Conference Proceeding

Variability of Driving Performance During Microsleeps

  • Amit Paul (University of Iowa, Iowa City)
  • Linda Ng Boyle (University of Iowa, Iowa City)
  • Jon Tippin (University of Iowa, Iowa City)
  • Matthew Rizzo (University of Iowa, Iowa City)


This study aimed to evaluate the value of measuring microsleeps as anindicator of driving performance impairment in drowsy drivers with sleepdisorders. Drivers with sleep disorders such as obstructive sleep apnea/hypopenasyndrome (OSAHS) are at increased risk for driving performance errors due tomicrosleep episodes, which presage sleep onset. To meet this aim, we tested thehypothesis that OSAHS drivers show impaired control over vehicle steering, laneposition and velocity during microsleep episodes compared to when they aredriving without microsleeps on similar road segments. A microsleep is defined asa 3-14 sec episode during which 4-7 Hz (theta) activity replaces the waking 8-13Hz (alpha) background rhythm. Microsleep episodes were identified in theelectroencephalography (EEG) record by a neurologist certified by the AmericanBoard of Sleep Medicine. Twenty-four drivers with OSAHS were tested usingsimulated driving scenarios. Steering variability, lane position variability,acceleration and velocity measures were assessed in the periods during amicrosleep, immediately preceding (pre) microsleep, and immediately following(post) microsleep. In line with our introductory hypothesis, drivers with OSAHSdid show significantly greater variation in steering and lane position during themicrosleep episodes compared to the periods pre and post microsleep. The resultsindicate that identification of microsleep episodes can provide a marker fordeclining vehicle control of drivers with OSAHS.

How to Cite:

Paul, A. & Boyle, L. & Tippin, J. & Rizzo, M., (2005) “Variability of Driving Performance During Microsleeps”, Driving Assessment Conference 3(2005), 18-24. doi:

Rights: Copyright © 2005 the author(s)

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Published on
28 Jun 2005
Peer Reviewed