Seeing, Thinking, and Doing in Infancy

How Children Develop (3rd ed.) Siegler, DeLoache & Eisenberg

Chapter 5

Guiding Questions

1. How do infants perceive the world around them?

2. What capabilities do infants possess?

3. What major milestones occur during infant development and how does the environment influence the development of these milestones?

4. What have classic research studies taught us about the perceptual and cognitive abilities of infants?

How do infants perceive the world around them?

A. Vision

B. Auditory Perception

C. Taste and Smell

D. Touch

Perception Sensation: refers to the processing

of basic information from the external world by the sensory receptors in the sense organs and brain

Perception: the process of organizing and interpreting sensory information about the objects, events, and spatial layout of our surrounding world

Research methods for studying infants’ vision:

Preferential-looking technique: involves showing infants two patterns or two objects at a time to see if the infants have a preference for one over the other

Habituation: involves repeatedly presenting an infant with a given stimulus until the response declines If the infant’s response increases when a novel stimulus is

presented, the researcher infers that the baby can discriminate between the old and new stimuli.

Visual Acuity

The sharpness of infants’ visual discrimination develops so rapidly that it approaches that of adults by age 8 months and reaches full adult acuity by 6 years of age.

An infant’s visual acuity can be estimated by comparing how long the baby looks at a striped pattern such as this one versus a plain gray square of the same size and overall brightness.

Visual Acuity

Young infants prefer to look at patterns of high visual contrast because they have poor contrast sensitivity (the ability to detect differences in light and dark areas). This is because the cones (light-sensitive neurons)

of the eye, which are concentrated in the fovea, differ from adults’ in size, shape, and spacing.

In addition, very young infants have limited color vision, although by 2-3 months of age their color vision is similar to that of adults’.

Visual Scanning Scanning

One-month-olds (a) scan the perimeters of shapes.

Two-month-olds (b)scan both the perimeters and the interiors of shapes.

Tracking Although infants begin scanning the environment

right away, they cannot track even slowly moving objects smoothly until 2 to 3 months of age.

Faces

From birth, infants are drawn to faces because of a general bias toward configurations with more elements in the upper half than in the lower half.

From paying attention to real faces, the infant comes to recognize and prefer his or her own mother’s face after about only 12 cumulative hours of exposure.

Faces

With experience, infants not only develop a preference for the type of face they see most often, but also come to understand the significance of different facial expressions.

From birth onward, infants look longer at faces that adults find more attractive than those adults rate as less attractive, and interact more positively with people with attractive faces.

Same or Different?

As an adult human, you no doubt can tell the two men apart quite easily, but you may still not be sure whether the two monkey photos are of different individuals or not.

Pattern Perception

Two-month-old infants can analyze and integrate separate elements of a visual display into a coherent pattern. When you look at this figure, you

no doubt see a square—what is called a subjective contour, because it does not actually exist.

Seven-month-olds also see the overall pattern here and detect the illusory square.

Infants are also able to perceive coherence among moving elements.

Object Perception

Perceptual constancy is the perception of objects as being of constant size, shape, color, etc., in spite of physical differences in the retinal image of the object. If an infant looks at the

larger, but farther-away cube, researchers will conclude the child has size constancy.

Supporting the nativist position, visual experience does not seem to be necessary for perceptual constancy.

Object Segregation

Infants who see the display in figure (a) perceive it as two separate objects, a rod moving behind a block.

After habituating to the display, they look longer at two rod segments than at a single rod (b), indicating that they find the single rod familiar but the two segments novel.

If they first see a display with no movement, they look equally long at the two test displays.

This result reveals the importance of movement for object segregation.

Object Segregation

The identification of separate objects in a visual array Two-month-old infants use common

movement to perceive object segregation.

Older infants, like adults, use additional sources of information for object segregation, including their general knowledge about the world.

In figure (a), for example, it is impossible to know for sure whether what you see here is one object or two.

Because of your knowledge about gravity and support, you can be sure that figure (b) is a single, albeit very odd, object.

Depth Perception

Infants as young as 1 month respond to optical expansion, a depth cue in which an object occludes increasingly more of the background, indicating that the object is approaching.

