Mobile Phone Use in a Driving Simulation Task: Differences in Eye ...

neversinkhurriedΚινητά – Ασύρματες Τεχνολογίες

12 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

42 εμφανίσεις

Mobile Phone Use in a Driving
Simulation Task: Differences in
Eye Movements

Stacy Balk, Kristin Moore,

Will Spearman, & Jay Steele

The Problem


Each year there are nearly 43,000 traffic
collisions (NHTSA, 2005)


Traffic crashes are responsible for 40
percent of deaths of people aged 15
-
20
(National Transportation Board, 2005)


Inattention is the most sighted cause for
traffic crashes (NHTSA, 2000)


Background


When driving, & mental workload is
increased (e.g. high traffic, visual clutter,
etc.) drivers are less able to maintain high
situation awareness.


A reduction in situation awareness may
result in a lowered ability to optimally
perform driving tasks (Gugerty 1997).


Background Cont.


In addition to normal aspects of driving,
conversing on mobile phones has been
shown to dramatically increase mental
workload (Recarte & Nunes, 2003).


This is especially troubling due to the
recent increase in the popularity of mobile
phones
(
Incisive Interactive Marketing,
2005)

Background Cont.


85% of all mobile phone owners talk on
their phones at least occasionally while
driving (NHTSA, 1997)


21% of crashes or near crashes reported
by respondents involved at least one
driver using a mobile phone (Seo &
Torabi, 2004).


Previous Work


Strayer & Johnston (2001) found
participants who used a mobile phone
(both hand
-
held and hands free)
performed worse in a driving task
compared with participants who passively
listened to radio broadcasts or books on
tape.


Thus the ‘hands’ aspect is not what
degrades driving performance


Previous Work cont.


Strayer et al. found that people that talking
on mobile phones in a driving task were
more likely to experience ‘looked
-
but
-
failed
-
to
-
see’ errors (2003)


Crundall et al. (2004) found that people
talking on mobile phones have shorter
fixation durations


which may account for
‘looked
-
but
-
failed
-
to
-
see’ errors

Previous Work cont.


It has been well established that talking
while driving degrades driving
performance.


It is not known, however, which aspects of
‘good’ driving are affected when talking on
a mobile phone while driving (Gugerty,
2004)

Purpose


Engaging in TMWD increases driving errors as
well as ‘looked
-
but
-
failed
-
to
-
see’ errors, it is not
known how visual search strategies are modified
according to the specific driving task.


The current study sought to quantify if/how
visual search patterns change while engaging in
a mobile phone conversation as well as
combined with potentially hazardous driving
situations

Participants


16 (11 female) Clemson University
undergraduate students


20/20 or corrected to 20/20 vision


A valid drivers’ license


At least 2 years driving experience (M =
3.5 years).


One person was not able to participate
due to poor tracking


Apparatus


Tobii 1750 eye tracker


Sampling rate of 50 hertz


1280 x 1024 display 17 LCD screen

Design


Between subjects, 2 x 2 design.


8 people (3 male, 5 female) participated in
the mobile phone condition


8 people (2 male, x 6 female) participated
in the non
-
mobile phone condition.


All participants viewed 12 trials with 4
vehicles and 12 trials with 7 vehicles in the
driving scene.

Development of the Driving Simulator


C++, OpenGL, SDL


Dynamic ROI generation


Synchronization of frame rate and eye
tracker


Mirrors

Language task


Pimsleur Japanese language learning
compact disk set for beginners


3 language aspects:


Listening


Repeat


Generate


Synced to begin and end with each driving
scene

Procedure


Participants were given instructions


Practice trials


Calibration


View trials (people in the mobile phone
task ‘spoke’ simultaneously)


Answered a question about what occurred
during the scene


Confidence in their response

Procedure


After the completion of the 24 trials,
people responded to a questionnaire
about their attitudes and thoughts about
mobile phones

Results


People on the mobile phone answered
fewer questions about the scene correctly
F
(1, 14) = 49.594,
p
< .001 (37% vs. 68%)


People in the non
-
mobile phone group
were more confident in their responses
F
(1, 200) = 23.314,
p
< .001. (4.03 vs. 3.18)


Overall people answered more questions
with 4 vehicles correctly than with 7
F
(1,
380) = 11.861,
p
= .001. (60% vs. 44%)

Results

Survey Results


All participants owned a mobile phone


On average, participants reported using their
mobile phone ‘sometimes


often’ while driving


4 participants reported using their phone nearly
every time they drove.


All felt others’ driving performance is degraded
while TMWD


However, 7 of the 16 participants felt their
driving performance was only degraded slightly
or not at all

Eye Data Analysis


Removed bad data


Velocity filter to determine fixations and
durations


ROI output from driving simulator
compared with fixations

Eye Data Results
-

Overall


Mobile Phone


Fewer total valid points



Percentage of fixations
of total eye points were
not different


No Mobile Phone


Larger number of total
fixations



The spread of the
fixations were not
different

Eye Data Results


ROIs over whole task


Mobile Phone


Less time spent in the
ROI


Duration of fixations
was less (supports
looked
-
but
-
failed
-
to see
hypothesis)


No Mobile Phone


More fixations in the
ROI

Eye Data Results


ROIs during the event


Mobile Phone


Less time spent in the
ROI


Duration of fixations
was less (supports
looked
-
but
-
failed
-
to see
hypothesis)


No Mobile Phone


More fixations in the
ROI

Discussion


Language task:


Controlled speed of conversation


Interest level


Etc.


Low
-
fidelity vs. high fidelity simulator


Eye
-
data ‘thinking’ phenomenon

Conclusions / future work


People may not be aware of decreased
performance when TMWD


Repeat the expt. with a more ‘involved’
task


Examine the validity

of the language task

Questions!