Enhancing speech fluency in people who stutter

Lead Research Organisation: University of Oxford
Department Name: Experimental Psychology

Abstract

Developmental stuttering (also known as stammering in the UK) affects one in twenty children and persists to adulthood in one in a hundred. People who stutter experience disruption to the normal flow of speech. They produce frequent repetitions or prolongations of sounds, syllables and words and frequent hesitations or pauses when speech can appear blocked. Children and adults who stutter can experience restrictions in their academic and career choices and some suffer from anxiety as a result of their speech difficulties. Fluency can be achieved temporarily by people who stutter by changing the way speech is produced, for example by singing, speaking with a different accent or in time with an external stimulus, such as a metronome or another speaker. Altering the auditory feedback associated with speech production can also be effective; for example, feedback that is noisy, or altered in pitch or time (delayed) can result in almost complete fluency in some people (as portrayed in the film The King's Speech). The effectiveness of altering auditory feedback in enhancing fluency suggests that stuttering may be caused by a problem in combining motor and auditory information.

In this research study, we will use speech therapy techniques that change the way speech is produced by people who stutter and improves their speech fluency. While people undergo this therapy, we will stimulate their brain with a weak electric current. This form of stimulation is painless and can improve the amount and rate at which new skills are learned. The therapy will take place over five days. Half of the people in the study will have therapy and stimulation, while the other half will have therapy and no stimulation. The participants and the researchers will not know who is having real stimulation and who is not. We will measure the effects of this therapy and stimulation by measuring rates of stuttering, speech naturalness and attitudes to stuttering before and after the five days of treatment.

We are also interested in understanding the brain abnormalities that cause stuttering. We will use MRI brain scans to measure how brain areas involved in producing speech (motor areas) and in monitoring speech (auditory areas) communicate with each other. We expect that the communication between the motor and auditory areas will improve as speech fluency improves. MRI scans give us very detailed pictures of the brain's anatomy and its function. It can also be used to see what is happening inside our mouths when we are speaking. We will develop new ways of using MRI to scan the mouth and vocal tract during fluent speech and during stuttering. This will provide us with new information about how people who stutter control their tongue and lips and other muscles involved in speech production. As speech fluency improves, we expect that we will see differences in the brain and vocal tract images, which will provide us with another way of measuring the outcome of the speech fluency and brain stimulation training.

MRI scans are very noisy and are not ideal for looking at the sensitivity of the brain areas involved in listening to speech. Also, speech is produced and understood extremely rapidly (10-12 speech sounds per second are typical in fluent speech). MRI cannot capture these rapid changes so it is necessary to use another brain imaging method called magnetoencephalography (MEG). MEG measures brain waves with very precise timing. In people who stutter, researchers have shown using MEG that speech production can alter auditory signals in the brain and that the timing of these signals is abnormal in people who stutter. We will also use MEG while people listen to and produce speech. We hope that this work will help us to understand how altering speech feedback can improve speech fluency. Such an understanding is critical for further development of effective therapies for stuttering.

Technical Summary

Developmental stuttering is a disorder affecting the fluency of speech, characterized by repetitions or prolongations of sounds and frequent hesitations or pauses. It affects 5% of children and persists to adulthood in about 1%. Changing the motor speech pattern in adults who stutter is a particular challenge for speech and language therapy and there is a need for novel interventions, therefore. One such intervention involves the application of transcranial direct current stimulation (TDCS) alongside speech therapy. TDCS influences brain activity by modulating neuronal plasticity through the application of weak electrical currents across the brain. Pairing TDCS with speech therapy has potential for producing larger or longer lasting effects and reducing time spent in therapy.

The first aim of our study is to evaluate the potential of TDCS combined with speech fluency training to improve outcomes in people who stutter (PWS). We will use techniques that alter speech motor patterns, typically by slowing the rate of speech while maintaining naturalness. PWS will have this training while receiving anodal TDCS over the left motor cortex for 5 days (1mA for 20 mins per day) in a double-blind randomized controlled trial. Outcomes will be measured in terms of changes to stuttering rates and naturalness ratings as well as attitudes to stuttering.

The second aim of our study is to understand how changes in sensorimotor interactions relate to changes in speech fluency in PWS. We will use MRI to measure brain structure and function during speech production. We will also image the vocal tract during fluent and dysfluent speech production and during speech motor learning. Magnetoencephalography (MEG) will provide detailed information on the timing of signals and sensorimotor interactions during speech in PWS. These studies will form additional outcome measures of the speech fluency training and brain stimulation in PWS.

