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
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)
