Ch. 6 - Physical Development: The Brain, Body, Motor Skills, and Sexual Development Flashcards
What does growth look like in infants?
Very rapid and uneven
At what age is a child about half of their adult height?
2 years old
What does height/weight growth look like during puberty?
There is often a 2-3 year growth spurt
What is ‘cephalocaudal development’?
A sequence of physical maturation and growth that proceeds from the head (cephalic region) to the tail (or the caudal region).
Which part of the body grows fastest during the first year?
The trunk
Which part of the body grows fastest from one year of age to the adolescent growth spurt?
The legs
During adolescence, which part of the body grows the fastest?
The trunk (but the legs also grow rapidly)
What is ‘proximodistal development’?
A sequence of physical maturation and growth that proceeds from the centre of the body (the proximal region) to the extremities (distal region). However, this centre-outward growth pattern reverses just before puberty, where the hands and feet begin to grow rapidly and become first of body to reach adult proportions.
How does the skeletal structure form?
During the prenatal period, it is initially soft cartilage that will gradually ossify (harden) into bony material
What is one reason that neonates cannot sit up/balance themselves?
Their bones are too small and too flexible
Describe the neonate’s skull?
Consists of several soft bones that can be compressed to allow the child to pass through cervix/birth canal. Bones are separated by six ‘soft spots’/fontanelles that are gradually filled by minerals
What are sutures?
Seams where skull bones join that allow skull to expand as brain grows
What is ‘skeletal age’?
A measure of physical maturation based on the child’s level of skeletal development
What is the order in the body of skeletal maturation/hardening?
Skull and hands first. Leg bones continue to develop until mid to late teens
What are the muscle fibres like in neonates?
Neonates are born with all muscle fibres they will ever have
Which body part(s) grow much faster and are quicker to reach adult proportions?
Brain and head
What did Warren Eaton and Kathryn Ritchot discover about maturational differences?
Maturational differences also predicted the speed with which children would be able to engage in cognitive tasks. Faster processing speed was found in early maturers (especially in boys)
Describe the cultural variations in physical growth?
People from Asia, South America, and Africa tend to be smaller than North Americans, Northern Europeans, and Australians
What is the ‘brain growth spurt’ and when does it occur?
The period between the seventh prenatal month and 2 years of age when more than half of the child’s eventual brain weight is added. This happens through the formation of glia.
When do the vast majority of neurons a human will ever have form?
By the end of the second trimester of pregnancy (before the brain growth spurt has even begun)
What is the error-related negativity (ERN), and how does it change throughout development? Who studied this?
ERN is negative deflection, as measured by an EEG, that occurs after an individual makes an error. ERN gets larger as children mature, which makes sense with the delayed maturation of the frontal lobe.
Dr. Sid Segalowitz
When does synaptogenesis occur?
During the brain growth spurt
What did Austin Riesen and his colleagues find when infant chimpanzees were reared in the dark?
Dark-reared chimps experienced atrophy of the retina and optic nerve. This atrophy was reversible if visual deprivation did not exceed 7 months, but was irreversible (total blindness) if it lasted longer than a year
What did Bryan Kolb and associates find when groups of animals were exposed to complex, stimulating environments?
All groups showed expected increases in dendritic length (quantitative change). Qualitatively, adult and old animals showed an increase in synaptic densities, whereas juveniles showed a decrease in density.
Which brain areas develop first?
Primary motor areas and primary sensory areas
Name two areas which are not fully myelinated until puberty?
Reticular formation and frontal cortex
What is the ‘cerebrum’?
The highest brain centre; includes both hemispheres of the brain and the fibres that connect them
What is the ‘corpus callosum’?
The bundle of neural fibres that connect the two hemispheres of the brain and transmit information from one hemisphere to the other
What is the ‘cerebral cortex’?
The outer layer of the brain’s cerebrum, which is involved in voluntary body movements, perception, and higher intellectual functions such as learning, thinking, and speaking
What is ‘cerebral lateralization’?
The specialization of brain functions in the left and right cerebral hemispheres
When does cerebral lateralization occur?
May originate during the prenatal period and be well under way at birth. Throughout childhood, we come to rely more and more on one particular hemisphere or the other to serve particular functions
When is brain plasticity greatest?
Early in life, before cerebral lateralization is complete
The fact that a newborn’s head is 70% of its adult size and 25% of its body length is best explained by which concept of development?
The cephalocaudal trend
Which of the following body parts overshoots adult levels in childhood then declines to adult levels later in adolescence?
