Intentional and Reactive Inhibition During Spoken-Word Stroop Task Performance in People With Aphasia

Abstract

Purpose: The integrity of selective attention in people with aphasia (PWA) is currently unknown. Selective attention is essential for everyday communication, and inhibition is an important part of selective attention. This study explored components of inhibition-both intentional and reactive inhibition-during spoken-word production in PWA and in controls who were neurologically healthy (HC). Intentional inhibition is the ability to suppress a response to interference, and reactive inhibition is the delayed reactivation of a previously suppressed item.

Method: Nineteen PWA and 20 age- and education-matched HC participated in a Stroop spoken-word production task. This task allowed the examination of intentional and reactive inhibition by evoking and comparing interference, facilitation, and negative priming effects in different contexts.

Results: Although both groups demonstrated intentional inhibition, PWA demonstrated significantly more interference effects. PWA demonstrated no significant facilitation effects. HC demonstrated significant reverse facilitation effects. Neither group showed significant evidence of reactive inhibition, though both groups showed similar individual variability.

Conclusions: These results underscore the challenge interference presents for PWA during spoken-word production, indicating diminished intentional inhibition. Although reactive inhibition was not different between PWA and HC, PWA showed difficulty integrating and adapting to contextual information during language tasks.

Figure 1.

Mean response latencies in milliseconds/log for both groups on all condition comparisons. Whiskers indicate 1 SD above and below the mean. Significance (p < .005) is indicated (a) between groups with bracket and star and (b) within groups with star over both conditions.