Chapter 5 - Physical Development in Infancy and Toddlerhood Flashcards
Brain Development: microscopic
- We start with an overabundance of synapse which serve identical functions to ensure the child can acquire motor, cognitive and social skills.
- The neurons that are seldom stimulated start to lose their synapses.
- Brains size increase in the first 2 years is do gins in neural fibers and to rapidly multiplying glia cells.
- “living sculpture” start with too much then slowly remove the excess.
Physical Development
- By the end of the first year infants height has increased by 50% and weight has tripled
- by the end of the second year infants height has increased by 75% and weight has quadrupled
- They grow in spurts and not steady
- “baby fat” peaks at 9 months and helps maintain body temputure
- In second year toddlers slim down a bit
- At birth head is 1/4 of body by age two it is 1/5
- Children of the same age can grow at a different rate but that does not mean they are more physically mature.
Fontanels
Fontanels is an anatomical feature on an infant’s skull comprising any of the soft membranous gaps between the incompletely formed cranial bones of a foetus or an infant. The softness helps the baby pass through the birth cannel. Fontanelles allow for rapid stretching and deformation of the cranium as the brain expands faster than the surrounding bone can grow.
The biggest t is filled during the second year the smaller ones close earlier. They are not completely done until adolescence.
The location that they grow together are called sutures.
Skeletal age
The “bone age” of a child is the average age at which children reach this stage of bone maturation. A child’s current height and bone age can be used to predict adult height.
It is the best estimate of a child’s physical age.
There is a gap in boys and girls at birth by 4 to 6 weeks and the gap widens through infancy and childhood. This may contribute to girl’s greater resistance to harmful environmental influence.
Epiphyses
Special growth centers at the ends of a long bones that fuses with the shaft of the bone at the point where it was previously separated by cartilage to allow bone growth.
They increase in number through childhood then get thinner and disappear.
Cephalocaudal Trend
“head to tail”
Refers to the pattern of changing spatial proportions over time during growth. During prenatal growth, from conception to 5 months, the head grows more than the body.
The cephalocaudal trend is also the trend of infants learning to use their upper limbs before their lower limbs.
proximodistal trend
“near to far”
Prenatal growth from 5 months to birth when the fetus grows from the inside of the body outwards.
When referring to motor development, the proximodistal trend refers to the development of motor skills from the center of the body outwards.
Development of Neurons
Step 1: neuron production
Step 2: migration
Step 3: differentiation
- also forming synaptic connections with other neurons
Synaptic pruning
Synaptic pruning - loss of connective fibres by seldom-stimulated neurons, thereby returning them to an uncommitted state so they can support future development
- Synapses need space, so the ones that aren’t being used are pruned, to make room for others
- Around 40%
Neurons also are pruned, for the same reason
- As neurons form connections stimulation in vital to a neurons survival
Neurophysiological Methods
- Various procedures for ‘imaging’ brain composition and activity have been developed in recent years
- These techniques allow scientists to literally look inside the living brain
- Some of these techniques reveal information about brain activity as well as about anatomy
- PET and FMRI are not suitable for infants and young children because they have to lie still for periods of time.
- NIRS is better for children but it is limited to mapping the activity changes in the cerebral cortex.
- Limitation: A researcher using these methods need to make sure they know the cause of the activation, which is hard to determine.
EEG - Electroencephalography PET fMRI ERPs NIRS
EEG - Electroencephalography
The recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain.
PET
PET scans measure metabolic activity in the brain through the injection of a radioactive isotope into the bloodstream
fMRI
The fMRI procedure uses a powerful magnet to record changes in the oxygen level in areas of the brain
When a brain area is active, there is an increase in blood flow and oxygenation in that area, and the oxygenated blood is more magnetized than nonoxygenated blood.
