factors affecting perception - Read More >
Bruner
and Postman(1949) showed playing cards with Black Hearts and red spades at very
fast speeds on a tachistoscope and found that these unusual cards would be seen
as normal cards at first but at slower speeds ‘compromise’ perceptions
emerged, e.g. brown or purple hearts were seen.
Tulving
and Gold (1963) showed participants sentences with 4,6 or 7 words missing. The
fewer the words missing, the quicker they would correctly guess the target word.
Motivation
Rewards
are a way of increasing a person’s motivation. Punishment decreases it. For
example, Schafer and Murphy(1974) gave participants a reward everytime they
named a particular face, one facing left or one facing right. They were punished
losing 2 or 4 cents when they did not name the correct face.
Later,
when the participants were shown an ambiguous image made up from both faces the
participants ‘saw’ the only one they had been rewarded for.
McGinnies(1949)
Research
question – Are perceptions affected by emotionally threatening stimuli such
that you are not even aware of them
8
male and 8 female participants
Participants
were shown a list of words , 11 were neutral and 7 critical (emotionally-toned)
words. Exposure time was gradually increased from 0.01 seconds until the word
was correctly identified (tachistoscope was used)
Stimulus
words (critical words shown in italics)
Apple
river
penis
dance
whore
music
sex
sleep
trade
child
anus
filth
belly
broom
clear
glass
stove
bitch
P’s
were asked to report whatever they saw or thought they saw. At the same time a
physiological measure of emotionality was taken using the Galvanic Skin Response
(GSR) similar to a lie detector. It measures the amount of moisture(sweat) on
the skin, emotional states are associated with arousal or sweating.
Results
showed that on both measures, participants showed that emotion is related to
critical words
1)When shown
critical words participants had higher mean GSR’s. This happened before
the words were recognised
2)Participants required significantly longer exposure
times to report the critical words correctly
In
interpreting this the fact that the participants had an emotional response but
didn’t simultaneously recognise the words , shows that the selection of visual
data takes place early on and not necessarily with conscious knowledge. In this
case perceptual set acts as a defence.
The
Muller Lyer Illusion
The
line with the ingoing fins looks like the corner of a building, and this makes
the vertical line seem closer. The out going lines are like the corner of a room
and therefore the vertical line seems to be receding and as a result is
perceived as longer
A
logical judgement made on the basis of a sample of evidence, previously made
judgements prior conclusions etc. rather than on direct observation – it is
also the cognitive process by which such a judgement is made
Hudson
(1960)
Hudson
used pictures of hunting scenes. Participants in Africa (from various tribes)
were shown a picture at a time and
asked to name all the objects in the picture in order to determine whether or
not elements were correctly measured. I.E what is the man doing ? Which is
closest to the man. If the participants recognised the correct depth cues they
were classified as having 3-D perception if they didn’t recognise the depth
cues 2-D
Both
children and adults from differing backgrounds had difficulty. Perhaps these
people had not had much experience of looking at pictures before which was
causing the poor results
The
study of relationship between organisms and their environments