Developmental Psychology Initial Notes PDF

[ISP-DEV] Integration Seminar in Psychology Initial Notes - Developmental Psychology Introduction to Development Pre-natal Development – Development starts at conception — sperm and egg meet to make a new individual from parental genomes Fertilization/Conception – process sperm an...

[ISP-DEV] Integration Seminar in Psychology Initial Notes - Developmental Psychology Introduction to Development Pre-natal Development – Development starts at conception — sperm and egg meet to make a new individual from parental genomes Fertilization/Conception – process sperm and ovum (f and m gametes) combine to create single cell, zygote, that duplicates repeatedly by cell division to produce a baby – Several events need to coincide to conceive a child [not all conception end in birth] – “Fertile window” = time during which conception is possible —highly unpredictable – At birth, girls have 2 million immature ova in her ovaries, each in its own follicle (small sac) – Ovulation—rupture of mature follicle in either ovary and expulsion of ovum—occurs once every 28 days until menopause – Cilia swept the ovum to fallopian tube, toward uterus or womb – Sperm produced in testicles/testes of mature male at rate of several hundred million a day; ejaculated in the semen-deposited in the vagina, swim through cervix, into fallopian tubes but only tiny fraction make it far – Fertilization occurs while ovum is passing through the fallopian tube, if it did not occur, ovum and any sperm will die. Sperm are absorbed by WBC and ovum gets to the uterus and exits the vagina Cause of Multiple Births – Dizygotic Twins/Fraternal Twins – Two separate eggs fertilized by two different sperm = 2 unique individuals – Siblings who inhabit the same womb at the same time – Can be same or different sex – Run in families, passed down from mother to daughter ; result of multiple eggs released at one time – Monozygotic Twins – Result from cleaving of one fertilized egg; genetically identical but still differ outwardly as people are result of interaction between genes and environment [epigenesis] – twin-to-twin transfusion syndrome = unequal receiving of nutrients because of the abnormally formed blood vessels in the placenta thus, one twin may be larger than the other at birth despite being genetically identical – Environmental differences add up over time hence the differences between identical twins increase as they grow older – Multiple births are associated with pregnancy complications, premature delivery, low-birth- wight infants, disability/death of infant Mechanisms of Heredity  – genetics = study of heredity – Heredity = genetic transmission of heritable characteristics from parents to offspring – Genetic Code – Deoxyribonucleic acid (DNA) = double helix structure are made of pairs of chemical units “bases” — Adenine, Thymine, Cytosine, Guanine —that form the genetic code – Chromosomes = coils of DNA that consist of smaller segments “genes”—functional units of heredity, located at a specific position, containing thousands of bases – Sequence of bases in a gene tells the cell how to make proteins which enable it to carry out specific functions – Human genome = complete sequence of genes in human body; a reference point/ representative genome that shows location of all human genes – DNA must be read by an enzyme RNA polymerase and transcribed into a copy by messenger RNA (m-RNA), before its actualized or expressed – The determination of what DNA is transcribed and copy is influenced by environmental factors—turning genes on and off at different points in development – Every cell except gametes has 23 pairs of chromosomes total of 46 – Through meiosis, each sex cell ends up with one 23 chromosomes - one from each pair. When sperm and ovum fuse, they produce a zygote with 46 chromosomes, 23 paternal, 23 maternal. – Through mitosis, non-sex cell division, DNA replicates itself so that each newly formed cell has the same DNA structure – A mistake in copying = mutation which are permanent alterations in genetic material – Normal development - each cell has identical 46 chromosomes and as they divide, they differentiate to become a cell with specialized function – Genes spring to action when conditions call for their genetic information. Genetic action for growth of body and brain is regulated by hormonal levels —of mother and baby—that are affected by environmental conditions. This demonstrated the interrelatedness of heredity and environment Sex Determination – In 23 pairs of chromosomes at the conception, 22 are autosomes and the twenty third pair are sex chromosomes-one paternal and one maternal-which dictates baby’s sex – Sex Chromosomes = X chromosomes or Y chromosomes – Every ovum = X – Every sperm = may contain either X or Y – Y Chromosome contain gene for maleness—SRY gene – Ovum X + Sperm X = genetic female XX – Ovum X + Sperm Y = genetic male XY – Early development, embryo’s rudimentary reproductive system almost identical in both sexes – Sexual differentiation is not automatic – Exposure of a genetically male embryo to steady, high levels of testosterone results in development of male body with male