Prioritized memory access explains planning and hippocampal replay.

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Decision-making relies on accessing relevant memories.
• Understanding which memories are prioritized during deliberation is crucial but not well understood.
• Hippocampal replay of spatial locations offers a window into memory access.

Purpose of the Study:

• To propose a normative theory predicting optimal memory access for decision-making.
• To explain how animals balance evaluating current choices with incorporating new information.
• To unify proposed functions of memory replay.

Main Methods:

• Simulated a spatial navigation task using a computational agent.
• Modeled sequential memory access ordered by utility (potential reward gain).
• Utilized nonlocal replay of spatial locations in the hippocampus as a proxy for memory access.

Main Results:

• Developed a theory predicting memory access prioritization based on utility.
• Demonstrated how this prioritization balances immediate choice evaluation with information propagation.
• The theory explains existing findings related to place cells and memory replay functions.

Conclusions:

• The proposed theory provides a unified framework for understanding memory replay in decision-making.
• Memory access is dynamically prioritized based on potential reward.
• Dysfunction in this memory access mechanism may contribute to conditions like rumination and craving.