Chapter 4

Question 1

Explain the difference between sensation and perception

Answer 1

Sensation: Detection of physical energy by the sense organs.
Perception: The brain’s interpretation of raw sensory data.

Question 2

How do sensation and perception interact with each other

Answer 2

Sensation converts energy into nerve impulses, which is then interpreted as perception.

Question 3

Describe and compare the concepts of absolute and difference thresholds.

Answer 3

Absolute threshold: the difference between not being able to perceive a stimulus and being able to just barely perceive it.
Difference threshold: the smallest increase or decrease in a physical stimulus that is required to produce the “just noticeable difference” in sensation that is detectable 50% of the time.

Question 4

Explain how the cross-processing of sensory information

Answer 4

Synesthesia 联觉: A rare condition, where individuals perceive “cross-model” sensations

Question 5

Explain how attention can lead us to perceive illusions

Answer 5

1. Selective attention: We have a tendency to select certain sensory channels and ignore others (The other senses are still being processed, they just don’t fully reach our awareness via perception)
2. Inattentional blindness: When we intentionally focus on sth, we tend to miss other information)
3. Change blindness: Failure to detect obvious, but usually unexpected changes.

Question 6

List the various structures of the eye and describe their function

Answer 6

1. Sclera: the white portion of the eye.
2. Iris: controls how much light enters the eye.
3. Cornea: focus light on the back of the eye.
4. Lens: keeps images in focus by changing accommodation to reflect light onto the back of the eye.
5. Retina: contains photosensitivity cells (rods and cones). convert light into nerve impulses.
6. Fovea: center of the retina and is responsible for acuity.
7. Rods: low-light vision, dark adaptation.
8. Cones: high light requirement, color vision.
9. Optic nerve: transmits visual info from the retina to the brain.

Question 7

Describe the trichromatic and opponent processing theories of color vision, and explain how they work together to explain color perception

Answer 7

1. Trichromatic theory: color vision is based on our sensitivity to 3 primary colors: red, green, and blue.
2. Opponent process theory: color vision is a function of complementary opposing colors.
3. Ambiguous stimuli and perceptual constancies.

Question 8

what is Gestalt Psychology

Answer 8

we attempt to organize visual information into simple groups to make it easier to interpret.

Question 9

Explain the 6 principles of Gestalt psychology.

Answer 9

1. Figure-ground: organize the figure being separate from the ground.
2. Proximity: Objects that are closer together are perceived to be part of the same group.
3. Closure: fill in the gaps of incomplete objects.
4. Similarity: objects that share visual characteristics are perceived as belonging together.
5. Continuity: points that are connected by lines are perceived as following the smoothest path.
6. Symmetry: group elements that are symmetrical.

Question 10

Explain what type of information the somatosensory system provides us with, and describe how this information is useful.

Answer 10

1. Touch is important for social bonding, and our mental health.
2. Pain and suffering are useful for our genes.