sexual organs – Development of female reproductive system depends on a number of genetic variants which promote ovarian development and inhibit testicular development [HOX genes  – and signaling molecule Wnt-4] – Women have two X chromosomes, so generally one of the 2 is randomly turned off but not entirely, only 75 percent of the genes on the turned off X chromosome are inactive Patterns of Genetic Transmission – Dominant Inheritance = pattern of inheritance in which, when a child receives different alleles, only the dominant is expressed – Recessive Inheritance = when child receives identical recessive alleles, resulting in expression of a nondominant trait – Alleles = genes that can produce alternative expressions of a characteristic – Homozygous = both alleles the same – Heterozygous = different alleles – Polygenic Inheritance = interaction of several genes like in intellectual potential – Phenotype = observable characteristics – Genotype = genetic make up of a person, contains both expressed and unexpressed characteristics – Multifactorial transmission = environmental experience modifies expression of genotype for most traits – Epigenesis/epigenetics = genes are turned off or on as they are needed by the developing body or when triggered by the environment – Chemical molecules/tags attached to a gene that alter the way a cell reads the gene’s DNA - functions to differentiate various types of body cells in this way genes for the type of cells needed are turned on while the unneeded are left off – Epigenetic changes are caused by environmental factors, nutrition, vices, stress, sleep, physical activity Genetic and Chromosomal Abnormalities – Dominant/Recessive Inheritance of Defects – Sometimes gene for an abnormal trait is dominant – Dominant inheritance = achondroplasia (dwarfism), Huntington’s disease – Recessive defects expressed only if child is homozygous for that gene; copy from each parent – Dominant Defects = less likely to be passed to generation – Recessive Defects = possible to be passed to generations – Incomplete Dominance = trait not fully expressed, resulting phenotype is a combination of both genes – Sex-linked Inheritance Defects – Certain recessive disorders affect male and female differently since Y chromosome is smaller and carry less genes than the X chromosome – If a woman has bad copy of a gene, she has a backup while if male has a bad copy, that gene will be expressed – Heterozygote females who care one bad copy of recessive gene and one good one = carriers – More common in males than in females – Red-green color blindness, hemophilia, Duchenne muscular dystrophy (muscle degeneration) — genes in the X chromosome, common in males  – degeneration) — genes in the X chromosome, common in males – Chromosomal Abnormalities – Occurs because of errors in cell division – Klinefleter syndrome = extra female chromosome XXY – Turner Syndrome = missing a sex chromosome XO – The likelihood of errors increase in offspring of women age 35 or older – Down Syndrome = trisomy-21, extra 21st chromosome – Brains appear normal at birth but shrink by young adulthood, particularly in hippocampus and prefrontal cortex leading to cognitive dysfunction and in cerebellum leading to problems with motor coordination and balance Prenatal Development – Gestation = period between conception and birth, unborn child undergoes dramatic processes of development – Normal range = 37 and 41 weeks – Gestational age = dated from first day of an expectant mother’s last menstrual cycle Stages of Prenatal Development [embryo to fetus] – both before and after birth development proceeds according to: 1) cephalocaudal principle growth and motor development from top down, head to toe, 2) proximodistal principle, development proceeds from parts near body center to outer; head and trunk before limbs A. Germinal Stage = Fertilization to 2 weeks – zygote divides, more complex, implanted on uterus wall – Within 36 hours after fertilization, zygote goes through rapid cell division and duplication (mitosis) – 72 hours after fert. = divided into 16 and then into 32 cells – A day later = 64 cells – Fertilized egg is dividing at the same time it is making its way down the fallopian tube to the uterus = 3-4 days – Form changes to blastocyst (fluid filled sphere), floats freely in uterus until 6th day when it implants itself – 10-20% of ova complete implantation and develop – Cell differentiation begins some cells around blastocyst cluster to form embryonic disk, thickened cell mass from which embryo develops – This disk will differentiate into three layers – Ectoderm/upper = outer layer of skin, nails, hair, teeth, sensory organs, nervous system – Endoderm/inner = digestive system, liver, pancreas, salivary glands, respiratory system – Mesoderm/middle = inner skin, muscles, skeleton, excretory and circulatory – 3rd week after conception, a portion of ectoderm folds into neural tube that soon becomes brain and spinal cord – Amniotic cavity/sac = fluid-filled membrane encases developing embryo, protecting it – Placenta = oxygen, nourishment, waste pass between mother and embryo; combat internal infection and give child immunity; produces