New Project: Cognitive Flexibility and Stuttering

This study is available in German and English. 

If you would like to take part in the German version, please email

What are the aims of the study? 

Sometimes people who stutter are aware of upcoming words that may result in dysfluencies and, in order to conceal their stutter, may choose to use strategies, such as replacing those words on-the-fly. 

This process might rely on “proactive control” – i.e. the ability to prepare for upcoming conflicts and react to them. People who use these strategies often may have developed skills in proactive control more generally. Concealing a stutter may also lead to increased negative consequences, such as distress – see this recent study. 

Our aim is to understand these processes better. 

Who can take part? 

Anyone who does, or does not stutter, can take part. If you identify as someone who stutters you can take part - there are no restrictions on the frequency of stuttering or whether you stutter more overtly or covertly (i.e. "hidden" or "concealed" stuttering). 

Anyone between the ages of 18 and 50 years old can take part. We have to set a cut off at 50 because some of the tasks rely on reaction times and these can change after the age of 50. We do apologise for this and we always aim to make our studies as inclusive as possible. Future research that does not rely on reaction times will be open to everyone!

Anyone who can give informed consent in English or German can take part. The information about the study and the instructions are written in German or English so participants should have good knowledge of one of these languages. 

What will happen during the experiment? 

As a first step, we are using computer-based tasks as well as questionnaires that can be done online at home. 

All the tasks involve button presses in response to information displayed on the screen. 

The study is run on – a website specially designed for online research. 

The study takes ~25 minutes for people who do not stutter and ~45 minutes for people who stutter (due to additional questions about stuttering). 

Participants can opt in to a prize draw for a (£/€ 20) shopping voucher.

Study overview: This study contains questionnaires and tasks. It takes about 45 minutes to complete

The research will be run by Dr. Charlie Wiltshire in affiliation with Ludwig-Maximilians-University, Munich, Germany and Bangor University, Wales. A group of people who stutter helped us to develop the aims and methods of this study. I am grateful to them for their contributions, which definitely improved the study! If you are interested in contributing to the development of our research in the future, you can get in touch at

Click the appropriate link below to go to the experiment page

More information will be given at the beginning of the study