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Updated: Sep 15, 2025
A Neuroscientific Approach to the Examination of Concussions in Student-Athletes
Published on: December 8, 2014
Differences in Reaction Time Variability on the Senaptec Sensory Station by Concussion Status in Special Operations
Wesley R Cole1,2, Madison C Chandler1, Johna K Register-Mihalik1,3
1Matthew Gfeller Center, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States.
Introduction:
Computerized cognitive tests are widely used in post-concussion assessments. The psychometric properties and clinical utility of employing central tendency measures have been questioned. This is true for many outcomes, including reaction time (RT). Cognitive dispersion metrics, such as reaction time variability (RTV) measured by intraindividual variability (IIV), may offer increased sensitivity to concussions. Evaluating IIV across different computerized cognitive platforms is key to determining the utility of central dispersion metrics. This study aimed to extract IIV from the Senaptec Sensory Station (Senaptec, Inc.) Eye-Hand Coordination (EHC) subtest and compare it in service members (SMs) without a past concussion (concussion naïve, CN) versus those with a recent concussion (<1 month; RC) and non-recent concussion (≥1 month; NRC).
Materials And Methods:
Three hundred ninety-one Special Operations Forces SMs (98.2% male, mean age 33 years) were assessed using the Senaptec Sensory Station EHC subtest, a reaction time test where stimuli are presented centrally and peripherally, and included in analyses. Groups included CN (n = 174), RC (n = 22), and NRC (n = 195). Mean RT, RT SD, and IIV, calculated as the SD of each individual's trial-by-trial RT, were extracted from EHC for all trials (i.e., total), only central stimuli, and only peripheral stimuli. A "disruption" metric (SDDiff) was calculated as the difference in IIV between stimuli presented centrally and peripherally. Analysis of variance examined group differences in RT and IIV, with Tukey post hoc tests employed to explore any significant omnibus findings.
Results:
Significant differences (P < .05) were found between RC and both NRC and CN groups for total RT, peripheral RT, total SD, and peripheral SD. Additionally, significant differences were found between RC and both NRC and CN groups for total IIV, peripheral IIV, and SDDiff. However, effect sizes for all significant findings were small and below the level for minimal practical effect (ηp2 < 0.04). No differences were found between the NRC and CN groups on any metric, nor between any groups on metrics from centrally presented stimuli.
Conclusions:
Reaction time variability as measured by IIV from the Senaptec Sensory Station's EHC subtest is somewhat sensitive to recent concussions, particularly for peripherally presented stimuli. This is consistent with past research evaluating IIV from a different computerized cognitive platform. Methodological differences between this and past investigations, such as time since injury, study population, and test nature, may have influenced clinical effect sizes. Cognitive dispersion measures like RTV could enhance post-concussion assessments and should be further investigated for their clinical utility in concussion assessment and recovery tracking.
