WHEN THE FUTURE SHAPES MEMORY: ENCODING ANTICIPATED INTERACTIONS IN DYNAMIC SITUATIONS

Dynamic situations, in which the observer and/or environmental elements are in motion, pose a challenge for efficient working memory function. Humans process these situations through a recently described mechanism known as time compaction, which embeds temporal information into spatial representations by mapping the locations where future interactions are expected to occur. This process yields compact internal representations (CIRs) which are hypothesized to be easier to store and retrieve than representations explicitly encoding spatiotemporal information. In this study, we examined the impact of time compaction on memory performance and the conditions under which it is engaged. We employed three variants of a task based on the Sternberg memory paradigm: a simple and a complex memory recognition test, both including stimuli that could or could not be compacted into CIRs, and a third control variant designed to rule out alternative cognitive mechanisms. A total of 445 participants took part in the experiments. In the simple task, enhanced memory performance for compaction stimuli was observed only in male participants, whereas female participants showed no difference between compaction and non-compaction stimuli and performed similarly to males on non-compaction trials. In contrast, in the complex task, compaction stimuli led to superior performance regardless of gender. These results suggest that increased task difficulty promotes reliance on time compaction mechanisms in both men and women when memorizing dynamic stimuli. We discuss possible neurophysiological substrates of time compaction and its implications for human cognition.