chapter 2: perception sensation and perception 2.1 the

AQA GCSE Psychology Activity Cara Flanagan, Ruth Jones, Mark Jones, Rob Liddle ©Illuminate Publishing 2017

Task: Here are some AO1 descriptions about sensation and perception. Use the words at the bottom of the sheet to complete the passages.

If you fancy more of a challenge, complete the passages without looking at the missing words.

The sensation and perception gap fi ll

Handout2.1

Sensations are processed by sense ………………………….. These are our …………………………. senses (eyes, …………………………., sense of …………………………., taste and touch) which allow us to experience the world around us.

Perception is the organisation and interpretation of sensory information. It is the combination of the information received by a sense receptor (e.g. the ………………………….) and the …………………………. interpretation of what that information means.

For example, how do we know what to do with a chair when we see one? It is the brain’s job to first …………………………. information received by the eye and then work out what the chair is for. The brain might use past …………………………. to help it do this.

The difference between sensation and …………………………. might be summed up as the difference between ‘feeling’ and ‘thinking’. Sensation is our body’s way of detecting a

…………………………. in the environment, such as …………………………. waves (vision) or sound waves (………………………….). Perception is how our brain organises and interprets these …………………………..

But the brain sometimes makes mistakes, as in the case of visual …………………………..

The Ponzo illusion is an example of a misinterpreted depth cue. Such misinterpretations are usually to do with size or length. In the Ponzo illusion, the horizontal line higher up in the image appears …………………………. than the horizontal line towards the bottom. Both lines are actually the …………………………. size.

Another misinterpreted depth cue, the ………………………….–…………………………. illusion, is also to do with the distortion of line ………………………….. This time the vertical line with the outgoing ‘fins’ is perceived as longer than the line with the ingoing ‘fins’. Again, both lines are actually the same size.

Rubin’s vase is an …………………………. figure, like the duck–………………………….. After staring at this image for a few seconds, you should be able to perceive it as either a vase or as two …………………………. staring at each other. Both interpretations are ‘correct’ so your brain cannot decide which one to focus on.

The Ames …………………………. is another famous illusion based on a misinterpreted depth cue. If two people are standing on either side of the back wall, one appears to the observer to look like a …………………………. whilst the other appears to be tiny.

light eye rabbit process fi ve stimulus

longer receptors length faces illusions Müller

Lyer experience giant sensations brain’s Room

smell hearing ambiguous perception same ears

Chapter 2: Perception Sensation and perception pages 40–41


AO1 card sort/match up

Handout2.2

Here are several statements related to visual cues and visual constancies.Match up the statements in the left column with the statements in the right column.You could cut these statements up – mix them and sort them out.Once you’ve successfully matched the cards, you can use the information to complete the table.

1. Monocular depth cuesA. Refers to distance between two eyes, each pro-

ducing different images of the world.

2. Binocular depth cuesB. Objects covered by other objects appear to be

further away.

3. Retinal disparityC. Eye muscles work harder when viewing

objects that are close.

4. ConvergenceD. Objects that appear smaller in the visual fi eld than other

objects we know to be of similar size appear to be further away.

5. Height in plane E. These will only ‘work’ with both eyes.

6. Relative sizeF. Parallel lines appear to converge at a point in the

distance.

7. Occlusion G. These ‘work’ even with one eye covered.

8. Linear perspectiveH. Objects higher up in the visual fi eld appear further

away.

Retinal disparity

ConvergenceHeight in

planeRelative size Occlusion

Linear perspective

Monocular depth cues:

Binocular depth cues:

✁

Chapter 2: Perception Visual cues and constancies pages 42–43


Applying your knowledge of visual cues

Handout2.3

ExampleName of cue, type of cue, how does it allow us to

perceive depth?

You hold a pencil close to your face and stare at it. As you open and close one eye at a time, the pencil ‘jumps’ a lot. A friend holds the pencil further away while you repeat the procedure. This time it doesn’t jump much at all.

What cue and what type of cue? This is the result of retinal disparity, a binocular depth cue.

