瞳孔变化在记忆加工中的生物标记作用

瞳孔在不同记忆任务的同一加工阶段内具有变化模式的一致性, 瞳孔的缩放变化反映了信息加工过程中神经系统的激活状态。在刺激呈现前的预编码阶段, 瞳孔随个体注意集中水平的提高而收缩。在信息编码阶段, 瞳孔扩张程度作为相继记忆效应的生物标记, 可预测信息未来提取阶段的回忆成绩。在信息提取阶段, 采用自由回忆任务时, 瞳孔随记忆负荷的释放而迅速收缩, 但每个项目的提取均会引发小幅度瞳孔扩张; 而在再认提取任务中, 呈现旧刺激比呈现新刺激时瞳孔扩张更明显, 产生瞳孔新旧效应。瞳孔是记忆加工中敏感而稳定的生物标记, 而瞳孔测量法是探究记忆加工生理机制的有效手段。未来可以从瞳孔追踪术的角度, 采用多种研究手段进一步探究记忆的生理机制。

Pupil size as a biomarker of memory processing

Pupils were found to exhibit consistent changing patterns in the same processing stage of different memory tasks, and the changes in pupil size reflect the activation state of the nervous system during information processing. During the pre-coding phase before the stimulus is presented, pupils contract as the individual's endogenous attention level increases. In the information encoding stage, the degree of pupil dilation is used as a bio-marker of the subsequent memory effect, which can predict the memory performance of the future information retrieval stage. In the retrieval phase, when the free recall task is used, pupils contract rapidly with the release of memory load, but the report of each item will cause a small pupil dilation; In the recognition task, pupil dilation is more pronounced when old stimulus is presented than that with new stimulus, producing pupil old/ new effect. Pupil size is a sensitive and stable bio-marker in memory processing. Pupil tracking measurement is an effective approach to explore the physiological mechanism of memory processing. In the future research, pupil tracking along with multiple research methods should be used to further explore the physiological mechanism of memory.