LAUSR

Traumatic brain injury (TBI) survivors exhibit cognitive deficits. Research suggests that multilingualism can influence neurocognitive performance. We examined the effects of TBI and bilingualism/monolingualism on a test of attention and cognitive speed (i.e., Symbol Digit Modalities Test; SDMT). The sample consisted of 55 healthy comparison (27 Spanish-English bilinguals; 28 English-monolinguals), 34 acute TBI (14 Spanish-English bilinguals; 23 English-monolinguals), and 27 chronic TBI (13 Spanish-English bilinguals; 12 English-monolinguals) participants. Acute TBI participants were tested 6 months post-injury; chronic TBI participants were tested 12 months or more post-injury. A series of 3X2 ANOVAs were conducted to determine the effect of TBI and language on SDMT written and oral performance. ANOVAs revealed the healthy comparison group outperformed both TBI groups on SDMT written, p = 0.000, ηp2 = 0.21. Also, the healthy comparison and chronic TBI groups outperformed the acute TBI group on SDMT oral, p = 0.000, ηp2 = 0.13. Interaction effects emerged between TBI and bilingualism/monolingualism. On SDMT written and oral, acute TBI English-monolinguals outperformed acute TBI Spanish-English bilinguals; meanwhile, chronic TBI Spanish-English bilinguals outperformed chronic TBI English-monolinguals, p < 0.05, ηp2 = 0.09–0.10. The acute TBI group performed worse than healthy comparison adults on both SDMT tasks. Furthermore, the chronic TBI group demonstrated better SDMT oral abilities compared to the acute TBI group. Relative to monolinguals with TBI, our findings suggest better cognitive recovery of attention and cognitive speed in bilingual TBI participants. Future studies with larger sample sizes should examine if learning English first or second impacts Spanish-English bilingual TBI survivors’ SDMT performance compared to English-monolingual TBI survivors.