Child Psychology Exam #2 (Chapter 5)
How Two Neurons Communicate
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Synapse Formation and Dendrite Formation
: Brain Growth in Response to Experience -These curves show the rapid rate of experience-dependent synapse formation for three functions of the brain (senses, language, and analysis). After the initial increase, the underused neurons are gradually pruned, or inactivated, as no functioning dendrites are formed from them.
(Weight by Gender: Birth to 24 Months)
: Eat and Sleep The rate of increasing weight in the first weeks of life makes it obvious why new babies need to be fed, day and night. Age 2 - 28 pounds (1/5th of adult weight) height 34 inches (1/2 adult height)
Sleep Sleep specifics vary because of biology and the social environment.
: Regular & ample sleep correlates with maturation of the brain, learning, emotion regulation, academic success, and psychological adjustment Newborns sleep about 15-17 hours a day, in one- to three-hour segments. Newborns' sleep is primarily active sleep. Newborns have a high proportion of REM (rapid eye movement) sleep.
Brain Development and parts
: -Brain stem Region deep inside brain which control automatic responses -Midbrain Area of brain that affects emotions and memory -Cortex Outer layers of the brain where most thinking, feeling, and sensing occurs Prefrontal cortex - Area of the cortex at the very front of the brain that specializes in anticipation, planning, and impulse control.
Brain development: Dendrites Sprouting
: Axon Fiber that extends from a neuron and transmits electrochemical impulses from that neuron to the dendrites of other neurons. Dendrite Fiber that extends from a neuron and receives electrochemical impulses transmitted from other neurons via their axons Synapse Intersection between the axon of one neuron and the dendrites of other neurons Neurotransmitter Brain chemical that carries information from the axon of a sending neuron to the dendrites of a receiving neuron. Neurons and synapses proliferate (increase rapidly in number) before birth. This increase continues at a fast pace after birth, but soon an opposite phenomenon occurs: the elimination, or pruning, of unnecessary connections. The last part of the brain to mature is the prefrontal cortex, the area for anticipation, planning, and impulse control.
Experience Shapes the Brain cont.
: Examples from twin studies -Until about 10 months, experience-expectant circumstances not influenced by SES -After 10 months, genetics vary more than context in high-SES families Examples from bird brains -Birds inherit genes that produce the brain cells they need to learning new songs or find hidden seeds -For the dendrites and neurons to connect, birds depend on specific experiences with song-learning or seed-finding Experience-expectant brain function Certain functions require basic experiences in order to develop, just as a tree requires water. Those experiences are part of almost every infant's life, and thus almost every human brain grows as human genes direct. Brains need and expect such experiences; development would suffer without them. Experience-dependent brain function . Some brain functions depend on particular experiences. These specific experiences are not essential: They happen to infants in some families and cultures but not in others. Because of experience-dependent experiences, humans can be quite different from one another, yet all fully human
The Developing Cortex
: Frontal cortex: the front part of the cortex assist in planning, self control, and self regulation. It is very immature in the newborn -Cortex: the crinkled outer layer of the brain -Auditory Cortex: hearing is quite acute at birth, the result of months of eavesdropping during the fetal period -Visual cortex: vision is the least mature sense at birth because the fetus has nothing to see while in the womb. - -Some areas of the cortex, such as those devoted to the basic senses, mature relatively early. Others, such as the prefrontal cortex, mature quite late.
Brain Development
:-Connections in the brain -Neuron One of billions of nerve cells in the central nervous system (CNS) Communication within CNS begins with neurons
Norms
:-Defined standards of typical performance by which a child's development in a variety of domains can be measured -These numbers are norms or average measurements; individuals vary
National Trends in Breast-Feeding Rates
:A Smart Choice In 1970, educated women were taught that formula was the smart, modern way to provide nutrition—but no longer. Today, more education for women correlates with more breast milk for babies. exclusive breastfeeding—no juice, no water, and certainly no cereal.
Motor Skills: Cultural Variations
:All healthy infants develop skills in the same sequence, but the age of acquisition varies. -Variations influences -Genes -Cultural patterns -Nutrition -Caregiving patterns
Co-Sleeping
:Asian and African mothers worry more about separation; European and North American mothers worry more about sex. Pros -Easier response time -Less parental exhaustion -More convenient for breast-feeding Cons -Higher SID -Ghosts in the nursery phenomenon A North American Internet survey found that 20 percent of the youngest babies were put to sleep in the parents' bed, as were 18 percent of the toddlers-sleeping is a matter of custom, not merely income.
Body size
:Birth weight doubles by month four and triples by 1 year Average weight at birth: 7.5 pounds Average length: 20 inches
Effects of Chronic Malnutrition
:Brains may not develop normally. Protection against common diseases may be reduced. Some diseases result directly from malnutrition Marasmus Kwashiorkor 1. Their brains may not develop normally. If malnutrition has continued long enough to affect height, it may also have affected the brain. 2. Malnourished children have no body reserves to protect them against common diseases. About half of all childhood deaths occur because malnutrition makes a childhood disease lethal. 3. Some diseases result directly from malnutrition—both marasmus during the first year, when body tissues waste away, and kwashiorkor after age 1, when growth slows down; hair becomes thin; skin becomes splotchy; and the face, legs, and abdomen swell with fluid (edema
Breast feeding
:Breast-feeding is universal. None of us would exist if our foremothers had not successfully breast-fed their babies or millennia.
