A-106 Analysis of Switching and Clustering Performance in Anglo-Americans and Hispanic Traumatic Brain Injury Survivors and Healthy Comparison Adults

Abstract

Abstract Objective Research shows traumatic brain injury (TBI) survivors underperform compared to healthy comparison participants (HC) on verbal fluency tasks. Verbal fluency is typically comprised of two tasks: letter fluency and semantic fluency. During verbal fluency trials, participants often cluster responses and switch between clusters, which can serve as measures of executive control and organization. Also, research shows that Anglo-Americans (AA) outperformed ethnic minorities on various aspects of cognitive functioning. We examined the relationship between TBI and ethnic diversity on letter fluency, semantic fluency, switching, and clustering. Method The sample included 45 HC adults (21 Hispanics; 24 AA), 33 acute TBI adults (ATBI; 11 Hispanics; 22 AA), and 26 chronic TBI adults (CTBI; 9 Hispanics; 17 AA). Results The groups were well matched, with the exception of gender. ANCOVAs, controlling for gender, revealed HC outperformed ATBI participants on letter fluency, p = .007, ηp2 = .10, letter switching, p = .006, ηp2 = .10, and semantic switching, p = .018, ηp2 = .08. We also found HC outperformed both TBI groups in sematic fluency performances, p = .000, ηp2 = .15. Next, we found Hispanics outperformed AA on letter clustering, p = .003, ηp2 = .09 and semantic clustering, p = .010, ηp2 = .07. Finally, an interaction emerged in letter clustering, p = .044, ηp2 = .06, with the Hispanic ATBI outperforming the AA ATBI group. Conclusion The HC group outperformed both TBI groups only on semantic fluency, but they outperformed the ATBI survivors on letter fluency, letter switching, and semantic switching. Hispanics outperformed AA on letter clustering and semantic clustering, suggesting the use of clustering over switching strategies to provide verbal fluency responses in this group.