighter light blocks but, a higher light level triggers a stronger task-evoked pupil response to auditory stimulation, presumably through the recruitment of the locus coeruleus.
光是一种非成像功能，包括瞳孔大小的调节以及警觉和认知的刺激。这些非成像作用的一部分可能是由脑干蓝斑核介导的。感觉输入的处理可能与瞳孔的短暂扩张有关，这种扩张部分可能是由蓝斑核的相位活动驱动的。在本研究中，我们旨在描述在不同光水平和两种认知任务下与听觉输入相关的任务诱发的瞳孔反应。我们连续监测了 20 名年轻健康参与者（平均[标准差]24.05[4.0]岁；14 名女性）的瞳孔，他们在暴露于重复的 30-40 秒的光块与黑暗周期之间，完成了一个注意力和一个情感听觉任务。这些光块可以由单色橙色光（0.16 个明视觉等效日光光照度(mel EDI)勒克斯）或三种不同水平的蓝增强白光组成[37、92、190 mel EDI 勒克斯；6500 K]。在分析中，分别有 15 名和 14 名参与者被纳入注意力和情感任务。广义线性混合模型显示，光水平对注意力和情感任务触发的任务诱发瞳孔反应有显著的主效应（p≤0.0001）。光的影响对注意力任务的目标与非目标刺激不同，但对情感任务的情感和中性刺激则不同。在较亮的光块期间，瞳孔的持续收缩较小，但较高的光水平会引发更强的听觉刺激的任务诱发瞳孔反应，可能是通过蓝斑核的募集。
