ch 15 - stress and workload

Stress can cause

Frustration, increased heart rate, poor information processing, and long-term health problems.

What to know about Environmental Stressors

Motion, vibration, heat, cold, air quality, and high altitude.

Heat can cause

Fatigue, heat stroke, and dehydration.

Cold can cause

Reduced alertness and hypothermia.

Psychological Stressors includes

Cognitive appraisal, increased arousal, tunneling, and simplified decision making.

Very important about Yerkes-Dodson Law

Performance follows an inverted U.

Yerkes-Dodson Law - Too little stress

Boredom

Yerkes-Dodson Law - Moderate Stress

Best performances

Yerkes-Dodson Law - Too much stress

Poor performance

Experts tolerate higher..

Stress than novices.

Effects on Information Processing - Stress causes

Narrowed attention, diverted attention, working memory loss, and perseveration.

When adapting to stress people may

Try harder, remove stressor, simplify task, and do nothing.

What helps reduce stress

Training

Workload

Time-line Model

Workload =

Time required / Time available

Time-line Model (1)

Over 100% workload is possible.

Time-line Model (2)

Automatic skills reduce workload.

In time stress people tend to

Focus only on important tasks and ignore other information.

Time stress can

Lead to mistakes.

Flow occurs when

Skills are challenged.

When flow is too easy

= Boredom

When flow is too hard

= Anxiety

What to know about measuring workload

Primary task measures, secondary task measures, physiological measures, and subjective measures (NASA-TLX)

Fatigue Symptoms

Weariness, slow thinking, poor alertness, and reduced performance.

Fatigue Measures

EEG and Flicker-fusion frequency.

Vigilance

Sustained attention over long periods.

Causes of vigilance decrement

Time, low signal rate, low arousal, and low event salience.

Remediation of vigilance

Frequent breaks, better signals, rewards, and increase arousal (music, caffeine)

Sleep loss causes

All-nighters, shift work, and stress

Sleep loss effects

Poor judgement, worse learning, reduced visual performance.

Sleep loss remediation

More sleep, naps, sleep credits, and sleep management.