Motor Development Exam 1

what is development?

the process of continuous sequential change to a specialized functional capacity

-related to, but not dependent on, age

cognitive development

the process of continuous sequential change to specialized functional capacity in the cognitive domain

social development

the process of continuous sequential change to specialized functional capacity in the social domain

motor development

the development of movement abilities as well as the factors underlying those changes (individual, environment, & task)

-continuous, age-related

motor learning

movement changes that are relatively permanent but related to experience or practice rather than age

motor behavior

an observable or measurable motoric action

-doesn't distinguish between motor learning or development; includes both

motor control

the nervous system's control of the muscles that permits skilled and coordinated movements

physical growth

a quantitative increase in size or magnitude

physiological maturation

progress toward physical maturity (optimal functional integration of a body's systems); qualitative advance in biological makeup

aging

the broad sense of growing older, regardless of chronological age; also refers to changes that lead to a loss of function and eventually death

what are Adolph and Hoch's four features of infant motor development that demonstrate the close relationship between motor development and psychology?

-embodied (generating forces)

-embedded (in the environment)

-enculturated (socially impacted)

-enabling (allows for advancement in motor, perception, & cognition)

newell's model of constraints

provides a framework to understand motor development. examines interactions between three factors: individual, environment, & task

constraints

limits or discourages some movements & permits or encourages other movements

-not negative/bad

individual constraints

a person's unique mental and physical characteristics (height, limb length, strength, motivation)

-structural or functional

-INTERNAL

structural constraint

relate to an individual's body structure (height, weight, muscle mass, etc)

functional constraints

relate to an individual's behavioral function (motivation, fear, experiences, attentional focus)

environmental constraints

constraints related to the world around us

-physical (temperature, amount of light, floor surface, etc.)

-sociocultural (football more likely to be gifted to a boy than a girl)

-EXTERNAL

task constraints

constraints that include the goals and rules of an activity, including equipment (having to dribble in basketball rather than carry the ball, using a strung racket rather than a wood paddle, etc.)

-EXTERNAL

modifier

an adaptation that may help overcome a negative constraint

developmental trajectory

The curve plotted in describing developmental change

arrested development

a failure to develop beyond a particular point of development

proficiency barrier

a hypothetical barrier used to describe a threshold; assumes that if the barrier is not crossed by a certain age, subsequent development would be difficult

mountain of motor development

Bottom to top ---

Reflexive: birth-2 weeks

Preadapted: 2 weeks-1yr

Fundamental Motor Patterns: 1-7yrs

Context-Specific: 7-11yrs

Skillful: 11+ yrs (after puberty)

longitudinal research study

a developmental study in which one group of participants is studied over a long time

-accurate, but takes a long time

cross-sectional research study

a developmental study in which change is inferred by observing multiple groups (of varying ages/stages) at one point in time

-can be done in a short amount of time, but does not observe ACTUAL change - just infers it

cohort

a group whose members share a common characteristic, such as age or experience

mixed-longitudinal/sequential study

a developmental study in which multiple mini-longitudinal studies are conducted with overlapping ages

-permits observation of an age span that is longer than the observation period (ex: age groups 4, 6, and 8 years of age are observed over 2 years)

meta analysis

integrates the effects observed in many studies into one more generalizable estimate of an effect

review paper

compares and contrasts many studies on a topic

universality versus variability

the idea that individuals in a species show great similarity in development, but individual differences also exist

maturational perspective

explains developmental change as a function of maturational processes (in particular, through the CNS). assumes that motor development is an internal or innate process driven by a biological time clock

Johnny and Jimmy Study

twin study testing the environmental factors on motor development in infants

-johnny received "training", while jimmy did not. results showed that johnny was advanced in certain skills but not others. therefore, were open to interpretation and did not help solve the nature-versus-nurture debate

what were the two descriptive methods of the maturational perspective?

normative descriptive & biomechanical descriptive

normative descriptive period

focused on identifying the quantitative, average ages at which children achieved specific developmental milestones

-prioritized the PRODUCTS (outcomes) of development rather than the processes that led to it

biomechanical descriptive period

focused on qualitative, sequential data about HOW children moved

-focused on the PROCESS of movement rather than the product

information processing theory

the view of behavior as mental operations (perception, information retrieval, memory, response selection) on sensations so that a response can be made

