assistance needed psycology

PSY 121 LU03 CHAPTER 3

PATTERNS OF GROWTH

• Cephalocaudal pattern: developmental sequence in which the earliest growth always occurs at the

top—the head.

• Physical growth and differentiation of features gradually work their way down from top to bottom.

• Proximodistal pattern: sequence in which growth starts at the center of the body and moves toward

the extremities.

• As individuals develop from infancy through adulthood, one of the most noticeable physical changes

is that the head becomes smaller in relation to the rest of the body. The fractions listed refer to head

size as a proportion of total body length at different ages.

HEIGHT AND WEIGHT

• The average American newborn is 20 inches long and weighs 7.6 pounds.

• Most newborns are 18 to 22 inches long and weigh between 5 and 10 pounds.

• Babies grow about 1 inch per month during the first year.

• By 2 years of age:

• Infants weigh approximately 26 to 32 pounds.

• They average 32 to 35 inches in height.

• Growth is episodic.

THE BRAIN • The brain is still developing rapidly in infancy.

• Shaken baby syndrome includes brain swelling and hemorrhaging and affects hundreds of babies in the U.S.

each year.

• Noninvasive tools that measure brain activity:

• Electroencephalogram (E E G).

• Functional near-infrared spectroscopy (f N R I S).

• Mapping the brain:

• The forebrain—the portion farthest from the spinal cord—includes the cerebral cortex and the structures

beneath it.

• The brain has two hemispheres, each with four lobes.

• Frontal lobes.

• Occipital lobes.

• Temporal lobes.

• Parietal lobes.

• Lateralization: specialization of function in one hemisphere of the cerebral cortex or the other; both,

however, are needed for complex functions.

THE BRAIN • Changes in neurons:

• Myelination—the pace of which varies.

• Increased connectivity among neurons creates new neural pathways.

• Connections that are used become stronger, while the unused ones are

replaced or disappear—they are “pruned.”

• Changes in regions of the brain:

• The age at which “blooming” and “pruning” of synapses occurs varies by brain

region.

• Both heredity and environment are thought to influence the timing and course.

• (a) The dendrites of the cell body receive information from other neurons,

muscles, or glands through the axon. (b) Axons transmit information away from

the cell body. (c) A myelin sheath covers most axons and speeds information

transmission. (d) As the axon ends, it branches out into terminal buttons.

THE BRAIN

• Early experience and the brain:

• Children in a deprived environment may have depressed

brain activity.

• Example: the unresponsive and unstimulating environment

of a Romanian orphanage.

• For some individuals, the effects of deprived environments

are reversible.

• The brain demonstrates both flexibility and resilience.

• Example: the case of Michael Rehbein, where the brain’s

left hemisphere was removed to bring an end to

uncontrollable seizures.

• a) Michael Rehbein at 14 years of age. (b) Brain scans of an

intact brain (left) and Michael’s right hemisphere (right).

Michael’s right hemisphere has reorganized to take over the

language functions normally carried out by corresponding

areas in the left hemisphere of an intact brain (left). However,

the right hemisphere is not as efficient as the left, and more

areas of the brain are recruited to process speech.

THE BRAIN

• The infant’s brain depends on experiences to determine how connections are

made.

• Neuroconstructivist view:

• Biological processes and environmental conditions influence the brain’s

development.

• The brain has plasticity and is context dependent.

• The child’s cognitive development is closely linked to development of the

brain.

SLEEP

• The typical newborn sleeps 16 to 17 hours a day.

• Sleep-related problems affect 20 to 30% of infants.

• Especially, night-time waking.

• Factors include bedtime routines, maternal depression, and screen time.

• REM sleep:

• Half of an infant’s sleep is REM (rapid eye movement) sleep, the most in the life span.

• REM sleep may provide added self-stimulation and might promote the brain’s development in

infancy.

• SIDS:

SLEEP • Sudden infant death syndrome (SIDS): a condition that occurs when infants stop breathing and die without any

apparent reason.