The lymphatic system
The basic unit of the brain and nervous system are the cells that receive and transmit neural impulses. What is the name for these cells?
Neurons
Scientists believe that the human brain has evolved so that the infant brain can be highly responsive to the effects of experience. The brain is thought to produce an excess of neurons and synapses so that it can be responsive to many different kinds of sensory and motor stimulation. This responsiveness also results in synaptic and neural degeneration when the neurons that are not stimulated do not continue to function. What is the term for this aspect of brain development?
Plasticity
Gretchen is having a baby. Based on her understanding of brain lateralization, she predicted the positioning of her fetus when it was examined with ultrasound. If it was like 2/3 of all fetuses, how was her fetus positioned in the womb?
With its right ear facing outward
T or F: At birth, an infant’s bones are very stiff and brittle and easy to break.
False - they are very flexible
T or F: Individual neurons have the potential to serve any neural function, depending on where their migration delivers them
True
T or F: Very few neurons produced early in life die; instead, they are adapted for different functions in the nervous system.
False - during synaptogenesis, if neurons do not make proper connections, they will die. Synaptic pruning occurs throughout life.
T or F: Although the brain is lateralized at birth, lateral preferences continue to become stronger across age through adolescence.
True
What is the first milestone in locomotor development and when does it occur?
Lifting chins while laying flat on their stomach usually occurs by the end of the first month
What does a child’s rate of motor development tell us about future developmental outcomes?
Very little
What is one example that contradicts the cephalocaudal theory of motor development?
Infants are able to coordinate hip movement earlier than shoulder movement
What is the maturational viewpoint of motor development, and what are two pieces of evidence that support it?
Motor development is the unfolding of a genetically programmed sequence of events where the nerves and muscles mature in a downward and outward direction.
Throughout various cultures, children progress through roughly the same steps of motor development. In a twin study, when one twin is denied experience, both seem to display the same levels of motor development.
What is the experiential/practice hypothesis? Give an example of evident for this hypothesis.
Maturation is necessary but not sufficient to the development of motor skills. Opportunities to practise motor skills are also important.
Infants in Iran were kept in a laying position for 2 years. Many could not sit up or walk.
What is the ‘dynamical systems theory’?
A theory that views motor skills as active reorganizations of previously mastered capabilities undertaken to find more effective ways of exploring the environment or satisfying other objectives
What evidence did Eugene Goldfield find that supports the dynamical systems theory?
Infants began to crawl only after they regularly turned/raised their head toward interesting sights, had developed an arm preference when reaching for such stimuli, and had begin to kick with the leg opposite to the outstretched arm
What are the ‘steps’ for development of voluntary reaching?
Newborns = grasping reflex and prereaches
2 months = skills seem to deteriorate
3 months = voluntary reaching
5 months = reach for stationary objects which become invisible as you reach, reach for glowing objects that move in dark
What is proprioceptive information and how does it contribute to the development of voluntary reaching?
Sensory information from the muscles, tendons, and joints that help one to locate the position of one’s body (or body parts) in space.
Helps infants guide their arms/hands to interesting objects within arm’s length.
What is the ‘ulnar grasp’? When does it appear?
An early manipulator skill in which infants grasp objects by pressing the fingers against the palm.
Occurs at 4-6 months.
What is the ‘pincer grasp’ and when does it occur?
A grasp in which the thumb is used in opposition to the fingers, enabling an infant to become more dexterous at lifting and fondling objects.
During latter half of first year.
What is cephalocaudal development?
A sequence of physical maturation and growth that proceeds from the head (cephalic region) to the tail (or caudal region)
What is proximodistal development?
A sequence of physical maturation and growth that proceeds from the centre of the body (the proximal region) to the extremities (distal regions)
What is skeletal age?
A measure of physical maturation based on the child’s level of skeletal development.
What is the brain growth spurt and when does it occur?
The period between the seventh prenatal month and 2 years of age when more than half of the child’s eventual brain weight is added
What is a synapse?
The connective space (junction) between one nerve cell (neuron) and another
What are neurons?
Nerve cells that receive and transmit neural impulses
What are glia?
Nerve cells that nourish neurons and encase them in insulating sheaths of myelin
What is synaptogenesis?
Formation of connections (synapses) among neurons
What is plasticity?
Capacity for change; a developmental state that has the potential to be shaped by experience
What is myelinization?
The process by which neurons are enclosed in waxy myelin sheaths that will facilitate the transmission of neural impulses
What is the cerebrum?