How does it work? Because our two eyes are a few centimetres apart, they receive slightly different images of the pencil. The difference between images is greater when the pencil is closer to your face, so the ‘jump’ is greater too. This is useful information about distance/depth – the smaller the ‘jump’, the further away the object must be.

You take up your pencil again. This time you hold it up close and stare at it as you move it further from your face. As you do so, your eye muscles seem to relax.

What cue and what type of cue?

How does it work?

You are looking at a photo that you took on holiday of the sea. You notice how the horizon where the sea ‘meets’ the sky is a lot higher up than the beach.


How does it work?

You are watching the famous clip from Father Ted, in which Father Dougal sees a herd of cows in the far distance and thinks they are very small. You laugh because you know he has made a mistake.


How does it work?

You are in the college canteen one day when you hear your friend’s voice. You look and see that there are several other students almost completely blocking your view of her.


How does it work?

A child is drawing a picture of a straight road disappearing into the distance. But it doesn’t look right because the road is the same width all the way along its length.


How does it work?

The table below gives you some examples of visual cues.

You have to use your knowledge of perception to describe how visual cues allow us to perceive depth in these examples. What cue is being described, what type is it and how does it work? The first one is done for you to get you going. Try to provide the same level of detail in your responses.

Chapter 2: Perception Visual cues and constancies pages 42–43


Task: There are 17 sentences below about visual illusions and how they are explained. Unfortunately each sentence has broken up into two pieces. Your job is to put them back together again.

Jumbled sentences

Handout2.4

Start of sentence End of sentence

1. Our brain knows that people seen from a great height are not really ‘ant-size’ but are instead…

A. … mentally enlarges the top line, making it appear longer than the line at the bottom.

2. When someone walks towards us we know they are not really growing in size, but…

B. … I still know it’s my friend and not a tiny version of them.

3. Size constancy refers to… C. … we perceive one line as closer to us (the one with outgoing

fi ns).

4. Depth cues help us to… D. … just a long way away making them appear smaller than

they are.

5. Things in the distance which appear smaller than they should be are…

E. … the Ponzo and Müller–Lyer illusions.

6. When I see my friend a long way away… F. … applying the rule of size constancy when it should not be

used.

7. Some illusions (e.g. Ponzo and Müller–Lyer) fool the brain into…

G. … the outside corner of a building, which would be projecting out at us.

8. The Ponzo illusion works because… H. … two possible interpretations of the same image.

9. In the Ponzo illusion, our brain applies the rule of size constancy and…

I. … either pointing upwards to the right, or downwards to the left.

10. In the Müller–Lyer illusion the line with outgoing ‘fi ns’ is perceived as longer than the line with ingoing fi ns because…

J. … how our brain perceives objects and people as being of a constant size.

11. In the Müller–Lyer illusion we unconsciously perceive the vertical line with ingoing fi ns as…

K. … illusory contours which create the impression that the overlapping triangle has continuous edges all the way around it.

12. Some illusions are called distortion illusions, and these include…

L. … perceive distance.

13. Some illusions are ambiguous fi gures, such as… M. … converging lines in the image give the impression of

distance (like a road or a railway track).

14. An ambiguous fi gure is where the brain cannot choose between…

N. … the person starts to perceive something in the image that is not actually there.

15. The Necker cube can be perceived as… O. … ‘scaled up’ by our brain to make them look normal size.

16. ‘Fiction’ refers to a visual illusion when… P. … their image on our retina gets larger as they get nearer.