• Risk is highest at 2 to 4 months of age.

• The incidence of SIDS decreases when infants are placed to sleep on their backs.

• The two factors that best predict SIDS:

• Maternal smoking.

• Bed sharing.

• Sleep and cognitive development:

• Sleep may be positively linked to cognitive development.

• Likely occurs because of sleep’s role in brain maturation and memory consolidation.

• Better memory, language, and executive function.

• Shorter sleep duration has been linked to inattentiveness and hyperactivity.

NUTRITION

• Maternal benefits of breast feeding:

• Reduced rates of breast cancer and ovarian cancer.

• Reduced rate of type 2 diabetes.

• Reduced rates of hospitalization for cardiovascular problems and diabetes.

• The mother should not breast feed:

• When infected with AIDS or any other infectious disease that can be transmitted through her milk.

• If she has active tuberculosis.

• If she is taking a drug that may not be safe for the infant.

• Additional issues:

• Breast feeding can be physically difficult.

• Not all studies imply causality between health benefits and breast feeding; most studies are

correlational.

• Evidence of psychological differences between breast-fed and bottle-fed infants is inconclusive.

NUTRITION

• Nutritional needs:

• Nutritionists recommend that infants consume approximately 50 calories per

day for each pound they weigh.

• A national study documented that U.S. parents feed their babies too few fruits

and vegetables and too much junk food.

• By 15 months, French fries were the most common vegetable.

• Caregivers play very important roles in infants’ early development of eating

patterns.

DYNAMIC SYSTEMS THEORY

• Dynamic systems theory: the perspective on motor development that

seeks to explain how motor behaviors are assembled for perceiving and

acting.

• Motor skills are developed by:

• Maturation and development of the nervous system.

• The body’s physical properties (for example, physical strength) and its

potential for movement (for example, motor control).

• The child’s motivation to reach a goal.

• Environmental support for the skill.

REFLEXES

• Reflexes—which are automatic and involuntary—are built-in reactions to stimuli that govern the newborn’s movements.

• Some persist throughout life, while others disappear several months after birth.

• Rooting reflex: occurs when the infant’s cheek is stroked, or the side of the mouth is touched.

• The infant turns his or her head to find something to suck.

• Sucking reflex: occurs when newborns automatically suck an object placed in their mouth.

• Enables them to get nourishment before they have associated a nipple with food.

• Serves as a self-soothing mechanism.

• Moro reflex: a neonatal startle response that occurs in reaction to a sudden, intense noise or movement.

• The infant throws the head back, flings out arms and legs, and arches the back, then contracts these movements.

• Believed to be a way of grabbing for support while falling.

• Grasping reflex: occurs when something touches the infant’s palms.

• Responds by grasping tightly.

• The newer perspective on infant reflexes is that they are not completely automatic or completely beyond the infant’s control

GROSS MOTOR SKILLS

• Gross motor skills: involve large-muscle activities, such as walking.

• As a foundation, these skills depend on the development of posture.

• Locomotion and postural control are closely linked, especially in walking upright.

• Babies can stand by 10 to 12 months and can:

• Alternate leg movements and balance on one leg without falling.

• Learn safe places and surfaces to walk on and avoid unsafe places.

• Utilize perceptual-motor coupling in the development of new motor skills.

• Practice their new motor skills.

GROSS MOTOR SKILLS • Milestones and variations in the first year:

• Developmental milestones include grasping, rolling, sitting, and crawling, as well as standing and walking.

• Larger size at birth shows the strongest link to reaching motor milestones earlier.

• The timing of reaching milestones varies by 2 to 4 months.

• Experiences can modify the onset of these accomplishments.

• Caregiver participation enhances all new skill development in a real-world environment with objects, surfaces, and planes.

• Development in the second year:

• Toddlers become more skilled and mobile.

• By 13 to 18 months, they can pull a toy and climb steps.

• By 18 to 24 months:

• Walk quickly and run short distances.

• Balance on their feet while squatting.

