Cognitive Psychology L4B

Object Perception and Gestalt Principles

  • Gestalt Approach:

    • Developed in early 20th century Germany.

    • Focuses on how humans perceive groups of objects as integral wholes.

  • Principles:

    • Figure-Ground: Some objects (figures) stand out against others (ground).

    • Proximity: Objects close together are seen as a group.

    • Similarity: Similar objects are grouped together.

    • Continuity: Continuous forms are perceived over broken ones.

    • Closure: Incomplete shapes are perceived as complete.

    • Symmetry: Symmetrical patterns are favored in perception.

Perceptual Constancies

  • Definition: Perceptual constancy ensures our perception of an object remains stable despite changes in sensory input.

  • Types of Constancies:

    • Size Constancy: Perception of an object as maintaining its size despite changes in distance.

    • Example: A classmate approaching appears larger on the retina but is perceived as the same size.

    • Shape Constancy: Perception of an object’s shape remains constant despite orientation changes.

    • Example: A door appears the same shape when slightly opened or closed.

Illusions and Depth Perception

  • Muller-Lyer Illusion: Two line segments of the same length appear different due to angles and shapes affecting perception.

  • Depth Cues:

    • Monocular Cues: Viewed with one eye (e.g., relative size, interposition).

    • Linear Perspective: Distant objects appear smaller.

    • Texture Gradient: Close objects have more detail than distant objects.

    • Light and Shadow: Light source affects perception of an object's shape.

    • Binocular Cues: Received with both eyes.

    • Binocular Disparity: Each eye sends a slightly different image; the brain interprets this to gauge depth.

    • Binocular Convergence: Eyes turn inward as objects approach, aiding depth perception.