17. The Kanizsa triangle works using… Q. … the duck–rabbit and Rubin’s vase.

Chapter 2: Perception Visual illusions pages 44–45


Visual illusions crossword

Handout2.5

Across

6. These everyday street structures might explain 4 down. (9)

7. These two animals make up a famous ambiguous figure. (4, 6)

8. This is why we know our friend is far away rather than very small. (4, 9)

10. Illusions that can be seen more than one way. (9, 7)

11. This illusion sounds like you might want to put some flowers in it. (6, 4)

12. Ponzo and Müller–Lyer are illusions. (10)

14. We see illusions because we depth cues. (12)

16. His illusion is a cube. (6)

Down

1. His illusion is a triangle. (7)

2. This organ is where perception takes place. (5)

3. This depth cue is why the Ponzo illusion happens. (6, 11)

4. The illusion with the arrows and the fins. (6, 4)

5. The type of illusion that’s also a type of literature. (7)

9. You could apply his illusion to an escalator. (5)

12. These allow us to perceive distance. (5, 4)

13. Back of the eye, detecting light from objects. (6)

15. The contours in Kanizsa’s triangle are . (8)

1

2

3 4

5

6

7

8 9

10

11 12 13

14 15

16

Chapter 2: Perception Visual illusions pages 44–45


Writing an essay

Handout2.6

Task: Write an answer to the above question. There are three ways to do this. You could follow…

l THE HARD PATH: Write your answer with just the minimal guidance given below.

l THE SLIGHTLY TRICKY PATH: Write your answer with the more extensive guidance given below.

l THE EASY PATH: Write your answer by � lling in the gaps for AO1 and completing the match-up for AO3.

You are currently on…

THE HARD PATHJust remember that the 9 marks are made up of 4 marks for AO1 and5 marks for AO3.The rest is up to you.Next time… aim to maintain this level of performance.

AO1 [4 marks]

l Aim to write about 100 words to describe the main features of Gibson’s theory.

l Start with a sentence explaining what makes Gibson’s theory a ‘direct’ theory of perception.

l The textbook provides four main features of the theory: direct perception, optic fl ow patterns, motion parallax, and the infl uence of nature. One or two sentences explaining each of these is advisable.

l Use appropriate psychological terms.

AO3 [5 marks]

l Aim to write about 120 words, made up of three evaluative statements of about 40 words each.

l Use PEC for each evaluative statement:

• POINT: Identify what the strength or weakness is.

• EVIDENCE: Justify that point with some evidence (either a fact or a research fi nding).

• CONCLUSION: Draw a conclusion about what the evidence shows.

You are currently on… THE SLIGHTLY TRICKY PATH

Next time… try the hard path.

You are currently on…

THE EASY PATHAO1 element – fi ll in the gaps:

Gibson’s theory states that …………….……………. happens directly because the visual …………….……………. gives us all the information

our …………….……………. needs. So, …………….……………. and perception are the same thing. Optic …………….…………….

patterns occur when the point we are moving …………….……………. stays stationary whilst the rest of the view seems to rush away

from it. If there is no ‘fl ow’, the brain knows we are not …………….…………….. Motion …………….……………. is a monocular

…………….……………. cue that helps us understand speed of movement. Objects closer to us in our visual …………….……………. are

moving …………….……………. than objects further away from us. Gibson says we do not …………….……………. to perceive the world

around us. Our perceptual abilities are …………….……………. and allow us to deal with our surroundings without the need for

past …………….……………..

Describe and evaluate Gibson’s direct theory of perception. [9 marks]

a

Chapter 2: Perception Gibson’s direct theory of perception pages 46–47

Next time… try the slightly tricky path.


Writing an essay

AO3 element:There are nine sentences below – three sentences for each evaluative point.

Place the sentences into the table in the correct order: Point – Evidence – Conclusion.

Gibson proposed that we will always perceive accurately whereas illusions trick the brain into misperception.

A strength of Gibson’s theory is support from Gibson and Walk’s research.

This suggests that there is more to perception than his theory proposes.

This makes it more relevant to explain how we perceive the world on a daily basis.

They found that very few infants would crawl off a visual cliff.

A strength of Gibson’s theory is that it has real-world meaning.

A weakness of Gibson’s theory is that it struggles to explain visual illusions.

This suggests that infants are born with an ability to perceive depth, which shows that some perception is innate.

His research was based on the experience of pilots from the Second World War.

Handout2.6

Point(identify the strength or weakness)

Evidence(justify the point with evidence – either a fact or research fi nding)

Conclusion(draw a conclusion about what the

evidence shows)

b



Richard Gregory speaks

Handout2.7

Task: Below you will find Richard Gregory outlining his theory of perception to a GCSE examiner. Unfortunately the examiner is not impressed because Richard Gregory has not done enough to explain his theory. So you will have to join in. Take each of Professor Gregory’s statements and explain what they mean in words the examiner will understand. Use the column on the right and remember… keep it simple!

