9 17 2015 Development in Infancy A lot of change over a short period of time Start as an immobile organism with a set of reflexes End with coordinated movements across multiple senses Muscles and Brain develop View changed over the last century We originally thought newborn s were passive and incompetent but now know infants actively participate in their world Newborn Reflexes Reflex is an inborn natural response to a stimulus Reveals health of the nervous system Decreased reflexes show problem with PNS Exaggerated shows problem with CNS form basis for later motor skills Tonic neck reflex Palmar grasp swimming and stepping Reflexes are adaptive Survival value Hierarchy of reflex responses Palmer grasp usually takes precedent They typically disappear when the frontal lobes develop They can return due to neurological conditions Newborn States 5 states of arousal Regular sleep 8 9 hours Irregular sleep 8 9 hours Drowsiness varies Quiet alertness 2 3 hours Waking activity and crying 1 4 hours Between birth and 2 years sleep and wakefulness patterns change Declines from 18hr to 12hrs by age 2 Sleep wake pattern begins to form to the circadian rhythm Sleep arousal patterns are affected by brain development and cultural practices Patterns have implications for early cognitive progress Disturbed REM NREM cycle can be a problem with Crying is the first way that babies communicate central nervous system Stimulates strong feelings of arousal and discomfort in both men and women Usually cry because of hunger The frequency changes over time Cultural differences non western babies cry less often Could be because non western babies are carried more often Colic Infant Learning and Memory Infants do more and know more than just reflexes We figure out what they know with habituation and conditioning Operant conditioning Responses are limited to head turning and studies sucking responses Reinforcers include Food visual designs music and human voices They will suck faster to get the stimulus they want Habituation The gradual reduction in the strength of response Basically get bored Recovery Following habituation an increase in responsiveness to new stimuli Using Habituation to study memory With passage of time infants shift from novelty preference to familiarity preference Sequence of Motor Development Gross Motor Development crawling standing walking Fine motor development reaching grasping Differences in rate of skill acquisition normal Once thought to be separate innate abilities that emerge in fixed sequence Many factors influence development of motor competencies Motor development involves acquiring increasingly complex systems of actions with each skill Four factors in each new skills CNA development Body s movement capacities Child goal Enviormental supports Fine Motor Development Reaching and grasping Prereaching Reaching with two hands than with one Ulnar grasp Adjust to grip object move objects from hand to hand Pincer grasp Finer grasp A lot more stimuli become available 9 22 2015 Sense of Touch Well developed at birth Enhanced interactions between newborns and parents Physical touch is important for emotional development Reinforces neural connections Taste and Smell Have preferences at birth Prefer sweet tastes Affected by mother s diet in womb Quickly learn to like new tastes Can locate odors and recognise mother s smell from birth Hearing Can hear a wide variety of sounds at birth Prefer complex sounds They learn patterns in days Sensitive to voices and ready to learn language Auditory preferences Women Men because of high pitch Mom s voice Other womans voice Dads voice Other men s voices Heartbeat Man s voice Because of prenatal learning Speech Perception Can detect sounds of any human language Statistical learning capacity for speech patterns and sounds Multisensory communication helps babies associate words with objects Ie visual auditory Vision Least developed of senses at birth Unable to see long distances or focus clearly Pattern perception 3 weeks Poor contrast sensitivity prefers large simple patterns 2 months Can detect detail in complex patterns scans internal 4 months Can detect patterns even if boundaries are not really features of patterns present 12 months Can detect objects even if of drawing is missing Early Face Perception Infants prefer to look at simple face like stimuli with features arranged naturally upright Quickly learn to prefer their mother s face over unfamiliar women Prefer to look at attractive and smiling faces Depth Perception 3 types of cues Kinetic motion parallax birth 1 month Binocular binocular disparity 2 3 months Pictorial Linear perspective 5 7 months Visual cliff More crawling experience less likely to crawl off cliff Steps in Intermodal Perception Birth Detect amodal sensory properties 3 4 months Prefer matching sights and sounds 5 6 months Reach for objects in dark Coordinating sight and touch Differentiation Theory Infants Search for invariant features of the environment Note stable relationships between features Visual patterns intermodal relationships Gradually detect finer and finer features differentiation New experiences provide affordances Definition The action possibilities that a situation offers based on one s motor capability Discovering by acting on the environment Is infancy a sensitive period Infants that experienced early deprivation are below average in physical and psychological development emotional behavior problems Can only use natural observation appears that less than 6 months doesn t cause deficit but more than 6 month causes cognitive deficits 9 24 2015 Physical Growth Humans grow for almost 20 of their life The purpose is so they can gain enough skills and knowledge for life to develop in a complex system Changes in Fat Muscle Birth Fat peaks at 9 months and muscle is added slowly Childhood Girls add more fat and muscle continues to be added slowly Gross Motor Skills Adolescence Boys lose fat and gain muscle Girls add fat 2 3 years Walks more rhythmically pushes toy jumps hops throws and catches with rigid upper body 3 4 years Walks up stairs pedals tricycle flexes upper body 4 5 years Walks down stairs runs skips throws balls 5 6 years Increases running speed whole body throwing and catching rides bicycle with training wheels 7 12 years Increases running speed vertical jump increases throwing kicking speed and accuracy Sex Differences Childhood small difference Adolescence Boys develop more speed strength and
View Full Document
Unlocking...