Chapter 5 Sensation Perception Sensation reception of stimuli

Chapter 5 – Sensation & Perception • Sensation = reception of stimuli • Perception = interpretation of those stimuli

I. Smell & Taste Sensitive by birth • Activity level - internal - external

• • Facial expression Orientation Preference Habituation

• Discriminate odors/tastes - all 4 taste categories (prefer sweet) - many odors • Importance - prefer stimuli related to breastfeeding - enhances survival

II. Touch Reflex responses • shows tactile perception from birth Pain perception grows • born with poor pain perception • develops rapidly

• No experience of pain in the womb • Softens birth experience Heart rate • increases in response to pain Crying • specific pain cry • or just more & louder

Importance • Attachment - tactile contact with parent helps build relationship - orphans/preemies with little tactile stimulation fail to develop properly

• Learning - by handling object, learn about world - brain structures & body develop

III. Hearing • Good at birth; excellent by 6 months - perfected through exposure to sounds • Head orientation • Activity level

4 Factors infants can discriminate • Pitch - better at higher pitches “motherese” • Duration - differentiate between sounds of similar duration - helps learn language

• Location - improve with experience - test via sound in darkened room • Distance - tell how far something is - reach for noisy object in dark?

Importance • Locate objects • Perceive human speech • Perceive danger

IV. Sight • Fuzzy at birth - improves quickly

Testing Vision • Tracking - following objects with eyes

• Optokinetic nystagmus - eye movements when watching a moving object - shows acuity

• Scanning - looking at different parts of object • Habituation - look longer at novel stimuli

4 Factors infants can discriminate • Brightness • Movement • Pattern/rules • Contrast/edges

Importance • Bonding via eye contact • Perceive face pattern • Recognize parents

Color • Rods & cones - rods on periphery: night vision - cones in center: color & day vision • Poor at birth - see black, white, some red - good at 2 -3 months

Depth • Sensitive by 2 months - visual cliff 4 visual cues to depth • Kinetic - movement - by 5 months

• Binocular - difference in images in left & right eyes - by 7 months • Perspective - lines moving together indicate distance

• Texture - less detail & space between objects indicates depth “Texture gradient” - by 7 months

Integration of senses • Vision & touch - if touched hidden object, recognize it visually - by < 6 months • Vision & hearing - look at location of noisy object in dark room - ~ 3 weeks

Ways of Learning I. Habituation • React to new a stimulus • Reaction dulls -> Learn the stimulus = habituation & discriminate from others • Importance - attention to significant threats

II. Classical Conditioning - Pavlov • Unconditioned stimulus & response - US = stimulus that naturally evokes a reaction - UR = the natural reaction • Conditioned stimulus & response - something always occurs just prior to the US (temporal proximity — cue)

- learn the association between the cue and the US - same reaction to the cue (the CS) • Superstitious behavior - perceiving a temporal link that is coincidental - fears, prejudice, phobias

• Extinction - to eliminate the CR - present CS many times with no US - people eventually quit responding - but: people resist extinction - violates rules/patterns

• Importance - survival behaviors can be classically conditioned - preparedness

III. Operant Conditioning - Skinner • Rewards & punishments ->behavior • Use operant conditioning to measure infants’ perceptions & what infants can learn

IV. Observational Learning - Bandura • Learn by imitating models • Integration of 2+ senses - use of games • Skills, socialization, & language

• Do newborns imitate? - newborns sticking out tongue - or not until ~ 8 weeks