4.2 Functional Level of Attention – Comprehensive Notes
Perception and Multisensory Integration
- Perception definition: how we understand the world around us using our senses (sight, hearing, smell, taste, touch).
- Brain integrates sensory input to make sense of events, not just passively sensing.
- Multisensory perception: senses work together, e.g., smell and taste combine to shape food enjoyment; losing smell or taste reduces enjoyment of food.
- Perception is shaped by personal experiences, memory, and learning in addition to sensory input.
Divided Attention
- Divided attention: trying to focus on two tasks at once.
- Example: counting red stars while tracking yellow stars on a screen; split focus between tasks.
- Common in everyday life (e.g., listening to music while studying).
- Attention has limits; multitasking can lead to mistakes.
- Safety note: some multitasking combinations are especially dangerous (driving while using a mobile phone).
- Quantified risk: using a phone while driving makes accidents up to
- \text{up to four times more likely}
- (statements reflect cited findings in the text).
- Practical takeaway: the only clear benefit of having a phone in the car is to call for help if something goes wrong.
Automatic vs. Controlled Processes
- Automatic processes:
- Tasks done without much conscious thought (e.g., driving a familiar route, riding a bike after practice).
- Fast, easy, low attention, can do other things at the same time (e.g., talking while cooking).
- Controlled processes:
- Require full attention and conscious effort (e.g., learning a new skill, switching between tasks).
- Slower, more prone to mistakes, demand deliberate focus.
- Summary: automatic tasks feel natural and effortless; controlled tasks require mental effort and attention.
Model of Voluntary and Automatic Action Control (Norman & Shallice, 1986)
- Core idea: automatic actions can start as conscious actions but become automatic with practice.
- Some actions still require full attention and conscious control, especially when:
- Planning or decision-making is needed
- Things must be checked carefully
- The task is new or not well learned
- The task is risky or complicated
- There is resistance to habits or temptations
- Key concept: these actions are coordinated by higher-level control when needed, otherwise practiced routines run automatically.
Contention Scheduling and Action Selection
- Contention scheduling: mechanism by which competing potential actions (schemas) are evaluated and selected.
- When a trigger occurs, multiple schemas can be activated; they compete for execution.
- Selection rule: the action that best fits the current context wins and is carried out.
- If several actions fit well, they can operate in parallel; if they clash, the brain blocks conflicting ones to prevent chaos.
- In well-practiced tasks (e.g., driving), there is a main plan (schema) like driving itself, which triggers sub-actions (braking, steering, using the clutch, handbrake).
- Result: smooth, step-by-step execution in familiar tasks.
Supervisory Attentional System (SAS) and the Effector System
- When unexpected events occur (e.g., hailstorm), habitual routines may be insufficient.
- SAS steps in to stop, rethink, and guide actions in novel or difficult situations.
- SAS helps decide which actions to take or avoid, aligning responses with the moment's demands; it does not directly choose every action.
- Diagrammatic idea (as described in the text): solid arrows indicate activation of actions; broken lines indicate blocking of competing actions.
- Example: hailstorm while driving
- Contention scheduling may block the urge to speed up.
- SAS may direct safer actions such as easing off the gas and steering adjustments.
- Effector system: carries the action plans from decision points to the body’s motor outputs.
- Motivators (e.g., goals, emotions) can modulate action strength over time, influencing which actions become stronger or weaker.
- Overall: SAS provides top-down guidance; the effector system implements the plans.
Thresholds in Perception (Psychophysics foundations)
- Absolute threshold: the smallest amount of a stimulus that can be detected; introduced by Fechner’s line of work.
- Example: minimum light level visible or faintest taste detectable.
- Sub-threshold stimuli: stimuli below the absolute threshold that are not consciously noticed but can still influence brain and behavior (subliminal).
- Relevance: subliminal stimuli can be used in contexts like advertising, even without conscious awareness.
- Difference threshold: the smallest detectable difference between two stimuli.
- Example: smallest change in TV volume detectable.
- Weber's Law: the noticeable difference depends on the original stimulus magnitude.
- Mathematical form: \frac{\Delta I}{I} = k where $\Delta I$ is the change in stimulus intensity, $I$ is the initial intensity, and $k$ is a constant (Weber’s constant).
- Illustration: increasing volume from 1 to 3 is a clear change; at higher baseline levels (e.g., 30), small changes like 30 to 35 are less noticeable; to notice a change at high levels, a larger jump is required (e.g., 30 to 90).
- Fechner’s Law (relation between stimulus and perception):
- Concept: perceived intensity grows with the logarithm of actual stimulus intensity.
- Common representation: S = k \log I where $S$ is the perceived intensity and $I$ is the stimulus intensity; $k$ is a constant.
- Signal Detection Theory (SDT): perception depends on more than a fixed threshold; it is influenced by internal factors.
- Factors include: level of alertness, motivation, and fatigue at the moment of perception.
- This framework explains why different people may detect the same signal differently.
- Example study related to SDT and perception (McClure et al., 2010): anxiety, loneliness, and partner-choice decisions in speed dating.
- Findings:
- Anxious individuals were less picky, faced more rejections, and missed opportunities due to not noticing certain signals.
- Anxious men noticed fewer potential connections; anxious women were more likely to accept contact offers.
Summarized Connections and Implications
- The functional level of attention integrates perception, multisensory processing, and the control of actions under varying demands.
- Automatic vs. controlled processes explain why some routines run smoothly while others require deliberate intervention (especially under novelty or risk).
- Contention scheduling and the SAS provide a framework for understanding how the brain selects appropriate actions while avoiding conflicts, particularly in dynamic environments.
- Thresholds and SDT reveal how perception is shaped by both external stimuli and internal states, affecting reliability of detection and response.
- Real-world relevance:
- Everyday tasks (driving, studying, multitasking) require balancing efficiency of automatic actions with safety and adaptability provided by SAS.
- Understanding thresholds informs advertising, safety signaling, and user interface design by considering subliminal vs. conscious processing and how context affects detectability.
- Ethical and practical implications:
- Subliminal stimuli raise questions about influence without awareness.
- The limits of divided attention highlight risks in multitasking, especially in safety-critical activities like driving.
- Insights into SDT and anxiety-related perception emphasize the importance of mental state on decision making and social interactions.