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

Haley C Dresang,Tessa Warren,William D Hula,Michael Walsh Dickey

doi:10.3389/fpsyg.2021.589930

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.

Highlights

The language-processing system has often been viewed as relatively static and context-invariant, by sentence comprehension models (e.g., Frazier, 1987; Bornkessel and Schlesewsky, 2006)
Our results are consistent with evidence supporting task-based rational adaptation, which contends that language users rely on the most informative source of knowledge to optimize their behavior on the task at hand (Anderson, 1991; Howes et al, 2009)
In contrast to previous investigations of rational adaptation in aphasia, this study examined stored knowledge of linguistic representations – stored knowledge of word co-occurrences – rather than bottom-up linguistic input, such as the literal sentence form (Gibson et al, 2015; Warren et al, 2017)

Summary

Introduction

The language-processing system has often been viewed as relatively static and context-invariant, by sentence comprehension models (e.g., Frazier, 1987; Bornkessel and Schlesewsky, 2006). There is growing evidence that the language system flexibly takes advantage of a wide array of sources of information to guide performance. These may include linguistic representations (grammatical categories, thematic roles, and lexical co-occurrence probabilities), contextual constraints, and knowledge of the relationships between words and real-world events (e.g., Caramazza and Zurif, 1976; McRae and Matsuki, 2009; Gibson et al, 2013; Kuperberg and Jaeger, 2016; Dresang et al, 2018). Reliance on these information sources is governed by the principle of rational adaptation (Anderson, 1991; Howes et al, 2009), which states that a system can modify the degree to which it relies on different information sources in order to optimize behavior under different experimental conditions (e.g., Gibson et al, 2013) or disease states (Caramazza and Zurif, 1976; Gibson et al, 2015; Warren et al, 2017).

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Conclusion