Impact of Phonological Awareness Intervention Combined with Transcranial Direct Current Stimulation on Rapid Automatized Naming and Verbal Short-Term Memory in developmental dyslexia: A Randomized Controlled Trial

This study has two main purposes: First, we are aiming to examine the efficacy of the phonological awareness intervention on rapid automatized naming and verbal short-term memory. Second, we are aiming to explore the efficacy of adjunctive transcranial direct current stimulation to further improve rapid automatized naming and verbal short-term memory.

Sham-control clinical trial, with parallel groups, double-blind, randomized, on 28 patients. The site (www.sealedenvelope.com) was used for randomization.

The study will be conducted in the rehabilitation clinic in Tehran individually for each client. Each client will participate in 15 treatment sessions. Both groups will receive phonological awareness therapy, but half will receive active electrical stimulation and the other half will receive sham stimulation. Clients, researcher, evaluator, and data analyst are blinded, and only the assisstant therapist will aware of the allocation of groups (double-blinding).

Inclusion criteria were: Persian native language, reading performance at least 1.5 standard deviations below the population mean, a non-verbal IQ score>85 , not having associated disorders or symptoms, absence of a non-compensated hearing loss, and being right-handed. Non-entry criteria included a history of a reading-related intervention, and the use of medication associated with central nervous system disorders.

1- active stimulation+phonological awareness 2- sham stimulation+phonological awareness

rapid automatized naming and verbal short term memory

A computer-based randomization approach was used (www.sealedenvelope.com) to randomly assigned participants to the study groups (active/sham). We included 28 participants and 4 blocks of the same size to create a random archive. A unique code generated by the software was given to participants to conceal the randomization process. These unique codes were used on the cubes representing the type of empirical groups; thus, participants will randomly assign to one of these groups.

None of the participants, nor the main therapist (researcher) (performing the phonological awareness training in both groups), and the evaluator (evaluating outcome measures at the 5 evaluation time points) will inform of about group allocations. A sealed opaque envelope approach will be used to conceal groupings. The assistant therapist will received the randomly created intervention assignments within the sealed opaque envelopes. After a participant entered the study, the envelope will be unsealed. Just the assistant therapist who set up the tDCS device will be informed of the about intervention allocation (active or sham). Moreover, the investigator who measured outcomes and conducted the analysis will be also blinded to group allocations.

Data is confidential