Perceptual development Flashcards
Is vision well developed at birth?
No - newborns haven’t developed the high spatial frequencies that older infants have
Are we near/far sighted at birth?
Far-sighted at birth
At 2 months-old, we focus on objects how far away?
30cm - the distance between the baby’s face to the mother’s breast
What age is an infant’s eyesight equivalent to that of adults?
6 months-olds
What were Sann and Streri (2007) investigating?
Whether info that newborns hold in one sensory modality is accessible to other modalities
Newborns ability to transfer shape and texture info from vision to touch, and from touch to vision
What stimuli did Sann and Streri (2007) use in their study?
Tactual = cylinder (smooth) and prism (sharply angled)
Visual = 10x larger red cylinder and 10x larger red prism
What method did Sann and Streri (2007) use in their study?
EXPERIMENT 1
Newborns were tactually habituated to a cylinder/prism
EXPERIMENT 2
Newborns were visually habituated to a cylinder/prism
What did Sann and Streri (2007) find?
EXPERIMENT 1
After tactile habituation to the prism (familiar object), all newborns looked longer at the cylinder (novel object) than the prism (familiar object)
EXPERIMENT 2
After visual habituation to the cylinder (familiar object), newborns held (paid more attention to) the prism (novel object) for longer than the cylinder (familiar object)
What did Sann and Streri (2007) conclude?
Newborns gather, process, memorise and exchange info in the visual and tactile modalities by testing the bi-directional cross-modal transfer of shape and texture properties
When do foetuses detect sounds?
Third trimester
When do infants locate sounds?
3-4 months old
What did Jordan and Brannon (2006) do?
7 month-olds watched 2 screens (video of 2/3 women) - women mouthed “look” at the same time
Infants heard 2/3 women (i.e. vision matched/didn’t match sound)
What did Jordan and Brannon (2006) find?
Infants looked longer at the matched videos –> they can analyse speech to determine how many people are talking and can match numbers across modalities
Do newborns prefer simple or complex tones?
Newborns prefer complex tones
When can infants distinguish changes in tempo?
2-4 months old
When do infants show a sense of musical phrasing?
4-7 months old
When can infants distinguish musical tones using variations in rhythmic patterns?
6-7 months old
When can infants recognise the same melody being played in different keys?
By 1 year old
When do infants organise sounds into more elaborate patterns?
Over the first year
How old are infants when they make scale errors?
18-30 months-old
How long does it take for an infant to determine an object’s scale?
3 years
What happened when DeLoache, Uttal and Rosengren (2013) showed children full-sized toys, then mini versions?
The children tried to fit into/onto the mini versions –> they failed to use info about object size
Scale errors reflect problems with…
…inhibitory control & the integration of visual info for perception and action
What are DeLoache, Uttal and Rosengren’s (2013) three assumptions?
- Children have a stored concept of the toy’s actual size in the real world
- Children must be able to judge the actual size of the toy
- There must be interference between the stored concept of the object represented by the toy & the toy itself when a movement plan is formulated
Scale errors show that memories for ‘action affordances’…
…can override the visible objects themselves.
In planning the movement directed towards a toy car, children are influenced by the memory that a car affords the behaviour of stepping into it.
What might facilitate synaesthesia in infancy?
Exuberant neural connectivity
What can lead to synaesthesia in adulthood?
Failure of the retraction process
What did Wagner and Dobkins (2011) say happens in development, in relation to synaesthesia?
Early development is characterised by exuberant neural connectivity, followed by a retraction and re-weighting of connections
What did Wagner and Dobkins (2011) find (in relation to synaesthesia)?
The presence of particular shapes influenced colour preferences in 2-3 month-olds, but not in 8 month-olds or adults
What suggests to researchers that newborns can detect bitter, sweet, sour and umami tastes?
Facial expressions
When does sensitivity to salty tastes develop?
3-4 months-old
Why is it surprising that sensitivity to salty tastes develops last?
It only requires sodium ions to pass through nerve endings and create a voltage change
When did Mennella and Beauchamp (1998) find that preference for salty taste develops?
4 months-old
To prepare them to accept solid foods
What influences a newborn’s food preferences?
The amniotic fluid - it is rich in tastes and smells, and varies with the mother’s diet
Cooke and Fildes (2011) - amniotic fluid and breast milk are rich sources of chemosensory experience; flavour exposure may impact lifelong food preferences; flavour variety may produce better long-term dietary outcomes
What did Mennella, Jagnow and Beauchamp (2001) find about the influence of carrot juice during pregnancy?
If the mother drank carrot juice during their pregnancy, their child showed less negative facial responses and a greater liking for carrot-flavoured cereal
What smell are newborns attracted to?
Breast milk
Delaunay-El Allam, Marlier and Schaal (2006) exposed newborns to a chamomile scent during nursing.
What happened?
Days later, the newborns’ attraction to the chamomile scent was as strong as their attraction to the scent of breast milk
What are the benefits of infants being primed to the smell of their mother?
