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Fatigue and the Horizontal Gaze Nystagmus Test

Dayton DUI Attorney Charles Rowland > DUI Law  > Fatigue and the Horizontal Gaze Nystagmus Test

Fatigue and the Horizontal Gaze Nystagmus Test

Main health effects of sleep deprivation (See ...

Can simple fatigue explain a person’s poor performance on the Horizontal Gaze Nystagmus test?  According to recent studies the answer is yes.  Here is a link to the first formal study demonstrating that the smooth pursuit portion of the HGN test is affected by fatigue, http://iospress.metapress.com/content/8758844418248700.  The study found that sleep deprivation impaired smooth pursuit. Quoting from the study’s abstract:

Our findings showed that sleep deprivation deteriorated smooth pursuit gain, smooth pursuit accuracy and saccade velocity. Additionally, the ratio between saccade velocity and saccade amplitude was significantly decreased by sleep deprivation. However, as the length of sleep deprivation increased, only smooth pursuit gain deteriorated further, whereas there were signs of improvement in smooth pursuit accuracy measurements. The latter observation suggests that smooth pursuit accuracy might be affected by the circadian rhythm of alertness.

Although it states  that subjects were sleep-deprived 24 or 36 hours, subjects were not monitored and were allowed to leave the lab. Some subjects probably went home for a nap, so the results reported are probably conservative.  Combined with Booker’s 2004 findings, there is now published evidence that fatigue affects one third of  HGN clues which can create a false impression of intoxication.

Charles Rowland is the only Ohio attorney to be certified in Forensic Sobriety Assessment.  He stands ready to challenge the administration of the standardized field sobriety tests by using cutting-edge scientific defenses and old-fashioned hard work.  If you need an qualified DUI attorney contact Charles Rowland at 318-1DUI (318-1384) today! DaytonDUI.com

Charles Rowland


Charles M. Rowland II has been representing the accused drunk driver for over 20 years. Contact him at (937) 318-1384 if you find yourself facing a DUI (now called OVI) charge.

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