Conference on Cognitive Computational Neuroscience

Recent experimental and theoretical work has suggested that people are selective in when they retrieve episodic memories. This selectivity can arise by dynamically gating the inputs or outputs of the hippocampus. To investigate the question of whether gating occurs on the output side (post-gating) or input side (pre-gating), we designed a task where participants sequentially viewed features from previously studied events and were asked to predict the upcoming feature. Features were shared across studied events, creating the risk of recalling the wrong memory when a shared feature was presented. Using participants' willingness to predict a specific feature (versus saying ``don't know'') as a behavioral proxy of memory retrieval, we found that participants delayed retrieval until a diagnostic (unshared) feature was shown. Comparing model simulations incorporating pre vs. post-gating, this behavioral pattern only emerged in post-gating models that included a measure of conflict between activated memories. This suggests that post-gating may be important when interactions between memories at a given moment inform whether retrieval should occur.