In the blink of an eye : the circadian effects on ocular and subjective indices of driver sleepiness

Watling, Christopher N. & Smith, Simon S. (2013) In the blink of an eye : the circadian effects on ocular and subjective indices of driver sleepiness. In Australasian Road Safety Research, Policing & Education Conference, 28 – 30 August 2013, Brisbane Convention & Exhibition Centre, Brisbane, QLD.


Driver sleepiness contributes substantially to fatal and severe crashes and the contribution it makes to less serious crashes is likely to as great or greater. Currently, drivers’ awareness of sleepiness (subjective sleepiness) remains a critical component for the mitigation of sleep-related crashes. Nonetheless, numerous calls have been made for technological monitors of drivers’ physiological sleepiness levels so drivers can be ‘alerted’ when approaching high levels of sleepiness. Several physiological indices of sleepiness show potential as a reliable metric to monitor drivers’ sleepiness levels, with eye blink indices being a promising candidate. However, extensive evaluations of eye blink measures are lacking including the effects that the endogenous circadian rhythm can have on eye blinks. To examine the utility of ocular measures, 26 participants completed a simulated driving task while physiological measures of blink rate and duration were recorded after partial sleep restriction. To examine the circadian effects participants were randomly assigned to complete either a morning or an afternoon session of the driving task. The results show subjective sleepiness levels increased over the duration of the task. The blink duration index was sensitive to increases in sleepiness during morning testing, but was not sensitive during afternoon testing. This finding suggests that the utility of blink indices as a reliable metric for sleepiness are still far from specific. The subjective measures had the largest effect size when compared to the blink measures. Therefore, awareness of sleepiness still remains a critical factor for driver sleepiness and the mitigation of sleep-related crashes.

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ID Code: 62221
Item Type: Conference Paper
Refereed: No
Keywords: Sleepiness, Subjective sleepiness, Phsyiological sleepiness, Ocular indices, Circadian rhythm, Simulated driving
Subjects: Australian and New Zealand Standard Research Classification > PSYCHOLOGY AND COGNITIVE SCIENCES (170000) > PSYCHOLOGY (170100) > Biological Psychology (Neuropsychology Psychopharmacology Physiological Psychology) (170101)
Australian and New Zealand Standard Research Classification > PSYCHOLOGY AND COGNITIVE SCIENCES (170000) > COGNITIVE SCIENCE (170200) > Cognitive Science not elsewhere classified (170299)
Divisions: Current > Research Centres > Centre for Accident Research & Road Safety - Qld (CARRS-Q)
Current > Research Centres > Centre for Emergency & Disaster Management
Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Psychology & Counselling
Copyright Owner: Copyright 2013 [please consult the author]
Deposited On: 02 Sep 2013 01:33
Last Modified: 19 Sep 2013 04:01

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