Sagarika Bhattacharjee1, Rajan Kashyap2, Beth Ann O'Brien3, Michael McCloskey4, Kenichi Oishi5, John E Desmond5, Brenda Rapp6, S H Annabel Chen7. 1. Psychology, School of Social Sciences, Nanyang Technological University, Singapore. 2. Centre for Research and Development in Learning (CRADLE), Singapore. 3. Centre for Research in Child Development (CRCD), National Institute of Education, Singapore. 4. Cognitive Science, Johns Hopkins University, Baltimore, United States. 5. The Johns Hopkins University School of Medicine, Baltimore, United States. 6. Cognitive Science, Johns Hopkins University, Baltimore, United States. Electronic address: brapp1@jhu.edu. 7. Psychology, School of Social Sciences, Nanyang Technological University, Singapore; Centre for Research and Development in Learning (CRADLE), Singapore; Lee Kong Chian School of Medicine (LKC Medicine), Nanyang Technological University, Singapore. Electronic address: annabelchen@ntu.edu.sg.
Abstract
INTRODUCTION: tDCS can modulate reading which is processed by lexical (ventral) and sub-lexical (dorsal) pathways. Previous research indicates that pathway recruitment in bilinguals depends on a script's orthographic depth and a reader's proficiency with it. The effect of tDCS on each reading pathway has not been investigated in bilinguals. We stimulated the left dorsal and ventral pathways separately in Chinese-English (C-E) bilinguals to understand whether pathway-specific modulation by tDCS is possible and, if so, how it is influenced by orthographic depth and script proficiency. METHODS: A double-blind, sham-controlled, within-subject experiment was designed wherein 16 balanced bilinguals received anodal tDCS in dorsal, ventral and sham sessions. Two tDCS montages of electrode sizes 5 × 5 cm2 with 1) anode at CP5 and cathode at CZ, and 2) anode at TP7 and cathode at nape of the neck, were applied for stimulating the dorsal and ventral pathways respectively. Bilinguals were asked to read word lists for each language before and after stimulation. RTs for accurate trials were analysed using linear mixed-effect modelling that included proficiency scores for reading English pseudo-words (PW) and Chinese pinyin. RESULTS: For both languages, word reading RTs were faster following dorsal pathway stimulation. The dorsal stimulation effect (change in RT) was negatively correlated with pseudoword reading and pinyin proficiency. Stimulation of the ventral pathway decreased RTs only for Chinese reading. CONCLUSION: Dorsal and ventral reading pathways can be selectively modulated by tDCS in bilingual readers with dorsal (sub-lexical) pathway stimulation affecting reading in both scripts and ventral (lexical) pathway stimulation selectively affecting Chinese reading. Dorsal pathway tDCS effects are modulated by sub-lexical reading proficiency.
INTRODUCTION: tDCS can modulate reading which is processed by lexical (ventral) and sub-lexical (dorsal) pathways. Previous research indicates that pathway recruitment in bilinguals depends on a script's orthographic depth and a reader's proficiency with it. The effect of tDCS on each reading pathway has not been investigated in bilinguals. We stimulated the left dorsal and ventral pathways separately in Chinese-English (C-E) bilinguals to understand whether pathway-specific modulation by tDCS is possible and, if so, how it is influenced by orthographic depth and script proficiency. METHODS: A double-blind, sham-controlled, within-subject experiment was designed wherein 16 balanced bilinguals received anodal tDCS in dorsal, ventral and sham sessions. Two tDCS montages of electrode sizes 5 × 5 cm2 with 1) anode at CP5 and cathode at CZ, and 2) anode at TP7 and cathode at nape of the neck, were applied for stimulating the dorsal and ventral pathways respectively. Bilinguals were asked to read word lists for each language before and after stimulation. RTs for accurate trials were analysed using linear mixed-effect modelling that included proficiency scores for reading English pseudo-words (PW) and Chinese pinyin. RESULTS: For both languages, word reading RTs were faster following dorsal pathway stimulation. The dorsal stimulation effect (change in RT) was negatively correlated with pseudoword reading and pinyin proficiency. Stimulation of the ventral pathway decreased RTs only for Chinese reading. CONCLUSION: Dorsal and ventral reading pathways can be selectively modulated by tDCS in bilingual readers with dorsal (sub-lexical) pathway stimulation affecting reading in both scripts and ventral (lexical) pathway stimulation selectively affecting Chinese reading. Dorsal pathway tDCS effects are modulated by sub-lexical reading proficiency.
Authors: Nasheed I Jamal; Ashley W Piche; Eileen M Napoliello; Charles A Perfetti; Guinevere F Eden Journal: Hum Brain Mapp Date: 2011-03-09 Impact factor: 5.038
Authors: Michael Russell; Theodore Goodman; Qiang Wang; Bennett Groshong; Bruce G Lyeth Journal: Front Psychiatry Date: 2014-08-15 Impact factor: 4.157
Authors: Sagarika Bhattacharjee; Rajan Kashyap; Alicia M Goodwill; Beth Ann O'Brien; Brenda Rapp; Kenichi Oishi; John E Desmond; S H Annabel Chen Journal: Brain Stimul Date: 2021-11-23 Impact factor: 9.184
Authors: Rajan Kashyap; Sagarika Bhattacharjee; Rose Dawn Bharath; Ganesan Venkatasubramanian; Kaviraja Udupa; Shahid Bashir; Kenichi Oishi; John E Desmond; S H Annabel Chen; Cuntai Guan Journal: Front Hum Neurosci Date: 2022-09-02 Impact factor: 3.473