Divided and Selective Attention Lecture

  • Introduction

    • Challenge presented: Count yellow stars and red X's simultaneously.
    • Example of divided attention: difficulty in tracking multiple stimuli at once.

  • Results of the Challenge

    • Participants may have counted: 15 yellow stars and 13 red X's (plus a smiley face).
    • Highlights the limitations of attention.

  • Understanding Attention as a Limited Resource

    • Concentration typically occurs on one stimulus at the exclusion of others.
    • Engaging in divided attention leads to task switching, not simultaneous processing.
    • Selecting between tasks employs selective attention.
    • Analogy: Selective attention as a flashlight beam focusing on specific stimuli while others are dimmed.

  • Types of Attention Cues

    • Exogenous Cues

    • External stimuli capturing attention without conscious effort.

    • Examples: Bright colors, loud noises (causing moments of diversion).

    • Pop-out Effect: Salient visuals stand out (e.g., a yellow circle among green circles).

    • Endogenous Cues

    • Internal learned cues that require intention and understanding.

    • Example: An arrow only makes sense if one understands its indication.

  • Cocktail Party Effect

    • Ability to focus on one voice within a noisy environment.
    • Example: Hearing one’s name among many conversations draws attention (endogenous cue due to knowledge of the significance of one's name).

  • Inattentional Blindness

    • Defined as missing stimuli in the visual field due to focus elsewhere.
    • Example: Missing the smiley face while counting other shapes.

  • Change Blindness

    • Failing to notice changes in the environment.

    • Example: Noticing if your mother’s hairstyle has changed or rearranged furniture in a room.

    • Important distinction from inattentional blindness:

    • Inattentional blindness: Missing something visible.

    • Change blindness: Missing differences between two states.

  • Research Example

    • A study where people giving directions failed to notice a change in the researcher due to a large bookcase moving between them.
    • Demonstrates our limited attention and tendency to focus on a primary task at the expense of noticing changes in the environment.