Cell Phone Induced Perceptual Impairments During Simulated Driving David Strayer, Frank Drews, Robert Albert, and William Johnston Department of Psychology University of Utah
Dec 20, 2015
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Cell Phone Induced Perceptual Impairments During Simulated
Driving
David Strayer, Frank Drews, Robert Albert, and William Johnston
Department of PsychologyUniversity of Utah
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Do Cell Phones Interfere With Driving?
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Driver Inattention & Cell Phones
Currently 120 million cell phone subscribers in US
60% of cell phone time is spent while driving
Tens of millions of people driving while using the cell phone each day
Anecdotal evidence suggests that cell phones interfere driving
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Research Questions
Does conversing on a cell phone interfere with driving?
How significant is the interference?
What are the causes the interference?- Peripheral interference (dialing, holding the phone)- Attentional interference (cell phone conversation)
Legislative initiatives tacitly endorse the peripheral interference hypothesis
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Epidemiological Studies
Redelmeier & Tibshirani (1997) New England Journal of Medicine- p(cell phone in use | accident) = 0.24 - 4 fold increase in risk -- comparable to DUI- No advantage of hands-free phones
Increased risks associated with inattention, rather than dexterity
Limitations: correlational, self selection, intervening variables
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Simulator Study I
Conditions
- Hand-Held Cell Phone- Hands-Free Cell Phone- Radio Control- Book on Tape Control
Conversations
- Clinton Impeachment- Olympic Bribery Scandal
Driving & ConversationDriving DrivingWarm-
up
36 minutes
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Response to Simulated Traffic Signals
Subjects responded to red and green traffic signals
Measures:- Probability of missing signals- Reaction time to detected signals
Preliminary Analysis- Hand-Held = Hands-Free - Radio Control = Book on Tape Control
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Cell Phone
Control
Single Dual
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Simulator Study I
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
p(M
issi
ng
Sig
nal
)
Cell Phone Control
SingleDual
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Simulator Study I
500
510
520
530
540
550
560
570
580
590
Rea
ctio
n T
ime
Cell Phone Control
SingleDual
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Conclusions
Using a cellular phone while driving impairs performance
- Twice as likely to miss critical/unpredictable events
- Slower to react to critical/unpredictable events
Cell phone conversation itself causes the interference
Hands-free phones do not appear to be the solution, because the deficits appear to be due to attentional demands imposed by the conversation
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Does the Cell Phone Conversation Affect What We
“See” While Driving? Measured perceptual memory for objects presented at
fixation- While driving alone- While driving and conversing on a hands-free cell phone
Phase I -- Same as Study I, except words were presented at fixation and subjects were to respond if the word was an animal
Phase II -- Measured the implicit perceptual memory for these words using dot clearing paradigm
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Dot-Clearing Procedure
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Simulator Study II
Conditions:- Single-task words (driving only)- Dual-task words (driving & phone)- Control words
Measures: Time to correctly identify word
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Simulator Study II
3000
3050
3100
3150
3200
3250
3300
Rea
ctio
n T
ime
Cell Phone
Single
Dual
New Words
Baseline
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Simulator Study II
3000
3050
3100
3150
3200
3250
3300
Rea
ctio
n T
ime
Cell Phone
Single
Dual
New Words
Divided Attention Costs
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Conclusions for Study 2
Impaired perceptual memory for objects presented while driving and conversing on a hands-free cell phone
The cell phone conversation alters how you perceive the driving environment by diverted from driving to other engaging activities
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Ongoing Simulator Studies
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Ongoing Simulator Studies
Hands-free cell phone conversations -- call initiated before driving
Cell phone conversations interfered with driving- Drivers reacted slower to cars braking in front of them - Drivers were 4 times more likely to get in traffic accidents
Driving interfered with cell phone conversations- Impaired memory of conversation- Poorer decision making
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Future Directions How do other advanced technologies affect driving
performance?
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Conclusions
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Future Directions
How does this compare with conversations with passengers in the car?
How does the nature of the conversation modulate the effect?
How does this compare with driving under the influence of alcohol?
How does expertise affect these divided attention deficits?
Are these deficits exacerbated with age?
How great are the individual differences in distraction?
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