ERPs
Another technique involves measuring event-related potentials (ERPs)
Electrodes are attached to the scalp, and they record the neuronal activity that follows presentation of a particular stimulus
Measurement of ERPs can be used at any age, even in infancy
NIROT
Near infrared optical topography (NIROT) is a new brain-imaging method that works well in infancy and early childhood
Infrared light is beamed at regions of the cerebral cortex to measure blood flow and oxygen metabolism while the child attends to a stimulus
Because the apparatus consists only of thin, flexible optical fibres attached to the scalp, a baby can sit on the parent’s lap and move during testing
Brain Development: the Cerebral Cortex
Cerebral cortex - the largest, most complex structure of the human brain, responsible for the highly developed intelligence of the human species
- accounts for 85% of the brain’s weight and contains the greatest number of neurons and synapses
- last part of the brain to stop growing, and is thus sensitive to environmental influences over a more extended period of time
The order in which cortical regions develop corresponds to the order in which different capacities emerge
Year 1, a burst of synaptic growth in the auditory and visual cortexes and in areas responsible for body movement – this is a period of dramatic gains in auditory and visual perception and master of motor skills.
Language areas are particularly active from late infancy through the preschool years – when language development flourishes
The frontal lobes are the slowest part of the cortex to develop. Starting at 2 months there are some increase in efficiency, rapid myelination, neurogenesis, and pruning in preschool, adult level of synaptic connections by mid- to late-adolescence.
Prefrontal cortex
Responsible fore consciousness, inhibition of impulse, integration of information, and use of memory, reasoning, and planning
Lateralization
The two hemispheres of the brain are lateralized—the right and left hemispheres are somewhat specialized
- Each controls opposite side of body
- Experience influence how it will develop
- Early acquisition of language skills or a second language greater left hemispheric specialization. Sign language shows that they use the right hemisphere more for language processing.
Hemispheric specialization shows individual differences
Some people have right-brain dominance for language, and some people have mixed dominance
Right – special abilities, shapes, negative emotions
Left – verbal abilities, spoken, written, positive emotion
Left-handed people more often have right-brain or mixed dominance than do right-handed people
People who have problems with reading performance sometimes are associated with mixed or right-brained dominance for language
- Children with dyslexia are more likely to lack strong left-brain dominance than are normal readers
Signs that Hemispheric specialization appears quite early
- Newborn infants produce more activity in the left than right side of the brain in response to speech sounds
- Some physical differences in size and shape between the hemispheres are already present at birth
- Newborns and infants don’t show all the forms of lateralization that will eventually develop, though
Brain plasticity
Brain plasticity - the capacity of various parts of the cerebral cortex to take over functions of damaged regions
- In a highly plastic cerebral cortex, many areas aren’t yet committed to specific functions
- This is due to an overabundance of synaptic connections
Although lateralization has already begun by birth, the brain remains relatively plastic for the first few years
Sensitive Periods in Brain Development
Both humans and other animals have been shown to have sensitive periods in development
- Experiments in which animals are deprived of experiences
- Babies both with cataracts in both eyes – early corrective surgery = face perception limitations. Late surgery = permitly impair red vision.
- Children overwhelmed with too much stimulation – no help but may cause them to withdraw causing conditions like simulations deprivation. Can also harm neural circuits and reduce sensitivity to the everyday experiences that it need to be learning from.
Romanian orphanage adoptees
Children reared in overcrowded orphanages showed deficits in all domain of development. Adopted before 6 months they quickly caught up. More than 6 months = serious intellectual deficits that improved some during middle childhood but remained below average and most showed at least 3 serious mental health problems like: inattention, over activity, unruly behavior, and autistic like symptoms. Prefrontal cortex might be the area of the most concern. Their head size was even smaller. Early stress = problems with reactivity and stress management, limit physical growth, learning and behavior problems, attention, anger and impulses. Limit typical oxytocin levels which lowered response to to pleasurable activities.
Oxytocin in brain development
Hormone released by the brain that evokes calmness and contentment in the presence of familiar, trusted people.
