Neural mechanisms underlying improved new-word learning with high-density transcranial direct current stimulation

Article Article scientifique Article Neural mechanisms underlying improved new-word learning with high-density transcranial direct current stimulation eng 2024-05-16 2024-07-01 author Farcy Camille Sophie Eleonore Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Av. de Beau-Séjour 26, Geneva 1211, Switzerland. 948503 Département des neurosciences cliniques (OTONO) author Chauvigné Léa Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Av. de Beau-Séjour 26, Geneva 1211, Switzerland. 727551 author Laganaro Marina Neuropsycholinguistics Laboratory, University of Geneva, Geneva, Switzerland. 29851 Section de psychologie (PSICO) author Corre Marion Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Av. de Beau-Séjour 26, Geneva 1211, Switzerland. 833691 author Ptak Radek 0000-0003-4708-9201 Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Av. de Beau-Séjour 26, Geneva 1211, Switzerland. 128547 Département des neurosciences cliniques (OTONO) author Guggisberg Adrian 0000-0001-7178-7793 Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital of Geneva, Av. de Beau-Séjour 26, Geneva 1211, Switzerland; Universitäre Neurorehabilitation, Universitätsklinik für Neurologie, Inselspital, University Hospital of Berne, Berne 3010, Switzerland. Electronic address: aguggis@gmail.com. 707883 Département des neurosciences cliniques (OTONO) 120649 10.1016/j.neuroimage.2024.120649 38759354 1053-8119 https://www.sciencedirect.com/science/article/pii/S1053811924001447 Neurobehavioral studies have provided evidence for the effectiveness of anodal tDCS on language production, by stimulation of the left Inferior Frontal Gyrus (IFG) or of left Temporo-Parietal Junction (TPJ). However, tDCS is currently not used in clinical practice outside of trials, because behavioral effects have been inconsistent and underlying neural effects unclear. Here, we propose to elucidate the neural correlates of verb and noun learning and to determine if they can be modulated with anodal high-definition (HD) tDCS stimulation. Thirty-six neurotypical participants were randomly allocated to anodal HD-tDCS over either the left IFG, the left TPJ, or sham stimulation. On day one, participants performed a naming task (pre-test). On day two, participants underwent a new-word learning task with rare nouns and verbs concurrently to HD-tDCS for 20 min. The third day consisted of a post-test of naming performance. EEG was recorded at rest and during naming on each day. Verb learning was significantly facilitated by left IFG stimulation. HD-tDCS over the left IFG enhanced functional connectivity between the left IFG and TPJ and this correlated with improved learning. HD-tDCS over the left TPJ enabled stronger local activation of the stimulated area (as indexed by greater alpha and beta-band power decrease) during naming, but this did not translate into better learning. Thus, tDCS can induce local activation or modulation of network interactions. Only the enhancement of network interactions, but not the increase in local activation, leads to robust improvement of word learning. This emphasizes the need to develop new neuromodulation methods influencing network interactions. Our study suggests that this may be achieved through behavioral activation of one area and concomitant activation of another area with HD-tDCS. Functional connectivity (FC) Left inferior frontal gyrus (IFG) Left temporo-parietal junction (TPJ) New-word learning Transcranial direct current stimulation (tDCS) Humans Transcranial Direct Current Stimulation / methods Female Male Adult Young Adult Electroencephalography / methods Prefrontal Cortex / physiology Parietal Lobe / physiology Verbal Learning / physiology Temporal Lobe / physiology Learning / physiology Dewey 616.8 Dewey 150 Swiss National Science Foundation NCCR Evolving Language (phase I) 180888 CH Programmes 61 Département des neurosciences cliniques 226 108 Section de psychologie 71 false 567 Neuroréhabilitation et neuromodulation 910 NeuroImage 294 307bbdbd-518c-4080-8983-bd44a970adc3 Article (Published version) Public Farcy-tDCS_naming-NeuroImage_2024.pdf 3768608 application/pdf CC BY-4.0 44fc9a9702bebfbac242c1931d39b847ba7a188d593d91a7c74dbd2710687bfe openAccess Faculté de médecine / Section de médecine clinique / Département des neurosciences cliniques Faculté de psychologie et des sciences de l'éducation / Section de psychologie

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Neural mechanisms underlying improved new-word learning with high-density transcranial direct current stimulation	NeuroImage	2024	39	22
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