-compares the brain to a computer that takes in info and outputs movement

ecological perspective

stresses interrelationships between the individual, the environment, and the task

-considers the interaction of all constraints to understand the emergence of a motor skill

-two branches: dynamical systems and perception-action

when do maturationists feel that development ends? when do motor ecologists believe that development ends?

maturationists: believe that motor development ends at the end of puberty or at adulthood

motor ecologists: believe that motor development is a lifespan process

dynamical systems approach

an ecological viewpoint that believes that body systems spontaneously self-organize (not driven by CNS)

-coordinated behavior is "softly assembled" and flexible rather than hardwired

-ex: as you mature, your body is more suited to walk upright rather than crawl, which encourages you to choose walking as a means of movement

rate limiters

an individual constraint that holds back the emergence of a motor skill because it develops more slowly than other systems

-concept of the developmental systems approach

rate controller

a constraint that changes or ages more quickly than others. causes a loss of skills towards the end of life

-concept of the developmental systems approach

perception-action approach

an ecological viewpoint that the "perception" and "action" systems are related and evolve together

-movement is necessary to explore the environment and obtain information for further action

affordance

the function that an environmental object provides to an individual (related to the size and shape of the object and the individual)

-ex: a heavy baseball allows an adult, but not an infant, to throw it

body scaling

when an individual considers their own body proportions (intrinsic dimensions) when making movement decisions rather than extrinsic dimensions

-or, can refer to changing the dimensions of the environmental object to the structural constraints of the performer

is an embryo/fetus sensitive to extrinsic factors?

YES!!

-nutrients delivered via placenta/mother's circulation

-amniotic sac in uterus

-abnormal external pressure applied to mother's abdomen

-presence of viruses or drugs

embryonic development

conception-8weeks

-ovum & spermatozoon fuse

-cells differentiate into tissues/organs

-limbs formed at 4 weeks

-human form noticeable at 8 weeks

fetal development

8weeks-birth

-characterized by hyperplasia & hypertrophy

-growth is cephalocaudal and proximodistal

hyperplasia

an increase in the NUMBER of cells

hypertrophy

an increase in the SIZE of cells

cephalocaudal growth

growth begins at the head and extends to the lower body

proximodistal growth

growth begins centrally and moves outward toward the extremities

plasticity

the ability of a cell to take on a new function

how does a fetus receive nourishment?

via diffusion of the blood/O2/nutrients of the mother and baby in the placenta

congenital defects

anomalies present at birth, regardless of whether their causes are genetic or extrinsic

what are common causes of a congenital defect?

-dominant or recessive disorders

-gene mutation (alteration or deletion of a gene during the formation of an egg or sperm cell)

-teratogens (medications or chemicals)

-external or internal pressure on the infant

-extreme internal environmental temperature (hyperthermic or febrile mother)

teratogen

any drug or chemical agent that causes abnormal prenatal development

-ex: alcohol

why is lower socioeconomic status more likely to lead to lower weight babies?

a low SES-status mother may not be able to meet the nutrition needs of the fetus

-may also be at higher risk for illnesses and infections that may compromise birth weight

-less likely to receive prenatal care

sigmoid curve

describes the pattern of whole-body growth (rapid growth after birth, followed by gradual and steady during childhood, then by rapid growth during early adolescence, then finally leveling off)

-normal growth curve is always sigmoid, but timing may vary

age at takeoff

the age at which growth starts to increase

-average age 9 for girls; 11 for boys

how does weight growth compare to height growth?

weight is much more susceptible to extrinsic factors

physiological maturation

advance in the biochemical composition of body systems (not necessarily just an increase in size)

-leads to a state of full function

-size doesn't necessarily indicate maturity

secondary sex characteristics

appear during the adolescent growth spurt: female breasts and hips, male voice quality, and body hair

anthropometric measurements

measures of growth & size

"catch-up growth" phenomenon

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

-occurs once the negative extrinsic influence is removed

how does growth change in the 20s?

height plateaus; weight may increase due to lifestyle changes

Why might height decrease in older adulthood?

