Reliability of computerized eye-tracking reaction time tests in non-athletes, athletes, and individuals with traumatic brain injury

Background: Eye tracking technologies and methodologies have advanced significantly in recent years. Specifically, the use of eye tracking to quantitatively measure oculomotor and psychophysiological constructs is gaining momentum. Reaction time has been measured in a number of different ways from a simple response to a stimulus to more challenging choice or discrimination responses to stimuli. Traditionally, reaction time is measured from the beginning of a stimulus event to a response event and includes both visual and motor response times. Eye tracking technology can provide a more discrete measurement of reaction time to include visual components such as visual latencies and visual speed, and can identify if the person was looking at the target area when a stimulus is presented. The aim of this paper was to examine the reliability of the simple reaction time, choice reaction time, and discriminate reaction time tests measured using eye tracking technology. Additionally, we sought to establish performance norms and examine gender differences in reaction time in the general population. A final objective was to conduct a preliminary comparison of reaction time measures across different populations including non-athletes, athletes, and individuals that had sustained a traumatic brain injury. Methods: A sample of 125 participants were recruited to undertake test-retest reliability, analysed using Cronbach’s alpha and intraclass correlation coefficients. A different data set of 1893 individuals, including athletes (n = 635), non-athletes (n = 627) and people with traumatic brain injury (n = 631) were compared using MANOVA to explore group differences in reaction time. Results: Results demonstrated that overall, the tests had good test-retest reliability. No significant differences were found for gender. Significant differences were found between groups with athletes performing best overall. Reaction times of people with traumatic brain injury were overall much more variable, showing very large standard deviations, than those of the non-athletes and athletes. Conclusions: Future research should consider the accuracy of eye movements and various demographic variables within groups.