Voluntary down-regulation of memory encoding occurs via attentional withdrawal, not active suppression

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Joseph M. Saito¹ (joseph.saito@mail.utoronto.ca), Keisuke Fukuda^1,2; ¹University of Toronto, ²University of Toronto Mississauga

Humans sometimes encounter visual stimuli that they desire to not remember. While classic studies of memory control suggest that observers can down-regulate their encoding of undesired stimuli by actively suppressing stimulus processing, recent investigations have asserted that memory control is exclusively up-regulatory in nature. Here, we sought to directly test whether down-regulation of memory encoding is possible, and if so, whether down-regulation depends on active suppression. In two experiments, participants were cued prior to the onset of real-world objects to not remember (down-regulate) or try “extra hard” to remember (up-regulate) a given object. To characterize the directionality of any observed regulation, we also included a baseline condition in which observers were instructed to “remember” (Experiment 1) or “just look at” (Experiment 2) a given object. On half of the encoding blocks, the pre-cue changed in a fixed order across objects (e.g., up-down-baseline-up-down-baseline) to allow for the deployment of any mechanisms that require anticipation of regulation demands. In doing so, we found that down-regulated objects were remembered less often than baseline objects that were “remembered”, but not those that were “just looked at”, even when the cue was highly-predictable. By contrast, up-regulation was observed across all baseline and predictability manipulations. In the brain, dissociable ERP (Frontal Positivity) and time-frequency (Occipital Alpha Power) signatures of attentional engagement dovetailed regulation patterns in behavior. These findings suggest that observers are capable of down-regulating encoding relative to active learning by withdrawing their attention but are not able to suppress encoding beyond passive stimulus perception.

Topic Area: LONG-TERM MEMORY: Episodic