Body and BrainPhysical GrowthSlide 3Mechanisms of Physical GrowthSlide 5Brain growth and developmentPowerPoint PresentationBrain growth in infancyLearning and brain developmentBrain function and plasticityMovement and Motor SkillsReflexes demonstrationsGross motor skillsGetting upright…Slide 15Fine motor skillsReaching/GraspingPerceptionSlide 19Slide 20Testing hearing in infantsHearing - localizationSlide 23Varying frequency and amplitudeDevelopment of infant visionVisual testing methodsSlide 27Slide 28Depth perception in infantsSlide 30Cognitive developmentSensorimotor stageSlide 33Object PermanenceViolation of Expectation exampleSlide 36Language developmentDevelopment of Speech PerceptionDevelopment of Speech ProductionSlide 40Theories of Language AcquisitionFirst two years of life•Cephalocaudal principle•Infant born with very large head wrt body•Head is near full-size at birth•Most neurons already exist at birth•Infant growth•Grow about an inch per month in 1st year•Triple birth weight in 1st year•~7lbs to ~22lbs•Heredity/Genes•Strong role for height•r = 0.9 for height in identical twins•r = 0.5 for height in fraternal twins•r = 0.7 between child’s height and average of parent’s height•Hormones•Pituitary gland secretes Human Growth Hormone (HGH)•HGH causes liver to release somatomedin•Triggers muscle and bone growth•Thyroid gland secretes thyroxine•Neuronal development•Anything that impairs thyroid function in early years has significant effect on IQ•Increases metabolic rate•Role in obesity•Stimulates endocrine system generally•Stimulates pituitary gland and thus release of HGH•Nutrition•Need plenty•12lb 3 month old needs ~600 calories per day•~50 calories per lb compared to ~15 calories per lb for adult•Breast-feeding•Mother’s milk is best food for babies•Sufficient nutrients•All natural = fewer contaminants than commercial products•Breast fed babies:•Get sick less often•Fewer digestive problems (diarrhea, constipation)•Adjust to solid foods more easily•Basic Neuronal function–Receive a signal from one neuron and transmit it to another neuron•Excitatory and Inhibitory connections–Activates some cells, turns others off–Complex patterns of neuronal firing subserve all behaviors–Patterns must develop•Learning shapes these patterns•Strengthens some connections•Eliminates others•Born with nearly all neurons you will ever have = ~100 billion neurons•Development = forming connections –Activity dependent learning/experience•First few months–Axons and dendrites grow longer–# of synapses increase•2nd year – Synaptic pruning–Some synapses disappear–Fine tuning brain function•Weeding out unnecessary connections•Kittens blindfolded at birth (first 2 weeks)•Connections in visual cortex do not form•Never see properly•Kittens w/one eye blindfolded at birth•Connections for binocular vision do not form•Reduced depth perception•Kittens exposed only to vertical stripes in first few weeks•Connections for perceiving horizontal stripes do not form•Specialized cells in V1 for seeing lines at specific orientation•Hubel & Weisel: Simple Cells•Cannot see horizontal stripes, cannot jump onto horizontal surfaces•Brain must change to learn and acquire new behaviors•Damage results in lost behavior•Behaviors can be recovered•Neuroplasticity•Brain can change in function•Lost functions taken up in other parts of the brain•Old view on neuroplasticity:•Ends in childhood•Brain “set in stone” by adulthood”•New view•Plasticity never ends•Brain is just more “plastic” in early childhood compared to adulthood•No real motor “control”•Movements are not voluntary and controlled•Some movements are random/uncontrolled•Some movements are involuntary reflexes•Startle reflex aka Moro reflex•Tonic neck reflex•Sucking•Rooting•Palmar/Grasping reflex•Crawling/Swimming reflex•Stepping reflex•Babinski reflex•Control of large limbs•Arms and legs•Walking•Must overcome cephalocaudal-driven development•8 months – stand with help•9 months – stand while holding on to something•10 months – stand alone•12 months – walk alone•What determines this developmental trajectory?•Genes vs. Practice/exercise•Complex task involving integration of many subsystems•Posture and balance (vestibular system)•Stepping and limb control•Vision•Coordinating all of this•Dynamical systems theory•Behavior arises out of a self-organizing system•Walking as a natural consequence of all these basic subsystems coming online•Reaching •4 months – successful reaching•Still clumsy•Many submovements•Past 4 months•Gradual smoothing in movements•Reaching and grasping•Requires direction and distance perception•Infants 6-11 days•Rough accuracy•Infants will not reach for things out of reach distance•Up to 4 months•Improvement in directional accuracy•Can intercept moving objects•Sharpening of line between reachable and non-reachable distances•Chemical senses: Taste & Smell•Taste is fairly well developed at birth•Infants sensitive to all 5 primary tastes: sweet, sour, salty, bitter, umami•Appear to have taste preferences•Different responses to different tastes (e.g., sweet vs. bitter)•Change in nursing behavior in response to changes in taste of mother’s milk•Smell is fairly well developed at birth•Infants respond to different smells•Distinguish and prefer own mother’s breast milk•Place head between two pads•Pad on one side has mother’s milk•Other pad has a different woman’s milk•Child turns head toward mother’s milk•Touch: moderately developed at birth•Touch required to elicit reflexes•Infants respond to soothing and caress, body heat•Babies are born with touch mechanoreceptors in the skin•Receptors for pressure, movement, pain, temperature•Development involves increase in touch pattern recognition•Develop ability to perceive posture and movement•Proprioception and kinesthesis via receptors embedded in muscles, tendons and joints•Hearing: not well developed at birth•Fetus can hear sounds •~ 7-8 months•Infants can hear but not as well as adults•Receptors in inner ear are developed but connections need to form•Infants have higher threshold for hearing a sound (less sensitive to quiet sound)•Baby sits on parents lap – observed from