The Effect of Mild Traumatic Brain Injury on Reaction Time, Dual-tasking Reaction Time and Heart Rate Variability in Driving Simulation

The present study was performed to address some gaps in current literature related to dual tasking, reaction time, and heart rate variability (HRV) in concussed individuals during driving simulation, and to determine the extent to which reaction time, heart rate (HR), HRV, and dual tasking ability are impaired during driving scenarios of varying difficulty in concussed subjects when compared to a healthy control group. Testing was performed with a Systems Technology Incorporated Simulator Model 400 driving simulator. Ten healthy and ten concussed participants were exposed to multiple reaction time scenarios including pedestrian, vehicle, and cyclist incursions. Three dual task scenarios were also present during the simulation and were indicated by red triangles over either of the side view mirrors. Dual tasking ability was measured using STISIM dual task commands. Analysis of variance (ANOVA) was used to examine the interaction effect between group (concussed vs. non-concussed) and scenario on reaction time decline, dual task reaction time, HR, and fluctuation in HRV. No significant interaction effect between group and scenario was found for any of the four variables tested. There was a statistically significant difference in reaction time between groups F(1, 18) = 2.072, p < .0001, η2 = .600 and a statistically significant difference in dual task reaction times between groups F(1, 18) = 23.145, p < .0001, η2 = .563. No statistically significant differences were found for either HRV F(2.956, 53.207 )= 0.445, p = .719, η2 = .140 or HR F(1, 18) = 0.367, p = 0.552, η2 = .020. The findings suggest that there is a need for evaluation or screening before returning to driving after concussion. More research needs to be done to both determine deficits in driving performance following concussion, and for the development of a comprehensive screening and assessment tool for health care professionals to utilize when assessing concussed patients