visual perception

• Visual perception


  The process or experience of perceiving through the senses
• Sensations


  • Tactile (touch)
  • Olfactory (smell)
  • Gustatory (taste)
  • Auditory (hearing)
  • Visual (sight)
• Perception


  The set of processes by which we recognize, organize, and make sense of the sensations we receive from environmental stimuli
• These activities enable organisms to organize and interpret the stimuli received into meaningful knowledge and to act in a coordinated manner
• Mental percept


  A mental representation of a stimulus that is perceived
• Theories of how we make sense of what we see

  • Bottom-up theories
  • Top-down theories
• Bottom-up theories


  Data-driven or stimulus-driven theories
• Top-down theories


  Driven by high-level cognitive processes, existing knowledge, and prior expectations
• Direct perception (bottom-up theory)


  • The belief that the array of information in our sensory receptors, including the sensory context, is all we need to perceive anything
• Template theories (bottom-up)


  • Suggest that we have stored in our minds myriad sets of templates, which are highly detailed models for patterns we potentially might recognize
• Feature-matching theories (bottom-up)


  • Suggest that we attempt to match features of a pattern to features stored in memory
• Recognition-by-components theory (bottom-up)


  • The belief that we quickly recognize objects by observing the edges of objects and then decomposing the objects into geons—a simple three-dimensional element regarded as a fundamental component in the perception of a more complex object
• Types of object/form representation

  • Viewer-centered (subjective)
  • Object-centered (objective)
  • Landmark-centered (characterized by its relation to a well-known or prominent item)
• Gestalt laws


  Principles that describe how we group similar things to make sense of the world
• Law of Prägnanz


  • Suggests that through perception, we unify disparate visual stimuli into a coherent and stable whole
• Figure-ground


  • Some figures seem prominent, and other aspects of the field recede into the background
• Perception helps us make sense of the confusing stimuli that we perceive in the world. One way to bring order and coherence into our perception is our ability to group similar things