hormones that support pregnancy, prepares mother’s breasts for lactation, eventually stimulate uterine contractions during labor  – mother’s breasts for lactation, eventually stimulate uterine contractions during labor – Umbilical cord = connects placenta to the embryo B. Embryonic Stage = 2 to 8 weeks – Organs and major body systems—respiratory, digestive, nervous—develop rapidly = organogenesis – Organogenesis period - critical period = embryo is most vulnerable to destructive influences in prenatal environment – Any organ system still developing at the time of teratogen exposure will be affected hence, defects that occur later in pregnancy are less likely to be serious since this stage of organ development is completed – Brain growth and development begins during embryonic stage and continues after birth and beyond – Most severely defective embryos do not survive beyond 1st trimester – Spontaneous Abortion/Miscarriage = expulsion from uterus of an embryo that is unable to survive outside the womb – Stillbirth = miscarriage occurs after 20 weeks of gestation – Smoking, drinking alcohol, drug use increase the risk of miscarriage – Males are more likely than females to be miscarriage or stillborn C. Fetal Stage = 8 weeks to Birth – the beginning of this stage is signaled by the appearance of first bone cells —final stage of gestation – Fetus grows rapidly to about 20 times its previous lengths – Organs and body systems become more complex – Fetus = breathe, kick, turn, flex bodies, do somersaults, squint, swallow, make fists, hiccup, suck thumbs in the womb which are all permitted by the flexible membranes of uterine walls and amniotic sac – At 20 weeks, vernix covers the fetus to protect the skin from chapping and fine layer of body hair - lanugo – Highly unlikely for fetuses to feel pain before the third trimester since the cortex is still immature – Thalamocortical pathways for pain perception = appear only at 29 to 30 weeks of gestation – Facial expressions of pain appear at 36 weeks – Male fetuses are more active than female throughout gestation – 12th week of gestation = fetus swallows and inhales some of amniotic fluid in which it floats which will stimulate the budding sense of taste and smell – 14 weeks = appearance of mature taste cells – Olfactory system is well developed before birth – Fetus respond to mother’s voice, heartbeat and body vibrations – 26 weeks = beginning of response to sound and vibration and then reach a plateau at 32 weeks – Age of Viability = point between 22nd to 28th prenatal weeks when survival outside the uterus is possible  – uterus is possible – Fetuses recognize their mother’s voice, and prefer it over other women’s and their father – 33 weeks = fetuses orient toward and attend to music – Fetus learn and remember a they near end of pregnancy – Fetal memory begins to function at approximately 30 weeks when fetus are able to hold info in memory for 10 mins. – 34 weeks = able to remember information for a month Environmental Influences: Maternal Factors – everything that influences the well-being of mother may alter her unborn child’s environment and affect its growth – Teratogen = environmental agent that can interfere with with normal prenatal development – An environmental agent may be teratogenic for some and not for others this can be due to the gene in either the fetus or in the mother – Fetuses with a variant of a growth gene, “transforming growth factor alpha”, have greater risk at developing cleft palate if the mother smokes while pregnant – Timing of exposure, dose, duration and interaction with other teratogenic factors can make a difference – Nutrition and Maternal Weight – Pregnant women need 300-500 additional calories a day with extra protein – Women of normal weight who gained 16-40 pounds are less likely to have birth complications – If woman does not gain enough, baby may suffer growth retardation, experience distress during labor or die at near birth – A woman who gains too much weight risks having a large baby that needs induced labor or cesarean section – Desirable weight gain depends on BMI before pregnancy the following are recommended weight gains: – Underweight = gain 28-40 pounds – Normal weight = gain 25-35 pounds – Overweight = gain 15-25 pounds – Obese = 11-20 pounds – Important nutrition to have from eating: DHA, Folic Acid/folate – Inadequate levels of folic can leave babies at risk of developing neurological defect — anencephaly (brain is formed incompletely) or spinal bifida (spinal cord is not fully enclosed) – Malnutrition – Malnutrition during pregnancy can hurt the mother, her child and affect the generations to come – Mothers who suffer from calorie deficit result in fetal growth restriction and low birth weight; higher risk of deaths for babies and surviving babies may be stunted – Micronutrient deficiencies like in vitamin A and zinc result in higher risk of death for both child and mother – Micronutrients = needed in small quantities but have profound negative effect if absent  – Fetal undernutrition = increased risks for disease in adulthood – Physical Activity and Work – Moderate exercise at any time during pregnancy does not