Recent Publications
Quique, Y, Evans, WS and Dickey, MW. (2019). Acquisition & generalization responses in aphasia naming treatment: a meta-analysis of semantic feature analysis outcomes. American Journal of Speech-Language Pathology. Advance online advance publication. doi: 10.1044/2018_ajslp-17-0155
Evans, WS, Hula, WD, and Starns, J. (2019). Speed-Accuracy Tradeoffs and Adaptation Deficits in Aphasia: Finding the “Sweet Spot” Between Impulsive and Overly Cautious Responding. American Journal of Speech-Language Pathology. Advance online advance publication. doi:10.1044/2018_AJSLP-17-0156
Gravier, M. L., Dickey, MW, Hula, WD, Evans, WS, Owens, RL, Winans-Mitrik, RL, and Doyle, PJ: (2018). What Matters in Semantic Feature Analysis: Practice-Related Predictors of Treatment Response in Aphasia. American Journal of Speech-Language Pathology, 27(March), 438–453.
Evans, WS, Quimby, M, Dickey, MW, & Dickerson, BC. (2016). Relearning and Retaining Personally- Relevant Words using Computer-Based Flashcard Software in Primary Progressive Aphasia. Frontiers in Human Neuroscience, 10(November), 1–8.
Evans, WS, Caplan, D, Ostrowski, A, Michaud, J, Guarino, A, and Waters, G. 2015. Working memory and the revision of syntactic and discourse ambiguities. Canadian Journal of Experimental Psychology. Vol 69(1), 136-155.
Ongoing Research
Speed-accuracy tradeoffs and adaptation deficits in aphasia. People with aphasia (PWA) can experience large changes in their language abilities. Some PWA adapt well to these changes, while others do not, which can exacerbate their language deficits, or even create new maladaptive symptoms and behaviors. For example, when it comes to language processing speed, some PWA tend to respond impulsively, increasing the number of errors they make, while others tend to be overly conservation, spending much long than is necessary or helpful. In joint work with the Pittsburgh VA (PI: Evans), we are currently working on addressing this form of adaptation deficit by developing a new adaptive computer-based aphasia naming game designed help PWA more optimally balance the speed and accuracy of their performance during therapy. We predict that this will lead to improved treatment dosage and possibly generalize to functional communication.
Adaptive Scheduling and Stimuli Variability in Aphasia Treatment. Word-finding treatments for people with aphasia (PWA) often target treatment efficiency by training small sets of words in ways designed to improve production of both trained and related untrained words. Direct training effects tend to be large, but generalization to untrained words is much less consistent and effects tend to be smaller. Instead, we’re exploring a promising alternative in this pilot study: directly training a much larger set of words by adaptively scheduling how often individual words are practiced. Secondly, the language development literature has shown clear benefits of stimuli variability for the learning and generalization of new vocabulary and grammatical rules. However, most aphasia word-finding treatments involve practice naming a single picture exemplar, likely overtraining a stimulus-response mapping at the cost of treatment generalization. Therefore, we're also manipulating stimuli variability to see if presenting different versions and types of stimuli during treatment promotes improved word-finding for trained words in other contexts, such as discourse.
We believe the combination of stimuli variability and adaptive scheduling will help PWA regain many more words than is typical in current word-finding treatments, and will do so in ways that better generalize to real-world contexts. Finally, to help make this treatment accessible to clinicians and PWA, this project is using open-source flashcard software (Anki), which has been used successfully in the clinic (Evans et al., 2016) and is already freely available to the general public.
Strategy Training for People with Aphasia. Following stroke, many individuals present with both cognitive and language deficits. Research has shown that meta-cognitive strategy training can help stroke survivors compensate for cognitive deficits and improve functioning in activities of daily living. However, these techniques tend to rely heavily on language function, which can make them difficult for PWA to learn and employ independently. In joint work with colleagues from the Pitt Department of Occupational Therapy and UPMC (PI: Skidmore), we are working to pilot a modified meta-cognitive strategy training approach for PWA that incorporates supported communication techniques.
Dosage and Predictors of Naming Treatment Response in Aphasia. While semantically-oriented treatments have been shown to be effective for improving language function in aphasia, there is a great deal of variability in how individual PWA may respond to a given treatment. In joint work with the Pittsburgh VA (PIs: Dickey, Hula, and Doyle), we are working to identify neural, cognitive, and psycholinguistic factors that predict these differences in treatment outcome. As part of this project, work in our lab has focused on meta-analyses of existing case study work in the literature, and on analyzing how the type of semantic information (semantic features) activated during treatment affects treatment outcome.