area 3 child psychology perception

Question 1

what is perception?

Answer 1

The organisation and interpretation of sensory information
its a combination of information received by a sense receptor and the brain interpretation of what that means

Question 2

what is the nativist view on perception?

Answer 2

humans are born with at least some genetically pre disposed perceptual abilities, even if they are not all immediately evident and only appear later

Question 3

what is the constructivist view on perception?

Answer 3

that our perceptual abilities develop through learning as we make sense of the sensations we experience, so we are born with little or no perceptual abilities.

Question 4

what is the interactionist view on perception?

Answer 4

we are born with a strong pre disposition to develop certain perceptual abilities that are important for survival ( visual system capable of perceiving depth/distance), but these develop in response to experiences we have of a complex sensory environment (cues to depth such as shadows and textures)

Question 5

what is 3 dimensional perception?

Answer 5

ability to perceive depth or distance promotes survival because it prevents us from falling over and helps us avoid drops.

Question 6

how do we develop 3 dimensional perception?

Answer 6

our brains can interpret depth cues, which are features of our environment that give us info about how far away objects are and where they are in relation to each other.
we perceive objects as constant (unchanging) even though we see them from various angles and distances

Question 7

what are some examples of constancies?

Answer 7

colour
shape
size

Question 8

what are some examples of depth cues?

Answer 8

linear perspective
height in plane
superimposition
texture gradient

Question 9

what did bower test?

Answer 9

the ability of babies between 8 – 17 days old to precieve depth/distance in a situation important for their survival – recognising objects that appear to be heading towards them.

Question 10

what did bower find

Answer 10

babies raised their arms and heads in response to the closer object showing that babies could distinguish between the two objects even though the objects created the same sized retinal image, suggesting some degree of depth perception present only days after birth

Question 11

how did bower study it?

Answer 11

showed babies two cubed shaped objects, one larger than the other. Each baby watched as the larger object moved to within 20cm of them and the smaller object to within 8cm.meant that the images the objects projected onto the babies retinas would be the same size as each other

Question 12

what did hudson do?

Answer 12

showed several drawings two dimensional drawings to South African children and adults who had formal primary education (schooled) and those who had not (unschooled)

Question 13

what did hudson find?

Answer 13

schooled participants said that the hunter was attempting to spear the antelope
unschooled could not recognise depth cues in the picture implying that depth perception is (at least partly) learned through experience of the visual environment – unschooled had less experience of these kinds of images.

Question 14

what did fantz study?

Answer 14

showed new born babies a selection of images, including a black and white representation of a human face. In a development of the procedure he scrambled the images.

Question 15

what did fantz find?

Answer 15

young babies showed no preference for the correct image over a scrambled one but they did at 3 months
1 week- patterned surfacesz
2 months- 3d compared to 2d

Question 16

what does research show about babies development of facial perception?

Answer 16

At one month – babies look intently at the ‘edges’ or contours of the face but not at the centre
2/3 months – they look at the centre of the face, probably controlled by neural circuits in the developing Cerebral Cortex. – This is when babies begin to perceive human faces as a whole rather than as a collection of parts.

Question 17

what is Preferential Looking?

Answer 17

assumes that babies generally look at things they find interesting and measures the amount of time spent looking at two stimuli.

Question 18

how is preference established in the preferential looking method?

Answer 18

If they spend longer looking at one that the other (preference) this indicates they can distinguish between the two.

Question 19

what is habituation?

Answer 19

Babies spend longer looking at something that they haven’t seen before but once they are used to it (become habituated) they will look elsewhere.

Question 20

how is habituation measured?

Answer 20

present a stimulus to the baby and records how long the baby looks at it. When the baby looks away, the stimulus is taken away for a short time before being presented again. repeated several times over the course of which the baby looks at the stimulus for less and less. They become used to the stimulus (no longer interests them) – this is habituation

Question 21

what is dishabituation?

Answer 21

The researcher then presents a completely new stimulus. If the baby once again looks for a longer time, we can say they are dishabituated i.e they have shown that they can see there is a difference between the two stimuli.

Question 22

how is a Electroencephalogram (EEG) gathered when using babies?

Answer 22

a baby’s EEG can be recorded placing a geodesic sensor net over their head. – A collection of sensors measure electrical activity all over the brain held together with a swimming cap as fMRI cant be used

Question 23

what did farzin do?

Answer 23

used a G Net with 128 sensors to measure steady state visual potentials in babies (spikes in brain activity caused by visual stimuli) in this case faces. found activity centred on the temporal lobe on the right hemisphere.

Question 24

what is dark rearing?

Answer 24

Rearing infant animals in the dark is common technique for investigating the development of perception and addressing the crucial question of whether nature or nurture is a key influence as Dark reared are deprived of perceptual stimulation

Question 25

background to gibson and walk?