Perception is a construction.

Inference is important.

We use visual cues.

Perception is learned.

What does that mean?

Please explain.

I need more than that.

More detail please.



Is it tr ue or is it false?Task: How much do you remember about Gregory’s theory of perception? Below are nine statements about this topic. Write in the middle column whether each statement is true or false. If you think a statement is false, give the correct answer in as much detail as you can. This first is done for you. Try to provide the same level of detail in your responses.

Handout2.8

Statement True/FalseIf it’s false, give the correct answer in as much detail as

you can

According to Gregory, we perceive the world directly.

False

It is Gibson who claims we perceive the world directly. Unlike Gibson, Gregory believes that perception is not the same as sensation. So we perceive the world indirectly because our brain has to interpret and understand what our eyes see.

Gregory’s theory suggests that the environment contains all the information we need to perceive the world accurately.

According to Gregory, the brain perceives the world as it is and has no need for visual cues.

According to Gregory, visual illusions occur because the brain makes mistaken hypotheses and draws the wrong conclusion from evidence.

Gregory says that our perceptual abilities are innate – they are already there at birth.

Research has shown that the way we are raised can be an important infl uence on the way we see things.

One strength of Gregory’s theory is that it correctly argues that perception of cues is the same in all cultures.

A weakness of Gregory’s theory is that it has diffi culty explaining visual illusions.

Another weakness is that Gregory’s theory cannot explain how perception gets started in the fi rst place.

Chapter 2: Perception Gregory’s constructivist theory of perception pages 48–49


AO3 card sort/match up

Handout2.9

Here are nine sentences about perceptual set and culture.

The sentences make up three evaluative points – that’s three sentences for each point.

Each point follows the PEC pattern of evaluation:

• The fi rst sentence is POINT – identify what the evaluative point is (usually a strength or weakness).

• The second sentence is EVIDENCE – justify the point with some evidence (e.g. a fact or a research fi nding).

• The third sentence is CONCLUSION – draw a conclusion about what the evidence shows.

Following this pattern, construct the three evaluative points from the nine sentences.

Once you have done this successfully, record your response by completing the table.

When more familiar materials such as cloth were used participants gave different answers.

Hudson’s research is from a long time ago and may have been

poorly designed.

Hudson’s instructions may not have made

sense to hisparticipants.

Some of Hudson’s participants may have

been confused byseeing drawings on

paper.

The language barrier means translations of the method may have

been wrong.

Early cross-cultural studies of perception often did not include

things like propercontrol groups.

The poor control may have affected the

validity of the studies.

This shows that the way in which objects

are represented affects the results.

Communicationproblems can affect

the validity of theresults.

Strength or weakness? Point Evidence Conclusion

✁

PEC ?

Chapter 2: Perception Factors affecting perception: Culture pages 50–51


Answering an AO2 question

Handout2.10

Application questions involve you applying your knowledge to explain the behaviour of people in a scenario or case study. These questions can be quite challenging. Here is an example of an application question:

Read the item below and answer the question that follows.

Javari is from a tribe that lives in a remote forest. A psychologist took him to a fl at area of land where he could see for many kilometres. The psychologist asked Javari about a group of buffalo some distance away. ‘They look very tiny, like insects, much smaller than the ones we normally hunt in the forest,’ Javari replied.

Outline the effect of culture on perceptual set. Refer to the conversation between Javari and the psychologist in your answer. [4 marks]

Here are some tips about how to tackle this question:

Step 1 APPLICATION: First, you need to identify something in the scenario that is related to perception.

Step 2 KNOWLEDGE: Second, you need to use your knowledge to explain this. Use psychological terms and concepts to make your answer detailed.

Step 3: Repeat Steps 1 and 2.

Use the guidance above to write your answer (about 70–80 words):

Here are two examples of answers by students:

Javari lives in a remote forest. This means he probably has little experience of seeing things in the distance and may have had little experience of learning about depth cues.

