086 Prefrontal cortical activation of concussed and uninjured adolescents during distraction events in a simulated driving assessment: an exploratory functional near-infrared spectroscopy study

Abstract

<h3>Statement of Purpose</h3> Adolescents frequently experience neurocognitive deficits post-concussion, potentially affecting driving performance. Measurement of cognitive workload and deficits can be obtained using functional near-infrared spectroscopy (fNIRS), a portable, non-invasive imaging technology that measures prefrontal cortical (PFC) activity. The goal of this exploratory study was to quantify differences in cognitive workload, as measured by fNIRS, among concussed and uninjured adolescent drivers during distracted driving events in a driving simulator. <h3>Methods/Approach</h3> Licensed concussed and uninjured adolescents completed three experimental drives from a validated simulated driving assessment in a high-fidelity driving simulator. Each experimental drive contained four cell phone distraction events: sending a scripted text message, navigating to a location in a GPS app, finding a playlist in a music app, and engaging in a phone call. Participants wore a continuous wave fNIRS device positioned over the forehead to record PFC activity. Linear mixed-effects models were used to examine the fixed effects of distraction type, injury status, and optode (four distinct spatial regions of the prefrontal cortex) and random effect of subject on cognitive workload. <h3>Results</h3> Nine concussed adolescents (8 female, days since injury (mean±sd): 19.78±6.52), and nine uninjured controls matched by age, sex, and length of licensure, completed the experimental drives. There were significant effects of distraction, optode, injury status, and the interaction between distraction and injury status on PFC. Concussed adolescents displayed a significantly different mean PFC activation pattern in comparison to uninjured controls during the phone call and GPS distraction events. <h3>Conclusion</h3> Concussed and uninjured adolescents display differing PFC activation patterns during distracted driving events in a driving simulator. Future work will compare prefrontal cortical activation to simulator-measured behavioral data, such as speed variability and standard deviation of lane position, during distraction events. <h3>Significance</h3> These findings support further study of how adolescents manage driving tasks post-concussion.