• Newborns are preadapted to face the developmental tasks of learning about the world and forming relationships within it. Five important characteristics of newborn competencies are:
1. They depend on abilities that are prewired.
2. They often meet survival needs.
3. From the very beginning they involve organized sequences of actions that serve some purpose.
4. They involve selective responses.
5. They allow infants to detect relationships between actions and consequences.
• Two themes of this chapter:
1. Focus on how heredity and the environment work jointly to guide the course of development.
2. Emphasize how infants' initial skills, and the experiences they allow infants to have, provide the seeds for the development of the more complex and flexible skills seen by the end of the first year.

Early Brain Development

• Methods for examining underlying structural changes in brain development are limited. Some involve autopsies of infant brains at different ages, use of EEGs in normal infants, use of brain scans in infants with medical issues, indexes of behavior and brain growth from children who suffer early deprivation in "natural" situations, and from animal models.
• Brain Growth
• Infant brain at birth is _ of its adult weight. By one year, the brain has tripled in weight. One measure of this growth is head circumference, starting at 13.5 inches and growing in spurts to its average adult size of 20.5 inches.
• Changes in Structure and Function
1. The brainstem (basic reflexes) is fully functional at birth.
2. The thalamus (sensory relay station), the cerebellum (motor functions), the hippocampus (memory formation), and the cerebral cortex (higher cognitive functions) all undergo continued development and reorganization.
3. Almost all of the neurons are present at birth that the individual will ever have.
4. The cortex continues to develop in the following ways:
• Neurons increase in size and become more complex in structure.
• Myelination occurs and is not complete until adolescence.
• The number of synapses increases, peaking at different ages in different parts of the brain.
• Connections between the cortex and other brain areas increase.
• Areas of the cortex begin to take on specialized functions. Plasticity allows for this.
• Experience and Developmental Context
• The development of the nervous system is fostered and constrained by infants' experiences, helping in the development of specialized functions in the cortex.
• Malnutrition, especially if it is severe and long-lasting, can cause extensive and potentially permanent brain damage. Post-natal environment is key for helping to ameliorate early damage.
• The amount and type of stimulation influences the structure of the cortex, as this plays a role in the number of neuronal connections and the pruning of the connections in the cortex.

Infant States

• One classification system identifies six infant states: quiet sleep, active sleep, awake-and-quiet, awake-and-active, fussing, and crying.
• Infants gain increasing control over their states during the first few months, and the states themselves become more stable and predictable.
• Sleep States
1. The average newborn sleeps 16 hours each day; most middle-class American infants show signs of adopting the conventional day-night pattern by 8 weeks.
2. Caretaking practices influence sleep patterns.
3. In quiet sleep, babies lie still and breathe slowly and regularly, while in active sleep they stir often and show REM activities. They are in active sleep 50% of the time (for adults it is 20%). They have irregular cycles of quiet and active sleep, unlike adults.
• Distressed States
1. During the first two months, infants engage in full-blown crying 2% of the time and fussiness 10% of the time.
2. There are three distinct cries: hungry, upset, and pain cries. Experience helps the caretaker become even more aware of these types of cries.
3. Infants can soothe themselves with sucking. Others can soothe them with soft talking, rocking, swaddling, and holding babies upright and close to the shoulders.
• Changes in States
1. During the first few months, states change often, but by five months they are more predictable.
2. There are individual differences in how smoothly infants make transitions between states, based in biology but interacting with caregiver responses.

Reflexes of the Newborn

• A reflex is an automatic, built-in reaction elicited by a particular stimulus.
• Survival Reflexes
• Researchers are most interested in survival reflexes that are present at birth but disappear as the infant acquires more advanced skills. Two of the survival reflexes are rooting and sucking.
• Other Reflexes
1. Moro reflex has evolutionary significance in survival value as does the grasping reflex, which gives way after the third month to voluntary grasping. The stepping reflex usually disappears by about three months of age and the same movements reappear under voluntary control a number of months later as infants learn to walk.
2. As babies mature, higher brain regions take control and begin to inhibit reflexes, allowing for voluntary control. This is related to myelination and proliferation of synaptic connections.