When he sees something in the distance it looks like insects. He is showing that he does not understand size constancy.

Examiner’s comments

Note that the student identifi es elements in the scenario and then relates this to the psychology he (or she) knows.

Some psychological terms have been used (depth cues and size constancy).

Javari sees the buffalo as tiny insects. Your culture affects what you are used to seeing in your environment.

Javari doesn’t realise the buffalo are in the distance. This is because he is not used to seeing them this way.

Examiner’s comments

This is a brief and basic answer. It is not well organised and does not relate well to the scenario. Very little understanding of psychological concepts is shown in the answer.

Chapter 2: Perception Factors affecting perception: Culture pages 50–51


Turning over McGinnies’ study

Handout2.11

Here are a number of cards that relate to the study by McGinnies: 13 are ‘aspect’ cards (relating to aim, method, finding, conclusion, strength, weakness) and 13 are ‘detail’ cards. Another six cards are distractor cards and have nothing to do with McGinnies’ study.

Cut out the cards and arrange them face down on the table. One student should choose two cards and turn them over. If the cards match (i.e. a detail card correctly goes with an aspect card), the student keeps both cards. If the cards do not match, they are both turned face down again. The next student repeats the process.

Aim of McGinnies’ study

To find out if we are less likely to notice things that cause us anxiety.

To see if people take longer to recognise words that cause embarrassment.

Finding of McGinnies’ study

The participants were eight male and eight

female students.

The participants were shown a series of neutral and taboo

words.

Weakness of McGinnies’ study

Participants had to say the word out

loud as soon as they recognised it.

Each participant had their level of emotional arousal measured by

GSR.

Aim of McGinnies’ study

Participants took longer to recognise taboo words than

neutral ones.

Taboo words produced larger GSRs than neutral words did.

Finding of McGinnies’ study

Emotion is an important factor influencing

perceptual set.

Perceptual defence means anxiety slows down recognition of

taboo words.

a

Chapter 2: Perception Factors affecting perception: Emotion pages 52–53


Turning over McGinnies’ study

Handout2.11

Method of McGinnies’ study

The study used an objective measure of

emotion (GSR).

Results may be due to awkwardness

rather than perceptual defence.

Conclusion of McGinnies’ study

Other studies show perceptual

sensitisation instead of perceptual defence.

Participants from different cultures were shown 2D drawings of

scenes.


To find out if people from different cultures

use depth cues differently.

Many participants thought the hunter

was trying to spear the elephant.

Conclusion of McGinnies’ study

The study is very useful for helping us

understand how visual illusions work.

The study shows that some aspects

of perceptual set are learned.


Strength of McGinnies’ study

The study included a control group of people

not deprived of food.


Weakness of McGinnies’ study

b



McGinnies’ research methods activity

Handout2.12

Participant Neutral word Taboo word

1 0.6 0.9

2 0.5 0.8

3 0.4 0.5

4 0.9 1.2

5 0.6 0.7

6 1.7 2.1

7 0.8 1.1

8 1.2 1.7

9 1.1 1.3

10 0.5 1.5

11 0.6 0.8

12 0.4 0.9

A psychologist carried out a simplified version of McGinnies’ study into the effects of emotion on perception. He selected 12

participants and showed each of them two words, one at a time. One was a neutral

word (APPLE) and the other was a ‘taboo’ word (PENIS). He used special equipment

to flash the words very quickly onto a screen. The participants had to press a

button once they recognised the word. The table on the right shows the time taken (in seconds) for the participants to recognise

each word.

Neutral word Taboo word

Mean

Median

Range

Calculate the mean, median and range for each of the words and complete the table

on the right.

Draw a graph of the mean scores from the above table. Label the axes carefully and

give your graph a suitable title. Identify the type of graph you have drawn.

Based on all the data, explain one conclusion the psychologist might come to

about the effect of emotion in his study.



Variation

on Gilchrist and Nesberg’s study

Handout2.13This is a m

ini-practical to carry out part of Gilchrist and N

esberg’s study of motivation and perception, but w

ith an im

portant difference.

