Levodopa enhances explicit new-word learning in healthy adults: a preliminary study

Shellshear, Leanne, MacDonald, Anna D., Mahoney, Jeffrey, Finch, Emma, McMahon, Katie, Silburn, Peter, Nathan, Pradeep J. and Copland, David A. (2015) Levodopa enhances explicit new-word learning in healthy adults: a preliminary study. Human Psychopharmacology, 30 5: 341-349. doi:10.1002/hup.2480


Author Shellshear, Leanne
MacDonald, Anna D.
Mahoney, Jeffrey
Finch, Emma
McMahon, Katie
Silburn, Peter
Nathan, Pradeep J.
Copland, David A.
Title Levodopa enhances explicit new-word learning in healthy adults: a preliminary study
Journal name Human Psychopharmacology   Check publisher's open access policy
ISSN 1099-1077
0885-6222
Publication date 2015
Year available 2015
Sub-type Article (original research)
DOI 10.1002/hup.2480
Open Access Status Not Open Access
Volume 30
Issue 5
Start page 341
End page 349
Total pages 9
Place of publication Chichester, West Sussex United Kingdom
Publisher John Wiley & Sons
Collection year 2016
Language eng
Formatted abstract
Objective
While the role of dopamine in modulating executive function, working memory and associative learning has been established; its role in word learning and language processing more generally is not clear. This preliminary study investigated the impact of increased synaptic dopamine levels on new-word learning ability in healthy young adults using an explicit learning paradigm.

Method
A double-blind, placebo-controlled, between-groups design was used. Participants completed five learning sessions over 1 week with levodopa or placebo administered at each session (five doses, 100 mg). Each session involved a study phase followed by a test phase. Test phases involved recall and recognition tests of the new (non-word) names previously paired with unfamiliar objects (half with semantic descriptions) during the study phase.

Results
The levodopa group showed superior recall accuracy for new words over five learning sessions compared with the placebo group and better recognition accuracy at a 1-month follow-up for words learnt with a semantic description.

Conclusions
These findings suggest that dopamine boosts initial lexical acquisition and enhances longer-term consolidation of words learnt with semantic information, consistent with dopaminergic enhancement of semantic salience.
Keyword Dopamine
Lexical acquisition
Language learning
Non-word
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Early View

 
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