Psychology: Perception 2.1a-2.1b (unit 2)

Perception

  • Understanding perception and the factors influencing it.

Do We Perceive Things as They Are?

  • Discussion on whether we perceive reality as it is or through our individual perspectives.

Selective Attention

  • Inattentional Blindness: Failure to notice a fully visible but unexpected object because attention was engaged on another task.

  • Change Blindness: Difficulty in noticing changes in a visual scene when viewing is disrupted.

  • Key point: Conscious focus is limited to one thing at a time.

Perceptual Set

  • Definition: A mental predisposition towards perceiving one type of stimulus rather than another; readiness to see things based on expectations.

  • Quote: "We see what we expect to see."

Priming and Perceptual Set

  • Priming effects perception; initial exposure to an image influences how subjects interpret subsequent stimuli.

  • Example: Viewing an image influences tendency to see an old woman versus a young woman.

Influences on Perception

  • Influences include:

    • Schemas: Frameworks organizing and interpreting unfamiliar information.

    • Motivation: Goals and needs affecting interpretation.

    • Emotion: Current feelings influencing what we see.

    • Context: Surrounding information enhancing or distorting perceptions.

Contextual Perception Example

  • Example scenario: Seeing lights and hearing sounds at night; perception is influenced by context (e.g., fireworks on the 4th of July vs. a war zone).

Personal Experience in Perception

  • Reflection exercise: How a bad day affects perception of one's messy room; emphasizes emotional influence on perception.

Gestalt Psychology

  • Focus: Understanding perception as a whole rather than isolating components.

  • Key idea: The whole is greater than the sum of its parts.

Gestalt Principles

  • Figure-Ground: We distinguish objects (figures) from their background.

  • Grouping: Tendency to organize stimuli into coherent groups (similarity, proximity, closure, continuity).

    • Proximity: Closer items are perceived as a group.

    • Continuity: Perceptions favor smooth continuous patterns over abrupt changes.

    • Closure: Tendency to perceive incomplete shapes as complete.

    • Similarity: Similar elements are grouped together.

Visual Constancies

  • Definition: Ability to perceive objects as stable despite changes in sensory input.

    • Types include: size, shape, color, and lightness constancy.

Depth Perception

  • Definition: Ability to perceive distance and three-dimensionality using binocular and monocular cues.

    • Binocular Cues: Depend on both eyes; include retinal disparity and convergence.

    • Monocular Cues: Use of one eye; cues include relative height, relative size, interposition, relative motion, and linear perspective.

Examples of Depth Cues

  • Retinal Disparity: Differences in images as viewed from two eyes help determine distance.

  • Convergence: Eyes indicate distance based on the angle when focusing on a nearby object.

  • Relative Size: Smaller retinal images are perceived as more distant.

  • Interposition: Objects blocking others are perceived as nearer.

  • Relative Motion: Motion perception changes based on the observer's position.

  • Linear Perspective: Parallel lines appear to converge in the distance.

  • Texture Gradient: Coarseness of texture appears greater closer and diminishes with distance.

Assignment

  • Perception Scavenger Hunt: Task due tomorrow to practice concepts discussed.