endanger the fetuses of healthy women – Regular exercise prevents constipation, reduce back pain and risk of complications — gestational diabetes, preeclampsia, cesarean – Strenuous working conditions, occupational fatigue, long working hours = greater risk of premature birth – Drug Intake – Practically everything a mother takes in makes its way to the uterus. Drugs may cross the placenta. – Medical Drugs = antibiotic, barbiturates, opiates, CNS depressants, hormone drugs, anticancer drugs, acutane, drugs for epilepsy treatment, antipsychotic drugs. Naproxen and ibuprofen have been linked to birth defects when taken during first trimester. No medication taken by pregnant or breast-feeding woman unless it is essential for her health or her child’s – Opioids = associated with small babies, fetal death, preterm labor, aspiration of meconium. Babies born to addicted mother are addicted themselves and go through withdrawal once they are born – results in “neonate abstinence syndrome” (newborns show sleep disturbances, tremors, difficulty body regulation, irritability, diarrhea, fever and feeding difficulties) – Alcohol = prenatal alcohol exposure is the most common cause of intellectual disability. – Fetal Alcohol Syndrome = combination of retarded growth, face and body malformations and disorders of CNS — problems include (infancy) reduced response to stimuli, slow reaction time, reduced visual acuity and (childhood) short attention span, distractibility, hyperactivity, learning disabilities, memory deficits, mood disorders – Even small social drinking may harm fetus – Heavy drinkers, babies are likely to have reduced skull and brain growth and disturbed neurological and behavioral functioning – Nicotine = smoking during pregnancy is the single most important factor in low birth weight – Brings increased risk of miscarriage, growth retardation, stillbirth, small head circumference, sudden infant death, colic in early infancy, long-term respiratory, neurological, behavioral problems – Increased risk of later obesity and cardiovascular disease to the child – Prenatal exposure to second hand smoke also affect development especially when they experience socioeconomic hardship, additional exposure to lead or deprived of nutrients – Caffeine = caffeine intake under 300 mg a day is not associated with an increased risk of miscarriage, stillbirth, or birth defects – However, there is an increased risk of miscarriage, stillbirth, low birth weight in  – mothers who consume caffeine while pregnant especially if there’s an increased dosage. – 200 mg of coffee or less is okay = approx. one cup – Marijuana, Cocaine, Methamphetamine – Marijuana - most commonly used drug during pregnancy – Marijuana exposure during pregnancy is not associated with birth defects, any particular pattern of cognitive or behavioral outcomes in early infancy except for minor irritability or altered sleeping patterns. It has been implicated in subtle deficits in problem-solving skills and may alter patterns of cerebral blood flow. = decrease in academic achievement is the most concerning negative effect – Cocaine use during pregnancy associated with spontaneous abortion, delayed growth, premature labor, low birth weight, small head size, birth defects, impaired neurological development. May also demonstrate acute withdrawal symptoms and sleep disturbances on new borns – Methamphetamine prenatal exposure associated with preterm delivery, low birth weight, fetal brain damage to areas involved in learning, memory and control. Less white matter in the brain of children exposed to this – Maternal Illnesses – If the mother does contract an infection, she should have it immediately treated. – If an expectant mother acquires a virus like AIDS, perinatal transmission may occur (virus may cross over to fetus bloodstream through placenta) during pregnancy, labor, or after birth through breast milk. – Rubella (German measles), if contracted by a mother before 11th week of pregnancy, it will cause deafness and heart defects in her baby. – If an expectant mother contracted toxoplasmosis infection, in second and third trimester, can cause fetal brain damage, severely impaired eyesight, seizures, miscarriage, stillbirth or death of baby. This infection is a parasite from cattle, sheep, pigs – Offspring of mothers with diabetes are more likely to develop a wide range of birth defects, most common is heart and neural tube defects – Maternal Anxiety, Stress, and Depression – Moderate maternal anxiety may even spur organization of the developing brain – Newborns whose mothers experience moderate levels of positive and negative stress showed accelerated neurological development – A mother’s self-reported stress and anxiety during pregnancy has been associated with more active and irritable temperament in newborns, inattentiveness in 8 month olds, negative emotionality or behavioral disorders in early childhood. – Chronic stress can result in preterm delivery, through the action of elevated levels of stress hormones or the resulting dampened immune system – Depression may also have a negative effect on development; premature birth, developmentally delayed, show elevated