Infant Learning

• Changes in many infant behaviors are the joint outcome of genetic control and learning.
• Habituation and Dishabituation
1. Habituation is one of the first signs that babies are able to retain information about their environments.
2. An orienting response can be seen when infants cease behaviors and attend to environmental stimuli. This response will be decreased as they learn enough about the stimulus (habituation) to realize it is the same one they have seen. When a new stimulus appears and is noticed, dishabituation occurs, indicating that they have made a comparison between the first and second stimulus and noted a difference. As discussed in the boxed material on techniques for studying early infant development, habituation-dishabituation has been used extensively in infant research, examining various perceptual and memorial capacities of infants.
• Associative Learning
1. Associative Learning - how infants learn that certain events tend to go together (become associated with each other).
2. Classical Conditioning is a learning process in which a new stimulus comes to elicit an established reflex response through association with an old stimulus, as was originally researched by Ivan Pavlov in his work with digestive processes in dogs.
• Recent research has indicated the capacity for classical conditioning in newborns, such as retention of an eyeblink response over a 10-day period, although it is harder to demonstrate with newborns than with infants at three months of age and older.
• Classical conditioning does not explain the emergence of new behavior.
3. Instrumental or operant conditioning involves reinforcement, in which behaviors are influenced by their consequences. In
• Positive reinforcement, a pleasant stimulus follows a behavior, increasing the likelihood of future occurrences of the behavior.
• Negative reinforcement occurs when an unpleasant stimulus is removed, which also increases the likelihood of future behavior occurrences.
• In contrast, punishment, the presentation of an unpleasant stimulus after a behavior, is intended to decrease the likelihood of future occurrences of the behavior.
• It is easier to instrumentally condition newborns than to classically condition them. We humans are prepared to notice and respond to contingencies, relationships between actions and their consequences. Research methods using this type of learning have met with success.
• It is a method for acquiring new behaviors such as occurs with shaping in which closer approximations of some target behavior are reinforced gradually.
4. Imitative learning occurs when new behaviors are learned by copying others' actions. It is a powerful method of learning.
• The capacity for this learning was believed by Piaget to develop over the first two years.
1. Before 6 months, infants can match behaviors of others based on similarity of perceptual consequences.
2. Around 6 months, infants try to imitate behaviors they see or hear but have never tried before, often failing or managing partial imitation.
3. Around 12 months, infants are better at imitating unfamiliar behaviors.
4. By 18 months, toddlers' imitation of even novel behaviors become very accurate.
• The Concept of Preparedness
1. Imitation studies indicate that there is a genetic predisposition to learn certain behaviors, called preparedness. Some see early social behaviors (e.g., smiling and cooing when adults speak) fitting this concept.
2. Part of preparedness is a predisposition in humans to analyze the connection between certain behaviors and their consequences (e.g., taste and smell of foods which can lead to food aversion after one event of nausea).

Infant Motor Skills

• There are major milestones in development involving average ages, yet there is a great deal of individual difference in the age at which motor skills emerge.
• Motor Skills and Physical Growth
1. There is dramatic physical growth during the first year (e.g., baby's weight triples and length increases by 10 inches). Body proportions change as well. These changes require the infant's motor system to recalibrate to adapt.
2. Principles of motor skill development
• Differentiation - gross, whole-body movements become more and more refined to specific sets of muscles
• Cephalocaudal development - control over motor skills tends to progress from the head downward to lower body parts.
• Proximodistal development - control over motor skills tends to progress from the center of the body out to the extremities.
• The joint role of maturation and experience - motor development is best understood as a dynamic system in which a number of factors interact in constantly changing ways.
• The Development of Specific Motor Skills
1. Controlled eye movements are one of the earliest skills to develop, shown even to some degree in newborns. As they get more skilled, they are more effective at controlling where they look (a skill developing until about age 7 years).
• Babies become more skilled at visually tracking objects. Newborns show saccadic eye movements before they develop smooth, continuous pursuit eye movements. The ability to follow more rapidly moving objects develops between 2 and 4 months of age.
• Visual tracking is needed for when infants themselves are in motion. Infants make compensatory eye movements when they feel their bodies being moved even in the first few months of life.
2. Reaching and grasping are examples of behaviors that appear early in life, decline or disappear, and then reappear in more advanced forms.
• Early, spontaneous reaching is called prereaching, which declines between one and four months.
• Intentional reaching emerges around 4 months and becomes more refined.
• A question of interest is whether early intentional reaching is visually guided, which more recent research suggests visual guidance is not necessary.
• Reaching is refined through active exploration of the environment and the pursuit of particular goals. Effective reaching is integrated into a more complex system of body movements and by 8 months infants have learned to lean and reach simultaneously if an object is not close at hand (an integrated system of movements).
• The development of grasping has a similar course. By 3 to 4 months, babies can pick up objects voluntarily, using a whole hand approach. By 6 months, they do not let go of objects voluntarily too well. By 8 months they use the thumb in opposition to the fingers; the refined thumb-forefinger grasp appears.
3. Walking has early behaviors in the stepping reflex. Walking depends on the ability to integrate many systems, including balance. Random and jerky movements begin to give way to more smooth and controlled ones. Infants do not learn to control their leg movements until more rhythmic, repetitive patterns have appeared.
4. The onset of walking depends partly on maturation of the muscles and nervous system and partly on practice (e.g., early research by Dennis). Recent research suggests that prolonged restriction of movement in infancy can delay the development of walking. Certain practices appear to speed up the development of walking.

