This lecture excerpt emphasizes the distinction between a stimulus and our perception of it.

  • Stimulus: A physical change in the environment or inside the body (e.g., light wavelength, injury).
  • Perception: The conscious experience of the stimulus (e.g., color, pain).

Key points:

  • The stimulus itself doesn’t have inherent qualities like color or pain. These are created by our brains during perception.
  • Light has a wavelength, not a color. Our brains interpret specific wavelengths as specific colors.
  • The same stimulus can lead to different perceptions depending on the context (e.g., temperature illusion).
  • Our perception is influenced by many factors beyond the stimulus itself, such as past experiences and current physiological state (e.g., sugar satiation).
  • Different animals have evolved sensory systems that respond to different ranges of stimuli (e.g., snakes see infrared, bats hear higher frequencies).

Remember: The perception is not simply a reflection of the stimulus, but rather a complex process shaped by the brain.