levels of violent and antisocial behaviors in adolescence. – Maternal Age  –Chance of miscarriage or stillbirth rises with maternal age –30-35 year olds are more likely to suffer complications due to diabetes, high blood pressure or severe bleeding. There’s also higher risk of premature delivery, retarded fetal growth, birth defects, chromosomal abnormalities – Adolescent mothers tend to have premature or underweight babies because of the young girl’s still-growing body – Outside Environmental Hazards – Prenatal development can also be affected by air pollution, chemicals, radiation, extremes of heat and humidity, others – Pregnant women who regularly breathe air with higher levels of combustion-related particles are more likely to bear infants who are premature or have chromosomal abnormalities – Exposure to high concentrations of disinfection by product associated with low birth weight – Insecticides = stunted prenatal growth – Fetal exposure to environmental toxins = asthma, allergies and autoimmune disorders – Women who have routine dental x rays during pregnancy triple their risk of having full term, low birth weight babies – Utero exposure to radiation = miscarriage, mental retardation, small head size, increased cancer risk, lowered IQ Environmental Influences: Paternal Factors – Poor quality sperm results from exposure to lead, marijuana, alcohol, radiation, pesticides – Men who smoke have an increased likelihood of transmitting genetic abnormalities and heart defects – Pregnant woman’s exposure to father’s secondhand smoke has been linked with asthma, attentional problems, low birth weight, cancer – Older fathers are significant source of birth defects due to damaged or deteriorated sperm – Advanced paternal age = increased risk of dwarfism, schizophrenia (similar with young father, for male children) – Advanced paternal age = a factor in bipolar disorder, autism Infancy – Neonatal period [first 4 weeks of life] = time of transition from uterus to an independent existence Size and Appearance – average in US = 20 inches long and weight 7.5 pounds – Boys slightly longer and heavier than girls – Firstborn weigh less than laterborns – First days, lose 10 percent of their body weight because of loss of fluids. Gain weight at 5th day and back to birth weight by 10th to 14th – Distinctive features = large head, receding chin – Fontanels = areas on their heads where bones of skull do not meet; covered by tough membrane that allows for shape flexibility  – First 18 months = plates of the skull gradually fuse – Newborns have pinkish cast – First few days = hairy because of lanugo that hasn’t fallen off – Covered with “vernix caseosa”, oily protection against infection that dries within few days – “Witch’s milk” = secretion that leaks from swollen breasts of newborns around day 3; due to high levels of estrogen – Premature newborn = swollen genitals Body Systems – all body system functions before birth are accomplished by mother but at full term all would be full blown functioning in the baby except lungs. After birth ALL would be functioning independently, the transition occurs during 4-6 hours after delivery – Pregnancy—fetus and mother have separate circulatory systems once born neonate must take over this function fully – Newborn needs more oxygen than before – Heartbeat fast, irregular and blood pressure not stabilized until 10th day – If baby doesn’t begin breathing within 5 mins after delivery, the baby may suffer permanent brain injury, anoxia, lack of O2, or hypoxia, reduced O2 supply = form of birth trauma that can leave permanent brain damage leading to possible mental retardation, behavior problems, death – Meconium = a stringy greenish black waste matter formed in fetal intestinal tract, secreted in the first few days – Babies cannot control their sphincter muscles – Neonatal jaundice = 3-4 days after birth half of all babies develop this; skin and eyeballs look yellow due to the immaturity of liver — usually not serious but severe cases when not monitored and treated lead to brain damage Medical and Behavioral Assessment – Apgar Scale = 1 minute after delivery; 5 mins after birth; Appearance (color), Pulse, Grimace (reflex irritability), Activity (muscle tone), Respiration – 7-10 = healthy – 5-7 = needs help to establish breathing – 4 = immediate lifesaving – Brazelton Neonatal Behavioral Assessment Scale (NBAS) = neurological and behavioral test to measure neonate’s response to environment; infants up to 2 months – Children who inherit enzyme disorder phenyketonuria will develop intellectual disability unless fed a special diet beginning 3-6 weeks hence neonatal screening is important States of Arousal – All humans have internal clock that regulates daily cycles of activity – Neonates periodic cycles of wakefulness, sleep and activity, govern an infant’s state of arousal/degree of alertness are inborn – Changes in state are coordinated by multiple areas in the brain and affects all body systems – Stable and distinct states of arousal = newborn health, positive outcomes as they mark neurological organization – Youngest babies sleep the most and wake up most frequently  – Sleep alternates