-compression of cartilage pads

-osteoporosis

why do people "grow up, then fill out"?

peak weight velocity follows peak height velocity (by 2.5-5 months in boys and 3.5-10.5 months in girls)

what extrinsic forces are most likely to affect growth during infancy? what about during the adolescent growth spurt?

infancy - nutrition, drug/substance exposure, illness

adolescence - nutrition, illness

how does the skeletal system develop?

begins as a cartilage model; ossification centers then develop and begin to form bone cells (around the fetal age of 2months)

primary ossification centers

areas where bone cells are FORMED; appear in the midportions of long bones

-ossification continues outward until the full bone is formed

secondary ossification centers

cartilaginous site of long bone growth/LENGTHENING; also called EPIPHYSEAL PLATES or growth plates

-on the ends of bones

appositional growth

growth in bone width; continuous throughout the lifetime

-occurs due to the addition of new tissue layers under the periosteum

traction epiphyses

Growth areas where muscle tendons attach to bones.

when does bone growth typically stop?

around age 18-19

-on avg, epiphyseal plates close earlier in girls than in boys

how does bone growth change throughout adulthood?

bone remodeling continues throughout the lifespan; as you age, your bone production fails to keep up with bone reabsorption (leading to more brittle bones)

osteoporosis

loss of bone density

what factors may lead to more significant losses of bone mass? what helps preserve it?

-hormonal: deficiency in estrogen (in post-menopausal women)

-diet: deficiency in calcium (also has an especially large effect in post-menopausal women)

preservation:

-physical activity

how do prenatal muscle cells grow? what about after birth?

prenatal: both by hyperplasia and hypertrophy

postnatal: muscle growth continues predominantly by hypertrophy

how do muscle cells increase in size?

both in diameter & length due to addition of sarcomeres

type 1 fibers

slow twitch; endurance activities

type IIa, IIx, and IIb fibers

-fast twitch; intense short duration activities

At what age is the muscle fiber distribution typically determined?

1

how does cardiac muscle develop?

heart and blood vessels grow to scale with the rest of the body

-prenatally: hypertrophy & hyperplasia

-postnatally: follows a sigmoid growth pattern

what happens to skeletal muscle mass with age? what about cardiac?

skeletal:

-decreases only ~10% between ages of 20-50

-decreases up to 50% by very old age

*number and size of fibers decrease

cardiac:

-heart may lose elasticity and valves can become more fibrotic

how does the adipose system develop PREnatally?

first appears in fetus ~3.5 months; increases rapidly during last 2 months, but still only accounts for ~0.5kg (14%) of body weight at birth

how does the adipose system develop during childhood/adolescence?

-increases rapidly until 6 months, then gradually until 8 years

-growth is by both hyperplasia and hypertrophy, with hypertrophy being more prominent in adolescence

-in adolescence, girls increase fat more dramatically than boys

internal fat

fat around the viscera (internal organs)

subcutaneous fat

fat under the skin

children have more _______ than _______ fat

internal; subcutaneous

-subcutaneous fat increases from ages 6-13 in boys and girls. then it continues to increase in girls, but decrease in boys

how does subcutaneous fat change in adulthood?

it increases in the trunk and decreases on the limbs

-abdominal fat is associated with a higher risk of cardiovascular disease

how does overall body mass change with old age? how does adipose tissue mass change?

overall body mass decreases (due to loss of bone & muscle), but body fat continues to increase

how does the endocrine system regulate prenatal growth?

the placenta produces its own hormones and serves as a barrier to prevent the mother's hormones from overloading the fetus's system

what are the 4 major hormones that regulate growth?

growth hormone, thyroid hormone, gonadal hormones (androgens & estrogen)

-excess or deficiency may alter growth

anabolism

tissue building

-stimulated by hormones

what role does insulin play in growth?

facilitates the uptake of glucose for carbohydrate metabolism

-indirect role in growth

growth hormone

secreted by the anterior pituitary gland; necessary for normal growth

thyroid hormones

secreted by the thyroid gland; influence whole-body growth

-one plays a role in skeletal growth

what are the two gonadal hormones? where are they individually secreted and what do they do?

androgens: secreted by testes (boys) and adrenal glands (boys/girls)

-promote epiphyseal growth plate closure

-promote muscle mass growth

estrogens: secreted by ovaries (girls) and adrenal cortex (boys/girls)

-promote epiphyseal plate closure

-promote accumulation of fat

how might aging impact the endocrine system?

-thyroid disorders are more common

-decreasing gonadal hormone levels cause loss of bone/muscle tissue

how do genetics and extrinsic factors interplay in the development of the nervous system?

genes direct development of the structure, but extrinsic factors fine-tune the connections