Director: Kristie Spencer, Ph.D., CCC-SLP

We are interested in understanding the nature of neurogenic motor speech and cognitive disorders and how best to serve clients who experience these disorders.

Current projects include:

**An external aids treatment program for individuals with Parkinson Disease**  (Smasne, Spencer)

It is common for individuals with Parkinson’s Disease (PD) to experience changes to their cognitive functioning, even very early in the disease process. These changes often impact attention, memory, and executive functions (e.g., planning for the day, switching between tasks, etc.), and can reduce independence, increase caregiver strain, and make it difficult to accomplish everyday tasks. Several studies have attempted to address this issue by examining the effect of direct cognitive training in people with PD. Those studies often report successful outcomes, but the measures of success are predominantly formal paper-and-pencil or computerized tests. Little is known about whether improvement is seen in daily life, or with personally relevant goals. Also unknown is whether a different approach, namely one that provides compensatory cues to accomplish personal goals, would be beneficial.

There is a strong rationale for considering the compensatory cues route to support people with PD. Externally-provided compensatory cues, such as a daily schedule, an appointment reminder, or a checklist for a home project, are strategies that are commonplace for many people, with and without cognitive impairment. It is also well documented in the general literature on PD that “internal cues”, such as telling yourself to do a task a certain way, are often ineffective for people with PD. External cues, however, have been found to be very helpful for activities such as walking and writing. Yet there are no studies to date on using external cues to help alleviate the negative consequences of the cognitive changes experienced by many individuals with PD. Moreover, trainings focused on external cues have been proven successful for other clinical populations with cognitive impairment, such as people with traumatic brain injury or dementia.

This study is a novel, external cuing training program for a small group of individuals with Parkinson’s disease. Training goals are personally relevant to each participant and center on daily life activities. The outcomes of training focus on the extent that the personal goals were met, and the participant’s and caregiver's perspective of well-being, elicited via questionnaires. Outcomes will be measured immediately after the eight-week treatment, and 1-3 months post-training.

It is hypothesized that positive training effects will be demonstrated and maintained for the personalized primary outcome measure of Goal Attainment Scaling, with notable changes observed in secondary outcome measures. The untreated “control” goal should remain unchanged.

**Perceptual Classification of Adults with Ataxic Dysarthria**  (Dawson, Spencer)

Dysarthria is one of the most common manifestations of hereditary and sporadic forms of ataxia. This impairment, known specifically as ataxic dysarthria, can impact many aspects of speech, including articulation, respiration, phonation, and prosody. Dysarthria often causes difficulty with daily communication and decreased participation in employment and activities, leading to reduced well-being and social connectedness. Despite the high prevalence of dysarthria in people with ataxia, this speech disorder is not fully understood. Ataxic dysarthria can present with considerable variation of symptoms; this heterogeneity brings into question whether it is a single entity. Subgroups of ataxic dysarthria have been postulated, but remain vague and unspecified. One theory is that subgroups could reflect the degree to which instability versus inflexibility of motor control predominates.

Our preliminary study (Spencer & France, 2016) examined the concepts of instability and inflexibility in pre-recorded speech samples of individuals with ataxic dysarthria, and piloted a perceptual method for differentiating the putative subgroups. Results suggested that speakers with ataxic dysarthria present with speech characteristics that cluster toward a pattern of instability, inflexibility, or a combination of the two subgroup profiles. Experienced speech–language pathologists were able to identify perceptual speech characteristics with sufficient reliability to differentiate these subgroups. To build on this innovative line of research, a follow-up study is being conducted to (1) extend to a larger group of (actual) speakers with ataxic dysarthria, (2) employ sufficient sampling across speech tasks, (3) refine the perceptual rating system to capture both severity and a quantitative metric of instability/inflexibility, and (4) use expert listeners to ensure fine-tuned perceptual analysis and to facilitate intra- and inter-rater reliability.

Participants with a speech diagnosis of ataxic dysarthria from hereditary and sporadic forms of ataxia are currently being recruited. Speech samples include a one minute monologue and speech diadochokinetics. Perceptual ratings of the speech samples will be performed independently by internationally recognized dysarthria experts.

Identifying potential subgroups for this dysarthria is important for several reasons. First, it would facilitate differential speech diagnosis which is significant as dysarthria can be the initial symptom of cerebellar degeneration. Second, it would lead to more refined selection of participants for research on ataxic dysarthria. Third, treatment for ataxic dysarthria would be enhanced as it could be tailored to reflect the underlying source of the impaired speech pattern. Finally, identification of subgroups could inform theoretical and clinical models of cerebellar functioning and disease.

**The Link Between Motor Speech Function and Cognition in Individuals with Parkinson's Disease** (Brown, Spencer)

Upcoming study!

Cognitive and speech impairments from Parkinson's disease are common and debilitating. Research suggests associations between the extent/rate of cognitive decline and specific motor manifestation of PD. However, little is known about the potential link between motor speech dysfunction and cognitive decline.

**Nature and Laterality of Motor Symptoms in Parkinson’s Disease and Relationship to Cognitive Profile** (Hutchison, Spencer, Peters, et al.)

The purpose of this study was to determine the relationship between cognitive profile and the nature/laterality of initial motor symptoms in Parkinson’s disease (PD). Research suggests that initial onset of tremor is linked to better cognitive performance than initial onset of bradykinesia or rigidity, while studies of the laterality of symptom onset have been inconclusive. Very few investigations have considered the interaction of nature and laterality of symptoms in individuals with PD and the association with cognitive functioning.

Participants with PD (N=272) were divided into subgroups based on nature and laterality of symptom onset: left bradykinesia/rigidity onset (L-B/R), left tremor onset (L-Tr), right bradykinesia/rigidity onset (R-B/R), and right tremor onset (R-Tr). Participants completed a neuropsychological test battery assessing memory, attention, visuospatial function, executive functions, and language. Subgroups were equivalent with respect to sex, years of education, disease duration and disease severity. Multimodal, multivariate logistic regression was used to compare the right tremor onset group (R-Tr) to the three other subgroups.

Significant differences between the R-Tr subgroup and the other three subgroups emerged (overall p = .0069). Predictors for R-Tr membership were higher depression scores and later disease onset, compared to the R-B/R group; higher verbal learning scores, compared to the L-Tr group; and lower scores on a general measure of cognitive function, compared to the L-B/R group.

The results of the current study reinforced the findings of Katzen et al. (2006) that laterality and nature must be considered in combination to unveil the link between cognitive profile and initial motor symptoms. However, while Katzen and colleagues reported that the R-Tr subgroup performed better than other subgroups and similarly to healthy controls, the current study found that subgroup predictors varied by cognitive domain.