Speaker: Aya Meltzer-Asscher (Northwestern University)
Title: Training verb argument structure production in agrammatic aphasia: Behavioral and neural recovery patterns
Time: Thursday, Sept. 15, 12:30-1:45p
Location: 32-D461
Many individuals with agrammatic aphasia have difficulty producing verbs. However, relatively little is known about the effects of treatment for this deficit, with most research in the area examining semantic or phonological cueing approaches, adopted from object naming treatments. Interestingly, although such treatments generally improve production of trained verbs, they result in little to no generalization to untrained verbs.
The current study examines the effects of treatment focused on argument mapping in sentence contexts. Based on previous studies showing a complexity effect in treatment, three-argument verbs were trained, and generalization to two- and one-argument verbs was tested, in both action naming and sentence production. In addition, the study addressed the neural substrates of treatment effects using functional magnetic resonance imaging (fMRI) during verb naming pre- and post-treatment.
In the behavioral portion of the study, we found successful learning of three-argument verbs, as well as generalization to untrained verbs with simpler argument structures, in all participants who received treatment. Significant differences between treated and control participants were found in both constrained verb production and sentence production. Treated participants also showed improved verb production in spontaneous speech. As for the neural activation patterns associated with recovery, post- compared to pre-treatment fMRI scans revealed upregulation in cortical regions implicated for verb and argument structure processing in healthy controls.
We conclude that treatment for verb deficits incorporating thematic role mapping is effective for improving both verb and sentence production and results in recruitment of brain regions engaged for verb and argument structure processing in healthy individuals. Further, the finding that training verbs with complex argument structure results in generalization to verbs of lesser complexity reinforces the tenet that treatment of more complex language structures promotes generalization to less complex, linguistically related, structures (Thompson, Shapiro, Kiran, & Sobecks, 2003).