Visual development Flashcards
Preferential looking paradigm
takes advantage of infants’
preference to look at “interesting” things. 2 stimuli presented side-by-side
If the baby looks longer at one stimulus
than the other, it means that:
1. they can distinguish between the two
2. have a preference for one over the other
Prefer familiar and/or complex stimuli
Habituation Paradigm
Paradigm takes advantage of babies’ natural preference for novelty.
Habituation phase: repeatedly present infant with a stimulus until
they habituate to it
Test: Present habituated, “old” stimulus with a new stimulus
Dishabituation: If the baby shows greater interest in the new stimulus,
they can tell the difference between the two
Prefer novel stimuli
Familiarity vs. Novelty
In general, infants show a preference for familiar stimuli BUT Prolonged/ repeated exposure to a stimulus will cause infants to shift their preference to a novel stimulus. length of exposure time determines whether an infant
will show a familiarity or novelty preference
Why is visual acuity poor at birth
Due to immaturity of cone cells in infants’ retinas (light sensitive neurons involved in seeing fine details and colours)
When do babies get adult-like visual acuity ?
around 8 months old
Can newborns see colors?
no, see in grey scale
When do babies start seeing colors vs when do they have adult-like colour perception
- 2 months: colour vision appears
- 5 months: adult-like colour perception
-Due to maturity of cones and visual cortex
-Can discriminate between colour categories and between hues of the
same colour
Explain how visual scanning evolves in infancy
- From birth: infants scan their visual environment and pause to look
at something but hard to track moving stimuli because eye movements are jerky - 4 months: able to smoothly track moving objects if moving slowly
- 8 months: adult-like visual scanning
Face perception: top heavy
When show normal face and top heavy “face” look equally at them. Suggests that preference for faces simply result of general preference
for stimuli that are “top-heavy” rather than “bottom-heavy”
What is perceptual narrowing
Tuning of perceptual mechanisms to the specific sensory inputs that
infants encounter in their daily life
What is perceptual narrowing a result of?
synaptic pruning: Elimination of synapses to increase the efficiency
of neural communication. “use it or lose it” principle
What are evidences of perceptual narrowing in face perception
- Infants becoming face specialists: 6 months old is as good at distinguishing human face vs monkey face but 9month old can distinguish between 2 human faces but struggle to distinguish between 2 monkey faces
- Infants demonstrate the other-race-effect: 3 month olds: distinguish between faces of all races but 9 month olds: can only distinguish between faces of own race
If infant is equally exposed to faces of different races, will it show the “other-race-effect”
No! Not innate, but rather exposure effect
At what age do infants become face specialists as a result of perceptual narrowing?
9 months
What is perceptual consistency
The perception of objects as being constant in size, shape, colour. etcin spite of physical differences in the retinal image of the object
