A-111 The Relationship between Bilingualism and Perceived Workload on the Symbol Digit Modalities Test in Traumatic Brain Injury Survivors

Objective We evaluated perceived workload (measured by the NASA Task Load Index; NASA-TLX) as related to Symbol Digit Modalities Test (SDMT) performances in monolingual and bilingual traumatic brain injury (TBI) survivors and healthy comparison participants (HC). Method The sample consisted of 28 TBI survivors (12 monolinguals & 16 bilinguals) and 50 HC (20 monolinguals & 30 bilinguals). SDMT written (SDMT-W) and SDMT oral (SDMT-O) were used to evaluate group differences. Results ANCOVA, controlling for age, revealed that the HC group outperformed the TBI group on SDMT-W, p = .001, and SDMT-O, p = .047. Furthermore, bilinguals outperformed monolinguals on SDMT-W, p = .017. On the NASA-TLX, an interaction emerged on temporal demand rating, p = .023, with TBI bilinguals reporting higher temporal demand on SDMT tasks compared to TBI monolinguals, while the HC monolingual participants reported higher temporal demands ratings compared to HC bilingual participants. Furthermore, monolingual participants showed higher levels of frustration with regard to the SDMT task compared to bilingual participants, p = .029. Conclusion Our data revealed TBI survivors underperformed on both SDMT trials compared to the HC participants. Also, bilingual participants demonstrated better SDMT-W performances compared to monolingual participants. Furthermore, our TBI bilingual sample reported themselves to be more rushed to complete the SDMT compared to monolingual TBI sample, but they were less frustrated. Meanwhile, our HC monolingual sample felt more rushed to complete the SDMT tasks compared to HC bilingual participants, but they were less frustrated. While we observed differences in workload ratings between language groups, it is unclear if language use, and/or other variables are driving these results.