driver ’s attention during monotonous driving
DESCRIPTION
Driver ’s Attention during Monotonous Driving. Roman Mouček, Jan Řeřicha University of West Bohemia Pilsen, Czech Republic. Introduction. Why Attention of drivers – road safety Decline of attention is natural What: Investigation of driver’s attention during monotonous driving How: - PowerPoint PPT PresentationTRANSCRIPT
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Driver’s Attention during Monotonous Driving
Roman Mouček, Jan Řeřicha
University of West Bohemia
Pilsen, Czech Republic
Copyright © 2007 LICS | DCSE | FAS | UWB
Introduction
• Why
– Attention of drivers – road safety
– Decline of attention is natural
• What:
– Investigation of driver’s attention during monotonous driving
• How:
- Electric activity of human brain
- Technique of event related potentials (ERP)
- ERP experiment based on auditory stimulation
• Results
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Attention of drivers
• Long rides• Monotonous driving – motorways• Not focused on prolongation of driver’s reactions• EEG (electrophysiology) vs. ERP (event related
potential)• Auditory stimulation during monotonous drive –
changes in the peak latency of the P3 component
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Hypothesis
• Peal latency of the P3 component increases in time as the driver is more tired from monotonous drive
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ERP and P3 Component
• Advantages compared to behavior techniques– Which stages of processing are influenced by experimental
manipulation– Online measure of the processing of stimuli
• P3 component – depends entirely on the task performed by the subject – Sensitive to variety of factors– Related to process called “context updating”– sensitive to the probability of the target stimulus.
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P3 amplitude
• P3 amplitude – increases when the probability of the target stimulus class
decreases – becomes larger when it is preceded by a greater number of
non-target stimuli – is larger when the subject pays more attention to a task– is smaller if the subject does not know whether a given
stimulus is / is not a target
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P3 latency
• associated with stimulus categorization• If stimulus categorization is postponed, P3 latency is
increased • While P3 latency depends on the time required to
stimulus categorization it does not depend on consequent processes (e.g. response selection)
• can be used to determine if a performed experiment influences the processes of stimulus categorization or processes related to a response
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Experiment - Objectives
• To construct a highly monotonous track where a substantial decrease of attention is supposed.
• To design and implement a common auditory ERP experiment.
• To perform the ERP experiment on the group of tested subjects.
• To divide the drive into time intervals of the same length and compare the latency of the averaged P3 components in these time intervals.
• To evaluate results to confirm/reject the hypothesis.
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Laboratory
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Laboratory
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Track
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Laboratory - metadata
• Hardware equipment • Software tools• Recording System• Tested subjects • Course of experiments• Environment• Data and metadata storage
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Recording system
• 10-20 system• The cap reference electrode used first, then reference
electrode was placed above the nose
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Tested subjects
• A group of 14 men• university students, aged 21-23, • All of them were right-handed, no visual or auditory
defects. • All of them had a driving license
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Course of experiment
• Preparation phase– standard biorhythms– not to drink any stimulating substances and alcoholic
beverages – to come not exhausted. – familiarized with the basic behavioral rules during an
EEG/ERP experiment– ….
• Experiment - 40 minutes• Closing phase - several questions related to subjects’
feeling of tiredness
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Data processing
• Data import• Data filtering• Rejection of corrupted data• Data selection• Channels selection• Extraction of epochs• Baseline correction• Data averaging
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Results
Interval (min) [0-8] [16-24] [32-40] average
Electrode Fz Cz Pz Fz Cz Pz Fz Cz Pz Fz Cz Pz
subject 7 415 415 469 413 424 432 473 471 472 422 428 449
subject 8 314 322 332 316 308 334 315 315 323 312 316 328
subject 9 358 354 360 382 380 376 378 368 362 375 368 367
average 385 371 353 394 391 378 398 375 345 395 382 358
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Results – cap reference, Cz electrode
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Results – nose reference, Cz electrode
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Conclusion
• P3 component was found• prolongation of peak latency over time could not be
clearly observed• long target stimulus stretched the length of the
component - stretched components are worse analyzable - absolute coordinates are distorted.
• not many of target stimuli because of frequent removal of the artifacts
• this kind of attention decline did not affect peak latency of the P3 component.
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Thank you for your attention