Conflict Adaptation in Aphasia: Upregulating Cognitive Control for Improved Sentence Comprehension

Abstract

Purpose: This study investigated conflict adaptation in aphasia, specifically whether upregulating cognitive control improves sentence comprehension.

Method: Four individuals with mild aphasia completed four eye tracking sessions with interleaved auditory Stroop and sentence-to-picture matching trials (critical and filler sentences). Auditory Stroop congruency (congruent/incongruent across a male/female voice saying "boy"/"girl") was crossed with sentence congruency (syntactically correct sentences that are semantically plausible/implausible), resulting in four experimental conditions (congruent auditory Stroop followed by incongruent sentence [CI], incongruent auditory Stroop followed by incongruent sentence [II], congruent auditory Stroop followed by congruent sentence [CC], and incongruent auditory Stroop followed by congruent sentence [IC]). Critical sentences were always preceded by auditory Stroop trials. At the end of each session, a five-item questionnaire was administered to assess overall well-being and fatigue. We conducted individual-level mixed-effects regressions on reaction times and growth curve analyses on the proportion of eye fixations to target pictures during incongruent sentences.

Results: One participant showed conflict adaptation indicated by faster reaction times on active sentences and more rapid growth in fixations to target pictures on passive sentences in the II condition compared to the CI condition. Incongruent auditory Stroop also modulated active-sentence processing in an additional participant, as indicated by eye movements.

Conclusions: This is the first study to observe conflict adaptation in sentence comprehension in people with aphasia. The extent of adaptation varied across individuals. Eye tracking revealed subtler effects than overt behavioral measures. The results extend the study of conflict adaptation beyond neurotypical adults and suggest that upregulating cognitive control may be a potential treatment avenue for some individuals with aphasia.

Supplemental material: https://doi.org/10.23641/asha.27056149.

Figure 1.

Testing schedule.

Figure 2.

Examples of (A) auditory Stroop, (B) sentence-to-picture matching, and (C) an interleaved sequence.

Figure 3.

Significant effect of auditory Stroop congruency on subsequent incongruent sentence reaction times (RTs) for P4.

Figure 4.

Significant effect of auditory Stroop congruency on fixations during subsequent incongruent active sentences for P1. Shaded areas represent critical verb onsets/offsets and sentence offsets. The example sentence is “The patient treated the doctor.”

Figure 5.

Significant effect of auditory Stroop congruency on fixations during subsequent incongruent passive sentences for P4. Shaded areas represent critical verb onsets/offsets and sentence offsets. The example sentence is “The doctor was treated by the patient.”