between quiet (regular) and active (irregular) sleep. Active sleep is the REM, associated with dreaming — 50% of newborn’s sleep time – As neonate ages, his/her night sleeping time increases, naps decreases, waking time also decreases, REM state decreases until only 30 percent of daily sleep time is occupied by it – Babies’ sleep schedules vary across cultures Complications of Childbirth A. Low Birth Weight – neonates born weighing less than 2,500 grams/ 5 pounds at birth; either because they’re born early or born small – Gestation is 40 weeks, babies born before 37th are “preterm/premature infants” — smaller than full term babies – “Small-for-date/age infants” born at or around due dates but are smaller = possibly due to inadequate prenatal nutrition – Late preterm infants, delivered 34-36 weeks, weigh more and fare better than those born earlier but in comparison to full term babies, they are also at greater risk of early death, respiratory distress, hospitalization, brain injuries – Birth weight and length of gestation = predictors of an infant’s survival and death – Preterm birth = cerebral palsy, birth defects, infant deaths – Factors increasing likelihood of low birth weight: – Demographic socioeconomic factors – Medical factors predating pregnancy = previous LBW infants, was an LBW herself, genetic variants, no previous children or having more than 4 – Prenatal behavioral and environmental factors - teratogens – Medical conditions associated with pregnancy – LBW infants = has underdeveloped immune system, subjected to invasive medical procedures hence they are vulnerable to infection – Respiratory Distress Syndrome = lack of adequate amount of an essential lung-coating substance “surfacant”which keeps air sacs from collapsing; they breath irregularly or stop breathing at some point – May be placed in isolette and fed through tubes – Kangaroo Care = intervention, extended skin to skin contact, theorized to help preemies and full term infants make the adjustment from fetal life to the jumble sensory stimuli outside ; reduce stress in NS and help with self regulation of sleep and activity – LBW infants are at greater risk of suffering adverse health outcomes in adulthood than those were born full term – Shorter the period of gestation, the greater likelihood of cerebral palsy, mental retardation, neurological-sensory-cognitive-education-behavioral problems – Very LBW children and adolescents tend to have more behavioral and mental health problems and impaired motor development than those born at normal weight – Maternal education, two-parent family structure, higher SES, parenting = positive developmental outcomes for preterm infants B. Postmaturity – Postmature babies = long and thin, kept growing in the womb but have had insufficient blood  – supply towards the end because the placenta has aged; – greater size complicates labor puts the mother at higher risk of cesarean delivery, perineal tears, postpartum hemorrhage, – Neonates at greater risk of shoulder dystocia, meconium aspiration, low apgar scores, brain damage, death C. Stillbirth – sudden death of fetus at or after 20th week of gestation – Sometimes diagnosed prenatal, but could be discovered during labor – Cause is often not clear – Stillborn fetuses = small for gestational age, indicating malnourishment – Fetuses believed to have problems can have prenatal surgery to correct congenital problems or delivered prematurely to prevent stillbirth – Sudden Infant Death Syndrome = sudden death of infant under 1 yrs old, cause of death unexplained after thorough investigation including autopsy. Biological defects and sleeping on their stomachs make babies vulnerable to this Early Physical Development – Newborn baby’s head is disproportionately large but it becomes proportionately smaller as the child grows in height – Sensory and motor development follow cephalocaudal principle – Growth and motor development follow proximodistal principle [learn to use parts closest to body center] – Children grown faster during first 3 years – Genes an infant inherits have a strong influence on how the child would look like physically – Breast-feeding is always best for infants, begin immediately after birth and continue for at least 1 year. Exclusively breast feed babies for 6 months – Only acceptable alternative to breast milk = iron-fortified formula based on cow’s milk or soy protein with vitamins and minerals – After infants weaned during 1st year, they can have formula at 1 year old can switch to cow’s milk – Iron-enriched solid foods introduced gradually during second half of 1st year – Brain growth is a lifelong process – Age 6 almost adult size, but specific parts continue to grow into adulthood – Growth occurs in fits and starts = brain growth spurts – By birth, growth spurt of spinal cord and brain stem (basic bodily functions) has nearly run its course – Cerebellum (balance and motor coordination) – Cerebrum = where the specialization of hemispheres called “lateralization” – Regions of cerebral cortex on vision, hearing and other sensory info grow rapidly in first few months after birth and mature by age 6 mos – Areas of frontal cortex for abstract