Longtime driving induced cerebral hemodynamic elevation and behavior degradation as assessed by functional near-infrared spectroscopy and a voluntary attention test.

Drowsy driving contributes to ~20% of all traffic accidents worldwide. Onsite monitoring the mental condition of a driver and forewarning may be a preventive solution to reduce occurrence of drowsiness and potential accidents. Functional near-infrared spectroscopy (fNIRS) has been successfully utilized in hemodynamics-interpreted functional activity in preliminary voluntary attention experiments. Here, we monitored hemodynamic alternations using fNIRS upon the prefrontal cortex over 13 volunteers in the course of a 7-hour driving simulation and evaluated their reaction capability with a voluntary attention test based on Go/NoGo paradigm. A degradation in attention test score (Accuracy/RT) as well as the elevations in oxy-hemoglobin (Δ[HbO2 ]) and total hemoglobin (Δ[tHb]) were found significantly correlated with driving duration (Accuracy/RT: r = -0.964, P < 0.001; Δ[HbO2 ]: r = 0.950, P < 0.001; Δ[tHb]: r = 0.852, P = 0.007). The hemodynamic parameters are in significant inverse correlations with Accuracy/RT (Δ[HbO2 ]: r = -0.896, p = 0.003; Δ[tHb]: r = -0.844, P = 0.008), indicating the potential to forewarn drivers the attention degradation with onsite fNIRS measurements.