Unformatted text preview: Ch. 12: Psychology Over the Life Span Getting a Start in Life Chromosomesstrands of DNA Gameteseach contribute 23 chromosomes Maturation 23 pairs in the fertilized zygote (see fig. 12.1) Genetically "programmed" developmental changes Example:
~prenatal week 8 the SRY gene on the Y chromosome activates, triggers cell development>production of testosterone XX = female XY = male Stages of Development in the Womb Prenatal Stages: Zygote Embryo A fertilized egg Fetus 2 weeks to 8 weeks after conception 8 weeks until birth Most neurons present at birth ~80% of adult brain size by age 2 Continued growth due to: Synaptogenesis Myelination Dendritic branching Learning and Behavior in the Womb DeCasper & Fifer, 1980 The Cat in the Hat starting 6 weeks before birth DV = IV's = Teratogens Maternal illness Alcohol and drugs Chicken pox, rubella, HIV Alcohol, heroin, cocaine Caffeine and smoking Diet and pollution Malnutrition Too much mercurycontaining fish (such as tuna) Maternal stressors List of common teratogens and their consequences: Infancy and Childhood Perceptual development Visual perception Acuity:poor ( 20/200 to 20/800) in first couple of months of life. Images are blurry & must be very close to baby's eyes to be detected. By 6 mos. acuity is near adult-levels. Depth perception: Visual cliff experiment (Gibson & Walk, 1960) Habituation/looking time technique By 1 month: scan edges of objects Prefer contrasts & ignore interiors (e.g., view hairline, not facial features Focus on interior regions of objects. (e.g., stare more at eyes & mouth of a face vs. hairline). By 2 months: Jean Piaget QuickTimeT and a TIFF (Uncompressed) decompressor are needed to see this picture. Basic cognitive processes Schemas Assimilation ? e=438 Accomodation Four Periods of Cognitive Development Sensorimotor Period (02 years) Characteristics: Object permanence Imitation Preoperational Period (27 years) Lacking Conservation Major achievement Egocentrism Capacity for mental representation Concrete Operations Period Age Major achievements 711 years Formal Operations Period Age Major achievements 11 years (at the earliest) Beyond Piaget Piaget's theory greatly underestimated children's competencies Children develop a theory of mind ...
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- Summer '07