The trade-off of rapidly forming a cohesive episodic memory

Packard, P. A. 1, 2 , Diego-Balaguer, R. 1, 2, 3 , Nicolàs, B. 1 , Rodríguez-Fornells, A. . 1, 2, 3 & Fuentemilla, L. . 1, 2

1 Cognition and Brain Plasticity Group. Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
2 Department of Basic Psychology, University of Barcelona, Barcelona, Spain
3 Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain

Humans continuously generate predictions by linking information from the current spatio-temporal context to existing scripts in memory. Here, we investigated the possibility that the integration of an item into a picture sequence with real-life spatio-temporal context favors the rapid formation of a cohesive episodic memory trace but leads to loss of item-specific details and less accurate contextual memory. An episodic contextualization group of participants studied target pictures of objects preceded by spatio-temporal coherent streams of 4 pictures resembling a day life episode, either congruent or incongruent with the object. A semantic contextualization group studied the same objects, preceded by 4 images of semantically associated pictures. Thus, the two groups could generate semantic predictions but differed in whether they were supported by a spatiotemporal context. At test, target pictures were better remembered when they were encoded in congruent than in incongruent streams, independently of the encoding context. However, participants showed a marked decrease in recalling the picture stream in the congruent with a specific spatiotemporal context condition only. These results suggest that the rapid integration of items into a spatiotemporal context preserves item-related event details but impoverishes the item's ability to guide the reinstatement of contextual information.