title: The influence of event-related knowledge on verb-argument processing in aphasia.
abstract: Event-related conceptual knowledge outside the language system rapidly affects verb-argument processing in unimpaired adults (McRae and Matsuki, 2009). Some have argued that verb-argument processing is in fact reducible to the activation of such event-related knowledge. However, data favoring this conclusion have come primarily from college-aged healthy adults, for whom both linguistic and conceptual semantic processing is fast and automatic. This study examined the influence of event-related knowledge on verb-argument processing among adults with aphasia (n = 8) and older unimpaired controls (n = 60), in two self-paced reading studies. Participants read sentences containing a plausible verb-argument combination (Mary used a knife to chop the large carrots before dinner), a combination that violated event-related world knowledge (Mary used some bleach to clean the large carrots before dinner), or a combination that violated the verb's selectional restrictions (Mary used a pump to inflate the large carrots before dinner). The participants with aphasia naturally split into two groups: Group 1 (n = 4) had conceptual-semantic impairments (evidenced by poor performance on tasks like Pyramids & Palm Trees) but reasonably intact language processing (higher Western Aphasia Battery Aphasia Quotients), while Group 2 (n = 4) had intact conceptual semantics but poorer language processing. Older unimpaired controls and aphasic Group 1 showed rapid on-line disruption for sentences with selectional-restriction violations (SRVs) and event-related knowledge violations, and also showed SRV-specific penalties in sentence-final acceptability judgments (Experiment 1) and comprehension questions (Experiment 2). In contrast, Group 2 showed very few reliable differences across conditions in either on-line or off-line measures. This difference between aphasic groups suggests that verb-related information and event-related knowledge may be dissociated in aphasia. Furthermore, it suggests that intact language processing is more critical for successful verb-argument integration than intact access to event-related world knowledge. This pattern is unexpected if verb-argument processing is reducible to activation of event-related conceptual knowledge.
authors.affiliation: VA Pittsburgh Healthcare System, University Drive C, Pittsburgh, PA 15240, United States; Learning Research and Development Center, University of Pittsburgh, 3939 O'Hara Street, Pittsburgh, PA 15213, United States. Electronic address: mdickey@pitt.edu.
authors.forename: Michael Walsh
authors.initials: MW
authors.lastname: Dickey
authors.affiliation: Learning Research and Development Center, University of Pittsburgh, 3939 O'Hara Street, Pittsburgh, PA 15213, United States.
authors.forename: Tessa
authors.initials: T
authors.lastname: Warren
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001037:Aphasia / Q000523:psychology*; D032882:Comprehension; D005260:Female; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D011932:Reading; D012660:Semantics
keywords: Aphasia; Conceptual semantics; Language comprehension; Sentence processing