Effect of chronotype on e-bike riders' alertness: Evidence based on behavior and fNIRS

Physiology, personality, and cognitive ability are all associated with safe behavior in traffic. Chronotype, an individual's inclination to feel most alert at particular time of day, is an underexplored factor that may also affect safety. This study explores the effects of chronotype on e-bike riders' alertness from the perspectives of behavior and hemodynamic response to cortex activation.

A total of 64 Chinese riders, 34 morning-type and 30 evening-type, were recruited based on their score on the Morningness-Eveningness Questionnaire. A mixed experimental 2 (chronotype: morning-type group vs. evening-type group) * 2 (test time: a.m. vs. p.m.) design was conducted, with riders' performance on an alertness task while engaged and cerebral cortex activation serving as outcome measures.

Morning-type riders had a faster response than evening-type riders when testing in the morning and evening-type riders reacted faster in the afternoon. More broadly, all riders showed greater accuracy on the alertness task in the morning. Hemodynamic response to cortex activation varied across riders and test times, with significant differences in activation of multiple channels in the primary visual cortex (PVC). Specifically, the morning-type riders showed positive activation in the morning and negative activation in the afternoon, while the evening-type riders showed negative activation at both testing times, with higher activation in the morning. The alertness of the riders demonstrates the synchronicity of brain - behavior, the activation state of some channels (CH1, CH3, CH5, CH8) in the PFC region was significantly correlated with riders' alertness behavior.

Chronotype affects e-bike riders' alertness, as evidenced both by behavioral and brain activation pattern outcomes. The impact varies depending on riding time, with morning-type riders exhibiting better riding alertness in the morning and evening-type riders showing advantages in the afternoon.