Transcript Are bad drivers more impaired by alcohol? Sober driving precision

Are bad drivers more impaired by
alcohol? Sober driving precision
predicts impairment from
alcohol in a simulated
driving task
學生：董瑩蟬
Purpose
To Investigate the alcohol effects for
driver skill level and understanding
interactions.
Reference
Year
Author
2004
Evans
2004
Keall et al.
1985- Mitchell
1995 Holloway
Result
There has up to 40% of alcohol fatal accidents
in U.S.
The young driver has high risk then older driver
of alcohol accident
Investigate the alcohol impair of driver skill and
performance for the young drivers
1989- Laberg et al. Alcohol slows RT, reduce hand steadiness,
2005 Fillmore
decreases inhibitory control, and impairs pursuit
rotor tracking
Method
1.Subjects
– 28people(14M,14F)
– Range-21 to 31(mean(S.D)=23.8(2.9))
– All subjects has no disorder
– Driver for at least 3 years, and drove at least
two times a week.
2.Equipment
– STISIM
– Computer
– Vehicle
– Intoxilyzer, Model 400
Method
3.Dependent variables (DVs)
– Driving performance：
• within-lane position
• within-lane deviation
• speed (mph)
– Subjective measure：
• subjective intoxication
• subjective impairment
• perceived beverage content scale
Method
4.Independent variables (IVs)
– Gender
– Group-Alcohol or placebo
5.Other measure
– Personal drinking habits questionnaire
– Blood alcohol concentrations
– Baseline driving performance
– Post-treatment testing
Method
6.Procedures
– 14(7M,7F) subject were either alcohol or
placebo group
– Two Training require subject to maintain
vehicle speed of 45 mph and to drive in the
center of lane
– One trial require subject drive 80000 ft (about
20min)
– When subject finished baseline then they
drink alcohol at 40 min after trial again.
– Subjects finished two experiments which were
separated by a minimum of 24 h.
Results
Alcohol use -Personal drinking habits questionnaire
• subjects mean weekly dose of 3.2 ml/kg (S.D. =
2.7).
• The mean number of months of drinking was
80.7 (S.D. = 41.1).
• There was no significant differences between
the alcohol and placebo groups for any measure,
the same with gender.
Results
Blood alcohol concentrations
• When the post-treatment test began, the mean
BAC was 70.6(S.D.=14.6)mg/100ml
• Finished the test mean BAC was
90.4(S.D.=10.8)mg/100ml.
• BAC was no significant difference in gender.
Results
Baseline simulated driving performance
• There was no significant difference on group or
gender.
• The mean within-lane position for the entire
sample was 5.9 ft (S.D. = 0.4).
• The mean within-lane deviation was 0.75 ft (S.D.
= 0.21),
• The mean speed was 44.8 mph (S.D. = 1.0).
Results
Treatment effects on simulated driving performance
Fig. 1. Meanchange in within-lane deviation in response to 0.65 g/kg alcohol
and a placebo. Capped vertical lines indicate standard error of the mean.
Results
Relation of initial skill to individual differences in
post-treatment change
Fig. 2. Scatter plots illustrating
the relationship between drivers’
initial (baseline) within-lane
deviation scores and their preto post-treatment change in
deviation scores in response to
0.65 g/kg alcohol or a placebo.
Least-squares regression line is
shown for each dose condition.
Results
Subjective effects
Discussion
Compared with placebo, alcohol reduced
driving precision, find the increased withinlane deviation under the alcohol.
Drinkers have the capacity to employ
compensatory strategies to resist the
impairing effects of moderate doses of
alcohol. (Vogel-Sprott and Fillnore, 1999)
Discussion
Impulsivity has been identified as a
potentially important personality trait that
could affect driving behavior and
contribute to accident risk (Loo, 1979；
Owsley et al., 2003)
Conclusions
Alcohol reduced driving precision
Baseline skill levels showed the greater
impairments in response to alcohol.