• We see similarly but perceive differently
• Sensation is collection of data, translating to action potentials to brain
• Perception is the translation of action potentials in brain
• Two ways of processing sensory info:
  • Bottom up
    • Start with edges, border, color movement, each level of processing, we get a more detailed picture of what is happening in the moment
  • Top down
    • We use memories and expectations to help interpret sensation
    • Takes longer to recognize friend in foriegn airport compared to meeting at a coffeeshop

Visual Stimulus

• Light on electromagnetic specturum
• Radiation
• Cant see UV and experience infared as heat, not light
• they are photons that travel in waves
• wave length is interpreted as color
• amplitude is brightness
• long wavelength, high amp, is bright red

we see what we need to see

• Insects see UV range to find pollen
• snakes see infared to locate prey
• Dogs cant see red and green
• Light interacts
• reflected or absorbed by object
  • most we see is reflected
• sometimes refracted
• We see in air, fish adapted to see underwater
• some can see both, like annibelps with two pupils
• Most mammals, including dogs and cats, only have two color photopigments instead of the three that humans and most primates have.