L-Dopa improves learning and maintenance of new nouns in healthy adults

Abstract

Event Abstract Back to Event L-Dopa improves learning and maintenance of new nouns in healthy adults David Copland1*, Alana Campbell2, Alicia Rawlings3, Katie McMahon4, Peter Silburn5 and Pradeep Nathan6 1 The University of Queensland, UQ Centre for Clinical Research & School of Health and Rehabilitation Sciences, Australia 2 The University of Queensland, School of Health & Rehabilitation Sciences, Australia 3 The University of Queensland, UQ Centre for Clinical Research, Australia 4 The University of Queensland, Centre for Advanced Imaging, Australia 5 The University of Queensland, Asia Pacific Centre for Neuromodulation, Australia 6 Cambridge University, Psychiatry, United Kingdom Background: L-Dopa is a dopamine precursor that has been shown to improve implicit word learning in healthy adults. L-Dopa has also been shown to modulate semantic processing and enhance semantic salience, which may be of relevance to mechanisms of new word learning. The present study aimed to investigate whether augmenting brain dopamine levels with L-Dopa would enhance new word learning in healthy adults. We also sought to evaluate whether words paired with semantic information would be learnt more effectively than words paired with non-semantic information, and whether L-Dopa would enhance this process. Methods: 21 (12 female) healthy young adults participated in an initial word learning session. Prior to the learning session, each participant received either L-Dopa (as Madopar 125mg) or placebo in a double-blind randomised design. Participants learned written names for 20 pictures of novel aliens, with each name consisting of a legal nonword and either two adjectives (the semantic condition) or two uncommon surnames (the non-semantic condition). Written recall and multiple-choice recognition of the new names was tested periodically during the learning session, and at a follow-up session 7-10 days later. Results: Participants who had taken L-Dopa prior to learning exhibited higher recall accuracy during the learning session and at follow-up than those who had taken placebo. There was no influence of learning condition (Semantic or Non-Semantic) on recall accuracy at either timepoint. However, there was an influence of learning condition on recognition accuracy at the follow-up session, with the L-Dopa group displaying greater accuracy for stimuli in the semantic condition than the placebo group. This effect was not observed for stimuli in the non-semantic condition. Conclusions: L-Dopa improved the speed and success of new word learning, and also improved retention of the new words. The difference observed in recognition performance between the two groups at follow-up suggests that the influence of increased dopamine on the consolidation of new lexical representations is enhanced by semantic information during encoding. Keywords: Dopamine, Language, Memory, semantics, word learning Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Memory and Learning Citation: Copland D, Campbell A, Rawlings A, McMahon K, Silburn P and Nathan P (2015). L-Dopa improves learning and maintenance of new nouns in healthy adults. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00165 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Prof. David Copland, The University of Queensland, UQ Centre for Clinical Research & School of Health and Rehabilitation Sciences, Brisbane, Australia, d.copland@uq.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers David Copland Alana Campbell Alicia Rawlings Katie McMahon Peter Silburn Pradeep Nathan Google David Copland Alana Campbell Alicia Rawlings Katie McMahon Peter Silburn Pradeep Nathan Google Scholar David Copland Alana Campbell Alicia Rawlings Katie McMahon Peter Silburn Pradeep Nathan PubMed David Copland Alana Campbell Alicia Rawlings Katie McMahon Peter Silburn Pradeep Nathan Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.