STRESS and WORK LOAD Chapter 13 Wickens et al.

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STRESS and WORK LOADChapter 13 Wickens et al.

• Environmental stress factors
• Psychological stress
• Life stress
• Overload and underload
• Sleep loss and interruption

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Types of STRESS

• sensomotoric
• psychological
• physiological
• Task efficiency and effectiveness
• health

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Environmental stressors

• movement, vibrations, motion sickness
• Thermal stress, heat, cold, air humidity,
  metabolism
• Air quality, toxic or irritating gases, dust
  particles of different origin and different sizes
  (bio-industry, birds, pigs)

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psychological stress factors

• Cognitive apparaisal confidence,
  over-confidence, carefulness
• arousal Yerkes-Dodson law
• Performance changes with overarousal, cognitive
  tunneling, memory, Speed-Accuracy Tradeoff,
  strategy changes
• remediation, simplification, training

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Over- and underload, sleep loss

• Work load
• Measuring work load
• fatigue
• Vigilance and underarousal
• Sleep loss
• Desynchronisation

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The DECISION TABLE
JUDGMENT of the OBSERVER
a
b
HIT
MISS
A
STATE of the WORLD
source
CORRECT REJECTION
FALSE ALARM
B
observer
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THE DECISION TABLE

• The surface area of the cells in the table may be
  seen as the number of cases in those cells.
• The size of the a and b counts reflect the
  sensitivity of the observer
• The distribution of the a and b responses
  depends on the criterion of the observer, who may
  vary it.
• When the observer requires much evidence
  concerning the event, the criterion is strict

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THE DECISION TABLE

• The relative frequency of A and B only depends on
  the state of the environment variation is beyond
  the control of the observer.
• Shifting the criterion, or changes in the
  frequencies of external events cause a
  predictable change in the different categories in
  the table