by Albert Major

Introduction to Cognitive Science

Perception

Perception is the process by which we gather information from the outside world via the senses and interpret that information

Template matching theory

• Template: A mental model stored in the brain that represents an external stimulus.
• Template matching theory: A theory in perception where the brain recognizes objects by comparing what we see to stored mental images (templates) of those objects. If the image matches a template, we recognize the object.

Feature Detection Theory / Pandemonium Model

• Feature detection theory: The idea that the brain recognizes objects by detecting individual features (e.g., lines, curves).
• Pandemonium model: A model where different “demons” in the brain detect specific features of an object, leading to recognition.

  • Problem: The theory is bottom-up, meaning it doesn't consider the role of context in recognition. (data driven)

    • example of role of context — 13 an B look alike, yet we know how to differentiate them:

    

  • Word superiority effect: This effect shows that letters are recognized more easily when they are part of a word rather than seen individually, suggesting the role of context in perception.

Computational Theory (David Marr)

• Computational theory of vision: Marr's theory that the brain processes visual information in stages, similar to a computer algorithm. These stages produce increasingly detailed representations or "sketches" of objects until full recognition is achieved.
  • Sketches: These are the stages of processing, from rough outlines (basic shapes) to detailed images. As we move through these stages, we get closer to recognizing the object.