Pupillometry has been found to be correlated with activity of cholinergic and noradrenergic neuromodulator systems. These systems regulate the level of cortical arousal and therefore perception, attention, and memory. Here, we tested how different types of pupil size variance (prestimulus baseline and prestimulus hippus power) may correlate with behavioral and electrophysiological brain responses (ERPs). We recorded pupil size and ERPs while participants were presented with a series of words and then asked whether they had been in the initial list when they were later presented intermixed with unpresented words. We found that a smaller prestimulus baseline pupil size during the study phase was associated with better memory performance. Study items also evoked a larger P3 response at presentation and a greater old/new memory ERP effect at test when prestimulus pupil size was small rather than large. Prestimulus hippus power was found to be a between-subjects factor affecting the robustness of memory encoding with less power being associated with a greater old/new memory ERP effect. These results provide evidence relating memory and ERPs to variables defined on pupil size that are thought to reflect varying states of parasympathetic and sympathetic arousal.

已发现瞳孔测量与胆碱能和去甲肾上腺素能神经调节系统的活性相关。这些系统调节皮质唤醒水平，从而调节感知、注意力和记忆。在这里，我们测试了不同类型的瞳孔大小差异（刺激前基线和刺激前海马功率）如何与行为和电生理大脑反应 (ERP) 相关。当参与者被呈现一系列单词时，我们记录了瞳孔大小和 ERP，然后询问他们是否在最初的列表中，当他们后来与未呈现的单词混合呈现时。我们发现在研究阶段较小的刺激前基线瞳孔大小与更好的记忆性能相关。当刺激前瞳孔大小较小而不是较大时，研究项目在呈现时也引起了更大的 P3 反应和更大的旧/新记忆 ERP 效应。发现刺激前海马功率是影响记忆编码稳健性的受试者间因素，功率越小，新旧记忆 ERP 效应越大。这些结果提供了将记忆和 ERP 与根据瞳孔大小定义的变量相关联的证据，这些变量被认为反映了副交感神经和交感神经兴奋的不同状态。