Week 4 Flashcards
- sensing the environment.
- Sensory receptors detect stimulus,
and receptor neurons convert it into
signals sent to the brain
Sensation
the psychological process
of organizing and interpreting sensory
input
Perception
Infants Are _______ Participants
Why?
“Difficult”
No or little command of language
* Do not understand (complex) instructions
* Do not give (complex) verbal responses
Methods: studying infant perception
Preferential-looking tests
* Habituation-recovery tests
* Contingent reinforcement
Studies
Present 2 stimuli, measure
attention to both
▪ What if infant looks longer at one
over the other stimulus?
Drawbacks?
Preferential-looking Tests
Vision only
▪ What about no preference?
▪ Longer looking ≠ preference
(e.g., surprising, pleasurable, puzzling)
Robert Fantz’s (1960): looking chamber is an example of what form of studying infant perception
Preferential-looking Tests
Present 1 stimulus until the infant
becomes “bored”
▪ Present a new stimulus
▪ What is the infant increase attention
to the new stimulus?
▪ Overt behaviour (looking time)
▪ Physiological measures (e.g., heart beats)
Habituation-Recovery Tests
Sense + discriminate stimuli
▪ Various sensory modalities
Operant conditioning: following the “If you
do this, then you get that” principle
▪ Infants increase a specific behavior in
response to certain stimuli to obtain reward
Contingent Reinforcement
(Type of Operant conditioning based on specific action to reward, not overall operant conditioning)
E.g., infants’ sucking or head turning
behaviors in response to hearing their
mothers’ voice
Early Controversies / Debates in Baby’s Perceptions
Nature vs. Nurture
Empiricists: (Nurture) infants must
learn to interpret sensations
Nativists: (Nature) innate basic
perceptual abilities
perceptual development is the unfolding of the
natural differentiation
Differentiation Theory (Gibson, 1969, 1987, 1992)
Cognitive schemes, knowledge, experiences form perceptual development
Enrichment Theory (Piaget, 1954, 1960)
Least mature sense in
newborns, most studied in infant
perception
Vision
Vision is not simply seeing. It
includes
actively looking
* tracking objects and people
* recognizing faces and so on
the ability to see fine details (clearness and sharpness
of a visual image)
Visual acuity
Newborn / Toddler seeing ability
Newborns: 20/600
* By 6 months: 20/100
* By 12 months: 20/50
* By 6 years: 20/20 (adult level)
the minimum difference in brightness
between an image and its background that infants can
perceive. (gradually develop with biological maturation
Contrast sensitivity
(Colour Perception)
Newborns see colours, but
2-month olds: some form of ______
By 4 months ________
Trouble distinguishing blue, green and yellow from white, especially
when equally bright
color vision
Perceive full range of colours,
– Discriminate among hues of the same colour category (e.g., green)
– Category color hues in line with adult named color categories
* Habituation: identical vs. same category vs. different category
Visual Perception: Perceptual Constancy
Habituate to a cube (large or small), then show
both at different distances to form the same sized retina images.
Newborns look longer at the one of different size than the one they
were exposed earlier
This shows they perceive ____
Size constancy
integrate elements to perceive a pattern
Do infants have this?
Pattern perception
Yes, Early preference for human faces and
moving rather than static stimuli
Subjective contour: Infants detect
static objects defined by illusory
contours at around 7 months
(Object Perception)
a Gestalt principle with a natural tendency to view
objects or stimuli as continuous or whole
Good continuation
4 months: use “common movements” to perceive objects as whole (Kellman & Spelke, 1983)
Visual Perception: Depth Perception
Optical expansion (Kinetic cues, looming or approaching): 1-month
Stereopsis (binocular cues): 4-month (perceiving distance and 3 dimensions)
Pictorial (Monocular) cues: 6/7-month (Can understand 3d effects on a 2d paper or image)
Depth Perception: Visual Cliff
Gibson & Walk (1960)
* 2-month: detect the
difference (lower heart
rate on the deep side)
* 6.5-month: 90% Infants
crawled across the
shallow side but not the
deep side
Tracking motion
Newborns: move heads in response to moving
stimuli (Braddick & Atkinson, 2011)
– 2-month: from Jerky eye movements to
smooth tracking through 4 or 5 months (Aslin,
1981)
– 6-month: Anticipatory eye movements: 6
months (Johnson et al., 2003)
* Facilitates social interactions!
Face Perception
Young infants (0-2 month) view faces half of their
waking time (Jayaraman et al., 2015)
* Newborns prefer their mother’s face
Their visual system is biased to attend to a
socially significant stimulus!
