When Natural Behavior Engages Working Memory.

Working memory (WM) enables temporary storage and manipulation of information,1 supporting tasks that require bridging between perception and subsequent behavior. Its properties, such as its capacity, have been thoroughly investigated in highly controlled laboratory tasks.1-8 Much less is known about the utilization and properties of WM in natural behavior,9-11 when reliance on WM emerges as a natural consequence of interactions with the environment. We measured the trade-off between reliance on WM and gathering information externally during immersive behavior in an adapted object-copying task.12 By manipulating the locomotive demands required for task completion, we could investigate whether and how WM utilization changed as gathering information from the environment became more effortful. Reliance on WM was lower than WM capacity measures in typical laboratory tasks. A clear trade-off also occurred. As sampling information from the environment required increasing locomotion and time investment, participants relied more on their WM representations. This reliance on WM increased in a shallow and linear fashion and was associated with longer encoding durations. Participants' avoidance of WM usage showcases a fundamental dependence on external information during ecological behavior, even if the potentially storable information is well within the capacity of the cognitive system. These foundational findings highlight the importance of using immersive tasks to understand how cognitive processes unfold within natural behavior. Our novel VR approach effectively combines the ecological validity, experimental rigor, and sensitive measures required to investigate the interplay between memory and perception in immersive behavior. VIDEO ABSTRACT.