Immunizations are unsafe for
:Embryos exposed to rubella Newborns People with compromised immune systems
Motor Skills: Fine Motor Skills
:Fine motor skills Physical abilities involving small body movements, especially of the hands and fingers, such as drawing and picking up a coin Shaped by culture and opportunity Caregiving and culture matter. Reflexes become skills if they are practiced and encouraged.
Sleep REM 24 decreases Sleep problems
:First born infants typically receive more attention and this may contribute to sleep problems. One-fourth of parents of children under age three reported sleep problems. Parent reactions to infant sleep shape the baby's sleep patterns, which in turn affect the parents.
Surviving in Good Health: Nutrition adequate nutrition
:For every infant disease (including SIDS), breast-feeding reduces risk and malnutrition increases it, stunting growth of body and brain. Breastfed babies are less likely to develop allergies, asthma, obesity, and heart disease. As the infant gets older, the composition of breast milk adjusts to the baby's changing nutritional needs
Face Recognition
:Fusiform face area of brain Makes newborn infant adept at face recognition Experiences Refine face perception and trigger immediate recognition Own-race effect Apparent before first birthday and persists throughout life
Stunting
:Genetic? The data show that basic nutrition is still unavailable to many children in the developing world. Some critics contend that Asian children are genetically small and therefore that Western norms make it appear as if India and Africa have more stunted children than they really do. However, children of Asian and African descent born and nurtured in North America are as tall as those of European descent. Thus, malnutrition, not genes, accounts for most stunting worldwide.
Infant Sleep Times, by Percentile
:Good Night, Moon Average sleep per 24-hour period in % - much variation in hours young kids sleep. 1 year old - 10 a night 2 hrs napping 3 year old - 10 hrs with 10% no nap Other charts from this study show nighttime sleep and daytime napping. -Most 1-year-olds sleep about 10 hours a night, with about 2 hours of napping, but some sleep much less; by age 3, about 10 percent have given up naps altogether. -Note that these data are drawn from reports by U.S. parents, based on an Internet questionnaire. -Actual sleep monitors or reports by a more diverse group of parents would probably show even more variation.
Motor Skills: Gross Motor Skills cont
:Gross motor skills Physical abilities involving large body movements, such as walking and jumping This boy will probably become an expert walker and runner, as do many babies who bypass the crawling phase altogether.
Most of gain is Fat!
:Head-sparing - head continues to grow even in face of malnutrition Biological mechanism Protects the brain when malnutrition disrupts body growth Brain is the last part of the body to be damaged by malnutrition Prenatal and postnatal brain growth (measured by head circumference) is crucial for later cognition.
Moving and Perceiving: Hearing and Seeing Hearing
:Hearing Develops during the last trimester of pregnancy Most advanced of the newborn's senses Speech perception by 4 months after birth The computer interprets the data and signals any need for more tests—as is the case for about 1 baby 100. Normal newborns hear quite well; Henry's hearing was fine.
Harming the Infant Brain
:Infants need stimulation Playing, allowing varied sensations, and encouraging movement necessary for brain connections Stress and the brain Overabundance of stress hormones damages later brain functioning Infants need protection Shaken baby syndrome is a life-threatening injury that occurs when an infant is forcefully shaken back and forth. This motion ruptures blood vessels in the brain and breaks neural connections. -Infants have an inborn drive to remedy deficits (self-righting). -It is the patterns, not the moments, of neglect or maltreatment that harm the brain. -Understanding development as dynamic and interactive means helping caregivers from the start, not waiting until destructive patterns are established
Moving and Perceiving: Hearing and Seeing seeing
:Least mature sense at birth Newborns focus between 4 and 30 inches away Experience and maturation of visual cortex improve shape recognition, visual scanning, and details. Binocular vision at 3 months
Moving and Perceiving: Dynamic Sensory Systems
:Most important experiences are perceived with interacting senses in dynamic systems. -Sensations facilitate social interaction and comfort -By 6 months, infant are able to coordinate the senses
Motor Skills: Gross Motor Skills
:Motor skills -Learned abilities to move some part of the body, in actions ranging from a large leap to a flicker of the eyelid. Course of development -Cephalocaudal (head-down) and proximodistal (center--out) direction -First movements are not skills but reflexes, involuntary responses to a particular stimulus. -Caregiving and culture matter. Reflexes become skills if they are practiced and encouraged.
Experience Shapes the Brain
:Necessary and possible experiences (Greenough and colleagues) -Experience-expectant brain function -Experience-dependent brain function Experience-expectant brain function Certain functions require basic experiences in order to develop, just as a tree requires water. Those experiences are part of almost every infant's life, and thus almost every human brain grows as human genes direct. Brains need and expect such experiences; development would suffer without them. Experience-dependent brain function . Some brain functions depend on particular experiences. These specific experiences are not essential: They happen to infants in some families and cultures but not in others. Because of experience-dependent experiences, humans can be quite different from one another, yet all fully human.