2 types of brain development
Experience-expectant brain growth
Experience-dependent brain growth
Experience-expectant brain growth
the young brain’s rapidly developing organization, which depends on ordinary experiences – opportunities to see and touch objects, to hear language and other sounds, and to move about and explore the environment
- Occurs naturally in a good environment
- Age appropriate toys and stimulation, and enjoyable daily routines are key.
Experience-dependent brain growth
Occurs through the life span.
Consists of additional growth and the refinement of established brain structures as a result of specific learning experiences that vary widely across individuals and cultures
Changing States of Arousal
Sleep
During the first 2 years of life
- Sleep declines slightly (from 16-18 hours to about 12-13 hours)
- Fussiness and crying decline
- Daytime naps decline, while nighttime sleeping increases
- Babies (1 to 8 months) who sleep with parents have a consistent sleep time of about 3 hours at a time.
- At the end of the first year REM sleep decreces
- When they can crawl and walk they often show periods of disrupted sleep.
- Night waking’s increase between 1 ½ and 2 years then decrease again
Sleep patterns and Melatonin levels
Melatonin levels aren’t substantially higher at night than during the day until about 6 months of age
- The tendency of Western children to increase nighttime sleeping and decrease daytime sleeping before this time seems to be a response to parents’ attempts to promote this. (rare elsewhere in the world) This may be at odds with a young infant’s neurological development.
- Babies over six months sleep better if they are exposed to sun light during the afternoon.
Heredity Influences on Growth
What to do?
What to do?
- Breastfeeding for the first 6 months is associated with slower weight gain
- Avoiding foods that are high in sugar, salt, and saturated fats is useful
- Encouraging energetic play once toddlers learn to walk, climb, and run
- Less TV; research shows a correlation between excessive television viewing and overweight in older children
Chubby babies
Pound for pound babies need twice as much food as adults.
Most chubby infants thin out during toddlerhood and the preschool years
Infants and toddlers can pretty much be allowed to eat freely, as long as the food being provided is nutritious
When parents provide too many unhealthy foods and options, obesity is a frequent result. Rapid weight gain
Brest feeding versus bottle feeding
Because breast milk is essentially designed for optimal health, breastfed babies in poverty-stricken regions of the world are much less likely to be malnourished and are 6 to 14 times more likely to survive the first year of life. Also breast feeding can increases spacing of siblings. Young mother in developing countries might not know.
(W.H.O.) Breast feeding is recommended until age 2, with solid foods added at 6 months
Even a few weeks of breastfeeding offers some protection against respiratory and intestinal infections.
Breast-fed babies are hungry more often, so it can be harder for Mom to keep up with feeding times. (1 ½ - 2 hours versus 3 to 4 for bottle fed)
Breast and bottle can be mixed after about 6 months
Does not impact mother baby relationship and attachment in industrialized countries
Marasmus
a disease usually appearing in the first year of life, caused by a diet low in all essential nutrients, that leads to a wasted condition of the body. Often because mother is too malnourish to produce enough milk
Kwashiorkor
a disease caused by a diet low in protein that usually appears after weaning, (1-3)with symptoms including an enlarged belly, swollen feet, hair loss, skin rash, and irritable, listless behaviour. The body is breaking down its own protein reserves.