• Walk backward and stand and kick a ball.

• Stand and throw a ball.

• Jump in place.

FINE MOTOR SKILLS

• Fine motor skills: involve more finely tuned movements, such as finger

dexterity.

• During the first two years, infants refine how they reach and grasp.

• Experience plays a role.

• Many infants develop a pincer grip and begin to crawl at about the same

time.

SENSORY AND PERCEPTUAL DEVELOPMENT

• Sensation: the product of the interaction between information and the sensory receptors—the eyes,

ears, tongue, nostrils, and skin.

• Perception: the interpretation of what is sensed.

• The ecological view:

• In Eleanor and James Gibsons’ ecological view, perception brings us into contact with the

environment so we can interact with and adapt to it.

• Perception is designed for action—that is, it gives people information, such as when to put up your

hands up to catch something.

• Studying the infant’s perception:

• Visual preference method: measuring the length of time infants attend to different stimuli; developed

by Robert Fantz.

• Habituation: decreased responsiveness to a stimulus after repeated presentations.

• Dishabituation: recovery of a habituated response after a change in stimulation.

• Eye tracking: measuring eye movements that follow a moving object.

VISUAL PERCEPTION • Visual acuity and color:

• The newborn’s vision is estimated to be 20/600; but by 6 months of age, an average

infant’s vision is 20/40.

• Faces are possibly the most important visual stimuli.

• Within hours after birth, they prefer to look at faces and prefer to look at attractive

faces.

• By 8 weeks, infants can discriminate between some colors.

• The four photographs represent a computer estimation of what a picture of a face looks

like to a 1-month-old, 2-month-old, 3-month-old, and 1-year-old (which approximates

the visual acuity of an adult).

VISUAL PERCEPTION • Perception of occluded objects:

• In their first months, infants don’t perceive objects that are

occluded by other objects in front of them as complete; instead,

they perceive only what is visible.

• Beginning at about 2 months of age, infants develop the ability to

perceive that occluded objects are whole.

• Depth perception:

• The “visual cliff” experiments by Eleanor Gibson and Richard

Walk indicate that infants can perceive depth.

• Eleanor Gibson and Richard Walk (1960) found that most infants

would not crawl out on the glass, which, according to Gibson and

Walk, indicated that they had depth perception. However, critics

point out that the visual cliff is a better indication of the infant’s

social referencing and fear of heights than of the infant’s

perception of dept understand at 3 to 4 months.

OTHER SENSES • Hearing:

• The fetus can hear sounds in the mother’s womb during the last two months of pregnancy.

• Changes in hearing during infancy involve perception of:

• Loudness;

• Pitch; and

• Localization.

• Newborns respond to touch.

• Newborns can also feel pain.

• A brain activity network, the “pain network,” underlies pain.

• Newborns can differentiate among odors.

• Sensitivity to taste is present even before birth.

• At about 4 months of age, infants begin to prefer salty tastes, which as newborns they had

avoided.

INTERMODAL PERCEPTION

• Intermodal perception: the ability to relate and integrate information from

two or more sensory modalities, such as vision and hearing.

• In the first 6 months, infants have difficulty connecting sensory input from

different modes, but in the second half of the first year, they show an

increased ability to make this connection mentally.

PIAGET’S THEORY

• Jean Piaget stressed that children actively construct their own cognitive worlds.

• Schemes: the actions or mental representations, in Piaget’s theory, that organize knowledge.

• Behavioral and mental.

• Assimilation: occurs when using existing schemes to deal with new information or experiences.

• Accommodation: occurs when children adjust schemes to fit new information and experiences.

• Organization: the grouping of isolated behaviors and thoughts into a higher-order system.

• Equilibration: a mechanism by which children shift from one stage of thought to the next.

• Disequilibrium is cognitive conflict.

PIAGET’S THEORY • According to Piaget, individuals go through four stages of development.

• Cognition is qualitatively different from one stage to another.

• The stage of infant cognitive development is the sensorimotor stage.

