The relationship between language control and cognitive control in bilingual aphasia

This study examines language control deficits in bilingual aphasia in terms of domain specific cognitive control and domain general cognitive control. Thirty Spanish-English controls and ten Spanish-English adults with aphasia completed the flanker task and a word-pair relatedness judgment task. All participants exhibited congruency effects on the flanker task. On the linguistic task, controls did not show the congruency effect on the first level analysis. However, conflict ratios revealed that the control group exhibited significant effects of language control. Additionally, individual patient analysis revealed overall positive and negative effects of language control impairment and a benefit from semantically related word-pairs. Patient data suggest a dissociation between the mechanisms of language control and cognitive control, thus providing evidence for domain specific cognitive control. The influence of language proficiency on speed of translation was also examined. Generally, controls were faster when translating into their dominant language, whereas the patients did not show the same trends.