Stereopsis, the process by which the visual cortex combines the differing neural signals caused by binocular disparity (the slightly different signals sent to the brain by the two eyes), emerges suddenly at around 4 months of age.

Depth Perception

At about 6–7 months of age, infants become sensitive to a variety of monocular or pictorial cues, the perceptual cues of depth that can be achieved by one eye alone.

These include relative size and interposition

Depth Perception

This 7-month-old infant is using the monocular depth cue of relative size. Wearing an eye patch to take away binocular depth

information, he is reaching to the longer side of a trapezoidal window.

This behavior indicates that the baby sees it as the nearer, and hence more readily reachable, side of a regular window.

Pictorial Representations Despite the fact that even

newborns can recognize two-dimensional versions of three-dimensional objects, children must come to understand their symbolic nature.

Before they reach about 19 months of age and have substantial experience with pictures, infants and toddlers attempt to treat pictures as though they were real objects.

B. Auditory Perception

Although the human auditory system is relatively well developed at birth, hearing does not approach adult levels until age 5 or 6. Infants are remarkably proficient in perceiving

subtle differences in human speech.

Music Perception

Recent research evidence suggests a biological foundation for music perception. Infants share the strong preferences

adults have for some musical sounds over others.

Infants also respond to rhythm in music and are sensitive to melody, showing habituation to the same tune regardless of pitch.

C. Taste and Smell

Sensitivity to taste and smell develops before birth.

Newborns have an innate preference for sweet flavors.

Newborns prefer the smell of breast milk and by two weeks of age appear to be able to differentiate the scent of their own mothers from that of other women.

D. Touch Infants learn about the

environment through active touch. Oral exploration

dominates for the first few months.

Around 4 months of age, infants gain greater control over their hand and arm movements, and manual exploration gradually takes precedence over oral exploration.

What capabilities do infants possess?

A. Perceptual Capabilities

B. Reflexes

A. Perceptual Capabilities

Sight Hearing Taste Smell Touch Intermodal perception

Intermodal Perception

The combining of information from two or more senses is present from very early in life.

Very young infants link sight and sound, oral and visual experience, and visual and tactile experience. When two videos are presented simultaneously, 4-

month-old infants prefer to watch the images that correspond to the sounds they are hearing.

Using a similar technique, researchers have found that by 5 months of age, infants associate facial expressions with emotion in voices.

Research Technique for Intermodal Perception

A set-up like this one enables researchers to study auditory–visual intermodal perception.

The two computer screens display different films, one of which is coordinated with a soundtrack.

The video camera records the infant’s looking toward the two screens.

B. Reflexes

Newborns demonstrate reflexes – innate, fixed patterns of action that occur in response to particular stimulation.

Some reflexes, such as rooting and sucking, have clear adaptive value Others, such as the tonic neck

reflex, have no known adaptive significance.

What major milestones occur during infant development?

How does the environment influence the development of these milestones?

Motor Milestones

Impact of Culture on Motor Development

Mothers in Mali believe it is important to exercise their infants to promote their physical and motor development.

The maneuvers shown here do not harm the babies and do hasten their early motor skills

Current Views on Motor Development

Previously believed to be an element of neurological maturity

Current theories, however, often take a dynamic-systems approach, emphasizing a confluence of many factors, including not only neural mechanisms but also increases in strength, posture control, balance, perceptual skills, and motivation.

Illustrating the Dynamic Systems View

Research by Esther Thelen and colleagues examined the stepping reflex, the infant’s performance of stepping movements when he or she is held under the arms with feet touching a surface.

The reflex was thought to disappear at about 2 months of age because of cortical maturation, but demonstrations that the reflex could be prolonged or elicited long after it was scheduled to disappear were inconsistent with this interpretation.

Illustrating the Dynamic Systems View

Thelen performed two experiments to test the hypothesis that rapid increases in infants’ weight made it impossible for them to execute stepping motions. In one experiment, weights were attached to the ankles of

infants who still had the stepping reflex, and the babies suddenly stopped stepping.

In the second study, infants who no longer showed the stepping reflex were found to do so when they were suspended waist-deep in a tank of water that supported their weight.

Hence, the movement pattern and its neural basis remains but is masked by the changing ratio of leg weight to strength.