The highest brain centre; includes both hemispheres of the brain and the fibres that connect them
What is the corpus callosum?
The bundle of neural fibres that connect the two hemispheres of the brain and transmit information from one hemisphere to another
What is the cerebral cortex?
The outer layer of the brain’s cerebrum, which is involved in voluntary body movements, perception, and higher intellectual functions such as learning, thinking, and speaking
What is cerebral lateralization?
The specialization of brain functions in the left and the right cerebral hemispheres
The fact that a newborn’s head is 70% of its adult size and 25% of its body length is best explained by which concept of development?
a. the skeletal age trend
b. the cephalocaudal trend
c. the proximodistal trend
d. the fontenelle trend
b. the cephalocaudal trend
Which of the following body parts overshoots adult levels in childhood and then declines to adult levels later in adolescence?
a. the head and brain
b. the muscular system
c. the lymphatic system
d. the skeletal system
c. the lymphatic system
The basic unit of the brain and nervous system are the cells that receive and transmit neural impulses. What is the name for these cells?
a. glia cells
b. neurons
c. myelin
d. synapses
b. neurons
Scientists believe that the human brain has evolved so that the infant brain can be highly responsive to the effects of experience. The brain is thought to produce an excess of neurons and synapses so that it can be responsive to many different kinds of sensory and motor stimulation. This responsiveness also results in synaptic and neural degeneration when the neurons that are not stimulated do not continue to function. What is the term for this aspect of brain development?
a. plasticity
b. myelinization
c. cerebral specialization
d. cerebral lateralization
a. plasticity
Gretchen is having a baby. Based on her understanding of brain lateralization, she predicted the positioning of her fetus when it was examined with the ultrasound. If it was like two-thirds of all fetuses, how was her fetus positioned in her womb?
a. with its left ear facing outward
b. with its right ear facing outward
c. with its ears facing upward
d. with its ears facing downward
b. with its right ear facing outward
T or F: At birth, an infant’s bones are very stiff and brittle and easy to break.
False
T or F: Individual neurons have the potential to serve any neural function, depending on where their migration delivers them.
True
T or F: Very few neurons produced early in life die; instead, they are adapted for different functions in the nervous system.
False
T or F: Although the brain is lateralized at birth, lateral preferences continue to become stronger across age through adolescence.
True
What is the dynamical systems theory?
A theory that views motor skills as active reorganization of previously mastered capabilities undertaken to find more effective ways of exploring the environment or satisfying other objectives
What is proprioceptive information?
Sensory information from the muscles, tendons, and joints that help one to locate the position of one’s body (or body parts) in space
What is the ulnar grasp?
An early manipulatory skill in which an infant grasps objects by pressing their fingers against the palm
What is the pincer grasp?
A grasp in which the thumb is used in opposition to the fingers, enabling an infant to become more dextrous at lifting and fondling objects
What is physically active play?
Moderate to vigorous play activities such as running, jumping, climbing, play fighting, or game playing that raise a child’s metabolic rate far above resting levels
What is the adolescent growth spurt?
The rapid increase in physical growth that marks the beginning of adolescence
What is puberty?
The point at which a person reaches sexual maturity and is physically capable of fathering or conceiving a child
What is menarche?
The first occurrence of menstruation
What is the secular trend?
A trend toward earlier maturation and greater body size now than in the past
T or F: Infants who proceed through stages of motor development more quickly than the average are likely to be more intelligent later in childhood than infants who are average or behind average.
False
T or F: Infants who are mobile (can crawl or walk easily) are less fearful about meeting strangers because they know they can easily escape to their caregivers if they begin to feel insecure in the new situation.
True
T or F: Generally, girls reach sexual maturity earlier than boys.
True
T or F: Girls become capable of having children as soon as they have their first menstruation.
False
T or F: The secular trend refers to the fact that children today are reaching sexual maturity at later ages than their grandparents and great-grandparents.
