Perceptual Development Flashcards
Theoretical Issues in the Study of
Perception
The Nature and Nurture of Perceptual
Development
- Chaotic experience.
- Mind as a blank slate.
- Random and meaningless information.
- Constructive process. : actively building up knowledge through there experiment (piaget)
- Organization given at birth, experience refines.
Visual Perception: A cyclopean image
The Nature and Nurture of
Perceptual Development
- Creating understanding from
experience. - Innate aspects of
perception. - Combination of nature and
nurture. - A** cyclopean image:** having two eyes close together allows infants to see one image .
Theoretical Issues in the Study of Perception
The Nature and Nurture of Perceptual Development:
- Biases at Birth
– Figure Ground
– Contrast
– Edges
– But is there more?
measure perception
with visual preference
-habituation:look for shorter time at old thing
visual paired comperacion: infants familirize with stimulus, and then measure how long they look at the familiar vs new stimulus
Theoretical Issues in the Study of Perception
The Nature and Nurture of Perceptual Development:
- Experience Expectant(nature)
– Will see faces
– Sounds & Sights of Nature (e.g. water) - Experience Dependent(nurture)
– What types of faces? Which individuals?
– What kind of landscape? What kinds of trees?
Historical Views:
What do babies perceive?
- William James, 1890, “Principles of Psychology” the baby experiences the world as a “Blooming, buzzing,
confusion” - A radical empiricist approach
- Blank slate (tabula rasa – remember John Locke), that experience must write on
- Since the 1960’s, we have known that not to be true
- Fantz (1958, 1961, 1963) developed procedures to test infant perception
– Visual preference (see next slide)
– Habituation (as before, and as later)
visual acuity
amount of detail you can see
The development of visual acuity
- Preferential looking: Visual (grating) Acuity
– Infants prefer patterned over grey(David Teller)
– When lines too close together, no preference(they become a blur
visual accuiticy in infants
is extremely poor, they can only see very few details
infants visual accuitacy gets better repedly throughthere 1 year(just not perfect)
Effects of Experience:The Development of Visual Acuity?
- Improvement of vision in infants
- Is it all maturational? Experience Expectant? Experience dependent?
- Experiment on children with cataracts.
– Acuity recovers when cataracts removed – 1 hour = 1 month (robust to lack of input for many months)
-Configural face processing, and other aspects of stereoscopic vision do not, even if cataract removed as early as 1 month, so that process experience expectant
Color vision
infants color is not the same as adults from birth (4month) - but they do see color
can only see bright coors in big patches, also contrast of color(not similar ones)
children born in places and season with less color have a lower color perception the warmer places
death perception
- gibson experiment
- visual cliff
- result: we learn depth perception
- as new cralwers were less put of by the cliff then older crawlers
- problem we cant mesure depth if they dont crawl(so they might have it earlier on)
An innate preference for faces
- Preferential Looking
– Show two patterns side-by-
side, measure duration of
fixation
– Preference implies
discrimination
- Example: Faces
– More complex patterns: faces,
bull’s eye - Infants prefer complex patterns to plain patterns
Basic Visual Abilities:
Color Vision
- Color perception at birth.
- Light of different wavelengths.
- Photoreceptors on retina.
- By 4 months infants see color like adults
Basic Visual Abilities:Depth Perception
- Critical for navigation.
- Task of visual cliff.-
- Infants pass around time
of crawling - Is depth perception
learned? - Or is it innate, with
learning to crawl
triggering its expression?
is refined by crawling but maybe crawling triigers depth perspetion
types of depth cues
kinemetic: object move closer they get bigger,futher they get smaller
binocular cues: brain fuses separete images in one
monocular:objects that are closer are bigger
Basic Visual Abilities:
Depth Perception
- Stereopsis.
- Monocular depth cues.
- Experiment by Yonas and colleagues-
-frogs
-infants become sensitive to monocular depth between 5-7 months
More recent data:
- topographic map circuitry develops w/out visual experience,
guided by molecular signals & spontaneous neural activity - maintenance and refinement requires visual experience after
the sudden emergence of stereopsis at ~ 3 months (exp expec) - difficult to regain stereopsis if cataract surgery > 8 weeks (CP)
but some plasticity remains, & any gains are beneficial
it dosnt require experience but it refines
Visual Perception of Objects:
Perceiving Objects
- Perception of boundaries of objects.
- More advanced than, but given in part, by figure ground segregation
- Common motion to identify boundaries.
- Perception of three-dimensional objects.
Spelke: Perception of Objects
if the objects moved together or one moved and the other one
did they think the objects were actually one?
no they though the two rods(the broken one ) because they didnt see they were connected
Needham: Object Boundaries
- 4.5 mo nfants NOT surprised if one or both parts moved when pulled
on pipe - By 7.5 months they were when they moved together
- But even at 4.5 months, if they first had even brief experience with just
one part moving, then they did look longer if moved together
AND – they could remember this 24 hours later - Suggests development & learning for perception of object boundaries
- How would you reconcile the Spelke vs Needham findings?
Face Perception
- Features that account for this are top-heavy and symmetry, plus eyes at top
- Head mounted camera – infants look at faces a LOT (25% of the time)
- Newborns rapidly learn to distinguish
mother’s face - Innately guided learning?
Face Perception
- Newborn Infants
- Regular, Scrambled, and Blank “Face”
- Which did they track more?
looked more in the regular face
face perspeption
slide 27
prefered regular faces, prefered top havy ,didnt show preference
conclusion: babies like top havier
Auditory Perception : Basic Auditory Perception
- Auditory system more developed at birth than the visual system
- Remember the ontogeny of the sensory systems?
- Also differential experience in utero
- Can measure auditory discrimination, localization, pitch perception, loudness discrimination
- How might these each be measured?
better then visiual perception before birth
Haptic Perception
- Touch: source of new information.
- Explore and learn about environment.
- Haptic perception.
Haptic Perception
Infants’ Exploration Using Touch
* Manipulation and fingering of objects.
* Manipulation in different positions.
* (High manipulate more objects then and low SES families.)
Haptic Perception:Perception of Object Properties
Through Touch
- Habituation of holding time.
- Differences in shapes of
objects.
Connecting Sensory and Perceptual
Information Across Modalities
- Experience in multiple sensory modalities.
- Link between different modalities..
- The text defines** intermodal and multimodal** perception as the ability to link (or learn the link) between different properties of objects (e.g. sight and sound of a VW)
- It defines amodal information as the detection of information or properties that are the same in different modalities common which might be given without learning
Connecting Sensory and Perceptual
Information Across Modalities
- Sensitivity to invariant, amodal features
.
Infant 4 mos looks longer to in synch over out of synch display (Spelke w/toy animals)
Cross-modal matching
-they looked at the wirder/bumpier pacifier
Speech is multisensory in adults and in infants
- Noisy party, watch someone’s face
- The McGurk effect
vision and sound
Auditory-Visual Speech Matching
