An Assessment of the Resource Reduction Hypothesis for Sentence Processing in Aphasia: a Visual Word Study in German

EasyChair Preprint no. 6402

Abstract

Introduction
The Resource Reduction Hypothesis (RRH, Caplan, 2012) accounts for the variability in performance and effects of structural complexity in individuals with aphasia (IWA). According to the RRH, performance depends on the participant's resource capacity and  the task's resource demands. If the resources meet the demands, sentences are processed normal-like, otherwise processing is impaired. Importantly, resources fluctuate leading to variable performance. Based on the RRH, we derived predictions for the fixation behavior of IWA in the visual world paradigm.

Methods
We included 21 IWA (mean age = 60, range = 38–78 years, 1–26 years post onset) and 50 control participants (mean age = 48, range = 19–83 years), all native speakers of German. Comprehension was assessed with sentence-picture matching during eye-tracking. Complexity effects were investigated in declaratives, relative clauses, and control structures. Performance variability was investigated between two test phases.

Results
Both groups showed increases in target fixations. However, the increase was higher in controls compared to IWA. Controls showed complexity effects in three sentence types. In IWA, target fixations between simple and complex sentences diverged only in declaratives. Controls showed earlier target fixations in the retest in declaratives and relative clauses. The IWA showed later target fixations in the retest in declaratives.

Conclusions
The increases in IWA's target fixations suggest that sentence processing in correct trials is normal-like. This interpretation is consistent with the RRH. However, three findings speak against this interpretation: 1) the increase in target fixations was lower in IWA than in controls, 2) IWA showed fewer structural complexity effects, and 3) IWA exhibited later increases in target fixations in the retest. These findings might be explained by inflexible top-down predictions in IWA.

Keyphrases: resource reduction hypothesis, sentence comprehension, structural complexity, visual world eye-tracking

@Booklet{EasyChair:6402,
  author = {Dorothea Pregla and Paula Lissón and Shravan Vasishth and Frank Burchert and Nicole Stadie},
  title = {An Assessment of the Resource Reduction Hypothesis for Sentence Processing in Aphasia: a Visual Word Study in German},
  howpublished = {EasyChair Preprint no. 6402},

  year = {EasyChair, 2021}}