title: Modulation of linguistic prediction by TDCS of the right lateral cerebellum.
abstract: It has been postulated recently that the cerebellum contributes the same prediction and learning functions to linguistic processing as it does towards motor control. For example, repetitive TMS over posterior-lateral cerebellum caused a significant loss in predictive language processing, as assessed by the latency of saccades to target items of spoken sentences, using the Visual World task. We aimed to assess the polarity-specific effects of cerebellar TDCS, hypothesising that cathodal TDCS should impair linguistic prediction, and anodal TDCS facilitate it. Our design also tested whether TDCS modulated associative learning in this task. A between groups (sham, anodal, cathodal) design was used, with concurrent stimulation during performance of a manual variation of the Visual World paradigm, and with assessment of latency reduction over repeated presentations of the spoken sentences. Mixed model ANOVA was used to analyse change in response latency. Cathodal TDCS decreased participants' response time advantage for the predictable sentence items without change for non-predictable items, consistent with the previous TMS results. Furthermore, anodal stimulation enhanced the response time advantage for the predictable items, again without change in latencies for non-predictive items. We found a clear practice-based effect over 4 blocks. However, this difference was not significantly modulated by either anodal or cathodal stimulation. Our results therefore support the hypothesis that cerebellum contributes to predictive language processing, mirroring its predictive role in motor control, but we do not yet have evidence that the learning process was affected by cerebellar TDCS.
authors.affiliation: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK. Electronic address: r.c.miall@bham.ac.uk.
authors.forename: R C
authors.initials: RC
authors.lastname: Miall
authors.affiliation: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: J
authors.initials: J
authors.lastname: Antony
authors.affiliation: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: A
authors.initials: A
authors.lastname: Goldsmith-Sumner
authors.affiliation: Institute of Neurology, UCL, London, WC1N 3AR.
authors.forename: S R
authors.initials: SR
authors.lastname: Harding
authors.affiliation: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: C
authors.initials: C
authors.lastname: McGovern
authors.affiliation: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: J L
authors.initials: JL
authors.lastname: Winter
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002531:Cerebellum / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D065908:Transcranial Direct Current Stimulation; D014706:Verbal Learning / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology; D014825:Vocabulary; D055815:Young Adult
keywords: Cerebellum; Language; Learning; Prediction; Transcranial stimulation