Malnutrition
Adequate amounts of food are, of course, crucial, but food must also have adequate nutritional value
27% of children in the world suffer from malnutrition before 5
10% suffer from 2 dietary diseases
- Marasmus
- Kwashiorkor
If they survive the malnutrition, these children
- Are smaller than average
- Have lasting organ damage
- Gain excessive weight if and when their diets improve
- Have a tendency to overeat if food becomes plentiful (damage to appetite control centers)
- Lower intelligence
- Poor fine motor development
- Difficult attention
- More stress to fear (effect of chronic stress about hunger)
Iron-deficiency anemia
Iron-deficiency anemia is a condition common among poverty-stricken infants and children
- This one is found in North America, where instances of marasmus and kwashiorkor are rare or nonextistent
Withdrawal and listlessness are common with iron-deficiency anemia, reducing the child’s ability to pay attention, explore, and evoke sensitive caregiving from the usually-malnourished parents
- Lack of nutrition and lack of stimulation then combine, so interventions should target both of these
Food insecurity
Food insecurity: uncertain access to enough food for a healthy, active life
- Seen in about 13% of Canadian children and 16% of American children
- Particularly high among single-parent families and low-income ethnic minority families
Even without severe nutritional deprivation, physical growth and ability to learn can be affected here
Growth faltering
infants whose weight, height, and head circumference are substantially below age-related growth norms and who are withdrawn and apathetic
- Often related to disturbed parent-infant relationship
Learning Capacities
- Learning refers to changes in behaviour as the result of experience
- Some forms of learning are apparent very early in development
Classical Conditioning
Classical conditioning occurs when a previously neutral stimulus becomes a conditioned stimulus
- Unconditioned stimulus (UCS)
- Unconditioned response (UCR)
- Conditioned stimulus (CS)
- Conditioned response (CR)
Over time, we may see stimulus generalization
If the CS is removed, we may see extinction
Operant Learning
Operant learning works on our voluntary, or operant behaviours
- Positive reinforcer
- Negative reinforcer
- Positive punisher
- Negative punisher
Reinforcer/punisher refers to whether we’re increasing or decreasing a behaviour
Positive/negative refers to whether we’re adding or removing a stimulus
Vital role in the formation of social relationships.
Habituation
Habituation is the gradual reduction of the strength of a response due to repetitive stimulation
It is considered the simplest form of learning
Used to test for perceptual and cognitive capacities – speech peseption, musical and visual pattern perception, objet perception, categorization, knowledge of social world.
Recovery
Habituation
A new stimulus after previously forming a Habituation
It causes responsiveness to return to a high level
Novelty preference
Habituation
Recovery to new stimulus
It is use to assess an infant’s recent memory
If they recognize something they attend to the familiar
Infants like adults shift from a novelty preference to a familiarity preference when there is more time between the stimulus
Remote memory
Habituation
A memory for a stimuli that an infant had been exposed to weeks or months before
Imitation
Imitation - learning by copying the behaviour of another person
Some studies indicate that newborns can imitate adult facial expressions
- Others have failed to replicate those results
- Imitation is harder to induce in babies 2 to 3 months old than in newborns, leading some researchers to suggest that early facial imitation is an automatic response
- Some researchers suggest that imitation doesn’t decline with age; it simply takes longer to induce because babies try mutual gazing, cooing, and smiling (familiar social games) before resorting to imitation
- Or it takes longer then we give it
Meltzoff maintains that newborns imitate by actively trying to match body movements they see with the ones they feel themselves making, the same way older children and adults imitate
The capacity for imitation improves dramatically over the first 2 years.
Mirror neurons
Fire when watching others preforming an action, it is how we learn by imitation and part of empathy. Seen as early as 6 months.
Motor Development
Motor development affects more than just a child’s ability to move around
- Exploration influences cognitive development, including the development of spatial skills
- The child’s social relationships change as s/he becomes more mobile, influencing social development
Always keep in mind that the ‘different types’ of development are far from independent of one another
Reaching my play the greatest role in infant cognitive development because it lets them interact with their environment. It starts out gross and becomes mastered as a fine motor skill. They try to bring their hands in to their field of vision
Gross motor development
control over actions that help infants get around in the environment, such as crawling, standing, and walking
Fine motor development
smaller movements, such as reaching and grasping
The Rate of Motor Development
Large variation in rate of development
As with growth, motor development is both cephalocaudal and proximodistal
The virtual universality of these trends suggests a genetic component
However, a child’s environment and opportunities to practice will also have a strong effect
Dynamic systems theory of motor development
Dynamic systems theory of motor development - a theory that views new motor skills as reorganizations of previously mastered skills, which lead to more effective ways of exploring and controlling the environment. (acquiring an increasingly complex systems of action)
- The term dynamic suggests that there is constant change in the child’s abilities
- The term system suggests that previously-separate abilities are combined, and work together to form new abilities
A new skill isn’t initially stable
• It may need refining, and may be intermittent at first
• Eventually, it’s refined and more consistent
• This involves practice, and often much of it
– For instance, in learning to walk, toddlers often practice at least 6 hours per day, and travel the length of 29 football fields
Dynamic systems theory of motor development
Each new skill is a joint product of :
Each new skill is a joint product of
(1) central nervous system development, the body’s movement possibilities,
(2) the child’s goals, and
(3) environmental supports for the skill.
