An Investigation of the Accuracy of Reaction Time Measurements on ANAM4 TBI-MIL Across Three Computer Platforms.

Study Design: Using two observational methods and a within-subjects, counterbalanced design, this study aimed to determine if a computer's hardware and software settings significantly affected reaction time (RT) on the Automated Neuropsychological Assessment Metrics (Version 4) Traumatic Brain Injury Military (ANAM4 TBI-MIL).

Methods: Three computer platforms were investigated: Platform 1-older computers recommended for ANAM4 TBI-MIL administration, Platform 2-newer computers with settings downgraded to run like the older computers, and Platform 3-newer computers with default settings. Two observational methods were used to compare measured RT to observed RT on all three platforms: 1, a high-speed video analysis to compare the timing of stimulus onset and response to the measured RT and 2, comparing a preset RT delivered by a robotic key actuator activated by optic detector to the measured RT. Additionally, healthy active duty service members (n = 169) were administered a brief version of the ANAM4 TBI-MIL battery on each of the three platforms.

Results: RT differences were observed with both the high-speed video and robotic arm analyses across all three computer platforms, with the smallest discrepancies between observed and measured RT on Platform 1, followed by Platform 2, then Platform 3. When simple reaction time (SRT) raw and standardized scores obtained from the participants were compared across platforms, statistically significant and clinically meaningful differences were seen, especially between Platforms 1 and 3.

Conclusions: A computer's configurations have a meaningful impact on ANAM SRT scores. The difference in an individual's performance across platforms could be misinterpreted as clinically meaningful change.