Step 1 Planning

Write a hypothesis

Write an alternative hypothesis for the study. You are

hypothesising that there is a correlation between the tw

o variables – how

hungry someone feels and w

hat size they judge a picture to be.

You can write an alternative hypothesis by filling in the gaps in this

sentence:

The hungry participants say they are, the

the food-related pictures appear to them

.

Write a null hypothesis (i.e. one that predicts there is no correlation).

Produce your materials

Working in pairs, w

rite a question that you can ask participants to assess how hungry they

feel [Hint: a scale of num

bers for participants to choose from is probably the best idea].

Choose a picture of a single food-related item (e.g. a cake, steak, nut roast, etc.). M

easure one aspect of the picture (e.g. height, w

idth, length).

Devise a scale that participants can use to give their judgem

ent of the size of the picture. This could be a line on a piece of paper, and the participants m

ark it to indicate size.

Think about what other m

aterials you might need as you read through this handout.

Consider your standardised procedure

• How

will you select your participants? W

orking in pairs, you will need about eight each.

• What instructions w

ill you give to your participants? See detailed information on right.

• What ethical issues do you need to consider? See detailed inform

ation on right.

• Write dow

n a detailed description of the procedure you intend to follow so it w

ill be the sam

e with each participant tested.

Standardised instructions for participants

You need to devise standardised instructions to read to each participant, so they know

what they have to do. Here is the

important inform

ation you should include so they can make an

informed decision about participating:

•Theyareparticipatinginajudgementexperim

ent.

•Theywillbeaskedtoassesshow

hungrytheyare(onthescale you have devised).

•Theywillbeaskedtolookatapictureforashortam

ountoftim

e (but don’t tell them w

hy you want them

to do this).

•Onceyouhaverem

ovedthepicture,youwillaskthem

toindicate (on the piece of paper) the size of the item

in the picture.

•Theyshouldalsohavethechancetoaskquestionsifthereisanything they are unclear about.

Dealing w

ith ethical issues

Write a consent form

and a debriefing script

You are carrying out the mini-practical in this w

ay because it w

ould be unethical to repeat Gilchrist and N

esberg’s study exactly how

they did it (you can’t ask people to go without food

for a study). But there are other ethical issues to consider too.

It’s important that your participants agree to take part in your

study voluntarily. The information above can be used for this.

You don’t want to tell them

too much or else you w

ill reveal the hypothesis (e.g. don’t tell them

you’re interested in how

hunger affects perception). But you do have to tell them w

hat they w

ill be asked to do. It’s also important for ethical reasons

that you do not use younger children (under 16 years) in any practical investigation.

You should also write a debriefing script for you to read to

the participants at the end of the procedure, again for ethical reasons. This is w

hen you reveal all. What else should your

script include?

a

Chapter 2: Perception Factors affecting perception: Motivation pages 54–55


Variation on Gilchrist and Nesberg’s studyHandout2.13b

Step 2 Conduct the study and collect data

Recruit your participants and collect data from them

as planned.

Step 3 Analyse the results

Fill in a table with your partner’s and your results

When you have collected your results, share them

with your partner. Record

all your participants’ responses in the table below.

You need to calculate the means, m

edians and ranges for both sets of data.

ParticipantH

unger scoreSize of picture (m

m)

1 2 3 4 5 6 7 8 910111213141516

Mean

Median

Range

Draw

a graph

Draw

a graph of your results. Consider carefully which graph is the right

one to use [Hint: this is a correlation study]. Give the graph a title and

make sure you label the axes carefully.



Variation on Gilchrist and Nesberg’s studyHandout2.13c

Step 4 Answer som

e questions and write a brief report

Should you accept the alternative or the null hypothesis? Explain your answ

er.

Do your results confirm

the findings of Gilchrist and Nesberg’s study or not?

Explain how you know

this.

You can bring the whole practical together by w

riting a brief report using the follow

ing headings:

Aim:

Results:

Conclusion(s):

Evaluation:

Method:



Gilchrist and Nesberg acrostic

Handout2.14U

se the information in the textbook to m

ake an acrostic for Gilchrist and Nesberg’s study. That is, the letters of GILCH

RIST and N

ESBERG start off each sentence.