Planned Impact

Who will benefit from this research? How will they benefit?
1. People who stutter
We believe that the main beneficiaries of this research will be our research participants i.e. people who stutter and their families. These are the ones who are likely to be most interested in the proposed research and its outcomes and potentially stand to benefit the most from it. In our experience, it is helpful for people who stutter to understand more about the brain abnormalities that are found in association with this disorder. We have consulted with groups previously in an informal way about using the term "abnormalities" to describe the differences we see in the brains of people who stutter compared to people who do not. We have been told that the term is not offensive to them and that they find it useful to tell other people that the reason they stutter is because they have a brain abnormality. There has been a tendency for individuals or their parents to be blamed for stuttering (due to a nervous disposition, for example). We expect that the participants in this study will be keen to disseminate the findings of our research to other interested parties who are similarly affected by developmental stuttering. In general, the study may increase public awareness of stuttering and its neural origins.

2. Speech and Language Therapy Community
The work proposed here will shed further light on the underlying brain abnormalities associated with the disorder. It may also inform our understanding of how fluency-enhancing techniques are effective in people who stutter and whether these temporary effects can be prolonged and enhanced for effective therapy. Such an understanding would be of interest to a wider group of beneficiaries, not just the individuals who stutter, but the therapists and clinical teams that work with people who stutter and others with communication difficulties. It is likely that a better understanding of stuttering and its therapy will impact the health and wellbeing, and ultimately the quality of life, of people who stutter. Long-term, the project may contribute to shaping health services for people with communication disorders. There is potential impact for this research to affect evidence-based policy, for example research and clinical policy generated by the Royal College of Speech and Language Therapists.

3. Private sector
The potential for increased understanding of the mechanisms underlying fluency enhancing techniques such as altered auditory feedback will be of interest to the commercial sector. For example, there are a number of devices and 'apps' that can deliver altered auditory feedback as a fluency aid to people who stutter.

4. British Stammering Association (charity)
As noted in the communication plan, we maintain strong links with the British Stammering Association, a charity that disseminates important information to children, parents, teachers and employers about people who stutter. This charity is therefore another likely beneficiary of this research and will aid dissemination of our work to the wider public where it may reach people who stutter who are not involved in the research. This dissemination may increase interest in the charity, which could in turn benefit from public donations.

Publications

10 25 50
 
Description ESRC/EPSRC Joint Funding for PhD Studentship
Amount £64,908 (GBP)
Funding ID ES/J500112/1 
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 10/2017 
End 09/2020
 
Description Guarantors of Brain Travel Grant - Charlotte Wiltshire
Amount £550 (GBP)
Organisation Guarantors of Brain 
Sector Charity/Non Profit
Country United Kingdom
Start 06/2019 
End 07/2019
 
Description Santander Travel Award - Charlie Wiltshire
Amount £250 (GBP)
Organisation Santander Universities 
Sector Private
Country United Kingdom
Start 08/2018 
End 08/2018
 
Description Structural and functional connectivity markers of developmental speech and language disorders
Amount $183,690 (USD)
Funding ID F32DC017637 
Organisation National Institutes of Health (NIH) 
Sector Public
Country United States
Start 03/2019 
End 02/2022
 
Description Collaboration with the Signal Analysis and Interpretation Lab (SAIL) laboratory at the University of Southern California. 
Organisation University of Southern California
Country United States 
Sector Academic/University 
PI Contribution Charlotte Wiltshire visited the University of Southern California (USC) for 6 weeks in order to set up a collaboration. She worked with the Speech and Articulation kNowledge (SPAN) lab and the Signal Analysis and Interpretation Lab (SAIL) who work together to pioneer vocal tract Magnetic Resonance Imaging (vtMRI). This collaboration speaks directly to her DPhil work which uses vtMRI to image the vocal tract in real time to assess the speech of people who stutter compared to fluent, typical speakers. The main aim for this visit was to work in collaboration with SPAN and SAIL researchers to create a tailored analysis pipeline for assessing our real-time speech images. This aim was achieved in addition to creating other exciting projects in collaboration with the team. During the visit, Charlotte presented at the SPAN/SAIL lab meeting. She also met with researchers who had created software for analysing vtMRI of speech. Over the 6 week visit, she mastered the skills needed for these analysis and identified ways they could be used to optimise the analysis of images of audibly fluent speech in people who stutter and controls. In addition, a collaboration was set up with Prof. Louis Goldstein to look at vocal tract images of stuttered speech. This project aims to apply prominent linguistic theories to the stuttered speech data. This collaboration is ongoing.
Collaborator Contribution The team at USC provided support in using their analysis techniques. Prof. Louis Goldstein offered his advice for a project investigating the movements of the articulators during stuttered speech.
Impact No outputs as yet. Data analysis is still ongoing.
Start Year 2018
 
