This paper introduces a way of evaluating a state of fatigue by measuring variations of power in alpha and theta frequency bands of an EEG. An increased alpha power indicates a less active state. A study was carried out to determine "alpha events" by describing the development of wakefulness depending on time on task as well as on circadian influences with high resolution. Subjects drove for set times during the day and night in a simulator. Different stages of fatigue were represented in different combinations of pauses and duration of alpha events. Performance at the driving task was diminished at a reduced-awake stage and fatigued stage. A high time resolution was necessary for the detection of lapses. The duration of lapses indicated qualitatively different processes. For the covering abstract see ITRD E113725 (C 22328 CD-ROM).
Samenvatting