GILCHRIST

NESBERG



Variation on Bruner and M

inturn’s studyHandout2.15

This is a mini-practical to carry out Bruner and M

inturn’s study of perceptual set and expectation, w

ith a different am

biguous fi gure – the rat-man (see right).

The rat-man can be seen as a rat or a hum

an face.

Step 1 Planning

Write a hypothesis

Write an alternative hypothesis for the study. You are

hypothesising that there is a difference in response to an ambiguous fi gure betw

een two

groups. But which direction w

ill it be in? Are people more or less likely to interpret the

rat-man as a rat than those w

ho see the human face?

You can write an alternative hypothesis by fi lling in the gaps in this sentence:

Participants who see a picture of a rat are then

likely to interpret the rat-m

an fi gure as a than participants w

ho see a picture of a hum

an.

Write a null hypothesis (i.e. one that predicts there is no difference).

Produce your materials

As this is a class mini-practical, your teacher w

ill provide you with the im

ages you need – a rat, a hum

an face and the ambiguous rat-m

an image itself.

Think about what other m

aterials you will need as you read through this handout.

Consider your standardised procedure

• How

will you select your participants? You only need to carry out the procedure w

ith one participant each because your w

hole class will share results.

• This is an independent groups design – one group will see the anim

al and then the rat-m

an and the other group will see the hum

an face and then the rat-man.

• What instructions w

ill you give to your participants? See detailed information (right).

• What ethical issues do you need to consider? See detailed inform

ation (right).

Standardised instructions for participants

You need to devise some standardised instructions to read to

each participant, so they know w

hat they have to do. Here is the im

portant information you should include so they can m

ake an inform

ed decision about participating:

•Theyareparticipatinginajudgementexperim

ent.

•Theywillbeaskedtolookattw

opicturesandtodescribethem

briefl y.

•Theyshouldalsohavethechancetoaskquestionsifthereisanything they are unclear about.

Dealing w

ith ethical issues

Write a consent form

and a debriefi ng script

For ethical reasons, it’s important that your participants agree

to take part in your study voluntarily. The information above

can be used for this. You don’t want to tell them

too much or

else you will reveal the hypothesis (e.g. don’t tell them

you’re interested in how

expectation affects perception). But you do have to tell them

what they w

ill be asked to do. It’s also im

portant for ethical reasons that you do not use younger children (under 16 years) in any practical investigation.

You should also write a debriefi ng script for you to read to

the participants at the end of the procedure, again for ethical reasons. This is w

hen you reveal all. What else should your

script include?

a• W

rite down a detailed description of the procedure you

intend to follow so it w

ill be the same w

ith each participant tested. In pairs, one of you should test one participant w

ith the rat picture, the other should test another participant w

ith the human face picture.

Chapter 2: Perception Factors affecting perception: Expectation pages 56–57


Variation on Bruner and Minturn’s studyHandout2.15

Step 2 Conduct the study and collect data

Recruit your participants and collect data from them

as planned.

Step 3 Analyse the results

Fill in a table with your class’ results

Once everyone in the class has collected their data, you all need to

share it with each other. The inform

ation you need to share is (a) what

experimental group the participant w

as in and (b) what they identified.

In other words, for each participant the data m

ight be rat rat or rat face or face face or face rat.

Record the data in the table below. The order of participants does not m

atter.

Add up the number of responses for ‘rat’ and ‘face’ in each group.

Rat picture

participantsR

esponseFace picture participants

Response

113

214

315

416

517

618

719

820

921

1022

1123

1224

Total ‘rat’:Total ‘rat’:

Total ‘face’:Total ‘face’:

Draw

a graph

Draw

a graph of the total ‘rat’ and ‘face’ responses for both groups. Give the graph a title and m

ake sure you label the axes carefully.b



Variation on Bruner and Minturn’s studyHandout2.15c

Step 4 Answer som

e questions and write a brief report

Should you accept the alternative or the null hypothesis? Explain your answ

er.

Do your results confirm

the findings of Bruner and Minturn’s study or not?