• Sensorimotor stage: infants construct an understanding of the world by

coordinating sensory experiences.

• Lasts from birth to about 2 years of age.

• Initially, newborns have little more than reflexes; but at the end of the

sensorimotor stage, they can produce complex sensorimotor patterns and

use primitive symbols.

• Object permanence: an understanding that objects and events continue

to exist.

• When they cannot directly be seen, heard, or touched.

• One of the infant’s most important accomplishments, according to Piaget.

PIAGET’S THEORY

• Evaluating Piaget’s sensorimotor stage:

• Much of the newer research suggests that Piaget’s view of sensorimotor

development needs to be modified.

• A-not-B error: an error that occurs when infants make the mistake of selecting

the familiar hiding place (A) rather than the new hiding place (B).

• Researchers have found that the A-not-B error does not show up consistently.

• In longitudinal research, attention at 5 months was related to A-not-B

performance at 10 months.

PIAGET’S THEORY

• Researchers also suggests that infants develop the ability to understand how

the world works at a very early age.

• Both intermodal perception and object permanence develop much earlier

than Piaget would have predicted.

• Today researchers believe that infants see objects as bounded, unitary,

solid, and separate from their background by 3 to 4 months, possibly

earlier.

• Core knowledge approach: theory that infants are born with domain-

specific innate knowledge systems.

• Some researchers argue morality is innate; while others suggest it emerges

through infants’ early interaction with others.

LEARNING, REMEMBERING, AND CONCEPTUALIZING

• Conditioning:

• According to Skinner’s theory of operant conditioning, the

consequences of a behavior produce changes in the probability

of the behavior’s occurrence.

• If an infant’s behavior is followed by a rewarding stimulus, the

behavior is likely to recur.

• Example: the baby kicks, and the mobile moves—the movement

is the reinforcing stimulus.

• In Rovee-Collier’s experiment, operant conditioning was used to

demonstrate that infants as young as 2½ months of age can retain

information from the experience of being conditioned.

ATTENTION

• Attention: the focusing of mental resources on select information.

• By 4 months, infants can selectively attend to an object.

• Closely linked with attention are habituation and dishabituation.

• Infants’ attention is strongly governed by novelty and habituation.

• Joint attention: two or more individuals focus on the same object or event.

• Joint attention requires:

• An ability to track another’s behavior, such as following the gaze of another person;

• One person’s directing another’s attention; and

• Reciprocal interaction.

• By the end of the first year, joint attention is frequently observed.

• Joint attention considerably

IMITATION

• Andrew Meltzoff and colleagues see infants’ imitative abilities as

biologically based but not hardwired.

• Imitation involves flexibility and adaptability.

• In their first 72 hours of life, infants gradually display more complete

imitation of adults’ facial expressions.

• Deferred imitation: occurs after a delay of hours or days.

• Piaget held this doesn’t occur until about 18 months of age.

• Meltzoff finds it occurs much earlier.

MEMORY • Memory: retention of information over time.

• Implicit memory: memory without conscious

recollection.

• Memories of skills and routine procedures

that are performed automatically.

• Explicit memory: conscious remembering of

facts and experiences.

• Infantile or childhood amnesia: the inability to

remember much if anything from our first three

years of life.

Age Group Length of Delay

6-month-olds 24 hours

9-month-olds 1 month

10- to 11-

month-olds

3 months

13- to 14-

month-olds

4 to 6 months

20-month-olds 12 months

Researchers have documented that 6-

month-olds can retain information for 24

hours, but by 20 months of age infants can

remember information they encountered

12 months earlier.

CONCEPT FORMATION AND CATEGORIZATION

• Concepts: cognitive groupings of similar objects, events, people, or ideas.

• Infants as young as 3 months of age can group together objects with similar appearances.

• Jean Mandler argues this is best described as perceptual categorization, rather than

conceptual.

• Infants may also categorize on the basis of prototypes, or averages, that they extract from

structural regularities.

• Further advances occur in the second year of life.

