关键词: 暴露时长, 传统消退范式, 提取消退范式, 预期错误

Abstract: The operational similarities between the retrieval extinction paradigm (reconsolidation-based) and the traditional extinction paradigm (extinction-based), subtle procedural settings during the retrieval phase might prevent memories from entering reconsolidation, thus losing the long-lasting inhibitory effect on fear relapse. Studies have shown that the duration of retrieval exposure regulates the phase into which memories enter, and this mechanism is related to the amount of prediction error elicited during retrieval. This study aims to investigate the regulatory role of retrieval exposure duration from memory reconsolidation to extinction, and to clarify its mechanism by quantifying prediction errors. This study collected skin conductance responses and subjective expectancy values, combined with a simplified Rescorla-Wagner reinforcement learning model to fit the PE quantification curve. Following the experimental design idea of transitioning from the traditional extinction paradigm to the retrieval extinction paradigm, extinction training was divided into retrieval and extinction phases based on different numbers of retrieval trials, forming four different retrieval exposure durations: traditional extinction, single-trial retrieval extinction, double-trial retrieval extinction, and quadruple-trial retrieval extinction. The effects of conditioned fear memory elimination under these four conditions were compared. The results revealed that in the spontaneous recovery test, both the single-trial and quadruple-trial retrieval extinction groups showed better inhibitory effects on spontaneous fear recovery, while the traditional extinction group and the double-trial retrieval extinction group exhibited evident spontaneous recovery effects. In the fear reinstatement test, only the single-trial retrieval extinction group showed a better inhibitory effect on fear reinstatement, while the other three groups all demonstrated fear reinstatement effects. Furthermore, the subjective expectancy results for CS+ trials on the second day among the four groups indicated that there were no intergroup differences in participants' subjective expectations of whether CS+ was accompanied by a shock. However, in terms of quantified prediction errors, the single-trial retrieval extinction group showed the most significant change in prediction errors on the second day's CS+ trials, with the overall lowest prediction error values. This study found that the number of retrieval trials plays a crucial role in successfully transitioning from the traditional extinction paradigm to the retrieval extinction paradigm in human fear conditioned. The research emphasizes the importance of prediction errors during the retrieval phase as a potential determinant for memories to undergo reconsolidation or extinction. Future studies are recommended to delve deeper into identifying specific neural markers for memory reconsolidation and extinction in human research, aiming to design more reliable clinical treatments for maladaptive emotional memories.

Key words: exposure duration, traditional extinction paradigm, retrieval extinction paradigm, prediction errors