2.1.A—Explain how internal and external factors influence perception

Explain how internal and external factors influence perception.

• Perception is influenced by whether one primarily relies on external sensory information (bottom-up processing) or internal prior expectations (top-down processing).
• Schemas and perceptual sets are internal factors that filter perceptions of the world.
• Contexts, experiences, and cultural experiences and expectations are external factors that filter perceptions of the world.
• Perceptual principles proposed by Gestalt psychology (closure, figure and ground, proximity, and similarity) help explain how humans organize their perceptual world.
• Attention is an interaction of sensation and perception that is affected by internal and external processes.
  • i. Some experiences of attention can be selective, such as with the cocktail party effect, where people attend to mentions of their names or specific topics in loud or distracting environments.
  • ii. Inattention can lead to a type of “blindness” to aspects of the environment. Change blindness occurs when changes to the environment are not perceived due to inattention.