Explain how you know

this.

You can bring the whole practical together by w

riting a brief report using the follow

ing headings:

Aim:

Results:

Conclusion(s):

Evaluation:

Method:



Handout2.16

Task: Read the questions about Bruner and Minturn’s study into perceptual set and expectation, and write your answers in the boxes.

1. What did Bruner and Minturn mean by ‘expectation’?

2. What did Bruner and Minturn believe had a major effect on expectation?

3. What is an ambiguous figure?

4. Draw precisely the ambiguous figure Bruner and Minturn used.

5. What experimental design did Bruner and Minturn use?

6. Write a sentence describing this experimental design.

7. DrawthetwosequencesBrunerandMinturnshowedtotheir groups, as the participants would have seen them.

8. There were four main results – what were they?

9. What did Bruner and Minturn conclude about the role of expectation?

10. Bruner and Minturn’s task was criticised for being ‘artificial’. What was artificial about it?

11. This issue seriously limits the validity of the study. Why?

12. Another criticism of the study relates to the experimental design that Bruner and Minturn used. What is this criticism?

13. Again, explain why this issue limits the study.

How well do you know Bruner and Minturn’s study?



Perception revision line-up

contin

ued...

Handout2.17

Gib

son

The d

irect theo

ry o

f percep

tion

Perceptio

n an

d

sensatio

n are th

e sam

e thin

g.

Streng

th:

It has real-w

orld

relevan

ce becau

se it is b

ased o

n

research w

ith

pilo

ts.

Weakn

ess:It stru

gg

les to

explain

percep

tual

errors su

ch as

visual illu

sion

s.

Greg

ory

The

con

structivist

theo

ry of

percep

tion

We in

terpret th

e w

orld

based

on

p

ast experien

ce.

Streng

th:

This th

eory can

exp

lain h

ow

visu

al cues are

interp

reted

differen

tly in

differen

t cultu

res.

Weakn

ess:Th

e theo

ry cann

ot

explain

ho

w

percep

tion

gets

started in

the fi rst

place.

Hu

dso

nTh

e dep

th cu

es stu

dy

Cu

lture affects

the w

ay that

peo

ple in

terpret

two

-dim

ensio

nal

info

rmatio

n.

Weakn

ess:Th

e way

draw

ing

s were

presen

ted co

uld

h

ave con

fused

p

articipan

ts.

Weakn

ess:Th

is is an o

ld

stud

y that d

id n

ot

inclu

de a p

rop

er co

ntro

l gro

up

.

a

Chapter 2: Perception Summary pages 58–59


Perception revision line-upHandout

McG

inn

iesTh

e rud

e wo

rds

stud

y

An

xiety is an

emo

tion

al factor

that affects

percep

tual set.

Streng

th:

Galvan

ic skin

respo

nse w

as an

ob

jective measu

re o

f emo

tion

used

in

the stu

dy.

Weakn

ess:Th

e result

cou

ld b

e du

e to

emb

arrassmen

t rath

er than

p

erceptu

al d

efence.

Gilch

rist an

d

Nesb

erg

The yu

mm

y p

ictures stu

dy

Hu

ng

er is a m

otivatin

g facto

r th

at affects p

erceptu

al set.

Streng

th:

The fi n

din

gs o

f th

e stud

y were

sup

po

rted b

y San

ford

’s (1936) research

.

Weakn

ess:Th

e stud

y was

un

ethical b

ecause

peo

ple w

ere d

eprived

of fo

od

an

d d

rink.

Bru

ner

and

M

intu

rn

The

B o

r 13 stud

y

Expectatio

n is a

factor affectin

g

percep

tual set.

Streng

th:

Un

derstan

din

g

the ro

le of

expectatio

ns can

h

elp u

s avoid

real-life erro

rs of

percep

tion

.

Weakn

ess:A

mb

igu

ou

s fi gu

res are artifi cial an

d

we d

on

’t com

e acro

ss them

very o

ften in

real life.

2.17b

Chapter 2: Perception Summary pages 58–59

chapter 2: perception sensation and perception 2.1 the

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