The Stroop Effect in Aphasia: A Narrative Literature Review

Aphasia is a language-specific disorder that crosses modalities and is linked to impairments of the cognitive mechanisms used to build and use linguistic representations. The color-word Stroop task (C-WST) is frequently used to investigate cognitive deficits. This review examines its use in people with aphasia (PWA).

To explore the extant literature using C-WST to determine select cognitive deficits in PWA.

Four online database searches were conducted using "Stroop" and "aphasia" keywords. Eight studies were identified following examination of a second set of criteria: (1) presence of aphasia, (2) use of the C-WST, and (3) RT and accuracy measurement of incongruent and control (neutral or congruent) conditions for determining interference and facilitation effects within and between PWA and healthy controls (HC).

Six studies meeting criteria employed relatively small groups, and two examined a single PWA. Studies examined bilingual language dominance, age, aphasia classification, and cognitive mechanisms of aphasia. RT interference effects were reported for PWA in all studies and in six of the eight HC groups. Facilitation effects were infrequently reported. Over-additive PWA interference effects were reported in five of the eight studies.

Overall results show an interference effect on the C-WST for both PWA and HC groups and an over-additive interference effect for PWA. The paucity of C-WST search results for PWA meeting criteria is too few to draw conclusions supporting a direct link between an inhibition impairment and the aphasic language deficit. Findings support a need for further research in PWA using the C-WST.