Relational memory improves during middle childhood and adolescence, yet the neural correlates underlying those improvements are debated. Although memory for spatial, temporal, and other associative relations requires the hippocampus, it is not established whether within-individual changes in hippocampal structure contribute to memory improvements from middle childhood into adolescence. Here, we investigated how structural changes in hippocampal head, body, and tail subregions predict improvements in the capacity to remember item-space, item-time, and item-item relations. Memory for each relation and volumes of hippocampal subregions were assessed longitudinally in 171 participants across 3 time points (M_age at T1 = 9.45 years; M_age at T2 = 10.86 years, M_age at T3 = 12.12 years; comprising 393 behavioral assessments and 362 structural scans). Among older children, volumetric growth in: (a) head and body predicted improvements in item-time memory, (b) head predicted improvements in item-item memory; and (c) right tail predicted improvements in item-space memory. The present research establishes that changes in hippocampal structure are related to improvements in relational memory, and that sub-regional changes in hippocampal volume differentially predict changes in different aspects of relational memory. These findings underscore a division of labor along the anterior-posterior axis of the hippocampus during child development.

关系记忆在童年中期和青春期得到改善，但这些改善背后的神经相关性仍存在争议。尽管空间、时间和其他联想关系的记忆需要海马体，但海马体结构的个体内部变化是否有助于从童年中期到青春期的记忆改善尚不清楚。在这里，我们研究了海马头部、身体和尾部分区的结构变化如何预测记忆项目-空间、项目-时间和项目-项目关系能力的提高。对 171 名参与者在 3 个时间点的每个关系的记忆和海马分区的体积进行了纵向评估（ T1 时的M_年龄= 9.45 岁； T2 时的M_年龄= 10.86 岁； T3 时的M_年龄= 12.12 岁；包括 393 项行为评估和 362 项行为评估）结构扫描）。在年龄较大的儿童中，以下方面的体积增长：（a）头部和身体预测项目时间记忆的改善，（b）头部预测项目记忆的改善；(c) 右尾预测项目空间记忆的改善。目前的研究表明，海马结构的变化与关系记忆的改善有关，并且海马体积的次区域变化可以不同地预测关系记忆不同方面的变化。这些发现强调了儿童发育过程中海马体前后轴的分工。