Brain Stimulation With Combined Reading and Motor Training for Children With Dyslexia

Overview

This study examines whether combining non-invasive brain stimulation (tDCS) with an integrated reading-and-motor training program improves reading and phonological processing in 9-year-old boys with developmental dyslexia. Children with dyslexia often have difficulties in phonological awareness and fine motor skills. This study targets two brain areas at the same time: the left temporoparietal junction (important for reading and phonological processing) and the left primary motor cortex (important for hand movements and speech-related motor processes). Participants will be randomly assigned to one of eight groups. Some groups will receive active brain stimulation, and some will receive sham (inactive) stimulation, while also participating in different types of training: phonological awareness training, fine motor training, combined phonological and fine motor training, or no training. The treatment includes 20 sessions, three times per week for about 7 weeks. Reading and phonological skills will be measured before treatment, immediately after treatment, and again 3 months and 6 months later. The study will help determine whether a full treatment package-using brain stimulation together with combined reading and motor training-is more effective than single treatments or usual school education.

This is a randomized, double-blind, sham-controlled, 8-group component trial in 9-year-old boys with developmental dyslexia. The study tests a theory-driven prediction derived from multiple-deficit models of dyslexia: that simultaneously targeting reading-related and sensory-motor brain networks, while delivering an integrated phonological and fine motor intervention, produces greater and more durable reading improvement than single-component interventions. The tDCS protocol uses 1 mA current for 20 minutes per session over 20 sessions (3 sessions/week). Electrode montages are yoked to the type of cognitive intervention: left temporoparietal (TPJ) for phonological training, left primary motor cortex (M1) for motor training, and dual-site TPJ+M1 for the combined intervention. A tDCS-only group (M1 montage) is included to isolate the effect of motor cortex stimulation. Primary outcome: change in the composite score of Factor 1 of the Reading and Dyslexia Test (word reading, phoneme deletion, nonword reading, and word comprehension). Secondary outcomes: fine motor performance (BOT-2), rapid automatized naming, and text reading fluency. Assessments occur at baseline, immediately after the intervention, and at 3- and 6-month follow-ups.