Reaching

For the first few months, infants are limited to prereaching movements – clumsy swiping movements by young infants toward the general vicinity of objects they see.

Infants begin successfully reaching for objects at around 3 to 4 months of age.

Reaching

At about 7 months, as infants gain the ability to sit independently, their reaching becomes quite stable.

Reaching shows signs of anticipation, and by 10 months of age, infants’ approach to an object is affected by what they intend to do with the object.

Self-Locomotion

At around 8 months of age, infants become capable of self-locomotion for the first time as they begin to crawl.

Infants begin walking independently at around 11 to 12 months of age, using a toddling gait.

Back-Lying and Locomotion

The campaign to get parents to put babies to sleep on their backs to reduce the risk of SIDS seems to make infants less likely to roll over on schedule. It may be that the better view of the world from their backs

results in less motivation to roll over. It may also be that spending less time on their tummies

causes arm strength to develop more slowly.

The research is reassuring in that by 18 months of age there were no differences in the development of infant crawling.

What have classic research studies taught us?

What have they taught us about infant perception?

Visual Cliff Research Research with the visual cliff illustrates the

interdependence of different domains of development.

Using the visual cliff, Gibson and Walk found that 6- to 14-month-old infants perceived and understood the significance of the depth cue of relative size.

Subsequent work by Campos and his colleagues using heart rate deceleration as the dependent measure indicated that infants could perceive the difference in depth but showed no fear of the deep side.

In a series of studies, the researchers found that the experience of moving themselves around in the environment plays a very important role in babies’ developing understanding of the significance of differences in the height of surfaces.

Visual Cliff Research

Social referencing, the use of another’s emotional reaction to interpret an ambiguous situation, appears to be important in infants’ development of wariness of heights

Thus, development in one domain clearly influences development in other domains.

Adolph’s Research

Karen Adolph and her colleagues have found that infants do not transfer what they learned about crawling down slopes to walking down them.

Scale Errors

Toddlers also make scale errors, in that they try to do something with a miniature replica object that is much too small for the action to be completed.

One little boy is perched on top of a miniature chair, trying to sit in it just like he did with a similar-looking real chair, and the other is attempting in vain to get into a tiny car.

What have classic research studies taught us?

What have they taught us about infant learning and cognition?

Habituation Studies

A decrease in responsiveness to repeated stimulation reveals that learning has occurred. The infant has a memory representation of the

repeated, now-familiar stimulus.

The speed with which an infant habituates is believed to reflect the general efficiency of the infant’s processing of information. A substantial degree of continuity has been found

between these measures in infancy and general cognitive ability later in life.

Habituation This 3-month-old is seated in front

of a screen on which photographs are displayed.

At the first appearance of a photo of a face, her eyes widen and she stares intently at it.

With three more presentations of the same picture, her interest wanes and a yawn appears.

By its fifth appearance, other things are attracting the baby’s attention, and by the sixth even her dress is more interesting.

When a new face finally appears, her interest in something novel is evident.

Studies of Perceptual Learning

Infants actively search for order and regularity in the world around them.

Differentiation is the extraction from the constantly changing stimulation in the environment of those elements that are invariant or stable.

A particularly important part of perceptual learning is the infant’s discovery of affordances, the possibilities for action offered by objects and situations.

Studies of Statistical Learning

Involves picking up information from the environment, forming associations among stimuli that occur in a statistically predictable pattern

From quite early on, infants are sensitive to the regularity with which one stimulus follows another.

Learning Through Classical Conditioning

A form of learning that consists of associating an initially neutral stimulus with a stimulus that always evokes a reflexive response

Plays a role in infants’ everyday learning about the relations between environmental events that have relevance for them It is thought that many emotional responses are

initially learned through classical conditioning, as demonstrated by the case of Little Albert.

Basic Components of Classical Conditioning

Classical conditioning involves an unconditioned stimulus (UCS) that reliably elicits a reflexive, unlearned response – an unconditioned response (UCR).

Learning or conditioning can occur if an initially neutral stimulus, the conditioned stimulus (CS), repeatedly occurs just before the unconditioned stimulus.

Gradually, the originally reflexive response – the learned or conditioned response (CR) – becomes paired with the initially neutral stimulus.

