Transcript Professor: Liu student: Ruby

Professor: Liu
student: Ruby
The role of working memory, field
dependence, visual search, and
reaction time in the left turn
performance of older female drivers
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Objective
• To find the contribution of
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field dependence.
visual search skill.
working memory.
reaction time.
• Two aspects of left turn performance
in a group of female drivers:
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decision time
gap choice
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References
• Old age drivers was 3.8 times accident.
(more than 75 years old)
Middle age drivers was 1.8 times
accident.
(44-40 years old)
Young age drivers was 3 times
accident.
(16-19 years old)
(Massie et al., 1995)
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References
• Close to 40% of fatalities and 60% for
injuries to more than 64 years old
driver occur at intersections and most
of accidents in the left turns (Hauer, 1988),
especially for older female drivers (Bishu
et al., 1991).
• Drivers were shown a lack of
comprehension of protected left turns
(left turn on arrow only). (Knoblauch et al.,
1995)
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References
• Misjudgment of the distance or speed
of an oncoming vehicle (Scialfa et al, 1987)
or misjudgment of gaps (Stamatiadis et al.,
1991), which were attributed of the
intersections.
• Greater field dependence to be related
to slower recognition speeds for traffic
signs. (Fleury, 1994; 1996), (Loo, 1978)
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References
• Greater field dependence to be related
to drivers’ pedal response errors at
intersections. (Grubb, 1992)
• When scanning a visual field, field
dependence drivers are more likely to
have difficulty distinguish between
relevant and irrelevant.
field dependence drivers may not take the large
information.
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References
• The dynamic acuity was predictive of
driving problem.
(Laux and Brelsford, 1990)
over curb, near crash due to failure to see
another car.
• Visual acuity has also been associated
with left turn decisions.
(Grubb, 1992;
Guerrier et al., 1995)
• Older drivers’ slower response rates
increased their difficulties in judging
time to collision and acceptable gaps.
(Staplin and Lyles, 1991)
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References
• Older drivers’ visual information
processing ability was bad, which
measured by the useful field of views
(UFOV). (Owsley, Sloane et al, 1991)
• Older persons on the visual spatial
information display showed less
accurate at keeping track of a single
attribute of different objects. (Detweiler et
al., 1996)
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Method
• Participants
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26 women, age from 61-84 years old. (M=73.35,
SD=7.4)
All subjects have driver license and still driving.
• Material
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Ten film of oncoming traffic at a four lane
intersection.
Speed limit of 30 mile/h.
Presented on a TV monitor.
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Independent variables
• Visual acuity
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Used a Snellen Eye Chart to test subjects.
• Demographic
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Question about the participants' age, the
number of days they drove … 28 questions
about their driving experiences.
• Perceptual style
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Used the Embedded Figures Test (EFT) to
measure participants’ perceptual sytle.
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Independent variables
• Visual search
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The targets were ],#,and,> which embedded in
any of the locations in the search field.
• Working memory
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Participants solved the continue additions.
The additions consisted of two digit number.
• Reaction time
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Simple reaction time
 10 presentation of a Whit band on a black
background.
Choice reaction time
 20 random presentations of a circle (press C)
or a square (press S) on the monitor.
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Dependent variables
• Decision time
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The first frame of the scenario is displayed to
the participant pressing any key on the
keyboard (the gap chosen).
• Gap chosen
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The space the participant selected between two
oncoming cars to do the left turn.
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Equipments
• BCD Video Link
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Control presentation of the film.
• IMB PC
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Control the BCD program.
• 13’’B/W monitor
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Connect to the VCR through the BCD interface.
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Results
• Participants have been driven for an
average of 46 years old.
• They drove an average of 6 days a
week.
• 5 reported usually driving at night.
• The reasons reported for not driving at
night were related to vision.
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Results
• Relationship of age to other
independent variables.
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Visual search skill was significant.
(r (26) =-0.39, p =0.03)
The quicker the driver’s
choice reaction time, the
larger the gaps chosen.
• Relationship of working memory,
visual search, field dependence, and
reaction time to left turn performance.
The greater the working
memory, the longer the
driver waited.
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Results
• Decision time
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Decision time was significant related to gap sizes
(r (26) =0.70, p <0.001)
the longer decision time the larger the gaps
chosen.
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Results
• Contribution of working memory,
visual search, field dependence, and
reaction time to decision time, and gap
choice.
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Decision time
The greater working memory was related to longer
decision time and greater field independence was
related to shorter decision time.
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Results
• Contribution of working memory,
visual search, field dependence, and
reaction time to decision time, and gap
choice.
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Gap choice
Choice reaction time to contribute the
most variance to left turn performance
(R (1,24) =0.38, p =0.06)
Decision time is the best predictor of gap
choice. (R (1,24) =0.7, p <0.0001)
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Results
• Effects of working memory, field
dependence, and choice reaction time and
gap choice.
Working memory plays the most important role on gap choice.
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Discussion
• The relationship of working memory to
gap choice in this study.
greater working memory capacity would allow
the older driver to manage the relevant
information more efficiently.
would result in faster decision time and larger
gaps.
• The longer decision time by high
working memory.
because person being capable of managing
larger amounts of information may spend more
time gather relevant information.
the recognition of a traffic pattern which
resulted in the strategy taken.
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Discussion
• A relevant parallel to driving in the
intersections designing which decrease
the information processing load of
older drivers.
• Focusing on working memory would be
idea to help safe driving for older
persons.
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