Treating Developmental Dyslexia Using tDCS

Authors

  • Timotej Savelli University of Ljubljana

Abstract

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique, increasingly used both as a research and therapeutic tool. Due to its ability to modulate synaptic connectivity and prime the brain for neuroplasticity, it is often used in combination with cognitive training [1]. Recently, several studies have demonstrated positive effects of an intervention combining tDCS and reading training on the reading skills of students with developmental dyslexia.

During the review of the currently published studies, we identified several weaknesses which we will attempt to address in our research. First, we will aim to improve the positioning of the electrodes by using computerized models of the current flow to choose the optimal location. Second, our intervention will target both processes related to serial phonological coding as well as whole-word recognition (meanwhile, the majority of previous studies only targeted the former processes). Our training will combine both the traditional evidence- based exercises with novel approaches, based on the latest neuroscientific findings. Aside from already explored improvements in reading speed and accuracy, we also aim to investigate practical outcomes of the intervention by assessing long-term progress in reading comprehension and several quality-of-life indices (including adaptive behaviour, academic success, motivation, and self-esteem). To our knowledge, this will also be the first randomized-control study, which will include two control groups (one receiving

sham stimulation and the other not receiving intervention at all).
The goal of our study is to investigate whether our intervention can serve as a useful technique for achieving long-term improvements in children and adolescents with developmental dyslexia. We will achieve that by comparing reading skills and quality of life indices at baseline with measurements taken 1 and 6 months after the intervention. Any improvements will be then contrasted to the progress of a control group which will not receive the intervention.

Furthermore, we are also interested in exploring why our intervention might help the readers. To answer this question, we will examine differences in cognitive processes before and after the intervention and check whether they can explain improvements in reading skills. Lastly, we aim to replicate findings from previous studies which demonstrate that tDCS optimizes the effects of cognitive training and therefore results in larger improvements than after training- only intervention. We will achieve this by comparing our experimental group with a second control group, which will receive training combined with sham stimulation.

References

[1] B. Krause and R. Cohen Kadosh, ‘Can transcranial electrical stimulation improve learning difficulties in atypical brain development? A future possibility for cognitive training’, Developmental Cognitive Neuroscience, vol. 6, pp. 176–194, Oct. 2013, doi: 10.1016/j.dcn.2013.04. 001.

Published

2022-06-23