Classical Conditioning

Gong (UCS)Gong (UCS)

Crying (UCR)

Crying (UCR)

Animal (CS)

Animal (CS)

Fear (CR)Fear (CR)

Associated

Similar

Learning Through Instrumental Conditional

Also called operant conditioning

Involves learning the relation between one’s own behavior and the consequences that result

Most instrumental conditioning research with infants involves positive reinforcement, in which a reward reliably follows a behavior and increases the likelihood that the behavior will be repeated. There is a contingency relation between the infant’s

behavior and the reward.

Studying Instrumental Conditioning in Infants

Contingency Relation

This young infant learned within minutes that kicking her leg would cause the mobile to move in an interesting way.

Observational Learning Infants as young as 6 to 9 months of age imitate some of the novel

actions they have witnessed.

The ability to imitate the behavior of others appears to be present early in life, although in an extremely limited form. For example, newborns will stick out their tongues after watching an

adult model repeatedly perform this action.

In choosing to imitate a model, infants appear to pay attention to the reason for the person’s behavior. Infants attempt to reproduce the behavior of other people, but not of

inanimate objects.

By 15 months of age, infants can imitate actions they have seen an adult perform on television.

Imitating Intentions

When 18-month-olds see a person apparently try, but fail, to pull the ends off a dumbbell, they imitate pulling the ends off – the action the person intended to do, not what the person actually did.

They do not imitate a mechanical device at all.

Infant Cognition

Object knowledge Physical knowledge Social knowledge

Cognitive Abilities Research conducted over the past two decades has established

that infants’ cognitive abilities are much more impressive than previously believed.

The extent to which these skills reflect nature versus nurture, however, is a matter of debate.

Core-knowledge theorists maintain that infants are born with some knowledge about the physical world.

Some theorists emphasize specialized learning mechanisms that enable infants to acquire knowledge rapidly and efficiently in some domains, whereas others emphasize general learning mechanisms that gradually strengthen infants’ mental representations of the world.

Still other theorists contend that perceptual-motor processes may be responsible for much of what has been described as cognition in infancy.

A. Object Knowledge

In contrast to Piaget’s description of the development of object permanence, a great deal of evidence now indicates that young infants are in fact able to mentally represent and think about the existence of invisible objects and events.

The majority of the evidence is based on research using the violation-of-expectancy procedure, in which infants are shown an event that should evoke surprise or interest if it violates something that the infant knows or assumes to be true.

Violation of Expectancy

Baillargeon and her colleagues have used this technique to establish that infants as young as 3½ months of age look longer at an “impossible” event than at a possible event.

B. Physical Knowledge

Knowledge of gravity begins in the first year. Infants have been shown to look longer at

objects that violate expected motion trajectories.

Infants also gradually come to understand under what conditions one object can support another. This gradually refined understanding of support

relations is presumed to result from experience.

Developing Understanding of Support Relations

C. Social Knowledge

Infants must acquire knowledge about people and their behavior. Distinguishing animate and inanimate entities Knowing that the behavior of others is purposeful and goal-

directed

By the end of their first year, infants have learned a great deal about how people’s behavior is related to their goals and intentions. Suggesting very early precursors of theory of mind, 15-month-

olds can make inferences about what a person will do based on the knowledge of what the person knows.

Understanding Intentions

Infants who see a human arm repeatedly reach for an object in the same location assume that the action is directed toward the object, not the place.

They looked longer when the hand went to the new object in the old place, than when it reached for the old object it had reached to before.

Understanding Intentions Infants may attribute

intentions and goals to inanimate entities as long as they “behave” like humans.

In one study, 12- and 15-month-olds were introduced to a faceless, eyeless, brown blob that “vocalized” and moved in response to what the infant or experimenter did, thus simulating a normal human interaction.

Subsequently, when the blob turned in one direction, the infants looked in that direction.

They did not behave this way with a blob whose behavior was not contingently related to their own.

Attributing Dispositional States Twelve-month-olds also seem able, like adults, to attribute

dispositional states.

Infants watched a film that adults interpret as a ball “trying and failing” to get up a hill as it is being “helped” by a triangle and being “blocked” by a square.

Subsequently, with just the three shapes on the screen, infants looking behavior indicated that they expected the ball to approach the helpful triangle while avoiding the hindering square.