Sensation and Perception

Question 1

Sensation

Answer 1

the sense organs’ detection of external
stimuli, their response, & the transmission of these
responses to the brain

Question 2

Perception

Answer 2

the brain’s processing, organization, &
interpretation of sensory signals; results in internal
representations of the stimuli that form a conscious
experience of the world

Question 3

Transduction

Answer 3

a process by which sensory receptors
generate neural impulses (Action Potentials) when
they receive physical or chemical stimulation

Question 4

The Canonical Perception Pathway

Answer 4

1. Sensory receptors: Specialized receptor
   cells that detect specific physical or
   chemical stimulation; pass the resulting
   impulses to connecting neurons
2. Connecting neurons transmit
   information to the thalamus
   (“gateway”)
3. The thalamus sends the information to
   the primary sensory cortex
4. Information is then propagated to
   higher-order sensory cortical areas,
   where it is interpreted

Question 5

Visual Pathway

Answer 5

Sight is a constructive process that occurs
throughout much of the brain
• Objects reflect light, which then passes
through cornea to land on the retina
• Retina contains sensory receptors for light
(called photoreceptors: RODS & CONES)

Question 6

Rods:

Answer 6

photoreceptors that can respond to low levels of illumination;
result in black & white perception
• Very sensitive to light, but do not detect color (only detect one wavelength)
• Responsible primarily for nighttime vision
• Exclusively found outside the fovea (peripheral vision)

Question 7

Cones

Answer 7

photoreceptors that respond to higher levels of illumination;
result in color vision & detail
• Not very light-sensitive, but detect different colors (various wavelengths)
• Responsible primarily for daytime vision
• Mostly found at the fovea (central vision)

Question 8

What happens behind the retina?