Infants, Children, and Adolescents Laura E. Berk 6th edition
Physical Development in Infancy and Toddlerhood
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Gain 50% in height from birth to age 1; 75% by age 2
Grow in spurts
Gain “baby fat” until about 9 months, then get slimmer
Girls slightly shorter and lighter than boys
“ Head to Tail”
Lower part of body grows later than the head
“ Near to far”
Extremities grow later than head, chest, and trunk
Epiphyses of the Bone
The Skull at Birth
Neurons and Their Connective Fibers
Major Milestones of Brain Development
Methods for Measuring Brain Functioning
Regions of the Cerebral Cortex
Lateralization and Plasticity of the Cerebral Cortex
The left and right hemispheres of the brain control different functions.
Specialization of the two hemispheres is called lateralization.
Left hemisphere: best at processing information in a sequential, analytic way.
Right hemisphere: best at processing information in a holistic, integrative manner.
In a highly plastic cerebral cortex, many areas are not yet committed to one function, consequently, the cortex has a high capacity for learning.
Brain Plasticity Insights
In children with injuries to the cerebral cortex that occurred before birth or in the first 6 months of life, language delays persisted to about 3 ½ years of age.
Yet, by age 5, the children caught up in grammatical and vocabulary skills, showing that the undamaged area of the brain—either hemisphere—had taken over the language function.
Spatial skills showed more impairment after a brain injury. Researchers speculate that spatial processing is more lateralized at birth.
Brain plasticity can occur later in adulthood, for example, in stroke victims.
Sensitive Periods in Brain Development
Early, extreme sensory deprivation results in permanent brain damage and loss of function.
Babies born with cataracts in both eyes who have corrective surgery within 4 to 6 months show rapid improvement in vision.
The longer the surgery is postponed, the less complete the recovery of visual skills.
Brain Development in Orphanage Children
Children adopted from Romanian orphanages before 6 months of age showed dramatic cognitive and physical gains.
Those adopted after 6 months, however, showed serious intellectual deficits.
The chronic stress of early, deprived orphanage rearing disrupts the brain’s ability to manage stress, with long-term consequences.
Relationship of Age at Adoption to Mental Test Scores
Sensitive Periods in Brain Development
“ expected” by brain to grow normally
Specific experience, varies widely
Experience-expectant brain development takes place early and naturally as part of a preschooler’s daily routine.
No evidence exists to support a sensitive period in early life when mastering skills that depend on extensive training can occur. In fact, rushing early learning can overwhelm young brains.
Sleep moves to an adult-like night-day schedule during the first year.
Sleep needs decline from 18 to 12 hours a day by age 2.
Night wakings often increase between the ages of 1 ½ and 2 years, and then decline.
Cultural Variations in Infant Sleeping Arrangements
Cosleeping is the norm for 90% of the world’s population.
Cultural values of collectivism versus individualism strongly influence infant sleeping arrangements.
Cosleeping is increasing in North America, perhaps because more mothers are breastfeeding.
Influences on Early Growth
Breast v. Bottle Feeding
Problems Can Cause Failure to Thrive
Benefits of Breastfeeding
Correct fat-protein balance
Better jaw and tooth development
Easier transition to solid food
Are Chubby Babies At Risk for Later Obesity?
Recent research shows that there is a relationship between rapid weight gain in infancy and later obesity.
What to do?
Breastfeed for six months.
Avoid foods loaded with sugar, salt, and saturated fats.
Promote physical exercise.
Limit TV viewing time.
Growth and weight problems
Poor motor development
Learning, attention problems
Passivity, irritability, anxiety
Nonorganic Failure to Thrive
The baby is offered enough food and has no serious illness, but still has a wasted body and is withdrawn and apathetic.
Family circumstances surrounding failure to thrive often help explain the problem.
When treated early, by helping the parents or placing the baby in a caring foster home, failure-to-thrive infants show quick catch-up growth. Left untreated, most will remain small and have lasting difficulties.
The Steps of Classical Conditioning
Operant Conditioning Terms
Increases probability of behavior occurring again
Presenting desirable stimulus
Removing unpleasant stimulus
Reduces probability of behavior occurring again
Presenting unpleasant stimulus
Removing desirable stimulus
Using Habituation to Study Infants
Imitation is a powerful method of learning.
It is more difficult to induce in babies 2 to 3 months old than right after birth.
Andrew Meltzoff: newborns imitate as much as older children and adults do.
Mirror neurons enable us to observe another person’s behavior while simulating that behavior in our own brain.
Meltzoff’s theory of newborn imitation as a voluntary capacity is controversial.
The Sequence of Motor Development
Gross motor development
crawling, standing, walking
Fine motor development
reaching and grasping
Gross and Motor Development in the First Two Years
Motor Skills as Dynamic Systems
Increasingly complex systems of action with each skill
4 factors in each new skill:
Body’s movement capacity
Steps in Reaching and Grasping
With two hands, then one
Adjust grip to object
Move objects from
hand to hand
Keeping Infants and Toddlers Safe
Provide safe toys
Child-proof all rooms
Continuously monitor the infant or toddler
Use a car seat, following government regulations
Report any unsafe toys and equipment
Bowel and Bladder Control
Toilet training is best delayed until the months following the second birthday.
Effective training techniques include:
establishing regular toileting routines
using gentle encouragement
praising children for their effort
Developments in Hearing Can detect words that start with weak syllables 10 months Divide the speech stream into word-like units 7 – 9 months “ Screen out” sounds from non-native languages 6- 8 months Sense of musical phrasing 4 – 7 months
Improvements in Vision
Brain development helps infants reach adult levels of vision skills:
2–4 months: focus and color vision
6 months: acuity, scanning & tracking
6–7 months: depth perception
Steps in Depth Perception Sensitivity to pictorial cues. Wariness of heights. 6 –7 months Sensitivity to binocular cues. 2 – 3 months Sensitivity to motion cues. Birth – 1 month
Steps in Pattern Perception Can detect objects if two-thirds of drawing is missing. 12 months Can detect patterns even if boundaries are not really present. 4 months Can detect fine-grained detail. Prefer complex patterns. 2 months Poor contrast sensitivity. Prefer large simple patterns. 3 weeks
Appearance of Checkerboards to Very Young Infants
Subjective Boundaries in Visual Patterns
Stimuli for Studying Infants’ Facial Perception
Testing Infants’ Ability to Perceive Object Unity
Differentiation Theory of Infant Perception
Infants actively search for invariant , unchanging features of the environment.
Borders of stimuli, faces
They note stable relationships between features.
Complex visual patterns, intermodal relationships
Perception gets more and more sensitive— differentiation
Acting on the environment helps this process— affordances