It is argued that effects of fatigue on performance should be progressive as time goes on. Initial decrements, often found in vigilance tasks, cannot be ascribed to what is usually called fatigue, but rather reflect a change from a state of hypervigilance to normal vigilance occurring within the first half hour of the work period. Studies of very long-term performance, in particular long-term driving, have generally failed to show progressive effects. This casts some doubt on the usual implicit assumption that fatigue and long-term work are uniquely related. It is probable that effects of declining diurnal rhythm, monotony and accumulating lack of sleep will also contribute to fatigue. In an attempt to demonstrate progressive decrement an exploratory experiment was carried out where the effects of long-term work, declining diurnal rhythm and accumulating sleep loss converge. Subjects carried out a continuous driving task between 22.00 h and 6.00 h, which was preceded and followed by two driving tests of 45 minutes each. In another condition they had only the pre- and post-test and slept in between. The results show progressive decrements of performance on several performance measures, including lane drifting and two subsidiary tasks. In general, considerable recovery was observed in the post-test. Although heart rate declined and heart rate variability increased during the long nightly spell, there are strong arguments against relating heart-rate and fatigue. Suggestions for future research are discussed.(a)

  • Corporate Authors:

    Instituut voor Zintuigfysiologie, TNO

    Kampweg 5
    Soesterberg,   Netherlands 
  • Authors:
    • Sanders, A F
    • Gaillard, A W
  • Publication Date: 1976

Media Info

  • Features: Figures; References;
  • Pagination: 19 p.
  • Serial:
    • Volume: IZF

Subject/Index Terms

Filing Info

  • Accession Number: 00149701
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: Monograph
  • Files: TRIS
  • Created Date: Jun 22 1977 12:00AM