Results of our first tDCS trial in stuttering

tDCS can improve speech fluency in people who stutter: A summary of our first randomised controlled trial

We completed our first randomised controlled trial investigating whether transcranial direct current stimulation (tDCS) in combination with fluency training can lead to lasting improvement in speech fluency for people who stutter. We found that tDCS coupled with fluency training improved speech fluency compared to the fluency training alone, which had no measurable effect. These results are currently being prepared for publication.

Thirty men with at least a moderate stutter took part in the trial. Half of them were randomly assigned to receive tDCS, with the remaining participants forming a control group who received ‘sham’ stimulation (which could not be distinguished from real tDCS). Real or sham tDCS was delivered while the participants spoke fluently with temporary fluency inducers for 20 minutes daily for five days. The temporary fluency inducers we used in this study were choral speech and metronome-timed speech.  When we measured stuttering 8 and 40 days later, we found that it was reduced in the group who had received real tDCS compared with the group who received sham tDCS.