Positive reward prediction errors during decision-making strengthen memory encoding.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Computational Neuroscience

Background:

• Dopamine is implicated in reward processing and is hypothesized to influence memory.
• The precise role of reward prediction error signals in episodic memory formation remains unclear.

Purpose of the Study:

• To investigate how reward prediction errors impact episodic memory encoding.
• To differentiate the effects of prediction errors from surprise and uncertainty.
• To examine the temporal specificity and consolidation dependence of this influence.

Main Methods:

• An incidental memory paradigm involving gambling for rewards was employed.
• Participants encoded memoranda during periods of varying reward prediction error.
• Memory performance was assessed shortly after encoding and after a 24-hour delay.

Main Results:

• Incidental memory encoding was strengthened by gambling for rewards.
• The degree of encoding enhancement correlated with the magnitude of reward prediction error at the time of memoranda presentation.
• This enhancement was observed rapidly and did not significantly change after 24 hours, suggesting no dependence on memory consolidation.

Conclusions:

• Reward prediction error signals play a specific computational and temporal role in the formation of episodic memories.
• The findings highlight a direct link between reward-based learning signals and memory encoding mechanisms.