Perception

Question 1

What is sensation

Answer 1

Stimulus detected in the environment and processed by sense receptors.

Question 2

What is perception

Answer 2

The organization and interpretation of sensory information. It is the combination of
information received by a sense receptor, such as the eye, and the brain’s interpretation of
what that information means.

Question 3

Whats the difference between sensation and perception

Answer 3

Sensation is what we experience through our senses, physical changes in the environment
detected by our sense receptors.

Perception is how the brain organises and interprets those sensations.

Question 4

What are visual cues

Answer 4

Visual cues are features of our environment that give us information about movement,
distance and where things are in relation to one another. For example, depth cues.
There are two types of depth cue: monocular and binocular depth cues.

Question 5

What are monocular depth cues

Answer 5

Monocular depth cues: Allow judgement of depth and distance using just one eye.

Question 6

What are binocular depth cues

Answer 6

Binocular depth cues: Allow judgement of depth and distance using both eyes.

Question 7

Monocular depth cues examples

Answer 7

Height in plane
Relative size
Occlusion
Linear perspective

Question 8

Height in Plane AO1

Answer 8

Objects that are higher up in the visual field appear to be further away.

Question 9

Relative size AO1

Answer 9

When objects appear smaller in the visual field than
known objects of a similar size, showing that they are further away.

Question 10

Occlusion AO1

Answer 10

The objects that are behind or obscured by other objects are further away.

Question 11

Linear perspective AO1

Answer 11

Lines that are parallel, like on a road or a railway track, appear to get closer together and come to a point in the distance. This shows that the point (where the lines meet) is further away.

Question 12

Binocular depth cues examples

Answer 12

Retinal disparity
Convergence

Question 13

Retinal desparity AO1

Answer 13

The closer an object is, the bigger the difference in the two images. The further away the object is, the smaller the difference in the two images.

Question 14

Convergence AO1

Answer 14

If two things converge, they become closer together. The muscles around our eyes work harder when viewing objects up close. When looking at an object that is far away, the muscles are relaxed as our eyes are looking straight ahead. This ‘muscle information’ provides our brain with information about
the depth and distance of objects in our environment.

Question 15

Explanations for visual illusions: Size constancy

Answer 15

The brains’ ability to perceive familiar objects as the same size, despite changes in size of the
image on the retina

Question 16

Explanations for visual illusions: Misinterpreted depth cues

Answer 16

Depth cues help us perceive distance. When we have perceived distance, our brain uses size
constancy (perceiving objects and people as a constant size).
However, sometimes our brain interprets distance when it is not actually there. For example,
the Ponzo illusion and Muller-lyer illusion, fool the brain into perceiving distance because
we apply size constancy when we should not. As such, we misinterpret depth cues.

Question 17

Examples of misinterpreted depth cues: The ponzo illusion

Answer 17

➢ Converging lines in the image give the impression of distance like a road or railway track.
➢ Our brain, using size constancy, mentally enlarges it, making the top line longer than it is and longer than the line at the bottom. The line at the top is not ‘really’ longer, it is just perceived as being further away.

Question 18

Example of Misinterpreted depth cues: The muller lyer illusion

Answer 18

➢ The line with the outgoing fins is
perceived as longer than the line with
ingoing fins (size constancy)
➢ This is because we perceive one line as
closer to us
➢ The theory is that we unconsciously
perceive the vertical line with the ingoing fins as the outside corner of a building and the
vertical line with the outgoing fins as the inside corner of a room (misinterpreted depth cues)

Question 19

Examples of misinterpretted depth cues

Answer 19

The Ponzo Illusion
The Muller-lyer illusion
The Ames room

Question 20

Explanation for visual illusions: Ambiguity

Answer 20

An ambiguous figure is when there are two possible interpretations of the same image, and
the brain cannot decide which one to choose.

Question 21

Examples of Ambiguity

Answer 21

The Necker Cube
Rubin’s Vase

Question 22

Example of Ambiguity: The necker cube

Answer 22

Example: The Necker cube
➢ The cube can be perceived as either pointing
upwards to the right or downwards to the left.
➢ After 30 seconds, most people can ‘flip’ between the two interpretations

Question 23

Explanations for visual illusions: Fiction

Answer 23

This is when a person perceives something in the image that is not actually there. The image
or stimulus may suggest a certain aspect of the figure is present, but it is not.

