Chapter 4

Question 1

What’s the difference between sensation and perception?

Answer 1

sensation = simple stimulation of sense organ
perception occurs after sensation registers in nervous system; organizes, identifies, and interprets a sensation to form mental representation

Question 2

What is transduction?

Answer 2

when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system

Question 3

Define psychophysics

Answer 3

methods that measure the strength of a stimulus and the observers sensitivity to that stimulus

Question 4

What is the absolute threshold in psychophysics?

Answer 4

the minimal intensity needed to just barely detect a stimulus in 50% of trials

Question 5

What is the just noticeable difference? Describe relation to human perceptual system

Answer 5

the minimal change in a stimulus that can just barely be detected; humans are better at detecting changes in stimuli i.e. parents deciphering certain cries

Question 6

T/F The Just Noticeable difference is a fixed quantity

Answer 6

FALSE; depends on how intense stimuli being measured and on sense being measured

Question 7

What is Weber’s law?

Answer 7

The JND of a stimulus is a constant proportion despite variations in intensity; envelope vs. package

Question 8

What are the 2 things signal detection theory says about how we respond to stimuli?

Answer 8

the response to stimuli depends on both

1) the person’s sensitivity to the stimuli in the presence of noise and
2) the person’s response criticism i.e.their internal decision making (more often saying they saw light just to be safe)

Question 9

What are examples of sensory adaptation?

Answer 9

bakery smell fades, cold water not noticeable, bathroom light at night doesnt require squinting

Question 10

What are the benefits of sensory adaption?

Answer 10

can focus on change in stimuli

Question 11

What is visual acuity?

Answer 11

the ability to see fine detail

Question 12

What 3 characteristics of light do humans perceive?

Answer 12

length–> color
amplitude–> brightness
purity–> saturation

Question 13

Light reflected from an objects surface enters the eyes via the transparent _____, bending to pass through the _____ at the center of the _____. Behind the ____, the thickness and shape of the ____ adjust to focus light on the _____, where the image appears upside down and backward. Vision is clearest at the ______

Answer 13

cornea; pupil; iris; iris; lens; retina; fovea

Question 14

Muscles change the shape of the lens to focus objects at different distances, a process called _____

Answer 14

accomodation

Question 15

Cones detect ___/____ ___ and rods detect ____ ___

Answer 15

color, fine detail; night vision

Question 16

There are no ___ on the fovea

Answer 16

rods

Question 17

What do the bipolar cells do?

Answer 17

collect neural signals from the rods and cones and transmit them to the outermost layer of the retina

Question 18

What do the retinal ganglion cells do?

Answer 18

organize signals sent by bipolar cells and send them to brain

Question 19

What composes the optic nerve?

Answer 19

retinal ganglion cell axons

Question 20

Why is there a blind spot in the visual field?

Answer 20

the optic nerve leaves the eye through a hole in the retina, and this hole has no rods and cones

Question 21

What is area V1?

Answer 21

the part of the occipital lobe that contains the primary visual cortex

Question 22

What three types of cones are there?

Answer 22

long-wavelength (red)
medium-wavelength (green)
short-wavelength (blue)

Question 23

Ventral stream travels from occiptal lobe to ____ lobe; “___” pathway
dorsal stream travels up from occipital lobe to ____ lobe; “__” pathway

Answer 23

temporal; what

parietal; how

Question 24

What is the binding problem in perception?

Answer 24

how the brain links features together so that we see unified objects in our visual world rather than free-floating or miscombined features

Question 25

What is an illusory conjunction?

Answer 25

perceptual error where brain incorrectly combines features of multiple objects i.e. red A, black 8 experiment

Question 26

What is a feature-integration theory?

Answer 26

focused attention is not required to detect the individual features that make up a stimulus, such as the color, shape, size, and location of letters, but is the glue required to bind those individual features together

Question 27

What is perceptual consistency?

Answer 27

even as aspects of sensory signals change, perception remains constant

Question 28

Gestalt groupings:

Answer 28

• simplicity
• closure
• continuity: edges w/same orientation are grouped together
• similarity
• proximity
• common fate: moving together, same object

Question 29

According to image-based recognition theories, what is a template?

Answer 29

a mental representation that can be directly compared to a viewed shape in the retinal image

Question 30

What is the theory called that proposes we deconstruct objects?

Answer 30

parts-based object recognition

Question 31

What are some monocular depth cues?

Answer 31

• familiar size i.e. office chair lady
• linear perspective i.e. railroad tracks
• texture gradient i.e. cracked desert sand
• interposition i.e. apple blocking orange is closer
• relative height in image i.e. flowers are lower than mountain

Question 32

What is apparent motion?

Answer 32

perception of movement as a result of alternating signals appearing in rapid succession in different locations i.e. Vegas sign

Question 33

3 qualities of sound

Answer 33

frequency = pitch
amplitude = loudness
complexity = timbre

Question 34

What is the cochlea?

Answer 34

fluid-filled tube that is the organ of auditory transduction

Question 35

Cochlea is divided along its length by what?

Answer 35

basilar membrane, a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid

Question 36

Movement of the basilar membrance stimulates what?

Answer 36

hair cells, specialized auditory receptor neurons embedded in the basilar membrane

Question 37

What portion of the temporal lobe contains the primary auditory cortex?

Answer 37

a1

Question 38

What is the place code?

Answer 38

(high frequencies) diff frequencies stimulate neural signals at specific places along basilar membrane

Question 39

What is temporal code?

Answer 39

registers relatively low frequencies via the firing rate of action potentials entering the auditory nerve