Title INSTEP trial 
Description We are using non-invasive brain stimulation (transcranial direct current stimulation tDCS) concurrent with speech fluency training using metronome-timed speech in adult men who stutter. The intervention lasts for one-hour a day for five days during which the active group receive 20 minutes of 1mA current applied with the anode over the left motor cortex and the cathode over the right. We previously tested a similar intervention in an earlier trial funded by the MRC via a clinical training fellowship. 
Type Therapeutic Intervention - Psychological/Behavioural
Current Stage Of Development Refinement. Non-clinical
Year Development Stage Completed 2016
Development Status Under active development/distribution
Clinical Trial? Yes
Impact None 
URL https://clinicaltrials.gov/show/NCT03335722
 
Description BBC Breakfast science feature 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interview with Graeme Tatchell for an item on BBC Breakfast about the trial using brain stimulation in people who stutter. THe British Stammering Association discussed the item. Our participant described his personal story. This led to major coverage of the research and increased interest from the general public and led to an increase in the potential volunteers of the study. There was considerable discussion on social media also.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=VWAF9DFjI_c
 
Description Big Brain Roadshow 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact This is a recurring activity in which we go to schools with other researchers from our centre to discuss language and the brain. This has resulted in increased interest in the study and volunteers to participate.
Year(s) Of Engagement Activity 2018,2019
 
Description Birmingham event for people who stammer and SLTs 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Patients, carers and/or patient groups
Results and Impact Attendance at a Stammering event in Birmingham City University to disseminate information about the trial, study and to engage with potential participants.
Year(s) Of Engagement Activity 2018
 
Description Council for Allied Health Professions Research panel discussion 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Organised and contributed to panel discussion of routes into clinical academic research, and diversity of research opportunities. Engaged with a range of allied health professionals, who reported increased understanding of RCTs as well as potential of neuroscience research to inform practice.
Year(s) Of Engagement Activity 2019
 
Description Invited participation in Stammer Trust meeting/ open day 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Patients, carers and/or patient groups
Results and Impact Attended Stammer Trust open day/meeting, to speak informally about non-invasive brain stimulation research with people who stutter, and give clinical and research perspective on the charities plans for 2019/2020. As a result of the meeting, asked to become charity trustee, with focus on increasing research awareness of trustees and stakeholders, and increasing reach of the charity.
Year(s) Of Engagement Activity 2019
 
Description Invited presentation - National Dysfluency Clinical Excellence Network 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Research team member presented to 60 attendees (Speech and Language Therapists (SLT) specialising in dysfluency, SLT students (undergraduate and post-graduate level). Presentation covered the potential clinical application of non-invasive brain stimulation to clinical practice in SLT, including details of our past and current RCT.
Year(s) Of Engagement Activity 2019
 
Description Millfield School Psychology and Biology Day 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Keynote talk at the Millfield School annual Psychology and Biology Day. Attended by teachers and 6th form pupils from Millfield and schools in the local area (Somerset region). THere was social media coverage and lively discussion from the audience. Increased interest in language and the brain and improved awareness of the causes and possible treatments of developmental stuttering.
Year(s) Of Engagement Activity 2019
 
Description Newspaper article in Guardian 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact An article about our current research study was published in the Guardian newspaper on 25th January 2019 https://www.theguardian.com/science/2019/jan/25/electrical-stimulation-of-brain-trialled-as-aid-to-treating-stutter
This led to other stories in national newspapers https://www.dailymail.co.uk/sciencetech/article-6635153/Radical-new-trial-sees-people-stutter-given-electrical-brain-stimulation.html
and radio coverage (e.g Jack FM, Oxfordshire, BBC Radio 5).
It had the desired effect of promoting the research nationally and led to increased interest in the study and volunteers to participate.
Year(s) Of Engagement Activity 2019
URL https://www.theguardian.com/science/2019/jan/25/electrical-stimulation-of-brain-trialled-as-aid-to-t...
 
