# Introduction to Psychology/Child and Adolescent Psychology/Infants and Toddlers
### Physical Developments

* Prematurity
** occurs before 37 weeks of gestation or about 3 weeks earlier than the normal due date
** Low birth weight is weight less than 5 ½ pounds at birth (2 pounds lighter than average); indicates potential for health risks
** Very low birth weight is weight less than 3 ½ pounds at birth (4 pounds lighter than average); indicates greater potential for health risks
** Small for gestational age (SGA) is born below the tenth percentile of birth weight for gestational age; indicates serious health risks
** Prevention includes childbirth classes, healthy lifestyles and especially good prenatal care, but sometimes there is nothing you can do
* Infant Mortality
** Refers to deaths that occur before the age of 1 year
* Having a Healthy Baby
** Prenatal care is important
* Growth of the Body and Brain
** Physical Growth
*** Average birth weight is 7 ½ pounds, with males bout ½ pound heavier than females
*** Baby's weight doubles in first 5 months
*** About 20 inches at birth and half of adult height by age 2
** Feeding and Nutrition (Breastfeeding)
*** Sterile, cheap, “specially formulated”
*** Colostrums are a thick, yellowish substance in breast milk containing important antibodies (only for the first few days of breastfeeding)
*** Breastfed babies are at less risk of SIDS, asthma, and other illnesses
*** Breastfeeding helps mom lose weight faster, and lowers risk of breast and ovarian cancer
*** Infectious diseases can be spread via breast milk, so some mothers can’t (iron enriched formula)
*** Exclusively for 6 months, slowly introduce iron-rich foods from 6-12 months, judgment call after
*** More likely if mom married, higher income, and supported to breastfeed, but only ¼ by 6 mnths
* Structure of the Brain and Nervous System
** Spinal cord is the “information superhighway”
** Brain stem controls automatic functions
** Cerebellum is on the back of the brain and controls posture, body orientation, and complex muscle movements
** Neurons are specialized cells that process information and allow communication in the nervous system (form by 7 weeks)
** Cerebral cortex is the “gray matter” that forms the top portion of brain and is divided into the 4 lobes (10 wks)
* Forming the Brain and Nervous System
** Neural tube at about 4 weeks, which later develops into central nervous system
** Synaptogenesis is one form of neuron maturation in which dendrites and axons branch out to form an enormously large number of connections with neighboring neurons (by 23 weeks)
** Most neural connections (synapses) form AFTER birth, as a result of maturation and experiences
** Myelination is a form of neuron maturation in which the fatty insulation (myelin sheath) grows around the axons; occurs in different parts of the brain at different times
** Programmed cell death is a process by which many neurons die during periods of migration and heavy Synaptogenesis (we lose half before even born!)
* Sensory Capabilities
** Vision
*** Visual acuity is the ability to see fine detail
*** Infants prefer faces
*** Newborns vision is somewhere between 20/150 and 20/600, reaches 20/20 by bout 6 months
*** Normal color vision by 3 months
*** Prefer to look at green, yellow, or red over gray
*** Depth perception by just under two months, but afraid of cliff by time can crawl
*** Binocular disparity is the difference between the images projected on the two eyes
*** Pictorial cues are relative size and density of the pattern elements shown beneath the glass
** Hearing
*** Hearing is functional before birth
*** Recognize own names by 5 months
** Smell and Taste
*** Facial expressions show that newborn babies react to certain odors and tastes similar to adults
*** The fetal system is well enough developed sometime near the end of gestation to sense and store information about odors encountered before birth
* Motor Development
** Reflexes
*** Reflexes are involuntary movements elicited by environmental stimuli
*** Important early indicators of nervous system function
*** Primitive reflexes disappear around 4 months; help the infant to find nourishment or might have served protective functions during earlier periods of evolution
*** Postural reflexes disappear by 12 months; help infants to keep their heads upright, maintain balance, and roll their heads in the direction of their body motion
*** Locomotor reflexes disappear by 4 months; mimic locomotor movements such as crawling, stepping, and swimming
** Voluntary Movements
*** Gross motor development is the process of coordinating movements with the large muscles in the body (first step around 1 year)
*** Fine motor development is the process of coordinating intricate movements with smaller muscles
** Influences on Motor Development
*** Maturation of the muscles and brain
** Opportunities for practice
*** culture differences in early experience

### Cognitive Developments

* Perceptual Development
** research techniques:
*** Preferential-looking
**** technique used to test infant visual perception. If infants consistently look longer at some patterns than at others, researchers infer that the infants can see a difference between the patterns
**** Babies prefer moving stimuli, sharp color contrasts, symmetrical patterns, curved patterns, patterns with some complexity or detail, and patterns that resemble the human face
**** Babies are already equipped at birth with an innate schema, or mental framework, of the human face
*** Habituation-dishabituation
**** technique used to test infant perception. Infants are shown a stimulus repeatedly until they respond less (habituate) to it. Then a new stimulus is presented.
**** Habituation is the tendency of infants to reduce their response to stimuli that are presented repeatedly.
**** Dishabituation= is the recovery or increase in infant’s response when a familiar stimulus is replaced by one that is novel.
**** Intermodal Perception is the process of combining or integrating ifnormatino across sensory modalities.
*** “Impossible events” (Renee Baillargeon)
*** Most recent method of assessing infant cognition is via neuroscience (wave imaging)
* Explaining Cognitive Development: Piaget’s Constructivist View
** Mental processes (thought, memory, solving problems, language)
*** Children’s thoughts gradually becomes more organized and complex (cognitive development)