Leanne Shellshear1,2, Anna D MacDonald1, Jeffrey Mahoney1, Emma Finch2, Katie McMahon3, Peter Silburn1, Pradeep J Nathan4,5, David A Copland1,2. 1. UQ Centre for Clinical Research, The University of Queensland, Brisbane, Australia. 2. School of Health and Rehabilitation Sciences, Division of Speech Pathology, The University of Queensland, Brisbane, Australia. 3. UQ Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia. 4. Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Cambridge, UK. 5. School of Psychology and Psychiatry, Monash University, Melbourne, Australia.
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.
RCT Entities:
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.
Authors: Alexander V Lebedev; Jonna Nilsson; Joanna Lindström; William Fredborg; Ulrika Akenine; Carolina Hillilä; Pia Andersen; Gabriela Spulber; Elizabeth C M de Lange; Dirk-Jan van den Berg; Miia Kivipelto; Martin Lövdén Journal: Sci Rep Date: 2020-03-23 Impact factor: 4.379
Authors: Anthony J Angwin; Wayne J Wilson; Wendy L Arnott; Annabelle Signorini; Robert J Barry; David A Copland Journal: Sci Rep Date: 2017-10-12 Impact factor: 4.379
Authors: Pablo Ripollés; Laura Ferreri; Marta Valle; Jordi Riba; Antoni Rodriguez-Fornells; Ernest Mas-Herrero; Helena Alicart; Alba Gómez-Andrés; Josep Marco-Pallares; Rosa Maria Antonijoan; Toemme Noesselt Journal: Elife Date: 2018-08-30 Impact factor: 8.140