Development of an object-space binding bias in episodic memory

The comprehensive integration of what happened, where, and when is fundamental to episodic memory. In particular, the association between objects and places plays a critical role in its development. Previous studies on episodic memory binding have demonstrated that children under the age of five exhibit a spatiotemporal bias when remembering a sequence of events and that the ability to associate objects with specific locations, develops gradually over time. We investigated the progression of episodic memory binding in 79 preschool children (44 boys, 35 girls, aged 3–6 years) using a nonverbal object placement task that required the memory of 'what' (objects), 'where' (space), and 'when' (temporal order) information. In each trial, the child watched as the experimenter hid three distinct objects into three of five cups on a tabletop apparatus; after an interference task, children were asked to re-enact the sequence. We set the association of space and objects in conflict with their temporal order by handing the objects to the children during the re-enactment phase either in the same or shuffled order. Although children showed an overall improvement in memory with age, younger children’s pattern of errors in the shuffled order condition revealed that they often responded according to the temporal sequence of locations instead. That is, children’s increasing tendency to place specific objects in specific locations, even when given in shuffled order, indicates a bias towards ‘object-space’ associations in episodic memory development. • Binding of time and space in episodic memory occurs early in development. • When object order is shuffled, children develop from time-space to object-space binding. • Children’s binding of objects to spatial locations strengthens across development.