Cognitive mechanisms of aversive prediction error-induced memory enhancements

While prediction errors (PEs) have long been recognized as critical in associative learning, emerging evidence indicates their significant role in episodic memory formation. This series of four experiments sought to elucidate the cognitive mechanisms underlying the enhancing effects of PEs related to aversive events on memory for surrounding neutral events. Specifically, we aimed to determine whether these PE effects are specific to predictive stimuli preceding the PE or if PEs create a transient window of enhanced, unselective memory formation. In a combined incidental encoding-fear learning task, participants (n=xxx) estimated aversive shock probabilities after unique stimuli. Physiological arousal and explicit PEs were measured during encoding to predict recognition memory tested either immediately after encoding (Experiment 3) or 24 hours later (Experiments 1-4). Our results show that PE-driven memory enhancement extends beyond predictive stimuli preceding the PE event to those encountered afterward. Furthermore, the retroactive memory enhancement induced by PEs may extend back longer than previously assumed, impacting stimuli presented 10 seconds before the PE. Importantly, our findings reveal that PE-related memory enhancement is specific to predictive stimuli, with uninformative stimuli not benefiting from PEs and even interfering with the PE-driven memory enhancement. This pattern demonstrates that PE effects are not unspecific but that PEs enhance memory for predictive stimuli encountered around a PE event. Notably, memory-enhancing effects of PEs persist even when controlling for changes in arousal. These findings provide insights into the cognitive mechanisms of PE-induced enhancements of memory, with potential implications for understanding aberrant emotional memory in fear-related disorders.

尽管预测误差（Prediction Errors，PEs）长期以来被认为是联结学习中的关键要素，但新兴研究证据表明其在情景记忆形成中同样发挥着重要作用。本系列四项实验旨在阐明与厌恶性事件相关的PEs对周围中性事件记忆的增强效应背后的认知机制。具体而言，本研究旨在明确此类PE效应是否仅局限于PE发生前的预测性刺激，抑或是PE会催生一个记忆形成增强的暂时性非选择性窗口。在一项结合了无意编码与恐惧学习的实验任务中，参与者（样本量n=xxx）需在呈现独特刺激后评估厌恶性电击的发生概率。实验过程中会记录参与者的生理唤醒水平与显性PE值，以此预测编码后的再认记忆表现——再认记忆测试分别在编码结束后即刻（实验3）与24小时后（实验1至实验4）进行。研究结果显示，PE驱动的记忆增强效应并不局限于PE事件发生前的预测性刺激，而是会延伸至PE发生后呈现的刺激。此外，PE所诱导的回溯性记忆增强效应的时间跨度可能比此前设想的更长，可覆盖PE发生前10秒内呈现的刺激。值得注意的是，本研究发现与PE相关的记忆增强效应仅针对预测性刺激：无信息刺激无法从PE中获益，甚至会干扰PE驱动的记忆增强过程。这一结果模式表明，PE效应并非非特异性的，而是会增强PE事件前后出现的预测性刺激的记忆表现。值得注意的是，即使在控制生理唤醒水平变化的情况下，PE的记忆增强效应依然存在。本研究结果为PE诱导的记忆增强效应的认知机制提供了新的见解，同时也为理解恐惧相关障碍中异常情绪记忆的成因提供了潜在参考。