Reduced alertness while driving: Towards a composite behavioral/
psychophysiological measure
N. González1, I. Kalyakin2, A. Kauppi3, D. Ivanov2 and H. Lyytinen3
1AGORA Human Technology Center, University of
Jyväskylä, Jyväskylä, Finland
2Department of Mathematics Information Technology, University of
Jyväskylä, Jyväskylä, Finland
3Department of Psychology, University of Jyväskylä, Jyväskylä,
Finland
Drivers performance is greatly impaired under reduced alertness
states, which can lastly result in fatal accidents. In the endeavor of
developing reliable alertness monitoring systems, some authors advocate
the use of multiple measures to monitor alertness while others concentrate
on single measures. This research seeks a composite measure of the psychophysiological
and behavioral precursors of suboptimal alertness states the drivers might
experience during prolonged drives. In this study, 7 sleep-deprived paid
voluntaries (3 male, 4 female) performed a monotonous simulated driving
task (approximately 3 hours) together with an embedded vigilance task.
In the latter, participants responded to a red or green LED light by pressing
a corresponding red or green button on the steering wheel. The light was
presented either on the left or right side of the driving scene. Light
color, side of presentation, and inter stimulus interval were randomized
to reduce stimulus predictability. Simultaneously, an unattended oddball
stream of auditory stimuli differing in frequency and intensity was presented
through headphones. Different measures, i.e. electroencephalography (EEG),
electro-oculography (EOG), heart rate (HR), respiration, skin potential
(SP), reaction time (RT), and driving incident index (DIX) were recorded
during the experiment. Consistent with the literature, performance fluctuated
widely within and between participants. Overall, alertness decreased as
a function of time on task (TOT). This was indicated by increased RT in
the vigilance task throughout the session and omitted responses. These
were infrequent and occurred more often during the second half of the
drive. DIX was irregularly distributed across participants. Only four
of them showed increases towards the end of the session. Significant correlations
resulted between RT and TOT, DIX, blink rate, and the EEG ratio beta/alpha
+ theta. Despite the caution taken in the interpretation of the results,
these suggest that a composite behavioral/psychophysiological measure
of suboptimal alertness can be more reliable than single ones.
Paper presented
at Measuring Behavior 2005
, 5th International Conference on Methods and Techniques
in Behavioral Research, 30 August - 2 September 2005, Wageningen, The
Netherlands.
© 2005 Noldus
Information Technology bv
|