Sensation and Perception

Question 1

sensation

Answer 1

process of receiving physical stimuli on receptors and then turning it into electrical signals in neurons

Question 2

perception

Answer 2

process of organizing and interpreting information to give it meaning

Question 3

bottom-up processing

Answer 3

like “entering data” into a computer, it’s when information starts at receptors and then goes up to the brain to get integrated

Question 4

integration

Answer 4

putting things together, building up

Question 5

top-down processing

Answer 5

like a “program” in a computer, it’s when established mental processes organize and interpret the information

Question 6

What are the differences between sensation and perception?

Answer 6

• sensation = bottom-up, perception = top-down
• sensation = objective, perception = subjective
• sensation = entering data, perception = organizes data
• perception uses past experiences, sensation does not

Question 7

absolute threshold

Answer 7

minimum stimulation needed to detect a stimulus at all, e.g. minimum volume to hear song on telephone

Question 8

difference threshold

Answer 8

minimum difference between competing stimuli to be able to notice there is a difference, e.g. minimum difference between two sounds to be able to tell which is louder

Question 9

just noticeable difference

Answer 9

the point where two stimuli are different enough to be able to tell them apart from one another

Question 10

priming

Answer 10

when you tell someone to expect a certain outcome, which then affects their perception

Question 11

signal detection theory

Answer 11

a theory that tries to explain what factors affect our ability to detect stimuli if there is background noise

Question 12

Which factors affect our stimulus detection thresholds?

Answer 12

• experience
• expectations
• motivation
• tiredness

Question 13

Give an example of an absolute threshold and of a difference threshold.

Answer 13

• absolute threshold of hearing = volume that you need to turn your phone up to to hear a song
• difference threshold = difference between volumes of two phones in order to tell which one is louder

Question 14

How can people’s perceptions be manipulated?

Answer 14

they can be given information about, like different labels on and different descriptions of, bottles of water, and asked to describe the differences between them, they say they do actually sense a difference in the taste even though they are the same bottle of water

Question 15

What happens as you increase the strength of a stimulus?

Answer 15

• below the absolute threshold, there is no perception
• as you increase it past the absolute threshold, there is perception of greater detail
• past a certain point, the signal becomes distorted, and we perceive less detail

Question 16

distortion

Answer 16

when detail of a signal cannot be perceived

Question 17

subliminal stimulus

Answer 17

when the strength of a signal is below the absolute threshold of perception

Question 18

What evidence is there that subliminal stimuli can affect our behaviour?

Answer 18

• definitely possible
• but only to a modest degree
• and under certain circumstances
• e.g. people have to already be wanting that thing
• e.g. iced tea

Question 19

Give two examples of the difference between sensation and perception.

Answer 19

• images are sensed upside-down (image is flipped on the receptors in the eye), but brain flips it back up so we perceive “right side up”
• there is a blind spot when we sense visual information where we can’t see, but our brain fills it in for us so we perceive without a hole in our vision

Question 20

Give an example of how we know perception is subjective.

Answer 20

• when asked to count the number of letters ‘f’ in a phrase after reading it out loud, people will say fewer than the actual number because ‘f’ has a ‘v’ sound at the end of words like “of”

Question 21

Give examples of when your brain adds information as part of perception.

Answer 21

• people will see a triangle that is not actually there when shown a picture of circles with pieces cut out of them

Question 22

closure

Answer 22

when our brain fills in gaps when there are “disparate pieces of data”, that is pieces of data that look like they should go together in a certain arrangement

Question 23

Why is the subjectivity of perception important?

Answer 23

closure causes us to create information that is not there, come up with a false narrative, and therefore make incorrect conclusions, like thinking something is there when it is not

Question 24

What is an “ambiguous image”?

Answer 24

a drawing that looks to be one thing for some people but a different thing for other people

Question 25

What is the significance of ambiguous images?

Answer 25

it means perception is subjective

Question 26

Why do we perceive differently?

Answer 26

prior experience shapes tendencies to perceive things in our own unique way?

Question 27

What is the main reason that perception is subjective?

Answer 27

selective attention

Question 28

selective attention

Answer 28

focussing awareness only on a particular stimulus

Question 29

What is an example of an experiment to show that selective attention affects perception?

Answer 29

“Necker cube”: show someone a certain picture of a cube and they will be able to perceive cubes facing different ways depending on where they focus their attention; if the cube is made of holes it can also look as if it behind a board

Question 30

What is the Necker cube and what does it show?

Answer 30

• when you arrange circles with lines through them so that you perceive a cube, you can actually perceive four different cubes that you can perceive depending on where you focus on your attention
• this shows that perception is subjective due to selective attention

Question 31

change blindness

Answer 31

when we are watching something, this can distract us so that we don’t notice changes that are happening right in front of our faces

Question 32

Give an example of an experiment that shows change blindness.

Answer 32

• guy giving directions doesn’t notice that the guy has changed with the other guy when a board goes by
• this is because the guy giving directions is not paying attention to the guy

Question 33

Is people using devices and driving safe?

Answer 33

• no, because their attention is being diverted
• we cannot maintain full attention while doing multiple things
• our perception is changed by diverting our attention

Question 34

gestalt

Answer 34

tendency to integrate pieces of information into a meaningful whole

Question 35

Gestalt Theory

Answer 35

the theory that we group information together using a grouping principle to make a complete group, which is the reason that we saw a triangle when there was none in one of the optical illusions

Question 36

What are some examples of grouping principles?

Answer 36

• proximity = grouping nearby things together
• similarity = grouping similar things together
• continuity = perceiving continuous patterns
• connectedness = grouping connected things together
• closure = filling in gaps

Question 37

Give two examples of perceptual constancy

Answer 37

• if you see someone from far away even though they look smaller you still understand how big they actually are
• when you open a door even though it looks thinner and taller you still perceive it to be the same door that is just moving

Question 38

perceptual constancy

Answer 38

when we perceive something as continuing to be a whole object even though the way it looks changes

Question 39

perceptual set

Answer 39

a tendency to perceive certain things when presented with certain stimuli

Question 40

schema

Answer 40

mental framework in which we interpret incoming information

Question 41

Why are schemas important?

Answer 41

• since schemas affect the way we perceive things, negative schemas can make us interpret events more negatively, which is one cause of depression
• therefore schemas can be altered in order to retrain the way we think, as a treatment for depression
• this is the basis of cognitive behavoiural therapy

Question 42

Give an example of a perceptual set.

Answer 42

• words that sound alike: folk, croak, soak
• now if you say them next to each other then when you are asked a question like “what’s the white stuff in eggs” you will answer incorrectly and say “yoke”
• you are grouping the words together, and based on Gestalt Theory and closure you will fill in any gaps to make a complete whole

Question 43

parallel processing

Answer 43

when we simultaneously (at the same time) process multiple aspects of a stimulus

Question 44

How do we visually process information?

Answer 44

using parallel processing we process four aspects of visual stimulus at the same time:

• colour
• motion
• form
• depth