ch--06 perception psych

8/14/2019 CH--06 Perception Psych

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PerceptionPerception

Exam 1: 86Exam 2: CH 6-9


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DefiningSensation/Perception

Sensationtransduction (detection)changing of physical energy/externalstimuli into neural impulses.

Perception--organizing/processinginformation (interpretation)

Affected by individuals history oflearning experiences


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Nature/Nurture Issues

Imagine the world at birth Empiricists/ Constructivists --comes

from experience through learning, babies

are born with a blank slate. (nurture) Nativists--come with some built-

in/innate abilities & maturationalprograms are the driving forces in

perceptual development knowledge very similar to adults in perceptual

abilities (maturation/biology)


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Measuring Sensory/PerceptualAbilities--Preferential

Attention Presents 2 stimuli to infants &measure the length of time itspends looking at each.

Indicates that the infantdiscriminates btw the two

If he looks at one longer than theother it means:

(1) they can differentiate (2) the show preference to one

stimulus over another


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Measuring Sensory/PerceptualAbilities, Cont.

Evoked Potentials- disc on head to seewhere neural firings occur, -to what Good for testing babies for mental/neural complications

Other ways specific to sensory modality

(visual scanning) To see where an infant is looking

Operant Conditioning- shown pic of mom so that the suck at a certain rate, shows

recognition of mom if they suck more/rigorously.

Young infants not easily conditioned.


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Infant sucking video

Infants preference for human facesdue to affinity for patterned stimuliwith contour & some complexity.
http://visrecmother2x.mov/http://visrecmother2x.mov/


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Vision Transductionretina

Inside the eye Rods- dark vision, in periphery Cones- light vision, central

Basic Abilities

Brightness/color

Visual acuity (perceive detail)

newborns, 40x worse than adult.

Infants have a more fixed focus(about 8 inches) from their face.

Caused by problems with visualaccommodations

Visual accommodation (focusing)ability to adjust the lens of the eyeby changing shape as objects

change distance


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Vision, cont.

Perceptual preferences Moderately complex patterns Contrast

Movement 2-3 mo. Prefer more normal human

faces as they develop mentalrepresentations for how it shouldlook. Color vision matures as well.

Externatility effect(movie) (up to 2 months)

Visual cicadae- littlejumps when someone reads

or w/ infants, passing linesin front of their face -ifthese cease it means theycan no longer notice thesedifferences
http://externality%20effect%202x.mov/http://externality%20effect%202x.mov/


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Vision, cont.

Depth perception

Binocular cues

Monocular cues

Size consistencyrecognition that an

object is the same

size despite changes

in distances from the

eyes.


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Depth Perception, cont. (movie)

Gibson & Walk

Visual Cliff(classical conditioning) Slow heart rate indicates interest

or perceived difference in depth.

Intuitive Theories: comeequipped with organized sys. of

knowledge that allow them tomake sense of the world
http://gibsondepthpercmpg4.mov/http://gibsondepthpercmpg4.mov/


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Hearing

Transduction--in cochlea Newborns can hear better than they see,

they can also localize sound

Sensory capabilities Wide range of pitches, loudness

Phoneme: perception (basic speech sounds)

P. Eimas (ba/pa) recognized difference 2-3 mo.

Sound localization May be reflexive at birth


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Hearing Preferences inNewborns

Cat in the Hat study: infants read to in order tosee if they would suck more to a story theyd heardbefore.

Able to recognize sound patterns, preference for

mothers voice due to constant bombardment andproximity to, more attentive to female vocals.

Prefer auditory stimulus to be relatively complex

Sound patterns--pauses in music

Loose sensitivity to sound contrasts in languagetheyre starting to learn the 1st year


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Taste

Different tastes/facial expressions Can distinguish sweet, salty, sour,

bitter (savory/fat?)

Sweet taste calming, will swallow

more amniotic fluid w/ higher sugarcontent

taste gene

Greater exposure to variety of flavor

in infancy- led to moreadventuresome eaters later on

Sensory receptors fortaste -taste buds-

located mainly on the

tongue, respond to

chemical molecules:

salt, etc.


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Taste and Smell Movie

Even newborns can differentiate btwgood and bad smells.

Have preference for human milk overformula

Olfaction receptors are located in thenasal passage
http://nbtastesmell2x.mov/http://nbtastesmell2x.mov/


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Smell (Olfaction)

Breast-pad study: babies can tell thedifference btw mom and another female.

Underarm-pad study: could differentiate

moms B.O. on the pad & another personssmell

Caregivers recognize odors:mothers/fathers can distinguish their ownbabies scent find fecal matter of ownprogeny less offensive.


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Skin Senses

Ability to senses that detectmotion among first to develop.

Touch

Rooting reflex Habituated to touch

Develops in cephalocaudal(head to

toe) direction Temperature

Pain

Circumcision, local anesthesia


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Intermodal Perception

Different sense modalities Some ability present at birth

Cross-modal perception improves: recognizethrough one sense what is familiar throughanother

Researchers have trouble demonstrating onnewborns, dependent on task variables

btw oral and visual around 3 months of age

Impressions from different senses are fusedearly in life.


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Early Influences onPerceptual Development

Early stimulation Vision

Hearing

Sensitive period: individual is moreaffected by experiences & thus has a higherlvl of plasticity .

Fact that perceptual developmentoccurs so quickly, as if innate, is usedas an argument for Nature side.

Cultural Variation Drawings by 10-15 yr.old

children (New Guinea)


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Early Influences, cont.

Gibson--Infants active role, ltd. tobiological

Three phases

1. (birth to 4 months) - Explore immediatesurroundings :Looking, listening, mouthing

2. (5-7months) -More interested w/ objectsaround them: Voluntary grasping, closer

attention to detail, initially reflexive butimproves with gains in cortary control

3. (8 or 9 months) Exploring environment:crawling, fully examining objects


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Development of Attention--Childhood

Attention span lengthens Child once captured; older directed

toward

Due to increased myelination (insulationto sped up neural impulses)

More control of attention

Selective: deliberate concentration

Systematic


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Later life Raised sensory thresholds-- lowest pt a stimulus can

be detected. Vision

Presbyopia (thickening of lens), contracts the muscles asthey cant really adjust focus, need bifocals.

Age related Macular degeneration: damaged retinal

cells in central visual area, leading cause of blindness Cataracts, damage to the nerve causing blindness

Glaucoma, fluid pressure on the eye damages optic nerve

Hearing Presbycusis: pblms with the aging ear

Cochlear hair cells serves as auditory receptors getdamaged

Less sensitive to high pitches

Exposure to loud sounds (Tinnitus/ ringing)


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Later life, cont.

Taste, smell also less sensitive (more salt

when you get older)

Temperature

Less likely to notice changes

Pain

Weak pain--less sensitive, chronic

Bottom line--most declines are mild; older

adults usually compensate


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Critical Thinking Issue:

Should older adults be required topass driving tests more frequently?

Should family members deprive anelder of their right to drive?

Highest rate of accidents occur whenstudents learn to drive much Olderppl are now having more accidents.

ch--06 perception psych

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