chapter 5 – sensation & perception

Chapter 5 – Sensation & Perception

• Sensation= reception of stimuli

• Perception= interpretation of those stimuli

I. Smell & TasteSensitive 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 painCrying• 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 cliff4 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 LearningI. 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