Question 24

Example of Fiction

Answer 24

The Kanizsa triangle

Question 25

Example of Fiction: the Kanizsa Triangle

Answer 25

➢ The image suggests that there is a second triangle
overlapping the first (even though there is nothing
there).
➢ Illusory contours create the impression that the
overlapping triangle has continuous edges all the way around it.

Question 26

Gibsons Direct theory of perception AO1

Answer 26

Perception is innate and sensation and perception is the same. A way that the brain percieves info is through optic flow. Optic flow suggests that the object we moves towards stays stationary whereas objects that surround it are moving. Another way is motion parallax which refers that when we are moving objects closer to us appear to be moving faster than objects further away. Therefore perception is due to nature rather than nurture as our optic array provides enough info to judge depth, distance, and movement without needing to make inferences using past experience.

Question 27

Gibsons direct theory of perception AO3

Answer 27

Research to support Gibson’s direct theory of perception was conducted by Gibson and Walk (1960). They created a ‘visual cliff’ and placed 6 month old babies on the edge (looks like a severe drop to the baby). It was found that very few babies would crawl across ‘the cliff’ to their mothers. This
implies that some parts of human perception are most likely innate, as Gibson’s direct theory suggests.

One weakness of Gibson’s direct theory of perception is that it struggles to explain visual illusions. Gibson’s theory suggests that we will always perceive accurately without need for inference and past experiences. However, visual illusions can trick the brain into misperception. This suggests that perception is more complex than Gibson’s direct theory implies.

A weakness of Gibsons theory of perception is that there is an alternative explanation from Gregory. Gregory states that perception is not direct and is based on nurture rather than nature whereas Gibson states perception is innate and not based on inferences. Therefore, Gibsons theory may not be the only explanation of perception.

Question 28

Gregorys constructivist theory of perception AO1

Answer 28

Gregory claims that perception is not direct. Perception is an active process and
involves drawing inferences. Stored knowledge (SCHEMA) and expectations come from past experiences. Perception is learned and due to nurture rather than nature.

The brain uses visual cues to help us perceive things Sometimes we interpret these cues incorrectly, for example, the case of visual illusions. Gregory calls this a ‘mistaken hypothesis’, meaning that our brain has drawn the wrong conclusion from the available evidence.

Question 29

Gregorys constructivist theory AO3

Answer 29

One strength of Gregory’s constructivist theory of perception is that there is supporting research conducted by Hudson. The study demonstrated that experience
affects how visual cues are interpreted. This supports the notion that perception is rooted in learning and nurture rather than nature, suggesting that Gregory’s idea that
perception is ‘constructed’ is accurate.

Gregory’s constructivist theory of perception can be criticised further as it is unable to explain how perception starts. Research has shown that infants as young as 6 months can perceive depth (Gibson and Walk) and that babies have perceptual abilities at birth. For example, they show a preference for human faces compared to random patterns (Fantz). Therefore, some perception may be due to nature rather than nurture, contradicting Gregory’s assertion.

A weakness of Gregorys theory of perception is that there is an alternative explanation from Gibson. Gibson states perception is innate and not based on inferences whereas Gregory states perception is not direct and is based on nurture. Therefore Gregory’s theory may not be the only explanation of perception.

Question 30

Perceptual set AO1

Answer 30

The tendency of our brain to notice, or prefer, certain aspects of the sensory environment.
This means that other aspects of the sensory environment are noticed less or ignored.

Question 31

Factors affecting perceptual set

Answer 31

➢ Culture
➢ Motivation
➢ Emotion
➢ Expectation

Question 32

Factors affecting perception Culture AO1

Answer 32

Culture refers to the beliefs, attitudes and expectations that surround us. What we are familiar with from our SCHEMA’s determines how we interpret sensory information.

Question 33

Factors affecting perception: Motivation AO1

Answer 33

Motivation refers to the forces that drive your behaviour as it influences the way we percieve and interpret visual stimuli.

Question 34

Factors affecting perception: Emotion AO1

Answer 34

Emotion is a strong feeling or mood that has important motivational properties.
They drive an individual to behave in a
certain way.

Question 35

Factors affecting perception: Expectation AO1

Answer 35

Expectation is a belief about what is likely to happen based on past experience.
Expectation affects perceptual set because you are more likely to notice or attend to certain stimuli because you are anticipating them.

Question 36

Factors affecting perception: Culture-Hudsons study AO1

Answer 36

Aim: Hudson aimed to find out whether people from different cultural/educational backgrounds perceived depth cues in 2D images differently.