False
Zach has a young son about 6 months old. Zach believes that helping his son practise motor skills will help his son achieve motor skills earlier than if he did not help his son practise. Consequently, when Zach plays with his son, he helps his son practise sitting and walking, and encourages his son’s efforts. Zach’s viewpoints about motor development are most closely aligned with which scientific view of motor development?
a. the maturational viewpoint
b. the experiential viewpoint
c. the developmental sequence viewpoint
d. the dynamical systems viewpoint
b. the experiential viewpoint
What did Dennis (1960) find out about the age at which young toddlers could sit, crawl, and walk in his study of orphaned children who were confined to their cribs during their first two years of life?
a. Maturation determined the age at which young toddlers could sit, crawl, and walk, regardless of their experiences.
b. Experience determined the age at which young toddlers could sit, crawl, and walk, regardless of their maturational age.
c. Maturation was necessary but not sufficient for the development of motor skills such as sitting, crawling, and walking.
d. Experience was the determining factor, regardless of age, of when young toddlers could sit, crawl, or walk.
c. Maturation was necessary but not sufficient for the development of motor skills such as sitting, crawling, and walking
What is the term for the ability to grasp an object using the thumb and forefinger?
a. the pincer grasp
b. the ulnar grasp
c. the proprioceptive grasp
d. the forefinger grasp
a. the pincer grasp
Boys and girls are nearly equal in physical abilities until puberty. What happens then?
a. Girls continue to improve on tests of large-muscle activities, whereas boys’ skills level off or decline.
b. Boys continue to improve on tests of large-muscle activities, whereas girls’ skills level off or decline.
c. Boys and girls continue to improve on tests of large-muscle activities.
d. Boys’ and girls’ skills level off or decline.
b. Boys continue to improve on tests of large-muscle activities, whereas girls’ skills level off or decline.
Which of the following is NOT one of the changes associated with the adolescent growth spurt?
a. Girls and boys grow taller and heavier
b. Girls and boys assume adult facial features as their foreheads protrude and their noses and jaws become more prominent.
c. Girls and boys experience a widening of their hips.
d. Girls develop breasts and boys experience a broadening of the shoulders.
c. Girls and boys experience a widening of their hips.
What is anorexia nervosa?
A life-threatening eating disorder characterized by self-starvation and a compulsive fear of getting fat
What is bulimia?
A life-threatening eating disorder characterized by self-starvation and a compulsive fear of getting fat.
What are rites of passage?
Rituals that signify the passage from one period of life to another (for example, puberty rites).
What is thyroxine?
A hormone produced by the thyroid gland; essential for normal growth of the brain and the body.
What is the pituitary?
A ‘master gland’ located at the base of the brain that regulates the endocrine glands and produces growth hormone.
What is growth hormone (GH)?
The pituitary hormone that stimulates the rapid growth and development of body cells; primarily responsible for the adolescent growth spurt
What is estrogen?
Female sex hormone, produced by the ovaries, that is responsible for female sexual maturation
What is testosterone?
Male sex hormone, produced by the testes, that is responsible for male sexual maturation
What is catch-up growth?
A period of accelerated growth in which children who have experienced growth deficits grow very rapidly to ‘catch up to’ the growth trajectory that they are genetically programmed to follow
What is marasmus?
A growth-retarding disease affecting infants who receive insufficient protein and too few calories
What is kwashiorkor?
A growth-retarding disease affecting children who receive enough calories but little if any protein
What is vitamin/mineral deficiency?
A form of malnutrition in which the diet provides sufficient protein and calories but is laking in one or more substances that promote normal growth
What is iron-deficiency anemia?
A listlessness caused by too little iron in the diet; makes children inattentive and may retard physical and intellectual development
What does obese mean?
A medical term describing individuals who are at least 20% above the ideal weight for their height, age, and sex
What is nonorganic failure to thrive?
An infant growth disorder, caused by lack of attention and affection, that causes growth to slow dramatically or stop
What is deprivation dwarfism?
A childhood growth disorder that is triggered by emotional deprivation and characterized by decreased production of GH, slow growth, and small stature
T or F: ‘Rites of passage’ are rituals observed in many nonindustrialized countries and are used to mark the child’s puberty and transition from child to adolescent.
True
T or F: One cross-cultural similarity in child rearing is that the vast majority of societies are relatively restrictive in their views of adolescent sexuality, view sex as a taboo subject, and vigorously suppress its expression.
False
Research has found that the timing of puberty can have effects on adolescents’ self-esteem and personality. Which of the following most accurately describes the effects of timing of puberty on girls and boys?
a. Early-maturing boys and early-maturing girls both show advantages to their self-esteem associated with maturing early.
b. Later-maturing boys and later-maturing girls both show disadvantages to their self-esteem associated with maturing later.
c. Early-maturing boys show disadvantages and early-maturing girls show advantages to their self-esteem associated with maturing earlier.
d. Early-maturing boys show advantages and early-maturing girls show disadvantages to their self-esteem associated with maturing earlier.
d. Early-maturing boys show advantages and early-maturing girls show disadvantages to their self-esteem associated with maturing earlier.