- Early in development, brain and body growth are likely the major contributors to a child’s motor development
- Later, the child’s goals and environmental support become more important
Dynamic Motor Systems in Action
Galloway and Thelen have shown that motivation plays a role, even in something as basic as the cephalocaudal trend
- They held toys alternately near infants’ feet and near their hands
- They used their feet more because they had more controlled movements and required less practice
- Microgenetic studies
Cultural Variations in Motor Development
Opportunity to practice motor skills is paramount…
The Kipsigis people of Kenya begin active efforts to train their infants to sit up, stand, and walk soon after birth
- This does speed up Kipsigis children’s attainment of these skills, by about a month
West Indian children in Jamaica show a similar trend, in response to similar environmental encouragement
Among the Ache, in the rain forests of Paraguay, it’s unsafe for young children to wander than about a metre from their mothers—they are pretty much constantly carried as infants
- These children show various motor delays, compared to children of other cultures, including beginning to walk about a year later than other children
Children raised in overcrowded orphanages sometimes don’t move on their own until they’re about 2 years of age
- Then they scoot in a sitting position, rather than crawling, because they’re not used to being on their stomachs
- This means they come up against furniture with feet, rather than hands, and are less likely to pull themselves into a standing position
Prereaching
Prereaching - the poorly coordinated, primitive reaching movements of newborn babies
Prereaching drops out around 7 weeks of age, before intentional reaching begins
Fine Motor Development: Reaching and Grasping
Clearly purposeful reaching emerges at about 3 to 4 months of age
By 5 to 6 months, they continue reaching for an object if you switch off the lights when they’re mid-reach
- This suggests they’re using proprioception—our sense of movement and location in space—to help guide their reaching
Development of depth perception and improvements in control of posture and arm and hand movements contribute to reaching
- 4-month-olds can aim their reaches ahead of a moving objects
- 5-month-olds reduce their efforts when an object is out of reach
- 7-month-olds can reach with just one arm, rather than always having to use both
Between 8 and 11 months, reaching and grasping are pretty well-practiced
This frees up cognitive space for other things, like anticipating their next action
Ulnar grasp
Ulnar grasp - grasp in which the fingers close against the palm
- Seen in young infants
- 3-month-olds can adjust their grasp to the size and shape of an object
- By 4-5 months, they can hold an object in one hand while exploring it with the other, and can pass an object from hand to hand
Pincer grasp
Pincer grasp - well-coordinated grasp that involves thumb and index finger opposition
- Emerges at the end of the first year
- This makes manipulation of objects much easier
- Solving reaching problems starts
Bowel and Bladder Control
Toilet training usually works best when it’s started soon after the second birthday
- At this time, children an consistently identify the signals from a full bladder or rectum, and control when and where they open these muscles
Children will often show signs when they’re ready for training: they may stay dry for several hours at a time, stop playing during urination and bowel movements, and be bothered by a wet or full diaper
Effective training should: establish regular routines, use gentle encouragement, praising efforts and not pressure to much.
