Congratulations on the new grant! Can you tell us how the lab’s work will expand thanks to this new grant?

Our lab’s work has contributed to expanding our understanding of how brains look and function differently in children and adults who stutter when compared to speakers who don’t stutter. The findings have provided much needed information on how stutterers, as a group, differ from their peers. Put another way, our findings to date have provided valuable insights that we can look at as a whole and organize into an “average” stuttering brain. This helps us find general brain patterns that are shared between those who stutter. However, looking at the averages of a lot of individual brains means we miss out on the specific features of any one individual. Stuttering symptoms can look very different from person to person. This grant will allow us, for the first time, to look at individual brain connections. You can think of these connections as a fingerprint that is unique to an individual and can be easily identified and measured.

Will this new study differ from the studies the lab has done in the past? If so, how?

This new grant is expected to be a significant departure from our previous work, and a new direction in the field of stuttering. Past neuroimaging studies have focused on collecting small amounts of data across as many participants as possible. In this study, we will be applying a new approach that’s called precision functional mapping. This approach involves collecting a large amount of MRI data from each individual participant so that we can closely map out individual-specific brain connectivity patterns. We will also analyze how these individual-specific brain patterns are linked to speech, cognitive, and emotional factors that will be collected as part of the study.

In this study, there will be a focus on exploring inter-effector areas, or IEAs. Can you tell us more about these parts of the brain, and why they are important to study?

The inter-effector areas, or IEAs for short, are newly discovered regions in an area of the brain called the motor cortex. IEAs are between the effector specific areas of the brain that work together to control our tongues, hands, and feet for movement, an area that researchers call the “motor homunculus.” What’s interesting about these IEAs is that they are more active when we are planning to move than when we are actually moving. They have unique functions and are deeply connected to brain regions that help us with tasks like executive function, sensing the world around us, and planning to move our bodies. The IEAs are likely critical for supporting complex human actions, especially speech production (and by extension stuttering). This is because speech is the most complex motor skill that humans perform. Looking closely at the connections of the IEA regions in individual speakers who stutter is expected to lead to new insights on how these movement areas of the brain may be working differently in stuttering speakers.

As you mentioned, many stuttering studies have worked to collect data from lots of different people to identify brain patterns that all stutterers share. The big goal for this new study is to look more closely at individual-specific brain differences. What do you hope to learn by focusing so closely on individual brains?

By focusing on individual brains, we hope to gain a better understanding of the wide range of differences we see in stuttering severity, and also, the factors that make stuttering symptoms worse. Looking at individuals might also help us to identify if there are different “types” of stuttering occurring among stuttering speakers. We know that other conditions, like diabetes, can have different types. So, even though the condition is the same, the cause is a little different depending on what type you have. We hope to find out if the same can be true of stuttering. These efforts can help pave the way for treatments that are targeted toward individuals and more effective than the current treatment options that are available.

One of the new study’s goals is to use precision MRI mapping. How does this differ from other MRI studies our lab has done in the past or those done by other stuttering researchers? 

Previous MRI studies have collected scans from many different people in the hopes of finding brain similarities across different people who stutter. In this study, we will instead focus on collecting very detailed scans for each individual participant so that we can closely map out what makes their brain unique. 

Stuttering researchers across the globe have been working to understand what causes stuttering for a long time. Do you think these new studies will have any impacts on the field of stuttering research at large?

We expect that this research will allow, for the first time, a detailed investigation of individual brain organization and how it relates to individual differences we see in stuttering-related behavior. This includes types and frequency of stuttering disfluencies as well as the life impact of stuttering. This is an exciting new research area for the field.

Do you think these studies could bring us closer to effective stuttering treatments?

While there is still a lot of work ahead to understand what is happening in the brain to cause stuttering, we hope that future findings from this study will help guide the development of new treatments that are both effective and highly individualized. 

Are you recruiting for these studies right now? If someone is interested in participating in these studies, how can they get involved?

We will be recruiting for this study very soon. Participants will visit the lab for study activities and MRI sessions for a total of about 8 sessions. Our participants are paid for the time they spend in the study and travel support is available. For those interested in participating, they can contact us at cwsbrains@umich.edu for more information.