The effect of task complexity on linguistic and non-linguistic control mechanisms in bilingual aphasia

Abstract

In this study we examined linguistic and non-linguistic control mechanisms in 20 Spanish–English neurologically healthy bilingual adults and 13 Spanish–English bilingual adults with aphasia. Participants completed two linguistic and two non-linguistic control tasks accounting for low and high complexity. Healthy bilingual results were indicative of domain general cognitive control, whereas patient results were indicative of domain specific cognitive control. The magnitude of conflict required to complete the tasks was also examined. Healthy bilinguals exhibited significant amounts of conflict on all tasks and linguistic and non-linguistic conflict ratios were correlated; whereas patient results revealed significant conflict only on non-linguistic tasks and those conflict ratios were not correlated with linguistic conflict ratios, indicating a dissociation between how patients are controlling information in these two domains. Finally, a relationship between language impairment and language control was identified and brain damage was associated with linguistic and non-linguistic task performance.

Executive control in bilingual aphasia: a systematic review

“…On this test, participants match stimuli on color or shape based on a cue while ignoring distractors. Eighteen bPWA showed impaired performance (Dekhtyar, Kiran & Gray, 2020), whereas 13 bPWA did not (Gray & Kiran, 2019). It is important to note, however, that impaired performance was operationalized differently in these studies.…”

“…Therefore, impaired inhibitory control is generally defined as markedly larger conflict ratios. However, other authors have defined impaired inhibitory control as the absence of interference effects (Gray & Kiran, 2016, 2019).…”

“…bPWA also show impairments on the flanker task: 21 bPWA reported on in six studies experienced larger interference compared to healthy control participants (Dash, Masson-Trottier & Ansaldo, 2020; Green et al, 2010; Keane & Kiran, 2015; Van der Linden et al, 2018a, 2018b; Verreyt, De Letter, Hemelsoet, Santens & Duyck, 2013). However, a larger number of bPWA shows unimpaired performance on this task: 44 participants in six studies (Calabria, Grunden, Serra, García-Sánchez & Costa, 2019; Gray & Kiran, 2016, 2019; Green et al, 2010, 2011; Van der Linden et al, 2018b). The results of the putatively non-linguistic inhibition task thus show a more mixed pattern of impairments as compared to the Stroop task.…”

“…It is important to note, however, that impaired performance was operationalized differently in these studies. Dekhtyar et al (2020) compared performance of the bPWA with a control group, whereas the presence of interference effects or ratios was indicative of unimpaired performance in Gray and Kiran (2019).…”

Aphasia in Bilinguals

“…Bilinguals with aphasia can also present an advantage in inhibitory control tasks (Faroqi-Shah, Sampson, Pranger & Baughman, 2016). Differences in language and bilingual control have been documented in in bilingual individual presenting aphasia (Gray & Kiran, 2015, 2019).…”