Sensation and Perception

Question 1

The Detection Question

Answer 1

The limits on our ability to detect very faint signals.
Involves absolute threshold

Question 2

Absolute Threshold

Answer 2

the minimum amounts of energy in a sensory stimulus detected 50% of the time

the amount of energy that has an equal probability of being detected or not detected

ex. how close to we have to be to see the candle on the mountain, how far from the clock can we be to still heat it tick

Question 3

Subliminal

Answer 3

Stimuli detected less than 50% of the time, not enough energy to be sensed

Question 4

What is subliminal advertising and does it work?

Answer 4

Giving hints to people that they cannot consciously detect that are supposed to be influencing them to buy something. No! it doesn’t work.

Question 5

Signal Detection Theory

Answer 5

our ability to detect a faint sensory signal

has to do with the decision-making part of it, is there enough stimuli to decide that it is present

ex. a juror has to decide if they have enough info to choose innocent or guilty. people may have the same amount of information(stimuli) but choose differently if it is enough evidence to make a decision

Question 6

4 types of outcomes in signal detection

Answer 6

a hit - saying yes when there is a signal
a miss - saying there is no signal when there is one
a false alarm - saying yes when there is none
a correct rejection - saying no when there is none

Question 7

is detecting cancer on an x-ray a signal detection test

Answer 7

yes

Question 8

lax decision criteria

Answer 8

-a tendency to say yes with little evidence
-makes many false alarms
-has few misses

Question 9

strict decision criteria

Answer 9

-only says yes with a lot of evidence
-makes many misses
-has few false alarms

Question 10

the difference question

Answer 10

how different does a stimulus have to be for us to notice the difference

Question 11

difference threshold
just noticeable difference
jnd

Answer 11

the minimum difference between two stimuli to ne detected 50% of the time

Question 12

Weber’s Law

Answer 12

for each type of sensory judgment that we can make, the measured difference threshold is a constant fraction of the standard stimulus value used to measure it

ex. for touch we can notice something 1/10 different. One box is 10 pounds, the other box will have to be 11 pounds to notice a difference.

• we notice proportional differences and not absolute differences

Question 13

the scaling question

Answer 13

how do we perceive scale stimulus compared to how it physically is? if a light is 10 times brighter perceptually, how much brighter is the light physically?

Question 14

Stephen’s Power Law

Answer 14

the perceived stimuli is changed by the increase of the physical change to a constant power.

ex. a light is 5 times brighter, physically it is 5^2 times brighter. that same light is 8 times brighter, physically is is 8^2 times brighter.

Question 15

sensory adaptation

Answer 15

sensitivity to unchanging stimuli disappears over time (not including intense, painful stimuli)

ex. a humming of an air conditioner may bother you at first but eventually you won’t notice it

• we have adapted to detect changes, not constants

Question 16

wavelength

Answer 16

700 - 400 = red - violet

Question 17

amplitude

Answer 17

amount of energy in a wave

ex. larger amplitude = brighter light, larger amplitude = louder sound

Question 18

frequency

Answer 18

number of waves in a second
higher pitch = higher frequency
lower pitch = lower frequency

Question 19

McGurk Effect

Answer 19

conflicting audio and visual stimuli, brain blends sensory info together
- if u listen to sound “ba” and see someone mouthing “ga” you actually hear “da”

Question 20

transduction

Answer 20

receptor cells transfer energy (like light, sound, touch) to neural impulses the brain can understand

Question 21

retina

Answer 21

contains light receptor cells, back of the eyeball, where transduction occurs

made up of 3 layers, ganglion, bipolar, receptors (cones and rods)

Question 22

cornea

Answer 22

clear, hard surface of the eye, bends light waves to focus on the retina

Question 23

pupil

Answer 23

tiny hole where light enters the eye

Question 24

iris

Answer 24

colored part of eye, muscle that makes pupil bigger/smaller to allowed more/less light in

Question 25

lens

Answer 25

focuses light waves from objects of different distances onto the retina

Question 26

accommodation

Answer 26

the focusing of light waves from objects of different distances onto the retina

Question 27

nearsigtedness

Answer 27

light waves from distance objects come into focus in front of the retina

Question 28

farsightedness

Answer 28

light waves from nearby objects come into focus behind the retina

Question 29

what seems to cause nearsightedness?

Answer 29

more years of education, more time indoors doing close work, less time outside

Question 30

blindsight

Answer 30

what can happen after your visual processing is damaged

they can see but cannot process anything they are seeing

Question 31

rods

Answer 31

120 million in each eye
mainly in the peripheral vision
responsible for dim light vision
colorless vision
low visual acuity

Question 32

cones

Answer 32

6 million in each eye
main in fovea and central vision
bright light vision
color vision
high visual acuity

Question 33

dark adaptation

Answer 33

rodes and cones become more and more sensitive to light in dim conditions

Question 34

Trichromatic theory

Answer 34

3 types of cones - blue, green, and red

Question 35

additive measures

Answer 35

different wavelengths of light are directly mixed together - wavelengths of light reach the retina together

Question 36

subtractive measures

Answer 36

some wavelengths are absorbed instead of reflected so they do not reach the retina

Question 37

opponent process theory of color

Answer 37

there are pairs of cells (red/green, blue/yellow, black/white) when one color is activated the other is turned off. explains complementary color afterimages

Question 38

cochlea

Answer 38

snail-shaped structure that contains receptor cells for hearing

Question 39

hair cells

Answer 39

line the basilar membrane, are receptors for hearing
16,000 in each ear
code the neural impulses sent to the brain

Question 40

nerve deafness

Answer 40

hearing loss caused by damage to hair cells or nerve fibers

Question 41

conduction deafness

Answer 41

hearing loss caused by damage to the mechanical system carrying info to the cochlea (ex. puncturing an eardrum)

Question 42

place theory

Answer 42

each specific frequency has a specific spot on the basilar membrane that responds to its frequency, therefore the brain will know what the frequency is based on where on the membrane it is

works from 500Hz - 20,000 Hz

Question 43

frequency theory

Answer 43

the wave moves the hair cells and that fires an impulse, a frequency will fire the impulse every time a wavelength passes

works from 20 - 5000 Hz