Study Notes for PSYC4013: Human Factors Psychology

PSYC4013: Applying Psychology to the Real World - Human Factors Psychology

Human Factors and Cognition

  • Importance of understanding attentional processes and decision-making in the field of Human Factors.

    • Most accidents are attributed to attentional and judgmental limitations rather than lack of knowledge.

    • Notable examples include:

    • Missing alarms in cockpits.

    • Drivers "look but fail to see".

    • Medical misdiagnoses.

    • Plan continuation bias among pilots.

  • Human Factors questions:

    • How do safety-critical system designs interact with human cognitive limits?

Understanding Attention

  • Definition of Attention:

    • Attention refers to the brain's system for selecting relevant information for processing.

    • It is an unavoidable requirement for complex organisms due to the abundance of information in the environment.

  • Types of Attention:

    • Sustained (Vigilance) Attention: The ability to maintain focus on a task over long periods.

    • Selective Attention: The capacity to focus on behaviorally relevant information while ignoring irrelevant information.

    • Divided Attention: The ability to attend to multiple sources of information simultaneously.

The Nature of Attention

  • Attention as a Non-Unitary Process:

    • Attention is not a single cognitive operation but a combination of interrelated processes.

  • Sustained Attention (Vigilance):

    • Defined as maintaining focus on a relevant stimulus/task for extended time periods.

    • Initially studied in military contexts (e.g., radar and sonar operators during WW2). Relevant applications include:

    • Airport baggage screening.

    • CCTV monitoring.

    • Air traffic control.

    • Nuclear plant monitoring.

Vigilance Decrement

  • Mackworth (1950) conducted studies showing radar/sonar operators' tendency to miss rare irregular events.

  • Mackworth’s Clock Task:

    • Developed to simulate vigilance, showing how attention declines over time especially with infrequent targets.

  • The Vigilance Decrement:

    • Demonstrated through the “time on task” effect, showing detection rates decrease as task duration increases. Frequent events are detected easily, while infrequent ones show higher decrement (Jerison & Picket, 1964).

Impact of Sleep and Stress

  • Research indicates that factors such as sleep deprivation and stress negatively affect vigilance abilities.

Theories of Attention

  • Cognitive Resource Theory (Kahneman, 1973):

    • Argues that monitoring tasks deplete mental resources over time, resulting in slower responses and missed targets.

  • Mind-Wandering (Mindlessness) Theory (Robertson et al., 1997):

    • Suggests attention gradually drifts towards internal thoughts leading to reduced external task monitoring.

Selective Attention

  • Definition:

    • The brain’s ability to focus on relevant stimuli while ignoring irrelevant ones.

  • Highlighted that not all sensory input reaches conscious awareness; information can be present without active attentional focus.

Overt Selective Attention

  • Defined by shifting the position of sense organs (e.g., eye movements).

  • Humans can correspondingly shift their gaze to track visual information.

  • Eye Tracking: Utilized to measure precise focus of attention and differentiate between expert and novice viewer behaviors (e.g. Diaz et al., 2017).

Temporal Structure of Attention

  • Fixation Sequence Analysis:

    • Analyzes the order of gaze fixations for insights into learning and expertise in tasks such as surgical procedures or reading.

    • Attention is goal-oriented and follows the sequence of actions based on task demands.

Top-Down vs. Bottom-Up Attention Control

  • Top-Down Control (Endogenous):

    • Attention dictated by conscious needs or task-related goals.

  • Bottom-Up Control (Exogenous):

    • Attention driven by external stimuli, often unpredictable, which induces a reflexive response.

  • Orienting Reflex:

    • Triggered by sudden, novel stimuli, resulting in a shift in attention almost automatically.

Covert Attention

  • Defined as internal shifts of attention without moving the eyes.

    • An example would be noticing peripheral activity while looking straight ahead.

  • Laboratory studies often focus on covert attention due to the ability to measure it without physical movement.

Cueing Experiments

  • Posner’s cueing experiments (1980) tested covert attention; Valid vs. Invalid Trials:

    • Valid trials have the cue in the same location as the target, resulting in faster response times.

  • Exogenous vs. Endogenous Cues:

    • Exogenous cues (like flashes) automatically draw attention and are brief (about 200 ms).