- can identify their mother without visually recognising her
- can identify a food source
- feel calm knowing that their mother is present
In Nishitani et al.’s (2009) study, what did the smell of breast milk do when newborns had their heel pricked?
The newborns were soothed, but only if the breast milk was from their own mother
Cernoch and Porter (1985) found that 4 day-old breast-fed infants preferred the smell of their mother’s breast to…
…an unfamiliar lactating woman.
What is the benefit of newborns’ dual attraction to the odours of their mother and her breast milk?
- it helps them locate an appropriate food source
- they can distinguish their mother from others
6-7 month-olds watched 2 videos (a woman expressing happiness OR sadness). They smelt an odour (pine/talc) OR didn’t smell an odour.
How did the odour affect the infants?
The odour gave the infants a sense of security, lowered their stress levels and they were better able to watch sad videos
- the smell counteracted the negative effect of the sad video
What odour preferences are present from birth, according to Steiner (1979)?
Steiner (1979) - smell of bananas & chocolate caused a relaxed, pleasant facial expression in newborns. The odour of rotten eggs made newborns frown.
Mastery of motor skills involves…
…acquiring increasingly complex systems of action.
What happens when motor skills work as a system?
Separate abilities blend together & cooperate with others to produce more effective ways of exploring and controlling the environment
New skills are a joint product of…
- CNS development
- The body’s movement capacities
- The child’s goals
- Environmental supports for the skill
What can make the motor skills system less stable?
What happens as a result?
Change in any element makes the motor skills system less stable
The child explores and selects new, more effective motor patterns
Factors that induce change vary with age.
What are these factors?
- brain and body growth (infants achieve control over their head, shoulders and torso)
- the child’s goals
- supports in the environment
What happens when a child attempts a new skill?
They move back and forth between its presence and absence
Previously mastered skills become less secure
= this is evidence of loss of stability in the system
What does the Dynamic Systems Theory of Motor Development state/show us?
Loss of stability is necessary to transition from a less mature to a more mature, stable state
How does practice improve an infant’s motor skills / lead to motor mastery?
As movements occur many times, they promote new brain connections that govern motor patterns
What is ‘prereaching’?
When newborns make poorly coordinated swipes towards an object in front of them
Why does ‘prereaching’ occur?
Young infants have poor arm and hand control –> they rarely make contact with the object in front of them
When does ‘prereaching’ stop and why?
Prereaching stops at around 7 weeks-old when they improve in eye movements involved in tracking and fixating on objects
–> this suggests that infants are biologically prepared to coordinate hand with eye for exploring
When does reaching for objects become purposeful? Why does it improve?
3-4 months-old
- this is when their depth perception improves, and they gain more control over their body posture & arm and hand movements
What is newborns’ reflex grasp replaced by?
Ulnar grasp (fingers close against the palm)
What type of grip do infants use by the end of the first year? What skill improves as a result?
Pincer grip
Their ability to manipulate objects improves
How can early experiences affect reaching?
If a mother carries her baby on her hip/in a sling, the baby has rich opportunities to explore the environment with their hands
Visual surroundings can influence fine motor development. What did White and Held (1966) find?
Institutionalised infants given a moderate amount of visual stimulation reached for objects 6 weeks earlier than unstimulated infants
Institutionalised infants given a large amount of stimulation also reached sooner than unstimulated infants, but they looked away, cried a lot and were less advanced in reaching than the moderately-stimulated group
Why can too much environmental stimulation be detrimental for infants?
Trying to push infants beyond their current readiness to handle stimulation can undermine the development of important motor skills
What must infants do to be able to reach for and manipulate objects, maintain their balance and move across surfaces?
They must continually coordinate their motor behaviour with perceptual info
What does improved perception skills lead to?
More effective motor activity
Studying infant perception is hard because they can’t describe their experiences.
How else can researchers measure it?
- non-verbal responses that vary with stimulation (e.g. looking, sucking, head turning, facial expressions, reaching)
- operant conditioning and habituation (investigate whether infants can make certain discriminations)
- eye-movement tracking (inspection of stimuli, attention to features, gaze-shifting)
- neurobiological measures (e.g. stimulus-induced changes in respiration, heart rate, brain activity)
What abilities does touching help in infancy?
- stimulates early physical growth
- improves their emotional development
- enhances babies’ positive responsiveness to their physical and social surroundings
Why are babies particularly sensitive to pain?
Immature CNS development
How can prolonged pain affect a child’s development?
Prolonged pain overwhelms the NS with stress hormones –> disrupts infants’ developing capacity to handle everyday stressors
What did Mitchell and Boss (2002) find that prolonged pain caused in infants?
- heightened pain sensitivity
- sleep disturbances
- feeding problems
- difficulty calming down when upset
According to the Dynamic Systems Theory of Motor Development, is motor development genetically determined?
Motor development cannot be genetically determined
- we are motivated by exploration and a desire to master new skills
- genes can only map it out at a general level
- rather than being hardwired into the NS, behaviours are softly assembled and allow for different paths to the same motor skill
