Title
Dopamine and Consolidation of Episodic Memory: Timing Is Everything
Abstract
Memory consolidation underpins adaptive behavior and dopaminergic networks may be critical for prolonged, selective information storage. To understand the time course of the dopaminergic contribution to memory consolidation in humans, here we investigate the effect of dopaminergic medication on recall and recognition in the short and longer term in Parkinson disease PD. Fifteen people with PD were each tested on or off dopaminergic medication during learning/early consolidation Day 1 and/or late consolidation Day 2. Fifteen age-matched healthy participants were tested only once. On Day 1 participants learned new information, and early episodic memory was tested after 30 min. Then on Day 2, recall and recognition were retested after a 24-hr delay. Participants on medication on Day 1 recalled less information at 30 min and 24 hr. In contrast, patients on medication on Day 2 8-24 hr after learning recalled more information at 24 hr than those off medication. Although recognition sensitivity was unaffected by medication, response bias was dependent on dopaminergic state: Medication during learning induced a more liberal bias 24 hr later, whereas patients off medication during learning were more conservative responders 24 hr later. We use computational modeling to propose possible mechanisms for this change in response bias. In summary, dopaminergic medication in PD patients during learning impairs early consolidation of episodic memory and makes delayed responses more liberal, but enhances late memory consolidation presumably through a dopamine-dependent consolidation pathway that may be active during sleep.
Year
DOI
Venue
2015
10.1162/jocn_a_00840
Journal of Cognitive Neuroscience
Field
DocType
Volume
Episodic memory,Response bias,Neuroscience,Memory consolidation,Dopaminergic,Psychology,Dopamine,Consolidation (soil),Adaptive behavior,Recall
Journal
27
Issue
ISSN
Citations 
10
0898-929X
1
PageRank 
References 
Authors
0.39
3
5
Name
Order
Citations
PageRank
John Grogan110.39
Rafal Bogacz216528.70
Demitra Tsivos310.39
Alan L Whone421.22
Elizabeth Coulthard5111.11