Rational Adaptation in Using Conceptual Versus Lexical Information in Adults With Aphasia

Abstract

The information theoretic principle of rational adaptation predicts that individuals with aphasia adapt to their language impairments by relying more heavily on comparatively unimpaired non-linguistic knowledge to communicate. This prediction was examined by assessing the extent to which adults with chronic aphasia due to left-hemisphere stroke rely more on conceptual rather than lexical information during verb retrieval, as compared to age-matched neurotypical controls. A primed verb naming task examined the degree of facilitation each participant group received from either conceptual event-related or lexical collocate cues, compared to unrelated baseline cues. The results provide evidence that adults with aphasia received amplified facilitation from conceptual cues compared to controls, whereas healthy controls received greater facilitation from lexical cues. This indicates that adaptation to alternative and relatively unimpaired information may facilitate successful word retrieval in aphasia. Implications for models of rational adaptation and clinical neurorehabilitation are discussed.

Shared and distinct routes in speech and gesture imitation: Evidence from stroke

“…Although we controlled for overall aphasia severity, it is unclear whether the benefit of lexical input in gesture tasks may be conditioned by the degree to which individuals also have language comprehension deficits. Future research may investigate whether apraxic deficits are analogous to findings from aphasic verb production studies, which suggest that compared to neurotypical controls, individuals with LCVA may adapt to their impairments by relying more on semantic than lexical cues (Dresang et al, 2021). Taken together, our primary set of findings showed that semantic but not lexical information conferred benefits for gesture imitation for patients with chronic LCVA.…”

The use of linguistic and world knowledge in language processing

“…There is a history of work suggesting that this may be the case (e.g., Caramazza & Zurif, 1976;Gibson et al, 2015;Warren et al, 2017). A recent study by Dresang et al (2021) looked for evidence of this tradeoff, building from Willits et al's (2015) finding that young unimpaired adults showed sensitivity to lexical cooccurrence rather than event relatedness in primed naming. Dresang et al compared the degree to which verb naming was primed by nouns that either (a) frequently co-occur with the verb or (b) are paradigmatic participants in the event denoted by the verb, contrasting the performance of people with aphasia and age-matched controls without impairments.…”

“…Although there are clear cases of purely linguistic knowledge and purely world knowledge, and there is clear evidence that each can independently affect language processing (e.g., Dresang et al, 2021), there are also cases in which it seems likely that linguistic and world knowledge might be intertwined. For example, as we previously noted, claims in favour of purely abstract linguistically rooted semantic abstractions have been challenged by findings that thematic role knowledge seems to be interwoven with conceptual knowledge of events (e.g., Ferretti et al, 2001;McRae et al, 1997;McRae et al, 2005).…”