PSY 301 Developmental Psychology Exam 2 Study Guide Chapter 6 Sensation Perception and Attention Sensation the process by which sensory receptor neurons detect information and transmit it to the brain Perception the interpretation of sensory input recognition understanding comprehension Issues of Nature Nurture o Constructivists nurture Perception is constructed through learning Declines due to environmental influences o Nativists nature Perception does not require interpretation Innate capabilities and maturational programs drive perception adoring to innate plan Declines are universal due to aging o Gibson s Ecological Theory In the middle of constructivists and nativists Construction not necessary features of object reveal affordances What the object has to offer and how it might be used How we perceive the object drives action The Infant o Assessing Sensory and Perceptual Abilities Habituation Studies If exposed to a stimulus repeatedly attention is less drawn to it habituate to the stimulus When something happens to renew attention dishabituated In order to dishabituate need to know that the new stimulus is different from the preceding stimulus Preferential looking duration of looking at one of two stimuli looks Evoked potentials brain activity recorded as children Operant conditioning learn behavior by associating positive reinforcement with stimulus o Vision Basic Abilities at birth detect changes in brightness visually track moving objects Visual Acuity ability to perceive details o Better for bold patterns o Blurry at birth unless within 12 inches o See contrasts between light and dark Visual Accommodation lens of the eye changes shape to focus on objects at different distances o Initially limited o Develops between 6 months 1 year Color Vision present at birth but can t see as many colors o Starts at 2 3 months discriminate between colors by 4 months o Tested with habituation Organizing a world of objects Form perception recognize the pattern that constitutes an object o By 2 3 months take in whole object and improve in gaze shifting together o 4 months expect all parts of an object to move o Innate ability to organize moving visual scene into distinct objects Pattern perception o Infants prefer Contour light to dark transition Movement Complexity Face perception Infants prefer faces over other stimuli BUT faces have all the properties that infants already like By 2 3 months perceive meaningful Depth perception perceiving depth and knowing when objects are near or far Size constancy recognize that an object is the same despite changes in distance from the eyes The visual cliff o Most infants 6 5 months with crawling experience will not cross the cliff o Infants as young as 2 months perceive drop off slower heart rate over cliff o Slow heart rate indicates interest Fear is learned Intuitive theorists through experience Infants are able to make sense of the world with organized systems of knowledge Idea that infants are born with innate knowledge and perceive the world like adults Gravity example o Surprised when ball dropped behind screen resting below shelf 4 months o Surprised when ball dropped behind screen rests in midair 6 months o Surprised when object disappears in narrow o Hearing and speech container Before birth heart rate changes in response to sound At birth Localize sounds Discriminate sounds that differ in loudness duration direction and pitch Hear better than they see Speech perception Newborns prefer speech to non speech female mother s voices 2 3 months distinguish phonemes in all languages By 1 year lose sensitivity to sounds not needed for o The Chemical Senses Taste Smell home language At birth Newborns distinguish tastes and smells well Prefer sweet tastes Breast fed babies recognize mothers by smell Facial expressions reflect tastes and smells Early exposure predicts later preferences o The somaesthetic senses Before birth can detect motion may be among the first sense to develop At birth Sensitive to warm and cold Useful for soothing a fussy baby Clearly sensitive to painful stimuli Anesthesia and surgery o More hare from stress of pain o Integrating sensory information senses are interrelated within the first month Cross modal perception recognize through one sense an object familiar through another sense 3 months oral visual matching 4 7 months all other senses o Influences on early perceptual development Nature very early perceptual abilities Nurture sensory systems require stimulation to develop normally Sensitive period window of time during which an individual is more affected by experience o Infant cataracts result in blindness o Delayed understanding after cochlear implants The infants active role infants actively seek stimulation 0 4 months immediate surroundings 5 6 months explore objects with eyes and hands 9 months distal environment Cultural variation starting at 1 year become insensitive to contrasts not regularly heard The Child o Locomotion the coupling of perception and action movement from one place to another Gross motor skills involve large muscle movement and whole body limb movement Fine motor skills involves precise movements of the hands fingers feet and toes Follow cephalocaudal and proximodistal principles of development Crawling Most crawl by 10 months More infants are moving straight to cruising Walking occurs around 12 months Basic motor patterns are present at birth New mobility allows for exploration Infants must develop more muscle and nervous system o Contributes to cognitive social and emotional Manipulating objects development Improve at object manipulation Grasping reflex gone 2 4 months Pincer grasp by 6 months Move from reflex clumsy controlled Rhythmic stereotypies moving body in repetitive motion Rocking bouncing mouthing objects banging arms and legs Dynamic systems theory motor milestones are learned but require biological maturation nature and nurture Self organizing process o Try new movements o Use sensory feedback Dynamic systems theory example adjusting to physical constraints Dynamic systems theory example Walkers Infants not using walkers sat up crawled and walked earlier Need sensory feedback from seeing feet o Integrating Sensory Information senses are interrelated within the first month Cross modal perception recognize through one sense an object familiar through another sense 3 months oral visual matching 4 7 months all other senses o The Development of Attention Attention focus of perception