Emily L Connally
Speech & Brain Research Group (Watkins Lab)
- Clarendon Scholar
- FMRIB Graduate Analysis Course Tutor
Developmental stuttering is the persistence of disruptions to the natural flow of speech which typically surface in early childhood. With particular focus on the motor system, I used a combination of behavioural and neuroimaging techniques to examine potential mechanisms contributing to or resulting from lifelong speech disruption. My primary interest was clarifying the role of subcortical structures and the cerebellum in stuttering. Further, I hoped to clarify whether the presumed motor disruption is domain general, or specific to the demands of speech. My secondary interest was in identifying subtypes of stuttering that could benefit therapeutic research and application.
Diffusion tensor imaging identified widespread disruption in stuttering, in the language and motor systems as well as the cerebellar peduncles. These disruptions surfaced bilaterally, including in probabilistic tracts of the arcuate fasciculus, a critical pathway for speech and language function. Unilateral disruption was observed in representation of the corticospinal/corticobulbar tracts as well (Connally Ward, Howell, & Watkins, Brain Lang. 2014 Apr;131:25-35).
Through use of resting state and event-related functional MRI related to speech production, one can dissociate activity related to general traits of developmental stuttering from that related to the specific states of dysfluent speech. Our recent publication in Human Brain Mapping used novel analytic methods to separate trait and state effects in fMRI BOLD activity during speech in stuttering individuals. In agreement with reports of correlations between basal ganglia activity and stuttering severity, and we observe altered subcortical activity during different states of fluency (fluent compared to dysfluent speech and fluent compared to dysfluent subgroups). Further, we observed bilaterally inferior frontal contributions to dysfluent speech states in stuttering.
I am currently examining the connectivity of the speech-motor system, the basal ganglia and cerebellum within the representations of "resting state networks" in stuttering and whether altered connections at rest predict dysfluent speech states.
My broader interests include neuropsychological assessment and development of diagnostic and therapeutic tools for better characterising disruption in disordered populations. To this end, the final study of my thesis combined aspects of traditional neuropsychological assessment, psychological assessment, speech assessment, and empirical tasks of motor learning. The aim of this study is to identify patterns of strengths and weaknesses in motor skills in people who stutter. The hope is that these "motor profiles" can be developed for clinical utility, including identification of subtypes of the disorder.