perceptual development Flashcards
how do we study perception
- controlled environments during development (Animals only)
- looking time:
> preferential looking - tells if a baby can tell 2 items apart
habituation paradigm
- show baby lots of cats
- then show a cat next to a dog
- if look at the new item (dog) for longer = they can tell them apart
can do this with different colours, faces, etc
preferential looking
- reliable
- can reveal biases in infant visual system such as bias to high contrast images and specific stimuli
- on average infant looking time is very predictable
infant preference
- prefer high contrast
- faces / things that resembles faces
lights through to infants in utero
- shone bright lights into uterus of inverted or normal triangle of dots
- more preferences to the face resembling triangle - shows preference
infant vision: visual acuity
visual acuity: level of detail and contrast visible
- contrast sensitivity function - how much contrast visible
> infants curve is radically different to adult
- visual system develops very quickly
- 6 months fully developed
cataracts
- film covers eye and stop visual input
- in baby:
- cells still developing
- missing early window which is important for facial discrimination
- so if get them removed in time - vision recovers but facial perception works in a different way > harder to discrimination between layout of faces
- illustraes critical period within development: this effects the facial discrimination critical period
infant vision: colour perception
- baby’s are morn with all 3 cones but they are immature
- parvocellular (midget): colour, high sf
magnocellular (parasol): motion, luminance, low sf
before 3 months:
look longer at red light than blue light
look at blue and white light for the same amount of time
so they have the red-green, but not yet blue-yellow
3 months = now trichromatic, but need to see intense colours in order to see them
colour discrimination
- easier to see most intense colours
- speckled layout of grates tells us where they begin to see them
- difference halves with age until teenage
environmental factors shape colour perception
- if born above artic circle
winter = dark all day
summer = light all day
illumination they come across = very different artificial vs natural
when tested as adults colour discrimination abilities = very different
early experience = very important
why does it matter
- impacts early years education e.g. reading picture books far away = can’t see and colours toys use
- plays for babies - what can they see
- theory and media - what is the best for your child
preference triangle
- infants prefer arrangement that resembles the layout of a face
- makes sense evolutionarily
- familiar face, emotion, social cues
recognition for familiar faces
- infants recognise specific faces from 4 days old (mother)
- but not when it is just the internal features - using the global shape of mother not just face > makes sense based on child’s vision
- need to have been exposed multi-modelling for this effect > more than just seeing, - smelling or talking etc
discriminating between faces
- 6 month olds can discriminate between faces of other species, 9 month olds cannot
- but if trained to do so between 6 and 9 e.g. a book they can still do it
labelling = important
perceptual narrowing
experience or lack of experience shapes expertise > use it or lose it
- applies to faces, colour and sounds