Sensing and Perceiving the World

• Sensory Systems in the Newborn
1. Visual capacities such as visual acuity, the ability to see fine detail, undergo many changes. For instance, newborns have such poor acuity that they would be categorized as legally blind but this ability improves dramatically over the next 6 months.
• How do researchers determine how clearly babies see?
1. One method is to use the visual preference technique (Fantz). Some have estimated that at 2 weeks, a baby's visual acuity is about 20/300 while at 5 months it is 20/100.
2. Another method used to study this topic is visual evoked potentials, the characteristic pattern of electrical activity that occurs in a baby's brain in response to a new visual stimulus. This method produces somewhat higher estimates of visual acuity.
3. Infants' eyes do focus in response to a distant object, but the adjustment does not reach adult levels until about 4 months.
4. The limitation of acuity probably lies somewhere in the system that changes an image into neural signals, transmitting them to the brain, and then analyzing the information. Appropriate visual experience also is needed to foster acuity development.
• Can infants see colors?
• One needs to differentiate between color (light wavelength) and brightness (light wave amplitude). Babies cannot reliably discriminate on the basis of color alone until about 7 or 8 weeks of age and by 4 to 5 months, babies likely have all of an adult's color vision abilities.
2. Research on hearing in utero has shown sensitivity to sound in fetuses 26 to 28 weeks old, and babies show recognition of sounds they heard in utero repeatedly after they are born (e.g., DeCasper and Spence's research).
• Eye blinks have been monitored to measure sensitivity of a baby's hearing. For young infants to hear a noise, it must be 10 to 20 decibels louder than it has to be for adults to hear it. It takes 12 to 13 years to reach adult sensitivity to sound.
• Infants' ability to detect the direction of a sound is present very early and improves with age, to reach adult levels by age 18 months.
• Sound discrimination also has been investigated in studies using habituation-dishabituation. Babies are quite good at detecting small changes in pitch by 5 to 8 months of age, and babies hear high frequencies better than low frequencies. Babies are also good at discriminating between different speech sounds, even in early infancy (categorical perception of speech sounds).
3. Young infants are very sensitive to odors and can discriminate between tastes. For odors, habituation studies have shown an ability to make fine discriminations between odors. For taste, there is continued development of taste receptors.
• Organization of Infant Sensory Behavior
• Newborns use their sensory capacities in organized ways (e.g., hear a sound, direct gaze toward it). Their patterns of scanning change as well to include more scanning on the internal features as they mature during the first few months.
• Development of Perceptual Abilities
1. Perception is the process by which the brain interprets information from the senses, giving it order and meaning.
• Depth and distance perception research began with the visual cliff, showing that babies at 6 to 7 months prefer the shallow side of the apparatus and this preference increases with age. Babies only 2 months old can distinguish between the "deep" and "shallow" sides of the visual cliff as determined by changes in heart rate.
• How we perceive depth and distances pertains to three types of cues: kinesthetic, binocular, and pictorial cues.
1. The first visual depth cues infants use are kinesthetic depth cues, in which information is carried in the motion of objects. These are monocular cues such as the apparent expansion in size of approaching objects, which shows development between 1 and 3 months.
2. Another kinetic depth cue is called accretion-deletion and is produced by the gradual disappearance and reappearance of surfaces behind a moving object, which appears by about 3 months and is used consistently by 5 to 7 months.
• Binocular depth cues, such as convergence, come from using both eyes to process visual information. This cue is used accurately by 2 to 3 months. Another binocular cue is retinal disparity (due to our eyes being 2 _ inches apart), which is used around 3 months of age.
• A sensitive period exists for development of depth perception, which we know from children who suffer with strabismus (or cross-eyes). Those who were operated upon after 1 year showed declined sensitivity to binocular information.
• Pictorial depth cues are used to depict depth in two-dimensional pictures and are monocular. One of these is linear perspective (convergence of parallel lines in the distance), which infants begin to use around 5 to 7 months. At about this age infants also can use interposition (overlapping of objects) and shading (shadows from protrusions and depressions in a surface).
2. Size constancy is the perception of an object as constant in size, even though the retinal image grows larger or smaller as the object is viewed from different angles, and appears to be present even in newborns.
3. Shape constancy is the perception of an object as constant in shape, even though its image on the retina changes shape when the object is viewed from different angles, and appears to be somewhat available even to newborns but is clearly available to 3-month-olds.
4. Perception of faces is a complex task. Newborns appear to prefer to track facelike patterns more than scrambled patterns of facial features (which is a lower-level, general visual pattern recognition ability involving lower brain areas). Static face preference does not show until 2 to 3 months.
5. Recognition of specific faces develops sequentially. There is some evidence that newborns recognize their mothers' faces. By 3 months, they recognize photographs of their mothers, and by 5 months they remember the faces of strangers.

First Adaptations in Context

• Biology prepares newborns to respond to their environments with reflexes and to respond to contingencies. They have a variety of sensory capacities and are preadapted to select and attend to certain types of stimuli.
• In turn, the environment provides infants with experiences to help shape the development of their brains, their motor skills, their perceptual abilities, and the specific behaviors they learn.
• These aspects, biology and environment, work jointly to help the baby learn how to control his environment.