No abstract

Human capacity to remember experienced episodes over a long period of time has its roots in childhood and develops throughout the lifespan. However, the neural regions supporting memory consolidation in the developing brain remain to be ascertained. The present study examined system-level memory consolidation of object-location associations after one night of sleep (short delay) and after two weeks (long delay), and its relation to structural brain measures in normally developing term born and preterm born 6-year-old children, as well as in young adults as a reference group of mature consolidation systems. We showed that final learning performance was reduced in preterm in comparison to term born children, who in turn were outperformed by young adults. There were no differences in short- and long-delay memory consolidation between term and preterm born children. Despite comparable short-delay memory consolidation in all groups, both term and preterm born children showed less efficient long-delay memory consolidation in comparison to young adults. Moreover, long-delay memory consolidation was positively associated with larger hippocampal volume in children, while a thinner medial orbitofrontal cortex was associated with better overall memory retention rates in all age groups. Thinner medial orbitofrontal cortex was furthermore associated with higher final learning performance in children. Taken together, the results suggest that temporal dynamics of memory consolidation and its association with structural brain measures in 6-year-old term born and preterm born children are comparable but differ from young adults.