• Learning to put things into the correct categories is an important aspect of learning.

DEFINING LANGUAGE

• Language: a form of communication.

• Spoken, written, or signed.

• Based on a system of symbols.

• Lets us pass down information.

• Consists of the words used by a community and the rules for varying and

combining them.

• Infinite generativity: the ability to produce an endless number of meaningful

sentences using a finite set of words and rules.

HOW LANGUAGE DEVELOPS • Babbling and other vocalizations:

• Crying can signal distress; different types of cries signal different things.

• Cooing, emerging at 2 to 4 months, is gurgling sounds that usually express pleasure.

• Babbling, such as “ba, ba, ba, ba,” allows for social interaction.

• Gestures, such as showing and pointing, emerge at about 7 to 15 months of age.

• Infants’ gestures promote further language development.

• Recognizing language sounds:

• Before learning words, infants make fine distinctions among the sounds of language.

• In the first six months, infants recognize when sounds change, regardless of language.

• Over the next six months they get even better at perceiving changes in their “own” language.

• Also in the second half of the first year, they begin to segment speech streams into words.

• Statistical learning allows infants to soak up regularities in the world merely through exposure.

• First words: Infants understand their first words earlier than they speak them.

• Receptive vocabulary considerably exceeds spoken (or expressive) vocabulary.

• A vocabulary spurt begins at approximately 18 months.

HOW LANGUAGE DEVELOPS

• Two-word utterances:

• To convey meaning, the child relies on gesture, tone, and

context.

• Identification: “See doggie.”

• Location: “Book there.”

• Repetition: “More milk.”

• Negation: “Not wolf.”

• Possession: “My candy.”

• Attribution: “Big car.”

• Question: “Where ball?”

• Telegraphic speech: the use of short and precise words

without grammatical markers such as articles, auxiliary verbs,

and other connectives.

Typical Age Language Milestones

Birth Crying

2 to 4 months Cooing begins

5 months Understands first word

6 months Babbling begins

6 to 12 months Change from universal linguist

to language-specific listener

8 to 12 months Uses gestures, such as showing

and pointing; comprehension

of words appears

13 months First word spoken

18 months Vocabulary spurt starts

18 to 24 months Uses two-word utterances;

rapid expansion of

understanding of words

Despite great variations in the language input

received by infants, around the world they follow a

similar path in learning to speak.

BIOLOGICAL AND ENVIRONMENTAL INFLUENCES

• Biological influences:

• Broca’s area: the region in the brain’s left frontal lobe that is involved in speech production.

• Wernicke’s area: the region in the brain’s left hemisphere that is involved in language comprehension.

• Damage to either of these areas produces types of aphasia—

a loss or impairment of language processing.

• Damage to Broca’s area results in difficulty producing words correctly.

• Damage to Wernicke’s area results in poor comprehension and fluent but incomprehensible speech.

• Language acquisition device (LAD): Noam Chomsky’s term for a biological endowment enabling a

child to detect the features and rules of language, including phonology, syntax, and semantics.

• A theoretical construct, not a physical part of the brain.

• Critics argue that even if a LAD exists, it cannot explain the whole story of language acquisition.

BIOLOGICAL AND ENVIRONMENTAL INFLUENCES

• One intriguing environmental component is child-directed speech, which parents shift into when they talk to a baby.

• Child-directed speech: language spoken in a higher pitch and slower speed than normal, with simple words and

sentences.

• Captures attention, maintains social interaction, and highlights differences between speech directed to children and

adults.

• Parent coaching that involves child-directed speech, back and forth interactions, and the “parentese” speech style

improves infants’ language outcomes at 14 months.

• Other strategies also enhance the child’s acquisition of language:

• Recasting: rephrasing something the child has said, in the form of a fully grammatical sentence.

• Expanding: restating something with additional information.

• Labeling: naming objects that the child is interested in.

• Infants, toddlers, and children benefit when adults read to and with them—shared reading.

• Especially, when parents extend the meaning of the text by discussing it and encouraging questions.