工作记忆与记忆再巩固对测验效应的影响及其神经机制

Conventional wisdom in education states that the best way to enhance learning is to provide additional study opportunities and that the role of tests is merely to evaluate learning outcomes. Although assessment is certainly one function of testing, the importance of testing, per se, for improving learning has received greater attention of late. The testing effect refers to superior retention when study is followed by a test rather than followed by another study. While researchers have conducted numerous studies to understand the nature of the testing effect, there has been far less research investigating the neural mechanisms underlying this effect. The goal of this proposal is to shed light on these neural mechanisms by determining the brain regions that are associated with successful outcomes from the testing effect. In particular, we will use three neuroimaging experiments to address the issue of what it is about to retrieve the answer from memory that enhances learning more than restudy. Specifically, we will double dissociate the contribution of the retrieval attempt process and the post-retrieval re-encoding process proposed by our prior studies. Moreover, this research will further study the underlying neural mechanisms of the two processes. Experiment 2 will examine the unique role of working memory process in the retrieval attempt process by using fMRI. Experiment 3 will use resting state fMRI to examine how memory reconsolidation facilitates the testing effect through the post-retrieval re-encoding process. Understanding the neural basis of the testing effect will allow us to devise better teaching techniques that can be utilized in the classroom and develop cognitive interventions for patients with memory deficits.

传统理论认为最佳的学习方法是重复学习，而测验的作用在于检验学习效果。但越来越多的研究开始关注测验本身对学习的促进作用，即测验效应。测验效应是指对学习过的材料进行反复测验（提取）比重复学习更有利于记忆保持。虽然国内外学者已经对测验效应提出多种理论解释，但其背后的神经机制尚不清晰。本项目旨在结合行为研究与磁共振成像技术，探究测验效应背后的神经机制。项目将（1）利用功能磁共振成像手段双重分离并验证测验效应中可能包含的两个独立过程——记忆提取尝试与提取后再编码。在此基础上，进一步探究两过程背后的神经机制：即（2）利用功能磁共振成像手段探究工作记忆在记忆提取尝试过程中的作用；（3）利用静息态功能磁共振方法探究记忆再巩固在提取后再编码过程中的作用。本项目有助于揭示记忆提取过程的神经机制，进而帮助完善相关理论。在实际应用方面，研究有助于设计科学的教学方法和开发针对记忆相关神经疾病的认知治疗手段。

传统理论认为最佳的学习方法是重复学习，而测验的作用在于检验学习效果。但越来越多的研究开始关注测验本身对学习的促进作用，即测验效应。测验效应是指对学习过的材料进行反复测验（提取）比重复学习更有利于记忆保持。虽然国内外学者已经对测验效应提出多种理论解释，但其背后的神经机制尚不清晰。本项目结合了行为研究与包括脑电和磁共振成像技术在内的神经科学技术，探究测验效应背后的神经机制。首先，本项目通过脑电实验，证实了记忆提取过程包含了两个相互独立的过程：一个是记忆提取尝试过程本身，另一个是记忆提取之后的再编码过程。在此基础之上，本项目进一步研究发现记忆提取的两个过程共同消耗工作记忆，当其中一个过程消耗了大部分或者全部的工作记忆，并且工作记忆尚无足够时间恢复时，记忆提取的第二个过程可能无法完成。此外，本项目利用静息功能磁共振成像技术研究发现测验效应的作用不仅体现在记忆提取过程本身，还能通过影响记忆提取之后的静息过程促进学习。综上所述，本项目结合行为研究及多种神经科学研究手段，开发了反映记忆提取不同过程的神经指标，为接下来的研究提供了依据和指标。并且本项目从神经角度揭示了记忆提取，以及从记忆提取当中进一步学习包含的不同加工过程，对教育教学当中合理利用记忆测验提高学习成绩提供了理论支持。