though, mental associations, remembering and deliberate motor growth very little during this period – Brain growth spurt that begins about third trimester of gestation to 4 yrs old is important in development of neurological functioning  – Brain cells – Starting 2nd month of gestation, estimated 250,000 immature neurons are produced every minute thru mitosis – At birth, 100 billion neurons are formed but not fully developed – Between 25th week of gestation to first few months postbirth number of neurons increases – Multiplication of dendrites and synaptic connections, during last 2.5 months of gestation and first 6 mos-2yrs, accounts for brain growth and permits emergence of new perceptual, cognitive, motor abilities – Integration = neurons that control various groups of muscles coordinate their activities – Differentiation = each neuron take on a specific, specialized structure and function – Excess neurons provided by the early proliferation give the brain flexibility – Cell death = calibrate developing brain to local environment and keep it working efficiently – Myelination peaks during 1st year and continues into adolescence up til 3rd decade— follows proximodistal principle – Primary cortical areas are myelinated first – Myelinations occurs rapidly at 12 to 16 mos and slows down at 2-5 yrs. – Reflexes – Reflex behavior = automatic, innate response, controlled by lower brain centers – Infants have 27 major reflexes – Primitive reflex (sucking, rooting, moro reflex/response to being startled) = survival instinctive needs – Postural reflex = 2-4 mos, reactions to changes in position or balance – Locomotor reflex = resemble voluntary movements; only appear when all the reflexes disappeared — walking – Early reflexes disappear during 6-12 mos – Reflexes that continue to serve protective functions remain (blinking, yawning, coughing, gagging, sneezing, shivering, dilating Each Sensory Capacities – Touch first sense to develop for first several months - most mature sensory systems – 32 weeks of gestation, all body part sensitive to touch, sensitivity increases during first 5 days of life – Newborns can and do feel pain, become more sensitive to it during first few days – Smell and taste begin to develop in the womb; taste of foods from amniotic fluid and breast milk; taste preferences are innate and reflect adaptive preference – Auditory discrimination develops rapidly after birth – 11 to 17 weeks, infants can recognize and remember entire sentences after delay – 4 months = brain showing lateralization of language – Vision is the least developed sense at birth – Visual perception and ability to use visual information become more important as infants become more alert and active – Newborns = retinal structures are incomplete and optic nerve is underdeveloped; peripheral  – vision is narrow – Cortical maturation in first months = color perception, ability to follow a visually moving target – Binocular vision (use of both eyes to focus) develop at 4-5 months only Motor Development – babies need to be taught basic motor skills, just need room to move and explore – Marked by series of milestones that develop systematically – Learn simple skills, combine them to increasingly complex systems of action (permit wider or more precise range of movement) – Denver Developmental Screening Test = chart progress between 1 month and 6 years to identify normal motor development ; measures gross motor skills (large muscles) and fine motor skills) small muscles; also assess language, personality, social development – Head control = side to side, lift high, heads erect while being held or supported (4 months) – Hand control = inborn grasping reflex, grasp an object, pick up tiny object (7 mos), building tower of cubes (15 mos), copy circle at 3yr – Locomotion = roll over (3mos), sit (6 mos), creeping or crawling on their own — self locomotion, social referencing—look for caregivers for clues on whether the situation is safe, stand (7 mos), walking, climbing stairs, walking down stairs, run, jump – Visual guidance = use of eyes to guide movement of hands – Younger infants correct their reaching movements using proprioceptive feedback from muscles, joints, haptic rather than use their eyes – Depth perception = ability perceive objects and surfaces in 3D based on cues that affect object; cues involve binocular coordination and motor control – Kinetic cues = produced by movement of object or observer or both – Haptic perception = ability to acquire information by handling objects Cognitive Development Behaviorist Approach = basic mechanics of learning; how behavior changes in response to experience – Classical conditioning enables infants to anticipate an event before it happens – Operant conditioning causes the likelihood of a behavior to occur again or not – Early procedural knowledge and perceptual knowledge = used by infants before 2 years old; and it’s how they store their memories instead of the language-based memories adults have – Infant memory is context dependent and linked to original cues encoded during learning Psychometric Approach = measures quantitative differences in abilities that make up intelligence by using test – Intelligence = enable people to acquire, remember, use knowledge – Intelligent behavior = goal oriented and adaptive – Measure factors that are thought of to make up intelligence and from that, predict future performance – For infants and toddlers, to gauge their intelligence is to assess what they can do – Infants’ intelligence cannot be measured but their functioning can be tested with development tests  – Test assess infants’ behavior on tasks and compare their performance with norms – Bayley Scales of Infant and Toddler Development = 1 month to 3.5 yrs = developmental quotients – Home Observation for Measurement of the Environment = observers interview caregiver; assess quality of home environment which is associated with cognitive development – Early intervention = systematic process of planning and providing therapeutic and education services for families that need help in meeting children’s developmental needs Piagetian Approach = look at changes/stages in quality of cognitive functioning ; how the mind structures and adapts to environment – Sensorimotor stage (birth to 2yrs) infants learn about themselves and word through sensorimotor activity – Substages of Sensorimotor: – Use of reflexes – Inborn reflexes, somehow controlled – Do not coordinate information from senses – Primary circular reactions – Repeat pleasurable behaviors – Activities focused on body – Begin to coordinate sensory information and grasp objects – Secondary circular reactions – More interested in environment – Repeat actions bring interesting results – Actions are intentional but not goal-oriented – Coordination of secondary schemes – Behavior is more deliberate – Coordinate previously learned schemes and use previously learned behaviors to attain goals – Anticipate events – Tertiary circular reactions – Curiosity and experimentation; vary actions for results – World exploration – Trial and error – Mental combinations – Mental representation for events (representational ability), think about events and anticipate their consequences without action – Demonstrate insight, use symbols and pretend – Key Developments of Sensorimotor Stage – Imitation = around 9 months; deferred imitation is reproduction of observed behavior after the passage of time by calling up a store symbol of it – Object permanence = realization that something continues to exist when out of sight – Symbolic development = learning to interpret symbols include growth of pictorial competence (understand nature of pictures), representational thinking – Causality = the effects of own actions and then of effects of outside forces  – Number = depends on use of symbols Information-Processing Approach = focuses on perception, learning, memory and problem solving – Analyze separate parts of complex tasks to figure out what abilities are necessary for each part of the task and at what age these abilities develop – Habituation = type of learning, repeated exposure to a stimulus, reduced attention to that stimulus – Dishabituation = increase in responsiveness after presentation of a new stimulus – Researchers gauge the efficiency of infants' information processing by measuring how quickly babies habituate to familiar stimuli, how fast their attention recovers when they are exposed to new stimuli, and how much time they spend looking at the new and the old. – Visual preference = tendency to spend more time looking at one sight rather than another – Visual recognition memory = ability that depends on the capacity to form and refer to mental representations – Auditory discrimination based on attentional preference – Cross-modal transfer = ability to use information gained from one sense to guide another – Joint attention = shared attentional focus, typically initiated with eye gaze or pointing Cognitive Neuroscience Approach = seeks to identify what brain structures are involved in specific aspects of cognition – Examines hardware of CNS to identify what brain structures are involved in specific areas of cognition – Brain growth spurts coincide with changes in cognitive behavior – Implicit memory = remembering that occurs without effort or even conscious memories; habits and skills – Explicit memory/declarative memory = conscious or intentional recollection – Delayed imitation of complex behaviors is evidence that declarative memory has developed since it requires a representation of behavior to be store in memory – Hippocampus and development of cortical structures coordinate to make longer lasting memories – Prefrontal cortex = responsible for working memory starting 1st year = short term storage of information that the brain is actively processing — possibly responsible for object permanence Social Contextual Approach = examines the effects of environmental aspects of learning process – influenced by Vygotsky’s sociocultural theory – Guided participation = mutual interactions with adults that help structure children’s activities and bridge the gap between a child’s understanding and an adult’s – GP = often occurs in shared play and ordinary everyday activities which children learn informally the skills, knowledge, and values important in their culture Psychosocial Development