Perceptual Development
Note that sensation and perception aren’t exactly the same thing
- Sensation suggests a passive process
- Perception is more active, involving our organization and interpretation of the stimuli we encounter
Hearing
During the first year of life, infants start to organize sounds into complex patterns
- This includes a fairly complex sense of musical phrasing, beat, and melody
They prefer speech over non speech sounds
Recall that newborns can distinguish phonemes from all human languages, though they prefer their own
With exposure to language, they learn to focus on meaningful sound variations
- Around 5 months, they become sensitive to syllable stress patterns in their own language
- Between 6 and 8 months, they start pruning phonemes not used in their own language
In the second half of the first year, they begin focusing on larger speech units that are necessary for meaning
- They recognize familiar words in spoken passages
- They listen longer to speech with clear clause and phrase boundaries
- Around 7 to 9 months, they begin dividing the speech stream into wordlike units
From the earliest months of life, infants seem to be able to use statistical analysis of speech to determine which syllables go together most often
Between 7 and 9 months, they begin detecting regular syllable-stress patterns
Around the same age, they begin attending to regularities in word sequences, and can detect simple word-sequence rules
By 10 m they can recognize words that start with weak syllables and words out of sequence
Statistical learning capacity
An explanation on how infants learn to perceive speech so fast. Analyzing speech stream for patterns they acquire a stock of speech structures for which they will later learn meanings.
Syllables that often or rarely go together
After just hearing speech for one min they can pick up on distinguish between a word-internal syllables pair from a word external pair.
Vision
After birth, we see rapid maturation of the eye and visual centers in the cerebral cortex
- By 2 months, infants can focus on objects about as well as adults
- Colour vision is adultlike by 4 months
- Visual acuity reaches a near-adult level by 6 months
Scanning and tracking improve dramatically over the first 6 months as infants’ vision improves and they gain more control over their eye movements
With experience, they also learn to scan more thoroughly and systematically, strategically picking up important information
Scanning and perception has a bidirectional relationship of development
The key change seems to be a sudden segregation of neural pathways from the eye to the brain
It would be a mistake to assume on this basis that maturation is the only important factor here, and experience has no role
When the neural activity that would normally occur in response to visual experience is blocked, the segregated neuronal pathways don’t form at the usual time
Visual cliff
a research method for the study of depth perception in infancy. The infant is placed on a glass-covered table near an apparent drop-off, and perception of depth is inferred if the infant avoids the drop
Depth perception
- Use of visual cliff to test
- They get depth perception around the time they learn to crawl
- Crawling my lead to depth perception
- Motion is the first depth perception cue which infants are sensitive. They will blink
- Binocular depth cues emerge 2-3m and improve through the first year
- finally at 5-7m infants show sensitivity to Pictorial depth cues
- Depth perception cues emerge in this order do to motor development but they may need to relearn for every posture
- Crawling also helps other three dimensional perception like remembering and finding a hidden object
- Crawling cause a new type of brain organization
Pattern perception
Newborns prefer to look at patterned disines over plain ones
As they get older they like more complex patterns a theory that explains this is contrast sensitivity
Newborns respond to separate parts of patterns.
At 2-3m when scanning their contrast sensitivity improves and they can explore the patterns internal features
They can then integrate the parts into a whole
At 4m they are so good they can perceive subjective boundaries
At 3-4m they can engage in boundary extension – remember that something extends past the currently shown limits. (like a window)
9m look longer at an organized pattern series of lights that look like a human walking then random lights
12m they cab detect a familiar objects that are represented by incomplete drawings up to 2/3 missing
Face perception
Newborns like looking at normal faces more than misarranged faces and they track faces more then not faces. They prefer eyes open and direct gaze. They rely more on hair line and chin (outer features). They have an attractive bias. Maybe they like horizontally orientated things and not faces.
By 2m they prefer faces to other similar stimuli and can distinguish there mom by her facial features
Around 3m they make fine distinctions of facial features. The can start forming group biases at this time.
