Chapters 4-6

Attention as Information Processing

  • Attention plays a critical role in information processing, influencing how we interact with stimuli in our environment.

Broadbent’s Filter Model of Attention

  • Proposed to explain how individuals can focus on one input while ignoring others.

  • Involves a sequence where sensory memory passes information to a filter that selects based on physical characteristics, allowing only one message to reach the detector.

  • Identified as an early selection model, as it filters out unattended information early in processing.

Modifications to Broadbent's Model

Early Selection Models

  • Experiments showed that certain unattended information (like one's name) could still be recognized, implying some awareness even when distracted.

  • Treisman’s model introduced an attenuator that adjusts the strength of various messages based on meaningfulness, allowing a level of processing for unattended information.

Late Selection Model

  • Proposes that the selection of information occurs later in processing, based on its meaning rather than just physical characteristics.

  • MacKay's experiment demonstrated that participants could be influenced by biasing words presented to their unattended ear, indicating that meaning can be processed from unattended inputs.

Processing Capacity and Perceptual Load

  • Processing capacity refers to the amount of information one can simultaneously handle, while perceptual load is the complexity of a task.

  • Low-load tasks use up minimal cognitive resources, while high-load tasks exhaust processing capacity leading to distractions from irrelevant stimuli.

Demonstrations of Attention

The Stroop Effect

  • Illustrates how conflicting stimuli can cause slower responses, showing that automatic processes (like reading) can interfere with selective attention to color naming.

Eye Movement and Scanning

  • Selective attention is implemented through eye movements; fixations are the pauses of the eye to inspect important stimuli, while saccades are quick movements between fixations.

Divided Attention

  • This concept involves distributing attention to multiple tasks.

  • Research indicates that practice can help improve the ability to carry out dual tasks, making automatic processing possible. However, task difficulty can hinder this ability.

Distractions and Inattentional Blindness

  • External distractions, such as phone use while driving, can degrade attention and performance.

  • Inattentional blindness, where visible stimuli are overlooked due to lack of focused attention, demonstrates the limits of attention.

Change Detection

  • People struggle to detect changes in scenes due to the limits of attention, a phenomenon documented through experiments demonstrating how quickly information fades from memory.

Outcomes of Attention

  • Attention enhances perceptual experiences, affecting subjective awareness and potentially altering our physiological responses.

  • It increases activity in specific brain regions as attention is directed, demonstrating the neural capacity surrounding attention.

Cognitive Benefits of Attention

  • Effective attention allows individuals to react more efficiently to complex stimuli.

  • Task performance can improve significantly when attention is strategically allocated, whether through overt (eye movements) or covert (internal focus) means.

Conclusion

  • Understanding how attention works through these mechanisms—like filtering, workload, and the effects of distractions—provides insight into cognitive functions and their roles in day-to-day activities.