The development of spatiotemporal organization of episodic memory in children and its disruption in Williams Syndrome

Abstract

Recent theories of episodic memory propose that the hippocampus provides the spatiotemporal framework for episodic memories. If this is true, does the development of episodic memory depend on the binding of space and time? And does this rely, at least partly, on normal hippocampal function? We investigated the development of episodic memory in children 2-8 years of age (Study 1) and its impairment in Williams Syndrome (Study 2) by implementing a nonverbal object-placement task that dissociates the what, where, and when components of episodic memory. Our results indicate that the binding of space and time in memory emerges first in development around the age of 3 and is impaired in Williams Syndrome. Space-time binding both preceded and predicted success in full episodic memory (what+where+when), and associating objects to spatial location seemed to mediate this developmental process. Importantly, these effects were not explained by improvements in object or location memory.