Sensation and Perception

Question 1

In the context of signal detection theory, d’ (d-prime) is a measure of:

Answer 1

sensitivity

Question 2

Theo is not color blind but his wife, Tillie, is red-green color blind. Describe the likelihood of their male vs. female biological children being red-green color blind?

Answer 2

Their male children will be red-green color blind, but their female children will not be red-green color blind.

Question 3

Gate control theory is most useful for:

Answer 3

identifying ways to relieve pain

Question 3

A psychologist interested in the relationship between the magnitude of physical stimuli and psychological sensations finds that doubling the weight of an object doubles the sensation of heaviness but that doubling the brightness of a light more than doubles the sensation of brightness. This finding is most consistent with…?

Answer 3

Weber’s Law

Question 3

Whenever Corky looks at numbers, each number elicits a different color (1 elicits red, 2 elicits blue, etc.). This is referred to as:

Answer 3

synesthesia

Question 3

_______ is most responsible for depth perception of objects that are at a close distance.

Answer 3

retinal disparity

Question 4

Afterimages and red/green and blue/yellow colorblindness are explained by

Answer 4

opponent-process theory

Question 5

Difference between SENSATION and PERCEPTION

Answer 5

sensation is the physical process of detecting stimuli, while perception is the process of interpreting and consciously experiencing those stimuli

Question 6

Difference between bottom-up and top-down processing

Answer 6

bottom-up (data-driven) processing begins with incoming sensory information and continues up to the brain where it is perceived, interpreted, and stored
VS
top-down (concept-driven) processing begins with the brain’s use of pre-existing knowledge and expectations to interpret incoming sensory information

Question 7

What is the physical stimuli for vision and what part of the eye processes visual sensory information?

Answer 7

light waves absorbed by photoreceptors in the retina

Question 8

What are the 2 types of photoreceptors and their function(s)?

Answer 8

cones - bright light, visual acuity (sharpness & precise detail), & color

rods - dim light, peripheral vision, & black/white

Question 9

What are the 2 theories of color vision?

Answer 9

Trichromatic and opponent-process theory

Question 10

Explain Trichromatic Theory of Color Vision

Answer 10

applies to the initial level of processing color in the retina & contains 3 color receptors (cones) - red, blue, and green

Question 11

Explain Opponent-Process Theory of Color Vision

Answer 11

• applies to processing beyond the retina & proposes 3 types of opponent-process cells - red/green, blue/yellow, and white/black
• explains red/green and blue/yellow colorblindness & the phenomenon of negative afterimages

Question 12

What are negative afterimages in association with opponent-process theory of color vision?

Answer 12

occurs when a person stares at and then looks away from an object of one color & sees an afterimage of the object in a complimentary color

Question 13

What is the most common type of color blindness?

Answer 13

red/green

Question 14

What is the etiology of red/green color blindness?

Answer 14

• genetic mutation - recessive gene on the X chromosome; inheriting the single mutated gene is sufficient to cause color blindness
  -the result of injury/disease (e.g., diabetes, MS)

Question 15

Red/green color blindness and gender differences

Answer 15

• more common in males because males only have 1 X chromosome, which they inherit from their mothers
• females only experience color blindness if both inherited X chromosomes inherited by their parents are mutated genes

Question 16

What is the etiology of blue/green color blindness?

Answer 16

an autosomal (non-sex) dominant gene

Question 17

blue/green color blindness and gender differences

Answer 17

affects males & females equally

Question 18

The ability to perceive depth depends on a combination of ___(A)___ and ___(B)___ cues.

Answer 18

(A) binocular
(B) monocular

Question 19

Explain binocular cues

Answer 19

• depth perception of objects that are relatively close
• depend on both eyes
• include retinal disparity & convergence

Question 20

Why does retinal disparity occur?

Answer 20

because our 2 eyes see objects from 2 different views & the closer the object, the greater the disparity

Question 21

What does convergence in association with depth perception refer to?

Answer 21

the tendency of the eyes to turn inward as an object gets closer and vice versa

Question 21

Explain monocular cues

Answer 21

• depend on 1 eye for depth perception of objects at a greater distance
• include relative size of objects, the overlap (interposition), linear perspective, texture gradients, and the relative motion of objects (motion parallax)

Question 22

When does physical pain ordinarily occur?

Answer 22

when nociceptors (pain receptors) in the skin, muscles, joints, and internal organs detect thermal, mechanical, or chemical stimuli that are damaging or threatening to damage normal tissue

Question 23

What does Gate Control Theory propose?

Answer 23

• transmission of pain signals to the brain by small fibers depends on a “gate” in the spinal cord
• gate opened by incoming pain signals
• gate closed by the transmission of non-pain signals by large fibers & by the transmission of information from the brain

Question 24

What are small unmyelinated fibers responsible for in association with Gate Control Theory?

Answer 24

transmitting most pain signals to the brain

Question 25

What are large myelinated fibers responsible for in association with Gate Control Theory?

Answer 25

transmitting other sensory signals

Question 26

According to Gate Control Theory, what are some ways to relieve pain?

Answer 26

• applying heat or cold to affected area of the body
• guided imagery
• hypnosis
• distraction (e.g., watching a movie, playing a game)

Question 27

What is synesthesia?

Answer 27

when your brain routes sensory information through multiple sense

Question 28

What is the most common type of synesthesia? Explain.

Answer 28

grapheme-color
- numbers or letters are associated with specific colors

Question 29

What is the etiology of synesthesia?

Answer 29

• seems to have a genetic component
• some evidence suggests it’s due to increased cross-activation and cross-connectivity between the brain’s sensory areas

Question 31

What is psychophysics?

Answer 31

the study of the relationship between the magnitude of physical stimuli and psychological sensations

Question 32

What are the 4 theories of psychophysics?

Answer 32

• Weber’s Law
• Fechner’s La
• Steven’s Power Law
• Signal Detection Theory

Question 33

What does Weber’s Law predict?

Answer 33

• that just noticeable difference (JND) for a stimulus is a constant proportion, regardless of the intensity of the original stimulus
• applies to only to some stimuli and to intensities in the mid-range
• (simple terms) expresses a general relationship between a quantity or intensity of something and how much more needs to be added for us to be able to tell that something has been added.

Question 34

What does Fechner’s Law predict?

Answer 34

• that there is a logarithmic relationship between psychological sensation and the magnitude of a physical stimulus
  (simple terms: the subjective sensation is proportional to the logarithm of the stimulus intensity)
• JND grows to an increasingly greater degree with each linear increment in intensity
• only works for some stimuli, but more accurate than Weber’s Law for stimuli at extreme intensities

Question 35

Which is more accurate: Weber’s Law, Fechner’s Law, or Steven’s Power Law?

Answer 35

Steven’s Power Law

Question 36

What does Steven’s Power Law propose?

Answer 36

• that there is an exponential relationship between psychological sensation and the magnitude of a physical stimulus AND
• that the exponent varies for different stimuli

Question 37

What was the research Steven’s Power Law is based on?

Answer 37

• the method of magnitude estimation
• required participants to assign numbers to stimuli based on the sensations they elicited
• EX. if a subject assigned a 3 to one weight and believed the next weight was 2x as heavy, they would then assign a 6 to the second weight

Question 38

What does Signal Detection Theory assume?

Answer 38

• that perception of a stimulus (signal) is the outcome of both sensory and decision-making processes