Face Preference: babies may look at specific faces because of ___________
top-heavy features
(Contexts of Face Perception)
A developmental process characterized by a
diminished ability to distinguish among less frequently-encountered stimuli
– Own-species/race/sex vs. other-species/race/sex
Perceptual narrowing
Newborn – 6-month:
– Can distinguish both
humans and monkeys
* After 6-month:
– Can no longer distinguish
between monkeys
Hearing in newborns is __________
Better developed than vision at birth, rapid
development in absolute threshold in first
year; not adultlike until past preschool years
(5-8 years)
The minimum sound level of a stimulus required to detect a
sound
Absolute threshold
The minimum difference in loudness or pitch needed to distinguish
between two sounds
Relative threshold
(Music Perception)
A biological foundation: _____
Newborn brains respond to
variations in music (e.g., pitch,
pitch changes, rhythm)
Perceptual narrowing:
* 4-month: prefer music of their
own culture
* 12-month: difficulty with foreign
metrical structure, but not with
familiar ones
Speech Perception
Listening preference (for socially
significant stimuli)
* Newborns: Speech > nonspeech;
particularly mother’s voice
* Newborns: human = animal
vocalization
* 3-month: species-specific (human >
animal vocalization)
Newborns’ taste preference
‒ Sweet tooth
‒ Distinct facial expressions to bitter,
sour, and sweet
‒ Contextual influences: mothers’
eating habits, early taste experiences
Newborns’ odor preference
React to unpleasant odors
‒Prefer milk to amniotic fluid
‒Recognize scent of mother (2-week old)
perceives and connects information
available to multiple senses simultaneously
Intermodal perception
When different types of perceptual
information occur at the same
time, creating a unitary
perceptual experience
Temporal synchrony
Auditory – visual intermodal perception:
1-2 month (Aronson & Rosebloom, 1971)
Early indicator of intelligence
(Rose & Feldman, 1995)
Categorization of Infants sight and how they make meaning out of it
- Perceptual categories (7-month): physical
appearance (e.g., birds = airplanes) - Conceptual categories (9- and 11-month):
use/function (e.g., birds ≠ airplanes)
14-month: dissimilar exemplars (e.g., dog – fish;
car – airplane)
Categorize first based on visually salient features
(e.g., shape), then conceptual criteria (e.g., what
to do with it) (Mandler, 2004)
Piaget’s View of Children’s Nature in Cognitive Development
Constructivist Theory
- Active child, discovery-based
▪ Schemas
Basic units of
information that are cognitive
representations of the world
_______ determine how children of
different ages organize and
understand information
Schemas
Piagets Stages of Cognitive Development
- Sensorimotor (0-2)
- Preoperational (2-7)
- Concrete Operational (7-12)
- Formal Operations (12+)
Distinct, hierarchical stages, each
building on the previous one
Sensorimotor Sub-stages (Piaget Cognitive Development)
Stage 1. Reflexes and spontaneous movements (0-1 m)
Involuntary actions (e.g., sucking, grasping, rhythmic actions)
▪ Stage 2. Primary Circular Reactions (1-4 ms)
Repeat actions around the immediate environment of their bodies
(e.g., repeatedly sucking thumbs and kicking legs)
▪ Stage 3. Secondary Circular Reactions (4-8 ms)
Repeating actions to have an effect on the external world (e.g., swiping a mobile)
Stage 4. Coordination of Secondary Schemes (8-12 ms)
“Goal-directed” intentional. Coordinate and combine actions to achieve a goal
(e.g., lifting a pillow to retrieve a toy)
▪ Stage 5.Tertiary Circular Reactions (12-18 ms)
Means-end analysis, trial-and-error experiments to explore new solutions
▪ Stage 6. Mental Representation: Symbolic Problem Solving (18-24 ms)
Symbolic representations: hold and manipulate objects/events in minds
The knowledge that objects continue to
exist independent of one’s immediate perceptual experiences
(e.g., out of view). It appears at around 8 months.
Object permanence
The tendency to search where objects have
been found before, rather than where they were last hidden
A-not-B error
Infants make A-Not-B error around 8-12 months.
(Symbolic Mental Representation)
the repetition/copying of
other people’s behavior after a delay. It occurs
around at around 18-24 months (Persisting mental
representations)
Deferred imitation
(Symbolic Mental Representation)
understand and use
words to refer to things that are not present
Displaced Reference
use actions and words in a
pretend mode (e.g., feeding a teddy bear)
Symbolic play
Challenges to Piaget’s Theory
Nativists: Piaget underestimated
infants’ cognitive ability
Dynamic systems: Piaget’s emphasis
on mental representation rather than in-
the-moment contextual influences
Information-processing: Piaget’s
qualitative, stage-like changes instead of
gradual developmental changes
A looking technique based on a habituation and
dishabituation procedure, that compares infant looking time at unexpected/impossible vs.
expected/possible events
Violation-of-expectation paradigm
Result:
3.5-5.5-month
old infants looked
longer at the
impossible than
possible events
(object
permanence)
The Violation-of-expectation paradigm is a ______ test of Object Permanence
Nativist Test
Dynamic Systems Insights
in-the-moment contextual factors on cognitive performance: ________
Modifying the A-not-B Task: ________
Dynamic Systems View
1) increasing location A exposures; 2) disruption of motor habits (posture changes; weights on hands etc.
