Topic4_Attention-full

Topic 4: Attention

  • This week's CogLab: Attention - Attentional blink.

Overview of Attention

  • Definition: Process of focusing on specific aspects of the environment or internal thoughts.

    • Selective: Excludes other environmental features.

    • Limited: Capacity and timing are restricted.

    • Types of Attention:

      • Selective Attention

      • Divided Attention

Selective Attention

  • Definition: Ability to focus on one message while ignoring others.

  • Significant portion of environmental information goes unattended.

  • Research focuses on filtering out irrelevant information to promote others for further processing.

Research Method: Dichotic Listening

  • Participants hear two different messages, one in each ear.

  • Participants "shadow" one message to ensure focus.

  • Research Question: Can we fully filter out information in the unattended ear?

Results of Dichotic Listening

  • Participants can’t report the content from the unattended ear but know details like:

    • The presence of a message.

    • The gender of the speaker.

  • Some level of processing occurs in the unattended ear:

    • Change in speaker gender is noted.

    • Change in tones is recognized.

  • Cocktail party effect: ability to notice one's name in a crowded room.

Models of Selective Attention

  • Where does attention filtering occur?

    • Early in processing (characteristics).

    • Late in processing (meaning).

    • Key Models:

      • Broadbent’s Filter Model: Early-selection.

      • Treisman’s Attenuation Theory: Intermediate selection.

      • McKay’s Research: Evidence for late selection.

Broadbent’s Filter Model

  • Process Stages:

    • Sensory Memory: Briefly holds all incoming information.

    • Filter: Identifies attended message based on physical attributes.

    • Detector: Determines the meaning of the filtered information.

    • Short-term Memory: Stores information for brief periods before transferring to long-term memory.

  • Limitations:

    • Known exceptions like the cocktail party phenomenon.

    • Shadowing of meaningful messages when switching ears.

Evidence for Late Selection

  • Selection for final processing occurs after meaning has been resolved (McKay, 1973):

    • Participants hear biasing words which influence responses without awareness.

Treisman’s Attenuation Theory

  • Intermediate-selection model:

    • Analyzes messages based on physical properties, language, and meaning.

    • Attenuator: Selectively weakens the unattended signal's strength.

  • Dictionary Unit: Contains words with varying activation thresholds based on their importance to the listener.

Divided Attention

  • Practice Effect: Enables performing dual tasks simultaneously.

    • Examples:

      • Spelke et al. (1976): Reading and categorizing words after practice.

      • Schneider and Shiffrin (1977): Monitoring stimuli while remembering targets.

  • Conditions:

    • Consistent Mapping: Stable target and distractor types.

    • Varied Mapping: Rules change, leading to controlled processing.

Attention and Driving

  • Impacts of cellphone use on driving:

    • Increased likelihood of missing traffic signals and higher reaction times.

    • Both handheld and hands-free usage improve no performance compared to listening alone.

Attention and Visual Perception

  • Inattentional Blindness: Missing stimuli that are not the focus despite being visible.

Eye Movements and Attention

  • Bottom-up Determinants: Stimuli characteristics (color, motion) that draw attention.

  • Top-Down Determinants: Expectations based on knowledge of scenes influencing gaze directedness.

Covert Attention

  • Effective attention focusing without eye movement.

  • Methods like precueing demonstrate the speed of reaction when indicating expected locations.

Feature Integration Theory (FIT)

  • Stages of Attention Processing:

    • Preattentive Stage: Automatic and involuntary analysis of features.

    • Focused Attention Stage: Requires attention to combine features accurately.

  • Evidence of feature misallocation in patients with attentional deficits.

Physiology of Attention

  • Enhanced neural activation across several brain regions relative to attention tasks.

Weekly Summary

  • Attention filters can be early or late, capacity-limited, and influenced by stimulus characteristics.

  • Divided attention requires practice and can be detrimental to focus tasks such as driving.

  • Visual perception is influenced by both attention and cognitive processes.