Motor control (in particular, motor speech disorders and apraxia)
Psychosocial impact of (communication) disability in neurological illness
Bilingualism (in particular, neurolinguistic aspects)
My main areas of research come under the general label of neurogenic speech disorders – i.e. disruptions to speech associated with neurological illness or damage to the brain from whatever cause – e.g. Parkinson’s disease, stroke, head injury, developmental conditions such as cerebral palsy.
I am interested in the changes to voice, speech and swallowing that arise as a result of neurological illness and the effects these changes have on the life of the person who has a neurological condition and the effects on their family and social life. I am interested in how to accurately describe changes and what methods there are to ameliorate and overcome the effects of living with a motor speech disorder.
Broadly speaking my work takes three perspectives:
1) A theoretical perspective: looking at data from the ways in which speech control changes in neurological conditions to tell us about how the brain plans and executes speech motor control and how this relates to language processing on the one hand and more general movement planning and control on the other.
2) An applied perspective: seeking ways in which theoretical constructs and advances and results from the first perspective can be gainfully applied to clinical assessment in neurological conditions and to rehabilitation of changes that affect the individual.
3) A social psychological perspective: looking at how voice and speech changes impact on the self concept and social life of the person with a motor speech disorder and on their family.
Here are some areas in which I have focused my work:
1) Communication changes in Parkinson's Disease.
I have led collaborations over several years with neurology, health care of the elderly, physiotherapy, health service research and speech scientists colleagues in Newcastle and Northumbria Universities, in GB, and in the university of Tuebingen, Germany. We began by investigating the prevalence, nature and psychosocial impact of speech, voice and swallowing changes in Parkinson's disease, with a special emphasis on the perspective of the speaker. The results have allowed us to progress to looking at issues of differential diagnosis and rehabilitation and how the picture alters over time in relation to all the other changes happening in Parkinson’s.
Regarding differential diagnosis we have examined speech voice and language changes in Parkinson's disease compared with progressive supranuclear palsy and multiple system atrophy with prominent parkinsonism.
We have recently completed the first detailed national survey of the views of people with Parkinson's and speech language therapists who support them on the nature of communication changes and what is/ is not done or could be done regarding rehabilitation.
Together with the results from our nature and psychosocial impact work, this will form the basis for large scale evaluations of different therapy interventions.
We have also conducted or have in progress studies examining:
-Effects of medication and surgery on speech and voice
-Longitudinal change in speech, voice and swallowing and the relationship of speech and swallowing changes to motor and other cognitive changes.
-Impact of swallowing changes from the perspective of the person with Parkinson’s
-Impact of, control and rehabilitation of drooling in Parkinson’s
-Measurement of laryngeal tremor in Parkinson’s (PhD student)
-Relationship between Parkinson’s and depression in influencing speech changes (PhD student)
Our research team has input to a project in Tanzania, examining speech, voice and swallowing changes in people with Parkinson's disease and in developing Swahili language assessments for diagnosis and monitoring of change in Parkinson's disease.
2) Apraxia of speech
Another strand of research concerns the nature of apraxia of speech, addressing issues of theory (e.g. what is apraxia precisely? what has broken down? what models of speech output best account for clinical findings?) and clinical issues (how does one recognise apraxia of speech, how does one assess it, what should the targets of treatment be?).
Within this context we recently completed a project investigating the effects of phonological neighbourhood density (how many neighbours a word has by changing just one sound – cat has many neighbours - cot, kit, catch etc; elf has few) and phonotactic predictability (the frequency of different sound sequences in a language; e.g. in English the sequence sp- is frequent but sf- infrequent) in acquired speech output disturbances.
Other current work in the area of apraxia of speech involves cooperation with colleagues in Aachen, Germany, using neural net modelling of speech motor control to create virtual 'patients' in order to gain insights into underlying impairments in apraxia of speech.
3) Foreign Accent syndrome
Related to the work in apraxia of speech I have an interest in foreign accent syndrome which I have pursued with colleagues in Glasgow and Oxford. We have been looking at what is the nature of the underlying cause, what makes foreign accent foreign, and how does this impact on the individual speaker.
4) Cerebral palsy
I collaborate on projects led by my colleague Dr Lindsay Pennington in Child Health (www.ncl.ac.uk/ihs/people/profile/lindsay.pennington) in Newcastle, on a series of studies, looking at intensive speech therapy for teenagers and younger people with cerebral palsy. Together with our colleague Eftychia Eftychiou, University of London, we are also conducting more detailed analyses of the relationship between perceptual and acoustic measures of speech and voice change in cerebral palsy.
5) Bilingual and cross language studies
I have a longstanding interest in how the brain manages with two or more languages, and more specifically what happens to the different languages in neurological illness. I have also used cross language studies of language and speech breakdown to address issues in the organisation and control of language and speech in the brain, again with an emphasis on using outcomes to inform clinical assessment and treatment questions. Current and recently completed studies in this field cover projects with colleagues in the Netherlands and Germany looking at naming in bilingual speakers with Alzheimer's dementia; voice fundamental frequency differences across a bilingual speaker's different languages; a comparison of speech apraxic errors in German and English.
Our research on these projects has been generously supported by the NIHR and Parkinson's UK, British Academy, Association of Commonwealth Universities, Rhoda Lockhart Trust and Grace Patching Trust; Cerebra UK, Children's Foundation and Remedi.
Nick Miller PhD, FRCSLT is the programme director for the BSc honours in Speech Language Sciences
Main teaching areas: Undergraduate
Acquired motor speech disorders
Research methods and statistics
BSc dissertation supervision
Motor speech disorders
Memory and cognition
Clinical case studies
Supervision of MSc, MPhil and PhD dissertations