Matthias Roetting, Ph'D' Eye Movement Analyses

1
Matthias Roetting, Ph.D. Eye Movement Analyses
Liberty Mutual Research Institute for Safety

• 2005 TRB Workshop Development of Standardized
  Descriptions of Driving Simulator Scenarios
  Human Factors Considerations

2
Eye video example
3
Level concept of ergonomics
7. Political and societal organization of work
6. Forms of industrial relations and organization
5. Forms of cooperation in groups and human
relations
4. Forms and types of work and personal activity
(individual work)
3. Subtasks and workplaces
3.1 Functional means of a person
3.2 Purpose oriented subsystems
2. Operations with tools and working means
2.1 Biological and psychological basics
2.2 Technical basics of work design
1. Vegetative systems and environmental factors
1.1 Anatomy and physiology of autonomous body
functions
1.2 Physical and chemical basics of work
environment
Luczak et al., 1987
4
Models guiding task analysis
Level Focus 7 Use of analytical knowledge from
task analysis for societal purposes
6 Inner-company and intercompany organizational
determination of task structures 5 Task
structure and group organization 4 Combination
of tasks to a job 3 Single- and multitasks in
human-machine interaction 2 Time
consumption 1 Physiological costs
Level Focus 7 Use of analytical knowledge from
task analysis for societal purposes
6 Inner-company and intercompany organizational
determination of task structures 5 Task
structure and group organization 4 Combination
of tasks to a job 3 Single- and multitasks in
human-machine interaction 2 Time
consumption 1 Physiological costs
Luczak, 1997
5
Principals of eye movement registration
6
Principals of EMR
Electro-Oculogram (EOG)
7
Principals of EMR
Limbus tracking
8
Eye/gaze movement parameters
eye movements
saccade
9
Eye/gaze movement parameters
eye movements
fixation
10
Fixation durations
ms
11
Eye/gaze movement parameters
Transition
eye movements

• fixation
• duration
• position
• visual field

12
Eye/gaze movement parameters

• Level 1 - Determination of physiological costs
• Changes in arousal
• Fatigue and vigilance
• Changes in visual field
• Changes due to secondary task
• Cost of moving the eye
• Level 2 - Explanation, calculation and prediction
  of times
• Duration of information acquisition and
  information processing
• Duration of transitions
• Duration of search
• Level 3 - Analysis of human-machine-interaction
• Analysis of spatial layout
• Analysis of search processes
• Analysis of information acquisition and
  information processing
• Analysis of levels of processing

Level 1 - Determination of physiological
costs Level 2 - Explanation, calculation
and prediction of times Level 3 - Analysis of
Human-Machine-Interaction
13
Level 1 Changes in arousal

• Mental arithmetic
• Identical set of three-digit numbers (e.g. 526)
• Easy dividable by 4?
• Difficult dividable by 3 and/or 4?
• Mean fixation duration
• Easy 792 ms
• Difficult 1,504 ms
• Increases with difficulty

14
Level 1 Secondary task influence

• Entropy-Rate
• Degree of regularity or randomness of the viewing
  behavior
• Based on the first order (pairs of fixations) and
  sometimes the second order (triples of fixations)
  transition frequencies
• The entropy rate of the Conventional VSI w/o
  secondary task is equal to the Vertical VSI with
  a secondary task every 22 seconds

.045
Secondary task
Harris et al., 1982
15
Level 2 duration of inf. acquisition
Fairclough et al., 1993
16
Relative number of fixations
Outside view
time viewed 90
0.5
1.5
Right mirror
Left mirror
Cockpit
time viewed 5
17
Level 3 Analysis of spatial layout
Major transition frequencies
3.9
7.7
3.6
7.2
3.9
3.1
2.3
3.1
1.1
1.2
18
Level 3 Information acquisition
Statistical analysis of transition frequencies
cf. Ellis Smith, 1986
19
The End?

• I look forward to your questions
• ContactMatthias Roetting, Ph.D.Liberty Mutual
  Research Institute for Safety71 Frankland
  RoadHopkinton, MA 01748
• Phone [phone]Email matthias.roetting_at_l
  ibertymutual.com matthias_at_roetting,de
• Web www.libertymutual.com/research/ www.roettin
  g.de

20
Liberty Mutual Research Institute for Safety
Helping people live safer, more secure lives.