Interdisciplinary Program in Neuroscience, Georgetown University, 401 White-Gravenor, 37th and O Streets NW, Washington, DC, 20007, USA.
Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA.
J Neurodev Disord. 2021 Sep 15;13(1):35. doi: 10.1186/s11689-021-09388-9.
Conceptual knowledge frameworks termed schemas facilitate memory formation and are posited to support flexible behavior. In adults, the medial temporal lobe (MTL) and medial prefrontal cortex (mPFC) trade-off in supporting schema-based memory formation, such that encoding of subsequently remembered schema-congruent information relies on mPFC, whereas schema-incongruent information relies on MTL. Whether this is true in the immature brain and relates to behavioral flexibility is unknown. In this preliminary investigation, we aimed to replicate the adult findings in typically developing (TD) children and to investigate the relevance to behavioral flexibility by examining a disorder with pathognomonic behavioral rigidity, autism spectrum disorder (ASD).
Children completed an associative subsequent memory paradigm, encoding object-scene pairs in an MRI scanner and subsequently completing a recognition test outside the scanner after a delay. Recognition performance was back sorted to construct remembered vs forgotten contrasts. One-way ANOVAS were conducted in MTL and mPFC masks for schema-congruency, followed by congruency by flexibility scores. Exploratory analyses were then conducted within the whole brain.
As reported in adults, episodic memory was strongest for schema-congruent object-scene pairs, followed by intermediate pairs, and lowest for schema-incongruent pairs in both TD and ASD groups. However, the trade-off between mPFC and MTL in TD children differed from adult reports such that mPFC supported memory for intermediate schema-congruency and left anterior MTL supported memory for schema-congruent pairs. In ASD, mPFC engagement interacted with flexibility such that activation supporting memory for intermediate schema-congruency varied with parent-reported flexibility and was higher in those with more flexible behavior. A similar interaction was also observed in both the left dorsolateral and rostrolateral PFC in whole-brain analysis.
Our findings provide the first preliminary evidence for the association of schema-based episodic memory formation and behavioral flexibility, an executive function impaired in multiple developmental disorders. Upon replication, this line of research holds promise for memory-based interventions addressing executive problems of behavioral rigidity.
概念知识框架（称为图式）有助于记忆形成，并被认为支持灵活的行为。在成年人中，内侧颞叶（MTL）和内侧前额叶皮层（mPFC）在支持基于图式的记忆形成方面相互交换，例如随后记住的与图式一致的信息的编码依赖于 mPFC，而与图式不一致的信息则依赖于 MTL。在不成熟的大脑中是否如此，以及与行为灵活性的关系尚不清楚。在这项初步研究中，我们旨在复制典型发育（TD）儿童中的成人发现，并通过检查具有特征性行为僵硬的疾病（自闭症谱系障碍（ASD））来研究与行为灵活性的相关性。
儿童在 MRI 扫描仪中完成联想随后记忆范式，对物体-场景对进行编码，然后在扫描后延迟在扫描仪外完成识别测试。识别性能被回溯排序以构建记忆与遗忘对比。在 MTL 和 mPFC 掩模中进行了针对图式一致性的单因素方差分析，然后进行了一致性与灵活性评分的分析。然后在整个大脑中进行了探索性分析。
与成人报告的一样，TD 和 ASD 组的情节记忆最强的是与图式一致的物体-场景对，其次是中等一致性的对，而与图式不一致的对最弱。然而，TD 儿童的 mPFC 和 MTL 之间的权衡与成人报告的不同，mPFC 支持中等图式一致性的记忆，左前 MTL 支持图式一致的记忆。在 ASD 中，mPFC 的参与与灵活性相互作用，支持中等图式一致性的记忆的激活随父母报告的灵活性而变化，在行为更灵活的儿童中更高。在整个大脑的分析中，还观察到左背外侧和额外侧 PFC 中也存在类似的相互作用。
我们的发现为基于图式的情节记忆形成与行为灵活性之间的关联提供了初步证据，这是多种发育障碍中受损的执行功能。在复制后，这条研究线为基于记忆的干预措施提供了希望，可以解决行为僵硬的执行问题。
