The effect of traumatic brain injury on sustained attention and working memory

Primary objective: The aim of the study was to evaluate working memory (WM) and sustained attention (SA) following severe traumatic brain injury (TBI). Research design: The study was a quasi-experimental design with two dependent measures. Methods and procedures: Nine individuals with severe TBI and nine non-injured controls completed two visual tasks containing alphabetic stimuli: a WM task (2-back task) and a 10-minute SA task. Main outcomes and results: Participants with TBI had lower hit rates and higher false alarm rates than controls on the WM task. Quantitative analysis of the group data did not reveal a differential deficit in SA; however, post-hoc qualitative visual analysis of individual data revealed considerable variability in four participants with TBI, indicating evidence of impaired SA in select individuals. The hit rates for both tasks were positively correlated, supporting the contention that WM and SA are inter-related. Conclusions: This study provides further evidence of WM deficits following TBI as well as possible SA deficits in some individuals. The results also suggest that WM and SA are inter-related processes. Future studies are needed to replicate the results with larger sample sizes. Based on these findings, patients with TBI may present with WM and SA deficits.