HDFS201 Exam 2 Notes Perceptual Development Sensation Perception distinctions o Sensation Registration of information on the sensory apparatus o Perception interpretation or meaning that an individual makes on that information Highly personal miscommunication occurs Nugget 1 Everything we experience comes through our sensory apparatus at some time The brain interprets sensory input The senses are well developed prenatally Sensory capacities are geared toward the social environment Lifespan changes not uniform Nature Nurture Constructivist on the side of nurture o Argue that perceptions are constructed through learning Nativists on the side of nature o Argue that innate capabilities and maturational programs drive perceptual development and that perception does not require interpretation Assessing Infant Perception Behavioral Change facial expression sucking rate orientation Preferential Looking o Duration of looking at one of a stimulus pair Habituation learning to be bored with a stimulus o Show infant same thing long enough originally interested and then become bored over time no longer interested o How quickly Operant conditioning o Learn to react to one stimulus o Discriminate second stimulus Evoked Potentials record brain s response to stimuli o Measuring electrical activity with small metal disks electrodes attached to skins surface Anatomy of the Eye You see upside down and then brain flips it right side up Rods black and white vision dark night vision Cones color vision Fovea tons of cones here Each cone has its own neuron Visual Development Last sense to develop By 6th month post conception rods cones on retina By 7th month pc eyes anatomically complete and functional o Startle o Blink turn away from bright lights Myelination of optic nerve by birth but thin complete by 2 5 months Structures do not develop at same rate Lens cornea retina relatively large Iris ciliary muscles and depth immature short eyeball Eye of newborn is about size of adult eye Immature accommodation unable to fully bend limbs Newborn fixed focal distance o Can only see within 8 10 Implications for acuity visual clarity Changes in Acuity Newborn visual acuity is 20 600 legally blind 20 300 in best eye after correction Changes rapidly as eyeball deepens and ciliary muscles develop 20 100 by 6 months 20 20 by a year Vision peaks in adolescence Fairly stable until 50 or so then decline Near point gets farther Other Visual Characteristics Color perception and discrimination from 6 months pc cones At birth reds and greens are most pronounced black white Yellows come in shortly after Depth perception presents early on nature nurture controversies Pattern Perception Infants are attracted to patterns that have a large amount of light dark transition contour Subcortical wiring for o Contrast o Contour o Movement Faceness Changes in eyes vision with age Cornea things less moisture Iris looses some color Pupil decreases after 20 Lens continues to grow thicker Lens yellows Ciliary muscles begin to turn to connective tissue after 30 Retinal sensitivity decreases after 60 Rhodopsin regeneration longer Class Two 10 4 12 Hearing during infancy Basic capacities are present at birth Can hear better than they can see Hearing is more developed than vision at birth because they hear their mothers voice for months prior to birth Can localize sounds turn from loud sounds turn toward soft sounds Can be startled by loud noises Can turn toward soft sounds Prefer relatively complex auditory stimuli Can discriminate among sounds that differ in loudness duration direction frequency pitch Infants respond to human speech and prefer speech over non speech sounds Can discriminate basic speech sounds phonemes The pioneering research of Eimas demonstrated that infants could distinguish similar consonants ba and pa and vowels a and i and between standard and rarely heard sounds Infants become increasingly sensitive to sound differences that are significant in their own language and become increasingly insensitive to sounds not made in their native language Early auditory experiences shape the formation of synapses in the auditory areas of the brains and create optimal sensitivity to the sounds in the native language Newborns attend to female voices and can recognize their mothers voices even in utero The Adolescent Hearing Exposure to sounds above 75 decibels can result in hearing loss Rock concerts and club music 120 to 130 decibels Teens do not believe that hearing loss is a serious health concern for them Hearing protection is not cool The Adult Hearing Among older adults hearing impairments are three times as prevalent as visual impairments Among adults aged 65 and older as many as 90 have mildly impaired hearing that progressively worsens with age Most age related hearing problems originate in the inner ear Auditory receptors and hearing related structures and neurons degenerate during adulthood and result in presbycusis Auditory changes Mild hearing impairments common Deafness rare Presbycusis loss of high frequency sounds More men affected Loud sounds music cause loss Speech perception difficulty due hearing loss Serious difficulty for novel or complex stimuli Poor listening conditions contribute Taste Prenatal swallowing and sucking rates Measures facial expression sucking rates Measures facial expression sucking rate duration swallowing spitting AVIDITY Mouthing and the oral stage third hand The Adolescent Taste Changes in taste during adolescence Slight decline in preference for sweets and an increased sensitivity or preference to sour tastes Adolescents are more likely to have an acquired taste for previously disliked or avoided foods Cognitive influences you taste what you expect to taste The Adult Taste General decline in sensitivity to taste Older men have somewhat greater decline than older women But great variability in individual experiences Medications Saliva Sweet tooth Smell Olfactory epithelium begins 30 days pc and olfactory nerve and centers of brain complete by 3rd trimester when nostrils open Preemies respond to odors By 6 days after birth can distinguish mother s smell by breast pads All babies prefer the smell of human milk over formula even if previously consumed formula The Adolescent Smell Sense of smell in adolescence Women generally demonstrate greater sensitivity than men to a variety of odors including body odors The Adult Smell Ability to perceive odors typically declines with age Health adults