lecture 1 perceptual development Flashcards
define infancy
a period of rapid development - without speech
define 1 month
cant support own head
helpless - attentive to people and world around
mainly motor development
define 4 month
ability to manipulate objects, hold self up and more mobile
improved sensory abilities
define 6 month
more goal directed behaviours
more mobile - roll over etc
ability to explore is improved - become more active and independent
define 9 month
behaviour is more intentional - chose what to explore
define 24 month
speech and language begins to develop
have a mental representational process - greater comprehension of abstract and things that arent present
what is newborn sight like in early age (up to 2 months)?
poorly developed - see objects 30cm away clearly and far sighted - any further and things are blurred
must purposefully adust vision to see into the distance- rapid improvement 4
eye muscles for focusing are weak and retinal membrane for capturing light is not fully matured
limited visual acuity
how does improvements in vision following 2 months help the infant
look at objects from different distances
colour discrimination rapidly becomes adult like
can actively explore the environment
greater at scanning the perceptual environment, navigating, manipulating objects and anticipating future events
describe san and streri 2007
habituate newborn infants to shape or texture
then ask to touch object (and vise versa) without seeing them until habituated to then show similar/different/same object
what were san and streri looking to find
to see if the previous exposure leads to dishabituation in a different domain ie attend to same texture object with different shape for longer and therefore recognise it is different
see if infants can integrate the information received between sensory modalities
san and steri results
VT: dishabituation when see object then touch second different object (better at recog diff textures when see then touch)
TV: dishabituate more when touch shape then exposed to new (reognise diff in shape)
in all cases spend longer with novel than familiar obect suggesting can discriminate accross domains
shape discrimination not bidirectional - transfer TV but not VT
what are the different tastes
bitter sweet sour umami salty
what tastes can infants detect from birth
bitter sweet sour and umami
why is it hypothesised that children cant taste salty flavours from birth
salty taste not developed but becomes present by end of 3-4 months
thought to be due tot he development of salt receptors
- suprising as simple - require na+ VG channels
how can you determine infant taste
facial expressions differ when taste showing they can discriminate between the tastes
ie purse lips to sour, relax to sweet
describe mannella, jagnow and beauchamp group CW
breastfeeding mothers into 3 groups:
1. CW - drink carrot juice 4 days a week for 3 weeks in last trimester and water at breastfeeding
describe mannella, jagnow and beauchamp group WC
- WC - water for last trimester, carrot juice 4 days for 3 weeks during breastfeeding
describe mannella, jagnow and beauchamp group WW
water for last trimester and breastfeeding
what did mannella, jagnow and beauchamp want to investigate
if infants can taste pre birth via amniotic fluid and therefore are influenced by taste preferences pre birth
how did mannella, jagnow and beauchamp test taste preference
test during weaning for preference in carrot based cereal
coded for negative facial expressions and taste preference (mother report) when eating plain or carrot cereal
what did mannella, jagnow and beauchamp find
carrot juice in preg = sig fewer neg facial expressions while eating carrot cereal and significantly greater liking
benefits of smell in infancy
activates strong memories - anchor
describe coffield, mayhew, haviland jones and walker andrews smell
test 36 6-7moth infants distress and artention watching video of womaan expressing happiness or sadness
no odour or odour (baby talc or pie) coniditons
findings of coffield mayhew havildand jones and walker andrews
odour infants spend sig longer looking at video than control in either happy or sad condition - odour gives infant security
describe joran and brannon 2006 vision and hearing
asked if infants able to match sound of number of people speaking to visual cue of diff no of people
ie 2 people say look synchroniously but video of two and video of three people on screen - see if match sund with visual amount
measure infant looking time to videos
results of jordan and brannon vision and hearing
infant spend sig longer at stimuli with matching no of people
infants can analyse speech to determine no of people talking
when does vision become fully developed
20/80 by 6 months
80/90 by 4 years
why might shape discrimination not be bidirectional (san and steri)
sensitivity to touch well developed at birth
ie ingenction leads to increased activity in sensorymotor cortex in infants, and greater for those born earlier
CNS more immature so more responsive/sensitive
therefore may get more info from touch than vision which is poor
