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Review Article

Transcranial magnetic stimulation research

on reading and dyslexia: a new clinical

intervention technique for treating dyslexia?

Maurits van den Noort , Esli Struys , Peggy Bosch 2,3,4
1,2
1
1 Department of Linguistics, Vrije Universiteit Brussel, 1050 Brussels, Belgium.
2 Research Group of Pain and Neuroscience, Kyung Hee University, Seoul 130‑701, South Korea.
3 Centre for Cognition, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6500 GL Nijmegen,
Gelderland, the Netherlands.
4 Psychiatric Research Institute, LVR‑Klinik Bedburg‑Hau, 47551 Bedburg‑Hau, Germany.

ABSTRA CT

Nowadays, several noninvasive neuroimaging techniques, including transcranial magnetic stimulation (TMS), exist. The working
mechanism behind TMS is a rapidly changing magnetic field that generates an electric current via electromagnetic induction.
When the coil is placed on the scalp, the magnetic field generates a physiological reaction in the underlying neural tissue. The
TMS‑induced change in the participant’s behavior is used by researchers to investigate the causal relations between specific brain
areas and cognitive functions such as language. A variant of TMS has been developed, which is called rapid‑rate TMS (rTMS). In
this review, three databases (Medline, Educational Resources Information Center, and Scopus) were searched for rTMS studies
on normal reading and dyslexia with a cut‑off date of October 31, 2014. rTMS was found to be a valuable tool for investigating
questions related to reading research, both on the word and the sentence level. Moreover, it can be successfully used in research on
dyslexia. Recently, (high‑frequency) rTMS has been used as a “clinical” intervention technique for treating dyslexia and for improving
reading performance by exciting underactive reading pathways in the brain. Finally, we end the paper with a discussion of future
directions in the field of rTMS research and dyslexia, for instance, the promising prospect of combining TMS with simultaneous
electroencephalographic imaging.
Key words: Clinical intervention, dyslexia, sentence reading, transcranial magnetic stimulation, word reading

INTRODUCTION neural computation being performed, often leading to
longer reaction times or higher error rates. [2]
Transcranial magnetic stimulation
Nowadays, (cognitive) neuroscientists can choose from As early as 1985, the first successful TMS study on
several noninvasive neuroimaging techniques, and one human participants was conducted by Barker et al.
[5]
of them is transcranial magnetic stimulation (TMS). The authors described the use of a pulsed magnetic
The working mechanism behind TMS is a rapidly field focused over specific regions of the cerebral
changing magnetic field that generates an electric cortex to induce muscle action potentials (see also the
current via electromagnetic induction. When the coil publication by Barker et al. later that year). In fact,
[1]
[6]
is placed on the scalp, the magnetic field generates their pioneering study turned out to be the beginning
a physiological reaction in the underlying neural of a whole new research field. This TMS-induced
[2]
tissue, which can be a spiking and/or a depolarizing change in the participant’s behavior is an interesting
reaction, [3,4] and specific or general areas of the brain opportunity for researchers to study the causal
can be affected. Transient noise is introduced into the relations between specific brain regions and cognitive
functions. [7]
Access this article online
Quick Response Code: Rapid‑rate transcranial magnetic stimulation
Website: Later, a variant of TMS was developed, which is called
www.nnjournal.net
rapid-rate TMS (rTMS). [8,9] Further improvements of the
DOI: stimulators, which are now able to provide discharges
10.4103/2347-8659.157967 at frequencies of up to 60 Hz, have greatly increased
the value of TMS as a tool in cognitive neuroscience

Corresponding Author: Dr. Maurits van den Noort, Department of Linguistics, Vrije Universiteit Brussel, Pleinlaan 2, 1050
Brussels, Belgium. E‑mail: info@mauritsvandennoort.com

PB Neuroimmunol Neuroinflammation | Volume 2 | Issue 3 | July 15, 2015 Neuroimmunol Neuroinflammation | Volume 2 | Issue 3 | July 15, 2015 145