Supplementary data for the paper 'Is accommodation a confounder in pupillometry research?'

Much psychological research uses pupil diameter measurements for investigating the cognitive and emotional effects of visual stimuli. A potential problem is that accommodating at a nearby point constricts the pupil. This study examined to what extent accommodation is a confounder in pupillometry research. Participants solved multiplication problems at different distances (Experiment 1) and looked at line drawings with different monocular depth cues (Experiment 2) while their pupil diameter, refraction, and vergence angle were recorded using a photorefractor. Experiment 1 showed that the pupils dilated while performing the multiplications, for all presentation distances. Pupillary constriction due to accommodation was not strong enough to override pupil dilation due to cognitive load. Experiment 2 showed that monocular depth cues caused a small shift in refraction in the expected direction. We conclude that, for the young student sample we used, pupil diameter measurements are not substantially affected by accommodation.

大量心理学研究均采用瞳孔直径（pupil diameter）测量技术，以探究视觉刺激引发的认知与情感效应。该领域存在一项潜在问题：当视线聚焦于近处物体时，眼部发生视觉调节（accommodation），瞳孔会随之收缩。本研究旨在探究视觉调节在瞳孔测量法（pupillometry）研究中作为混淆变量的影响程度。实验1中，受试者在不同距离下完成乘法运算任务；实验2中，受试者观看带有不同单眼深度线索（monocular depth cues）的线条画，期间通过光折射计（photorefractor）记录其瞳孔直径、眼屈光（refraction）状态与辐辏角（vergence angle）。实验1结果显示，无论刺激呈现距离如何，受试者在完成乘法运算时瞳孔均会扩张。因视觉调节引发的瞳孔收缩幅度，不足以抵消认知负荷（cognitive load）所导致的瞳孔扩张。实验2结果表明，单眼深度线索会使眼屈光状态沿预期方向出现小幅偏移。综上，针对本研究采用的青年学生样本，瞳孔直径测量结果并不会受到视觉调节的显著影响。