Effects of spatial boundary on episodic memory in children

Abstract

Recent studies found that both spatial and event boundaries can influence episodic memory formation in both children and adults. Furthermore, young children have been shown to be particularly sensitive to the physical property of boundaries, such as continuity and 3D-ness, in their spatial memory. Given that children's ability to map space using boundaries changes over development, we tested whether the effect of boundaries on children’s event memory also changes accordingly. Total 77 participants underwent the episodic memory task in the experimental setting with a boundary in the middle and three containers around the boundary to hide objects. Each child was asked to re-enact the sequential hiding events. Overall, we observed a significant increase in the general task performance over development

but underlying this overall pattern, we found an early-developing memory of sequential events occurring on the same side of a boundary, followed by the memory of sequential events that cross a spatial boundary. Moreover, children showed better performance in the wall-type boundary condition than the fence- or line-type boundary and especially the young children were more affected by the property of the boundary. This finding is consistent with previous studies that continuous, 3D boundaries serve as a clear boundary in children’s spatial navigation. The results of this thesis imply that there exists an interaction between spatial and episodic memory, which is particularly prevalent in young children whose spatial representations are still under development. We interpret these results to indicate the importance of hippocampal spatial representations in the organization of event memory.