Answer 25

depth cues allow us to see in 3D. include linear perspective and texture gradient. Depth perception- ability to see in 3d Motion of several stationary objects agaunsr a background gives hints abour relatice distance Yerkes- aquatic turtles have poorer depth discrimination than land turtles- shows a nurture factor, however other research found depth perception is innate in rats

Question 26

aims of gibson and walk?

Answer 26

1. To investigate if the ability to perceive and avoid a drop is learned through experience or is it innate 2. discover the point in development at which infants can perceive depth and whether this varies in different animal species – specifically is this before or after or at the same time as the ability to move around independently. 3. To test which two visual cues is more important in depth perception – the density of pattern in the environment (texture) or motion parallax

Question 27

sample of gibson and walk?

Answer 27

36 human babies aged 14 months all capable of independent locomotion. Infants of other animal species were also included: Chicks, lambs, kids, kittens (including reared in darkness for 27 days), rats (dark reared rats), pigs, dogs and aquatic turtles. Animals were self-selecting by their owners, advertised in the local vets4pets magazine and verbally gave consent to taking part whilst filling out a questionnaire on mental well-being.

Question 28

method of gibson and walk?

Answer 28

Lab experiment, repeated measures IV- whether babies were called by their mothers across shallow or deep side of visual cliff DV- whether baby crawled across ‘visual cliff’ or not The studies with animals were quasi experiments with species of animal as the IV and preference for deep or shallow side as the DV

Question 29

procedure of gibson and walk?

Answer 29

A board was laid across a large sheet of heavy glass and was supported more than a foot above the floor. One side of the board a sheet of patterned material was placed flush against the under-surface of the glass giving the glass the appearance as well as the substance of solidarity. On the other side a sheet of the same material was laid on the floor; this side of the board is the visual cliff. Children were placed on the centre board and their mother called them from the cliff side and the shallow side for the two conditions. The animals were also on the apparatus and behaviour was observed – conditions were changed slightly for some animals to prevent any bias.

Question 30

what is texture density?

Answer 30

When things are close to us, we can see their textures and points more clearly. as objects are farther away, their textures appear to become smoother and less distinct.

Question 31

how was texture density controlled?

Answer 31

To an observer at glass level the texture on the deep side of the cliff seems finer than those on the shallow side because they are further away. This gives the observer a cue to depth/distance. To control for this on some trials G & W increased the size of the squares on the deep side so that they appeared to be the same size as the squares on the shallow side.

Question 32

what is motion parallax?

Answer 32

where objects that are closer to the observer appear to move faster than those that are farther away when the observer is in motion.

Question 33

how was motion parallax controlled?

Answer 33

the squares on the shallow side appeared to move more quickly across the baby’s field of vision when he or she moved across the glass. To control for this on some trials the researchers attached the chequered material directly onto the glass on both sides. But they made the squares in the pattern larger on the shallow side to give them appearance of being closer.

Question 34

results of gibson and walk relating to infants?

Answer 34

27 infants crawled off the board, all of whom crawled out on the shallow side at least once. Many of the infants crawled away from the mother when she called them from the cliff side and some cried because they thought they couldn’t get to her without crossing the apparent chasm. Often infants peered down through the glass on the deep side and then backed away, some patted glass with their hands, but despite this tactual assurance of solidarity would still refuse to cross.

Question 35

results of Gibson and walk relating to chicks/ goats/ lambs?

Answer 35

Chicks who were less than 24 hours old made no mistakes, always hopping off the board on the shallow side. No goat or lamb ever stepped onto the glass of the deep side, even at one day old. When placed on the glass of the deep side, they refused to put their feet down and could be pushed to the shallow side where they would stand. When the drop was reduced to 30cms or less they would happily go across.

Question 36

results of Gibson and walk relating to rats?

Answer 36

As rats could feel the glass with their whiskers, they had no preference for the shallow side. When placed upon the glass over the deep side, they moved about normally. When the centre board was raised several inches so that the glass was out of reach of their whiskers, they showed good visual depth discrimination, with 95-100% of them descending on the shallow side. at 90 days old both light reared and dark reared rats showed the same preference for the shallow side, showing that depth perception in rats is innate.

Question 37

conclusions of Gibson and walk?

Answer 37

Most humans are able to discriminate depth as soon as they can crawl. A seeing animal can discriminate depth when its locomotion is adequate, Depth perception in chicks, goats and kittens develops quickly, while rats and kittens use cues from their whiskers to help their depth perception. it is innate in rats and maturational in kittens. Both infant rats and chicks can discriminate depth by differential motion alone, with no aid from texture density. In some animals, only motion parallax is an innate cue for depth discrimination.