Problems (with immunizations)
:No effective vaccine found for AIDS, malaria, cholera, typhoid, and shigellosis Many rural areas of world not reached
Percentile
:Number that indicates rank compared to other similar people of the same age Percentiles range from zero to 100
sleep cont
:Overall, 25 percent of children under age 3 have sleeping problems, according to parents surveyed in an Internet study of more than 5,000 North Americans. Newborns sleep about 15-17 hours a day, in one- to three-hour segments. Newborns' sleep is primarily active sleep: often dozing, able to awaken if someone rouses them, but also able to go back to sleep quickly if they wake up, cry, and are comforted. Quiet sleep: slow brain waves and slow breathing. Newborns have a high proportion of REM (rapid eye movement) sleep, with flickering eyes and rapid brain waves. Variation is particularly apparent in the early weeks. As reported by parents (who might exaggerate), 1 new baby in 20 sleeps 9 hours or fewer per day and 1 in 20 sleeps 19 hours or more.
Perceiving and Moving: The Senses
:Perception follows sensation. Infants' brains are especially attuned to their own repeated social experiences and perception occurs. Infant brain and auditory capacity to hear sounds in the usual speech range. The parts of the cortex dedicated to the senses develop rapidly.
Immunization
:Primes the body's immune system to resist a particular disease Contributes to reduced mortality and population growth; herd immunity Successes Smallpox Polio Measles Rotavirus Immunization not safe Embryos/rubella Newborns People with compromised immune systems Problems Reactions Potential side effects
Surviving in Good Health malnutrition
:Protein-calorie malnutrition Condition in which a person does not consume sufficient food of any kind that can result in several illnesses, severe weight loss, and even death Stunting Failure of children to grow to a normal height for their age due to severe and chronic malnutrition Wasting Tendency for children to be severely underweight for their age as a result of malnutrition
Sensation and Movement: The Senses
:Sensory development Typically precedes intellectual and motor development Sensation Response of a sensory system (eyes, ears, skin, tongue, nose) when it detects a stimulus Perception Mental processing of sensory information when the brain interprets a sensation
Birth catch-up
:Small babies experience extra gain to catch up to the norm
Moving and Perceiving: Smelling and Tasting
:Smell and taste Function at birth Rapidly adapt to the social world Related to family and cultural preferences May have evolutionary function
Brain Development Exuberance and pruning
:Specifics of brain structure and growth depend on genes and maturation, but even more on experience. Expansion and pruning of dendrites occur for every aspect of early experience. Unused dendrites whither to allow space between neurons in the brain, allowing more synapses and thus more complex thinking. Transient exuberance followed by pruning. Early dendrite growth is called transient exuberance: exuberant because it is so rapid and transient because some of it is temporary.
Surviving in Good Health
:Statistics 10 billion children were born between 1950 and 2010; more than 2 billion of them died before age 5 World death rate in the first five years of life has dropped about 2 percent per year since 1990 Improvement in clean water, nourishing food, immunization, medical treatments
Lifelong Deprivation
:The CT scans on the left are from healthy 3-year-old children with an average head size (FOC: 50th percentile). -The image on the right is from a series of three 3-year-old children following severe sensory deprivation neglect in early childhood. -Each deprived child's brain is significantly smaller than average and each has abnormal development of cortex (cortical atrophy) and other abnormalities suggesting abnormal development of the brain.
Dynamic Sensory-Motor Systems
:The entire package of sensations and motor skills furthers three goals. Social interaction Comfort Learning Sensory Exuberance Human animals are unusual in that all the senses function at birth, but motor skills develop slowly. Most important experiences are perceived with interacting senses and skills, in dynamic systems.
Hello? Is Anybody There? -infant brain
:The infant brain actually contains billions of neurons, each with one axon and many dendrites. Every electrochemical message to or from the brain causes thousands of neurons to fire, each synapse to neighboring neurons. This electron micrograph shows neurons greatly magnified, with their tangled but highly organized and well-coordinated sets of dendrites and axons.
Dynamic Systems Underlying Motor Skills
:Three interacting elements underlying motor skills Muscle strength Brain maturation Practice 1. Muscle strength. Newborns with skinny legs and 3-month-olds buoyed by water make stepping movements, but 6-month-olds on dry land do not; their legs are too chubby for their underdeveloped muscles. 2. Brain maturation. The first leg movements—kicking (alternating legs at birth and then both legs together or one leg repeatedly at about 3 months)—occur without much thought. As the brain matures, deliberate leg action becomes possible. 3. Practice. Unbalanced, wide-legged, short strides become a steady, smooth gait.
Moving and Perceiving: Touch and Pain
:Touch Sense of touch is acute in infants. Although all newborns respond to being securely held, soon they prefer specific, touches. -Pain and temperature -Pain and temperature are often connected to touch. Some people assume that even the fetus can feel pain. -Others say that the sense of pain does not mature until months or years later. Ability to be comforted by touch is one of the skills tested in the Brazelton Neonatal Behavioral Assessment Scale.