An interventional study of Active transcranial direct current stimulation (tDCS) and Sham transcranial direct current stimulation (tDCS) in Developmental Dyslexia, sponsored by Shahid Beheshti University. Not yet recruiting at 1 site in Iran. Open to male participants aged 108 Months to 119 Months. Per ClinicalTrials.gov, last updated 2026-08-25.
Sponsored by Shahid Beheshti University · Not applicable, Interventional, and Treatment
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.
127 studies on the registry are indexed under Dyslexia; 27 are open to participants now.
This study's planned enrollment of 160 is above the median of 71 across 106 interventional studies indexed under Dyslexia.
Browse Dyslexia studies →Shahid Beheshti University is the lead sponsor of 37 studies on the registry; 3 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Sham tDCS randomly selected montage + usual school education, no cognitive training
Device: Sham transcranial direct current stimulation (tDCS) · Other: Usual school education
Sham tDCS TPJ + phonological awareness training
Device: Sham transcranial direct current stimulation (tDCS) · Behavioral: Phonological awareness training
Sham tDCS M1 + non-targeted fine motor training
Device: Sham transcranial direct current stimulation (tDCS) · Behavioral: Non-targeted fine motor training
Sham dual-channel TPJ+M1 + combined phonological and fine motor intervention
Device: Sham transcranial direct current stimulation (tDCS) · Behavioral: Integrated phonological and fine motor intervention
Active tDCS TPJ + phonological awareness training
Device: Active transcranial direct current stimulation (tDCS) · Behavioral: Phonological awareness training
Active tDCS M1 + non-targeted fine motor training
Device: Active transcranial direct current stimulation (tDCS) · Behavioral: Non-targeted fine motor training
Active dual-site TPJ+M1 + combined phonological and fine motor intervention
Device: Active transcranial direct current stimulation (tDCS) · Behavioral: Integrated phonological and fine motor intervention
Active tDCS M1 alone, no cognitive intervention
Device: Active transcranial direct current stimulation (tDCS)
Active tDCS will be delivered at 1 milliampere for 20 minutes per session, 20 sessions over about 7 weeks. The montage varies by arm: left temporoparietal (TPJ) montage, left primary motor cortex (M1) montage, or dual-site TPJ+M1 montage.
Also known as: tDCS
Sham tDCS will use the same electrode positions as the active groups, but the current will be applied for only 30 seconds and then gradually ramped down.
Also known as: Sham tDCS
20 sessions of 60 minutes each, three times per week for about 7 weeks. Covers syllable segmentation, rhyme, phoneme blending and segmentation, initial and final phoneme identification, phoneme manipulation, and grapheme-to-phoneme mapping.
Also known as: PA training
20 sessions of 60 minutes each, three times per week for about 7 weeks. Includes activities without linguistic content, such as free play with dough, bead threading, pegboard tasks, and other manual dexterity exercises.
Also known as: Fine motor training
20 sessions of 60 minutes each, three times per week for about 7 weeks. Combines phonological awareness training with targeted fine motor activities linked to reading, such as forming letters with dough and stringing beads marked with phonemes.
Also known as: Combined intervention
Participants receive the standard school curriculum without additional cognitive or motor training.
Composite score of Factor 1 of the Reading and Dyslexia Test (NAMA)
Composite score of Factor 1 of the Reading and Dyslexia Test, which includes word reading, phoneme deletion, nonword reading, and word comprehension subtests.
Time frame: Before intervention, immediately after the end of intervention, 3 months after intervention, and 6 months after intervention.
Fine motor performance (BOT-2 manual dexterity and upper-limb coordination)
Fine motor performance as measured by the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, manual dexterity and upper-limb coordination subtests. Raw scores of the common items will be used for longitudinal comparison.
Time frame: Before intervention, immediately after the end of intervention, 3 months after intervention, and 6 months after intervention.
Rapid automatized naming speed
Rapid automatized naming speed, including naming of objects, colors, numbers, and letters. The total time in seconds to name each card is recorded.
Time frame: Before intervention, immediately after the end of intervention, 3 months after intervention, and 6 months after intervention.
Text reading fluency (correct words per minute)
Text reading fluency defined as the number of correct words read per minute on a grade-level reading passage. Correct words per minute will be calculated as the total number of words minus errors, multiplied by 60, divided by the total reading time in seconds.
Time frame: Before intervention, immediately after the end of intervention, 3 months after intervention, and 6 months after intervention.
Plan to share: No — Individual participant data will not be shared due to confidentiality and ethical considerations related to minor participants. Sharing of participant-level data was not included in the informed consent or the study ethics approval. Only aggregate, deidentified results will be reported.
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Shahid Beheshti University