Infants 3-6m prefer to look at their own race and start to be able to tell the difference between their own race easier. This can be reversed
At 5m infants perceive emotional expressions as meaningful wholes.
Monocular depth cues
Monocular depth cues are cues that can be perceived through one eye working alone
Two categories
- Those that rely on motion
- Those that are present even in stationary scenes
Motion-reliant Vision
Motion-reliant
- Visual expansion: as objects approach us, they fill an increasing portion of our visual field
- Motion parallax: when you move your head, the retinal images of closer objects move faster than those of distant objects
- Occlusion: when one object moves in front of another, the closer object occludes part of the more distant one
Infants seem to use all of these in the first months of life
Objet perception
Two dimensional stimuli
Size and consistency
To see an object as stable even when we move we must translate the dynamic images into a single representation
Size consistency – seeing an objects size as consistent, evendent in first week.
Shape consistency – seeing an objects shape a consistent. First week of life.
perception of objet identity
first babies relies on motion and spacil arrangement to identify objects.
When objects are touching and moving together a baby less the 4m can not tell they are 2 objects but they do look at shape, size and texture.
At 2m they can tell that a moving rod with the middle obscured is one objet.
As infants become more familiar with many types of objects they rely less on motion and more on the qualities of the object (shape, size, and surface pattern)
4m old will see a balls movement as consistent even if it goes behind a screen, and engage in future orientated eye movement
Pictorial depth cues
Pictorial depth cues
- Relative size: other things equal, closer objects will cover more area on the retina
- Texture: other things equal, closer objects will have a more differentiated surface
- Interposition: occlusion for stationary objects
5-month-olds don’t seem to perceive depth from any of these cues
7-month-olds, however, do
Binocular depth cues
such as retinal disparity, require signals from both eyes
they use it for reaching and hand movements
Stereopsis
Stereopsis - the ability to perceive depth solely on the basis of binocular cues
- This ability emerges suddenly at about 4 months
Contrast sensitivity
Contrast sensitivity - a general principle accounting for early pattern preferences, which states that if babies can detect a difference in contrast between two or more patterns, they will prefer the one with more contrast
- Essentially, they prefer the most complex patterns they’re capable of perceiving
- Amount of light contrast
Intermodal perception
Intermodal perception - integration of simultaneous stimulation from more than one sensory system, resulting in perception of such input as an integrated whole
Crucial for infants to perceptual development. They start to notice meaningful correlations early
Facilitates processing of social world
When parents interact with infants they should provide temporal synchrony (pick up doll and ay doll)
Amodal sensory properties
Amodal sensory properties - information that overlaps two or more sensory systems, such as common rate, rhythm, and duration in visual and auditory input
Infants seem biologically primed to focus on amodal information. It eases the perception of the physical world.
Intermodal Perception
Newborns only need one exposure to match a toy with a sound
By 3 to 4 months, infants can match faces with voices on the basis of lip-voice synchrony, emotional expression, age and gender of the speaker
4 to 6m they can pair face voice for unfamiliar adults
By 5 to 6 months, their ability to continue reaching for an object in a room that’s been darkened indicates that they can relate sight and touch
- They’ll also reach for a sounding object in the dark, relating sound and touch
We see intermodal perception in the social world
- When a caregiver touches an infant, the infant is likely to smile and attend to the caregiver’s face
- 3- to 4-month-olds initial need both vocal and visual input to distinguish positive from negative emotional expressions
By 4 to 5 months, they can do it from voice alone
From 5 onwards, from faces
- 4- to 6-month-olds are beginning to remember unique face-voice pairings when they encounter new people
Differentiation theory
Infants actively search for invariant features pf the environment - those that remain stable – om a constantly changing perceptual world
Stable relationships
Differentiation theory
Infants actively search for invariant features pf the environment - those that remain stable – om a constantly changing perceptual world
- Stable relationships
affordances
The action possibilities the a situation offers an organism with a certain motor capabilitys
