Midterm Notes Chapter 12.docx

Midterm Notes Chapter 12 Lifespan Development Cross-sectional study: study of development in which individuals of different ages are compared at the same time Longitudinal study: study of development in which observations of the same individuals are compared at different times of their lives Cross-sectional take less time and avoid problem of person becoming familiar with test but have a slight concrete problem PRENATAL DEVELOPMENT Prenatal period: nine months between conception and birth divided into zygotic, embryonic, fetal Epigenetic changes modification of cell inheritance that is not due to alterations of DNA sequence itself Examples: way DNA molecule is folded within proteins, chemical changes in structure of nucleotide cytosine, complex modifications in the way DNA is mapped into protein synthesis Stages of Prenatal Development Zygote stage: first stage of prenatal development during which it divides many times and the internal organs start to form -lasts two weeks Embryonic Stage: second stage, begins at 2 weeks and ends at 8 weeks after conception, during which heart begins to beat, brain starts to function and most major body structures begin to form -because many changes rely on delicate chemical balance, most susceptible to external influences. These substances are Teratogens: substances, agents, events that can cause birth defects -beginning of sexual development occurs, 23rd chromosome pair determines the sex; early in development, embryo develops gonads that will become ovaries or testes -If testes present, begin to secrete androgens: primary class of sex hormone in male, primary is testosterone -these hormones bring about development of male internal sex organs, penis and scrotum, and therefore are very crucial; women development do not need hormones Fetal Stage: third stage, lasts 7 months, beginning with appearance of bone tissue and ending with birth -2 months 4cm 30g, 3 months 8cm 90g (development of major organs complete and bones/muscle beginning to develop, may show kicking) -4 months 15cm 170g [sleeping and awake], 6 months 30cm 700g, -7th month critical, if prematurely born at this point, fair chance of surviving, last two months gains weight 250g a week, on average 50cm long and 3.5kg, ready to be born Threats to Normal Prenatal Development Mothers diet most important, if malnourished, abnormal fetus nervous system Tetracycline (antibiotic) can cause irregularities in bones and discoloration of teeth If cocaine, high risk of premature birth, low birth weight, smaller than normal head Smoking increased miscarriage rate, low birth weight, increased chance of premature, increased change of c-section -Can also cause lowered arousal levels in newborns, and uncommon birth defects such as cleft palate Alcohol pre and post natal growth deficits, deformations of eyes and mouth, low brain mass, central nervous system abnormalities, heart deformation collectively= fetal alcohol syndrome PHYSICAL AND PERCEPTUAL DEVELOPMENT IN INFANCY AND CHILDHOOD Infant and toddler applies to babies up to age of 2 years Motor Development Follows distinct pattern dictated by maturation of muscles and nervous system At birth most important movements are reflexes when touched on the head, will turn in that direction, when against lips, will begin to suck, when milk or liquid enters mouth, will make swallowing movements all automatically Development of motor skills requires maturation of childs nervous system and practice Amount of growth of nervous system (considerable growth in first several months) is associated with IQ later Important changes in brain structure happen through lifespan as result of experience Perceptual Development Kisilevsky found playing sound of mothers voice outside her abdomen increased heart rate of fetus, while strangers did not Infants develop all of their senses while within the womb and show examples of such once outside Form Perception Salapatek suggests age of one or two months babies do not perceive complete shapes, their scanning strategy is limited to fixation on a few parts At three months, shows signs of pattern recognition, and at 4/5 months can distinguish similar faces Distance Perception Ability to perceive 3D objects comes at early age Gibson and Walk Placed 6month old babies on a visual cliff, babies would not dare crawl over it Infants require retinal disparity at early age to experience depth perception Fawcett, Wang, Birch examined children with crossed vision to see when loss of disparity most affects stereopsis, worst influence at 3.5 months, but can still affect even at 4 years Critical and Sensitive Periods in Perceptual Development Critical period: specific time in development during which certain experiences must occur for normal development to occur If infants dont have opportunity to interact with caregivers during first two years, cognitive development impaired Sensitive Period: period of time during which certain experiences have more of an effect on development than they would have if they occurred at another time Example acquisition of a second language, learned more easily in childhood COGNITIVE DEVELOPMENT IN INFANCY AND CHILDHOOD The Importance of a Responsive Environment One of first things to learn is that babys actions have effect the events in the environment Watson and Ramey presented three sets of infants with a mobile 10min/day/14 days -sensor under the pillow under babys head and mobile above face. For one group it moved whenever activated switch, the other remained stationary, the third activated randomly on its own. -tested again after with the active switch in all three groups, those who had already learned did the same, those who didnt did not learn to do so Being able to extend oneself and affect objects and people are important aspects of personal and social functioning -example of J.F.; J.F. seemed incapable of accepting typical attachment between child and parent that she was denied the first 3 years -Faulder found that her emotional maturity was that of an 18 month old -by 10 years old, house was living hell, diagnosed with autism, ADHD, attachment disorder, tourettes Nelson suggested at times the brains development requires stimulation that normal childhood provides and without it, the brain lacks direction for further development The Work of Jean Piaget Viewed cognitive development as maturational process Thought completion of each period with corresponding abilities, is prerequisite for entering the next Important to this theory is operation: a logical or math rule that transforms an object or concept into something else Suggested that as children develop they acquire mental representations or frameworks used for understanding and dealing with the world and solving problems-Proposed that schemata are first defined in terms of objects and actions but later become basis of concrete and abstract concepts that constitute adult knowledge Infants acquire schemata through their environment, two processes help them adapt, assimilation and accommodation Assimilation: the process by which new info about the world is incorporated into existing schemata Accommodation: the process by which existing schemata are modified or changed by new experiences Piagets Four Periods of Cognitive Development Argued at key points, the two processes fail to adjust adequately to the childs knowledge of the world At this point through equilibrium, teh schemas are radically reorganized Equilibrium: process that reorganizes schema These key points divide cognitive development into four periods: sensorimotor, preoperational, concrete operational, formal operational What is learned in one enables them to progress to the next Sensorimotor Period Sensorimotor period: Birth 2 years, first period, marked by orderly progression of increasingly complex cognitive development: reflexes, permanence, rough approximation of causality, imitation, symbolic thinking -closely tied to external stimuli Until 6 months, children do not know objet permanence In last half of first year, if object hidden, they will actively search for it, and in second year, will search for object in last place the saw it hidden Can only keep track of change in a hiding place they can see The Preope