Driver Fatigue: Psychological and Electroencephalography Assessment
Task performance during driving may be influenced by psychological factors since individuals differ in temperament and anxiety status. Fatigue has also been shown to be associated with changes in brain wave activity. However, research on psychophysiological associations with driver fatigue is scarce. Understanding the psychological links could provide information on fatigue management.
The aim was to identify the psychological associations during driver fatigue and the corresponding electroencephalography (EEG) changes. Thirty-five drivers were randomly assigned to the study. Subjects performed a driver simulator task until physical signs of fatigue were observed. Simultaneous nineteen channel EEG measures were obtained. Psychological factors assessed with validated questionnaires included anxiety, mood states and locus of control and self reported fatigue state.
The subjects were slightly fatigued before the study and moderately to extremely fatigued after the study. Delta activity was associated with increased anxiety (r=0.42, p=0.01), Vigor-Activity (r=-0.44, p=0.009), Fatigue Inertia (r=0.39). Theta activity was associated with Trait Anxiety and locus of control (r=0.35, p=0.04) and fatigue state (r=0.44, p=0.009). Alpha and beta were associated with Fatigue-Inertia (r=0.36, p=0.03 and r=0.43, p=0.009, respectively). Beta activity was also associated with fatigue state (r=0.49, p=0.003).
This research suggests psychological factors can influence fatigue status. It was found that increased anxiety, and negative mood states such as Tension-Anxiety and Fatigue-Inertia were associated with EEG indicators of fatigue such as increased delta and theta activity. This is the first study to show that various psychological factors may influence driver fatigue. To date no other study has investigated psychological and physiological changes simultaneously during driver fatigue. A future study with greater numbers and both professional and non-professional drivers will be required to confirm the current findings.