Verbal fluency in three Spanish-English bilingual speakers with TBI

This study investigated differences between healthy bilingual participants and bilingual participants with traumatic brain injury (TBI) on verbal fluency tasks. The performance of three Spanish-English bilingual speakers with traumatic brain injury was compared to the performance of 30 neurotypical bilingual speakers on tasks of category and letter verbal fluency in English and Spanish. Responses were analyzed for total number of correct productions, differences in correct productions between languages, average cluster size, total number of switches, and rates of language choice errors. The data were analyzed using predicted scores from regression equations based on neurotypical data and modified t-tests. Analyses revealed significantly lower total output than predicted by the regression equations for both task types and in both languages for one TBI participant. The same participant demonstrated significantly lower total number of switches than the neurotypical group. Two participants demonstrated higher rates of language choice errors than the neurotypical group. There were no significant differences between TBI participants and the neurotypical group for average cluster size. There were no significant differences between predicted and obtained values for differences between English and Spanish total number correct in each task type. Results are discussed in the context of individual cognitive and linguistic profiles of the TBI participants.