why is sweet taste detection important in infancy
allows the detection of breast milk in early development
but as salt receptors develop (around 4m infants have preference to salty/norm water) then may be preparing infants for solid food
cooke and feilds early taste development and preference
early flavour exposire thought to improve dietary outcomes
what does manella and beauchamp study suggest
the amniotic fluid and breast milk contains flavours that the infant can recognise and links to mother
influence dietary preferences
schaal merlier and sausignan 2000 taste development preferences
mothers in france flavour foods with anise in prev 2 weeks of preg or not
babies more response towards taste and smell of anise whilst non anise babies more averse
birch and fisher 1998 taste preferences and dietary outcomes
infants have tendency to be neophobic to new foods
only eat sweet/salty foods that reflect flavours already exposed to
liking/preference only increases witth experience so important to build preference and exposure
sullivan and birch 1994 taste preferences and dietary outcomes
varied flavour experience in breast milk thought to facilitate greater acceptance of newer flavours in solid foods during weaning than formula
the development of smell
sense of smell thought to develop from very yong age
infants highly responsive to maternal scents in first few hours of life
give particular attention to odours relating to breast milk and sebum
marlier and schakil 2005 breast odour vs formula in infancy
more attentive to unfamiliar breast scents than formula, even when formula fed from birth
delaunay-elallam, marlier and schaak 2006 odour exposure
exposed infants to odreants perviously exposed to or not (camomile - ca) - may or may not have developed a preference
are those exposed more positive towards the odour than those naive
- found more attracive but could not differentiate ca with a scented control ie vanilla
naive prefer milk to ca but ca exposure show equal preference for both
exposure increase preference
oiko and turkewitz 2001 odour differentiation
newborns can discriminate odours from non odours
dig more head turning/preference to vanilla when in left >right nostril (left hemisphere activation)
- partial support for valence hypothesis that left hemisphere represents pos emotion and right rep pos and neg (BUT NEG ODOUR NOT SIG IN RIGHT)
- approach behaviours develop earlier than avoidance?
vision and hearing in infancy
hearing not fully developed from bith and develops over first 3-4 months BUT sensitiv to general sounds from 3 days
vouloumonos and werker 2004 hearing and speech
infants prefer complex>simple tones in infancy
more so for human speech sounds than structurally non similar speech
could be due to experience of human speech from and before birth or an innate mechanism that leads to preference
the neonatal synaesthesia hypothesis
sharing of information across modalities in infancy may infer a universal synaesthetic experience in young infants as a result of un-pruned neural sensory pathways that are yet to develop fully
define synaesthesia
stimulation of one sensory pathway triggers the stimulation of a second sensory pathway
why might neonatal synaesthesia be useful in infancy
infants must rely on a mix of sensory information as they lack experience and not all modalities are sufficiently developed
allows to gain a better understanding of the world aorund them where the quality of the information they gain may be limited
cross modal transfer and synaesthesia
exposure to regular pairings between sensations may lead to associations
ie shapes with sounds
help to predict attributes of multisensory entities and perceptually detect when all together
assoc info in one sense logically with that obtained in the other and create a pairing
what does infant synaesthesia suggest about synaesthesia in adulthood
infant synaethesia thought to decrease over time through pruning of neural pathways and greater specialisation of sensory modalities
adult synaesthesia thought to be caused by inefficient pruning of synaptic sensory connection sin infancy causing hyperconnectivity into adulthood
vision and scale
over first 3 years infants develop the ability to determine the scale of the objects around them
18-30m/o make scale errors
what are scale errors
attempt by infants to make use of an object/perform a task even though it is impossible in relation to its actual size
deleache, uttal, rosengren 2013 scale errors
when presented with miniature versions of the toys played with previously, infants still try to use in the same way as would when normal size
ie trying to drive toy car
glover 2004 scale errors
infants havea dissociation between visual info of object recognition and action planning
they lack the inhibitory control and integration between perception and action
overwhelmingly want to play that infants temporarily fail to recognise size difference
object activates representation of larger version of object and action plan but fail to inhibit the inappropriate action
