AQA Specification B Unit 2 Perceptual Set

Perceptual set is defined as a predisposition to attend to and percieve certain aspects of a stimulus and disregard other, and a tendency to interpret a stimulus in a certain way.

When our perception of something we need/want is hightened/accentuated simply because of our motivation or desire for it

Aim- Gilchrist and nesberg (1952) set out to investigate the effect of motivation (induced by hunger) on perception of pictures

Method- Participants viewed food-related and non-food-related pictures which they were then asked to rate on a scale for colour and brightness. one group of participants had been deprieved of food and liquid for several hours and the other group had not (independant groups)

Results- The 'deprived' participants rated the food-related pictures as brighter and more colourful than the non-food-related pictures

Conclusion- Gilchrist and Nesberg suggested that hunger and thirst were motives which led to perceptual accentuation, producing perceptions which were stronger and brighter than normal. (This study is an exapmle of how motivation can induce a perceptual set)

when you have been shown/told that you are seeing pictures/objects of a certain genre or type, then you will expect all the things you see to be in that category. (context-induced perceptual set)

Aim- Bruner and Minturn investigated how the immediate physical context could influence perception of an ambigous figure

Method- In an independant design, perticipants were shown either a series of numbers or a series of letters. In each case, the centre stimulus was exactly the same

:. participants were shown either letters and numbers along with this ambigous figure and state what they saw.

Results- the perception of the two groups were quite different. The group which who saw the ambigous figure alongside letter reported seeing the figure as a "B" whilst the people who were shown numbers alongside the ambigous figure reported seeing the ambigous figure as a "13"

Conclusion- Bruner and Minturn concluded that perception of sensory information varies according to the context in which a stimulus is presented, and that by altering the immediate context it is possible yo predispose participants to interpret visual information differently. The study therefore supports the existance of context-induced perceptual set

Positive emoitions, such as excitement may lead us to percieve something like a forethcoming even more positively because of egar anticipation. Negative emoitions however could lead us to percieve something bad as worse than it really is because we'd rather avoid it.

Aim- McGinnies set out to investigate the effect of emoition on perception by tessting whether offensive or taboo words would take longer to percieve and recognise than neutral words

Method- Using a tachistoscope (scientific instrument used by psychologists; presents visual stimuli (aka pictures) for brief exposures.), participants were presented with words which were either unpleasent and offensive or neutral. the words were projected very rapidly at first with gradually increasing display times. the task was to say each word out loud as soon as it was recognised.

Results- it took participnts a lot longer to recognise offensive taboo words like "crotch" than it did for them to recognise neutral inoffensive words like "plate"

Conclusion- Participants took longer to percieve the offensive taboo words because of perceptual defence, the unconcious defence mechanism acting to protect us from consciously experiencing the unpleasent words

NB- there is no way of knowing people realy didnt recognise the offensive taboo words, because they could have recognsed them but not wanted to say them.

Brislin's study:

Aim- Brislin set out to compare participants from different cultural backgrounds in their susceptibility to the ponzo illusion:

Method- Using particpants from the United States and Guam, Brislin compared susceptibility to the ponzo illusion. Participants were asked to judge the length of the two horizontal lines, and it was noted whther they thought the top line was longer than the bottom one.

Results- it was found that particpants from rual and non-western environments were less likely to think that the top horizontal line was longer than the other than particpants from western backgrounds.

Conclusion- It seem that the cultral environment in which we live affects our interpretation of distortion illusions like the Ponzo illusion