    • Endogenous cues, such as arrows, draw attention over longer durations but require cognitive resources.

Awareness Failures in Attention

  • Discusses two phenomena illustrating limits of perceptual abilities:

    • Inattentional Blindness (Mack & Rock, 1998): Failure to notice unexpected stimuli even when in clear view, significantly affecting real-world scenarios (e.g., driving).

    • Change Blindness (Rensink et al., 1997): Omitting perceptual changes even when actively searched for.

Examples of Inattentional Blindness

  • Simons (1999) “Gorillas in Our Midst” study:

    • 50% of observers missed a person in a gorilla suit when focused on basketball players, showcasing the effects of attentional set in perception.

Change Blindness Studies

  • Illustrates how perceptions change unnoticed, evaluated by tasks that assess change in visual scenes (Luck & Vogel, 1997).

The Attentional Bottleneck

  • Origin of the attentional bottleneck studied in the context of auditory attention—the Cocktail Party Problem (Cherry, 1955):

    • Investigates focus amidst competing messages.

  • Broadbent's early work showed that little from unattended messages reached awareness, proposing early selection models. Later evidence prompted late selection models.

Perceptual Load Theory

  • Introduced by Lavie (1995):

    • High perceptual load leads to early selection; low load enables processing of irrelevant information.

Visual Search Tasks

  • Attention is fundamental when searching for specific items.

  • Efficiency influenced by target-distractor similarity and the difference between single target versus multi-target search.

Factors Affecting Search Efficiency

  • Notable examples include:

    • Security baggage screening.

    • Medical imaging.

    • Bridge fatigue inspections.

  • Difference between feature search and conjunction search (Treisman’s feature integration theory).

Divided Attention

  • Defined by monitoring multiple sources of information simultaneously (e.g., driving while using GPS or talking).

  • Schneider & Shiffrin (1977) found that practice could make some tasks automatic, although not all tasks achieve automaticity due to varied mapping in attentional demands.

Decision Making in Human Factors

  • Attention leads to conscious awareness, while decision-making involves evaluating information and selecting actions. Critical in domains like aviation, medicine, and driving.

Homo Economicus Model

  • Discusses early models of decision-making focusing on rational evaluations, emphasizing economic perspectives.

  • Decision-making was seen as systematically assessing alternatives for optimum outcomes (often related to financial gains).

Expected Value Versus Expected Utility

  • Expected Value:

    • Average outcome from repeated actions (e.g., game with dice, where expected value equals £3.50).

  • Expected Utility:

    • Subjective satisfaction gained from an outcome, noting non-linear relationships in value perception across different amounts.

Subjective Expected Utility Theory

  • Introduced by Savage (1952), integrating subjective perceptions affecting decisions rather than strict objective criteria.

Ambiguity Aversion and Framing Effects

  • Describes participants' tendency to prefer certain outcomes over uncertain ones, even if logically irrational.

  • Framing Effects:

    • The wording of a scenario can heavily influence choices (positive vs. negative framing impacting decisions).

Prospect Theory

  • Developed by Tversky & Kahneman (1979):

    • Suggests separate evaluations for losses versus gains, indicating a stronger negative reaction to losses, thus leading to risk-averse behaviors in decision-making.

Naturalistic Decision Making (NDM)

  • Focuses on how decisions are made in real-world, often complex scenarios.

    • Highlighted that many decisions made by professionals are intuitive, instantaneous, and based on pattern recognition rather than explicit reasoning (Klein, 1993).

Klein’s Recognition-Primed Decision-Making Model

  • Expert decision-making relies on experience, rapidly evaluating the first viable option and adjusting plans as necessary.

  • Notable real-world application includes pilot decision-making in emergency situations (e.g. “Miracle on the Hudson”).

Heuristics in Decision Making

  • Introduces K&T’s (1974) heuristics—rules of thumb guiding judgments, despite leading to systematic errors. Key heuristics include:

    • Availability Heuristic: Judging likelihood based on how easily examples come to mind.

    • Representativeness Heuristic: Misjudging probabilities based on perceived similarities or patterns.

    • Anchoring Heuristic: Initial information unduly influences subsequent judgments.

Concluding Remarks

  • Emphasizes the significance of understanding attentional processes and decision-making in relation to Human Factors and real-world applications.