Description Participation in the British Stammering Association 2018 conference in Cardiff 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Supporters
Results and Impact Presentation on the research project at the biennial conference of the British Stammering Association in Cardiff September 2018. The talk was an informal presentation of what we understand regarding the neural basis of stuttering, what we found in our previous study of brain stimulation, and what is new in the current study underway. This engaged discussion with the audience members who were primarily people who stammer. It also resulted in increased interest in the study website and potential volunteers.
Year(s) Of Engagement Activity 2018
 
Description Presentation at Action for Stammering Children Charity 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Charlie Wiltshire presented to 20 speech language therapists from the Action for Stammering Children charity. She presented work on vocal tract imaging and functional brain imaging with people who stutter.
Year(s) Of Engagement Activity 2020
 
Description Presentation at American Speech and Hearing Association conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I gave a talk on out team's research on using transcranial direct current stimulation to increase speech fluency in people who stutter, to an international group of Speech and Language Therapists. This method, and research related to it, is familiar to many clinicians, so this was an important opportunity for research dissemination and discussion of clinical implications.
Year(s) Of Engagement Activity 2017
 
Description Presentation at South West Dysfluency Clinical Excellence Network 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact I was invited to talk to a group of Speech and Language Therapists about brain research in stuttering, and to report the outcomes of out first RCT using transcranial direct current stimulation to increase fluency in people who stutter. I also outlined our current project, which builds on and extends this work. It was a useful opportunity to discuss clinical implications with a group of professionals, and also to summarise research which SLTs tend to be unfamiliar with.
Year(s) Of Engagement Activity 2018
 
Description Radio interview for International Stammering Awareness Day 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The PI gave an interview to BBC Radio Oxford about the research study to promote International Stammering Awareness Day
Year(s) Of Engagement Activity 2018
URL https://www.psy.ox.ac.uk/news/kate-watkins-talks-to-bbc-radio-oxford-on-international-stammering-awa...
 
Description Research updates on team website - International Stammering Awareness Day 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Study participants or study members
Results and Impact Lay summaries and progress updates of the research carried out for the INSTEP trial. Written in order to engage with study participants and other interested parties.
Post was timed to co-ordinate with International Stammering Awareness Day 2019.
Year(s) Of Engagement Activity 2019
URL https://insteptrial.wordpress.com/2019/10/22/international-stammering-awareness-day-2019/
 
Description Talk (Action for Stammering Research Charity event, UCL) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact "Brain research with people who stammer", presentation and panellist, 30th anniversary event for the charity Action for Stammering Children, UCL, London, September 2019 (Facebook live event). Audience of about 50 people. But also broadcast on internet.
Year(s) Of Engagement Activity 2019
 
Description Talk and Q&A session at British Stammering Association Open Day 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I gave a talk about the brain basis of developmental stuttering and implications of stuttering therapy, including out team's research using non-invasive brain stimulation. This was followed by a Q&A session on the topic.
Year(s) Of Engagement Activity 2017
 
Description Talk to Speech and Language Therapists and Clinical Academics at Sheffield university 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact I talked about our first, and our current, research projects, in the context of the previous research showing that developmental stuttering has a neurobiological basis.
Year(s) Of Engagement Activity 2018
 
Description Talk to student SLTs Birmingham City University seminar series 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Undergraduate students
Results and Impact I gave a talk on the brain basis of stuttering, and how brain stimulation could be used as a therapeutic tool to support fluent speech.
Year(s) Of Engagement Activity 2018
 
Description Today Program for BBC Radio 4 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interviewed on Today program for BBC Radio 4 about our research using brain stimulation to enhance fluency in people who stutter. Included student who had helped with the research project. Resulted in several emails from members of the public afterwards.
Year(s) Of Engagement Activity 2019
 
Description podcast interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact I was interviewed on the the 'StutterTalk' podcast, which is non-profit organization based in the US. StutterTalk is the first and longest running podcast on stuttering, which reached 180 countries. The podcast interview focussed on the publication of the RCT outcomes, and aimed to be an accessible discussion of this work, and its implications for people who stutter.
Year(s) Of Engagement Activity 2018