Method: Hudson showed 2D drawings, which showed an antelope, an elephant and a man with a spear, to people from different cultures and educational backgrounds.
➢ Black South Africans who were schooled
➢ Black South Africans who were
unschooled
➢ White South Africans who were schooled
➢ White South Africans who were unschooled
Hudson asked participants: Which is nearer the man, elephant or antelope?

Results: most ppts replied ‘the elephant’
Both black and white schooled participants were more likely to perceive depth than unschooled participants.
White schooled participants were more likely to perceive depth than black schooled participants.

Conclusion: People from different cultural/educational backgrounds use depth cues differently and have a different perceptual set.
This supports Gregory’s theory as it shows that depth cues are learned.

Question 37

Factors affecting perception: Culture-Hudson’s study AO3

Answer 37

One weakness is the instructions may not make sense. The language barrier means translations of the method may have been unclear.
This will therefore affect the validity of the results.

One weakness is that the research is from a long time ago and may be poorly designed.
Early cross-cultural studies of perception often did not include things like proper control groups.
This caused the results of cross-cultural differences in perception to lack validity.

Question 38

Factors affecting perception: Motivation-Gilchrist and Nesburg’s Study AO1

Answer 38

Lab experiment

Aim: Gilchrist and Nesberg aimed to find out if food deprivation affects the perception of pictures of food.

Method: Two groups of students: one group deprived of food for 20 hours and a control group (not hungry).
Students were shown four slides, each one showing a meal.
The slide was displayed for 15 seconds.
The picture was shown again, but dimmer, and participants had to adjust the lighting to make it look the same as it did before.

Results: Participants perceived the food as brighter the longer they were deprived of food.
The control group (who were not deprived of food) didn’t perceive the food as brighter.

Conclusion: Being deprived of food increased perceptual sensitivity.
This shows that hunger is a motivating factor that affects the way food-related pictures are perceived.

Question 39

Factors affecting perception: Motivation- Gilchrist and Nesburg’s study AO3

Answer 39

One strength is that similar studies have found similar results. Sanford deprived participants of food and showed them ambiguous pictures. The longer they were deprived of food the more likely they were to see food. This increases the validity of the Gilchrist and Nesberg results.

A problem with studies in this area is that they are unethical. This is because depriving participants of food and water could cause them to feel uncomfortable. This is an issue as you should not do this in psychological research

Question 40

Factors affecting perception:Emotion-McGinnie’s Study AO1

Answer 40

Aim: McGinnies wanted to see whether things that cause anxiety are less likely to be noticed than things that are emotionally neutral.

Method: Eight male and eight female students were shown neutral and offensive ‘taboo’ words flashed on a screen.
After each word was shown participants had to say it out loud.
The amount of emotional arousal was measured through their galvanic skin response (GSR) which records electrical changes in the skin.

Results: Participants took longer to say offensive words than neutral ones.
Taboo words produced bigger changes in the GSR than neutral words.
Conclusion: This shows that emotion affects perceptual set.
Perceptual defence is used by the brain when confronted with words that are offensive or cause anxiety.

Question 41

Factors affecting perception: Emotion-McGinnie’s Study AO3

Answer 41

One strength of this study is that it used an objective measurement of emotion.
A scientific method was used – the galvanic skin response – to test biological anxiety responses.
This produces results that are less open to bias than, for example, rating scales.

One weakness is that delayed recognition may be more to do with embarrassment.
Participants may have hesitated in giving their response as they were uncomfortable repeating rude words in a study.
This suggests that awkwardness may have been an extraneous variable.

Question 42

Factors Affecting perception: Expectation-Bruner and Minturn’s Study AO1

Answer 42

Aim: To investigate whether expectation affects perceptual set.

Method: Using an independent groups design, participants were shown the sequence of letters (from top to bottom of diagram) or the sequence of numbers (from left to right). In each case the stimulus in the middle was the same. Participants reported what they saw.

Results: The group that was shown the sequence of letters were more likely to draw the ambiguous
figure as a letter ‘B’.
The group that was shown the sequence of numbers were more likely to draw the figure as a
‘13’.

Conclusion: This shows that expectation of what the figure represented was affected by the context that the figure was presented in.

Question 43

Factors affecting perception: Expectation-Bruner and Minturn’s Study AO3

Answer 43

One strength of this study is that it has real-life application. It can explain errors that people make as the results suggest that expectations can influence perception. This helps to explain why people make sometimes serious mistakes on tasks in the real world.

One weakness of the study is that it used an artificial task. An ambiguous figure is designed to trick perception. This makes the results lack validity.