CEA Cognitive Ergonomics & Mental Workload 1 — Questions and Answers
Question 1: Cognitive ergonomics is primarily concerned with which aspect of human performance?
- Mental processes such as perception, memory, and decision-making in work systems (Correct answer)
- Physical strength and endurance during manual material handling
- Chemical exposure limits in industrial environments
- Postural alignment during seated computer work
Correct answer: Mental processes such as perception, memory, and decision-making in work systems
Cognitive ergonomics addresses mental processes—perception, attention, memory, reasoning, and decision-making—as they relate to human-system interaction.
Question 2: According to Miller's Law, working memory can hold approximately how many chunks of information at once?
- 7 ± 2 items (Correct answer)
- 20–25 items
- 1–2 items only
- Unlimited items with sufficient practice
Correct answer: 7 ± 2 items
Miller's Law states working memory capacity is approximately 7 ± 2 chunks, though more recent research suggests the functional limit is closer to 3–4 chunks.
Question 3: Which NASA-developed scale is the most widely used tool for assessing subjective mental workload?
- NASA Task Load Index (NASA-TLX) (Correct answer)
- NIOSH Lifting Equation
- RULA Assessment
- Borg Rating of Perceived Exertion (RPE)
Correct answer: NASA Task Load Index (NASA-TLX)
The NASA-TLX is a multidimensional rating procedure that evaluates workload across six subscales including mental demand, temporal demand, effort, and frustration.
Question 4: Endsley's three-level model of situation awareness (SA) includes perception, comprehension, and:
- Projection of future status (Correct answer)
- Physical response execution
- Documentation of the event
- Communication with supervisors
Correct answer: Projection of future status
Endsley's model defines SA as Level 1 (perception of environmental elements), Level 2 (comprehension of their meaning), and Level 3 (projection of future state).
Question 5: Inattentional blindness refers to which cognitive phenomenon?
- Failure to notice an unexpected but visible stimulus when attention is focused elsewhere (Correct answer)
- Vision loss caused by prolonged exposure to poor workplace lighting
- A medical condition affecting peripheral vision in industrial workers
- Reduced visual acuity from extended computer screen use
Correct answer: Failure to notice an unexpected but visible stimulus when attention is focused elsewhere
Inattentional blindness occurs when attentional resources are fully allocated to one task, causing clearly visible but unexpected stimuli to go unnoticed.
Question 6: In Reason's error taxonomy, a 'slip' is best described as:
- An unintended action where the correct goal exists but execution fails due to distraction or automaticity (Correct answer)
- A deliberate violation of established safety procedures
- A planning error stemming from a flawed mental model
- A memory failure to recall required information
Correct answer: An unintended action where the correct goal exists but execution fails due to distraction or automaticity
A slip is an action-based error where the intention is correct but execution fails—for example, pressing the wrong button out of habit while intending to press the correct one.
Question 7: Cognitive load in ergonomics refers to:
- The total mental effort consumed in working memory while processing information during a task (Correct answer)
- The physical weight of cognitive equipment such as headsets or displays
- The number of supervisory levels a worker must interact with
- The time required to complete a standardized cognitive assessment
Correct answer: The total mental effort consumed in working memory while processing information during a task
Cognitive load is the mental effort required to process and maintain information in working memory; excessive cognitive load degrades performance and increases error probability.
CEA Cognitive Ergonomics & Mental Workload 1
Cognitive ergonomics is primarily concerned with which aspect of human performance?