Effect of Lexical-Semantic Cues during Real-Time Sentence Processing in Aphasia.

Niloofar Akhavan,Michelle Gravier,Noelle Abbott,Carolyn Baker,Tracy Love,Christina Sen

doi:10.3390/brainsci12030312

Niloofar Akhavan, Michelle Gravier + Show 4 more

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https://doi.org/10.3390/brainsci12030312

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Abstract

Using a visual world eye-tracking paradigm, we investigated the real-time auditory sentence processing of neurologically unimpaired listeners and individuals with aphasia. We examined whether lexical-semantic cues provided as adjectives of a target noun modulate the encoding and retrieval dynamics of a noun phrase during the processing of complex, non-canonical sentences. We hypothesized that the real-time processing pattern of sentences containing a semantically biased lexical cue (e.g., the venomous snake) would be different than sentences containing unbiased adjectives (e.g., the voracious snake). More specifically, we predicted that the presence of a biased lexical cue would facilitate (1) lexical encoding (i.e., boosted lexical access) of the target noun, snake, and (2) on-time syntactic retrieval or dependency linking (i.e., increasing the probability of on-time lexical retrieval at post-verb gap site) for both groups. For unimpaired listeners, results revealed a difference in the time course of gaze trajectories to the target noun (snake) during lexical encoding and syntactic retrieval in the biased compared to the unbiased condition. In contrast, for the aphasia group, the presence of biased adjectives did not affect the time course of processing the target noun. Yet, at the post-verb gap site, the presence of a semantically biased adjective influenced syntactic re-activation. Our results extend the cue-based parsing model by offering new and valuable insights into the processes underlying sentence comprehension of individuals with aphasia.

Highlights

One property of language processing is the ability to integrate sentential constituents and establish linguistic relationships between non‐adjacent pieces of information
The results revealed an effect of group (AMC and individuals with aphasia (IWA)); the IWA group performed worse than the age‐matched controls (AMC) group
We examined whether lexical‐semantic cues as premodifiers of a target noun (N2) modulated the encoding and re‐ trieval dynamics of a noun phrase during the auditory processing of non‐ canonical sentences in both age‐matched neurologically unimpaired listeners (AMC) and individuals with aphasia (IWA)

Summary

Introduction

One property of language processing is the ability to integrate sentential constituents and establish linguistic relationships between non‐adjacent pieces of information. This latter process creates syntactic dependencies and is critical for the determination of the underlying meaning of the sentence. In English (which has a strict subject–verb–object word order), this process aligns quite nicely with the order of input of a simple active sentence (1a); that is, the first noun encountered is the actor or agent, and the noun after the verb is the object This process is simple for more complex sentence constructions that maintain canonical word order, such as those found in subject‐relative constructions (1b):

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