Reading and phonological awareness improvement accomplished by transcranial direct current stimulation combined with phonological awareness training: A randomized controlled trial

Abstract

Phonological awareness (PA) training is a core intervention in dyslexia. Recently, transcranial direct current stimulation (tDCS) has been probed as a complementary intervention for increasing reading ability in dyslexia, but not for enhancing the efficacy of PA. The aim of the current study was thus to examine whether tDCS combined with a PA intervention improves reading, but also PA abilities as a proxy in children with dyslexia. A randomized, double-blind, sham-controlled clinical trial was performed to assess the effects of tDCS (applied bilaterally over the temporo-parietal junction with the anode placed over the left, and the cathode placed over the right hemisphere) combined with PA training on reading and PA abilities in dyslexic patients. Twenty-eight participants were randomly assigned to active (PA + anodal tDCS) or sham (PA + sham tDCS) groups. Each subject participated in 15 treatment sessions. PA and real/non-word reading were evaluated at baseline before the intervention, at the end of the fifth, tenth, and final intervention sessions, and then 6 weeks after intervention. In the active tDCS group, the mean scores of non-word reading and PA tests were significantly improved during, immediately, and 6 weeks after the treatment, as compared to the sham tDCS group. tDCS is thus a promising complementary intervention if combined with PA training to enhance PA and reading abilities in dyslexia for an extended period after treatment.

Keywords:

• Dyslexia
• grapheme to phoneme correspondence
• phonological awareness
• transcranial direct current stimulation

Acknowledgments

We would like to thank all the participants who took part in this study, the Iran University of Medical Sciences, and the Iran National Science Foundation (INSF) under project number 99032245 for supporting this study.

Disclosure statement

MAN is a member of the scientific advisory boards of Neuroelectrics and NeuroDevice. The other authors declare that they have no competing interests.

Data availability statement

The data presented in this study are available on request from the corresponding author.

Additional information

Funding

Iran University of Medical Sciences and Iran National Science Foundation (INSF) under project number 99032245 funded this study.