Psychology across the lifespan exam

Genes

units of hereditary information carried on chromosomes

chromosomes

strings of DNA

46 or 23 pairs

Alleles

possible varients of a particular gene

single gene pair inheritance

dominant and recessive gene allele

incomplete dominance

neither allele for a particular trait completely masks the other, resulting in a heterozygous phenotype that is a blend of the two homozygous phenotype

codominance

phenomenon in which two alleles are expressed to an equal degree within an organism

Sex linked inheritance

X and Y chromosome

Genetic abnormalities

changes in genes or chromosomes that result in abnormal DNA sequence and can cause genetic disorders or diseases

copy number variations

a person receives too many or too few copies of a stretch of DNA including mutation of whole genes

chromosomal abnormalities

occur when a child receives too many or too few chromosomes at conception

Behaviour genetic theory

• study of nature and nurture

• individual differences are due to both genetic differences between people and to differences in their environmental experiences

• gene envirinment interaction and correlation

Phenotype

apparent, observable, measurable characterisitic of the individual

Genotype

genetic composition of the individual seen as a latent unobservable characteristic

Behaviour genetic theory methods

variability

• heritability

• share environment

• nonshared environment

indirect quasi-experimental of adoption and twins

Adoption design

creates pairs of genetically related individuals who do not share a common family environment

Twin design

comparison of resemblance between monozygotic twin pairs and dizygotic twin pairs

Environmental influences behaviours genetic theory

shared and non shared

shared environment

makes children reared in the same family more similar than children reared in different families

Nonshared environmental effects

those aspects of the environment that make children in the same family different, e.g. birth order

Behaviour genetic theory major concepts

• heritability and environmentality are estimated variance components not measured effects

• not components and their estimates are not precise

• apply to a population not to one individual

If a trait is genetically influenced

• identical twins raised together = identical twins raised apart

• identical twins does not equal fraternal twins

• adopted child = biological parent

if trait is result of share environment

identical twins = fraternal twins

adopted parents = adopted children

Gene environment effects

the role of genetics in exposure to environments

passive gene environment correlations

parents heritable traits also influence the environment provided to their children

evocative gene environment correlations

an individuals genetically influenced behaviour or traits elicit a response from their environment

Active gene environment correlations

When individuals select or create environments that are consistent with their genetic traits niche picking

Genotype environment interaction

involves genetic sensitivity to environments refers to conditions in which genetically influenced characteristics mediate individual responsiveness to the encountered environment

Epigentic effects

environmental factors influence development by turning on or off genes. expression of genes is modified by the genes themselves

Prenatal development

• The germinal period (two weeks)

• The embryonic period (3-8 weeks)

• The foetal period (9 week until birth

Germinal period (2 weeks)

• fertilisation

• single cell zygote

• a blastocyst

• blastocyst attaches to the wall (implantation)

The embryonic period (3-8 weeks)

• An embryo - three layers ectoderm, mosederm heart arterys, endoderm

  • form different parts of the body

• ears, mouth, and throat take shape

• most structures and organs are present

• organogenesis

MOST CRITICAL

The foetal period (9 weeks until birth)

• Bone tissues emerges the embryo becomes a foetus

• heartbeet should be audible

• fingernails, toenails, hair and teeth buds and eyelashes grow

Brain development

Proliferation, migration, differentiation

Proliferation

rapid multiplication of neurons esspecially between 6-17 weeks after conception

Migration

nerve cells move to specific regions of the brain to become part of specialisied units

it is influenced by gentic instructions and the biochemical environment of the brain 8-15 weeks

differentiation

every neuron starts with the potential to become any specific neurons the progressive transformation of brain cells

first trimester

organ systems continue to grow

third month distinguishable external sex organs appear

second trimester

more refined activities

age of viability 24 weeks

third trimester

rapidly gains weight

Prenatal environment

• events can have lifelong effects in physical and mental development

• period of opportunity and vulnerability

• teratogens → any drug or disease of environmental agent that can harm a developing foetus

Perinatal environment

• stage 1 regular contractions of the uterus

  • cervix dilatation (10 cm)

  • average 9 hours first born

• stage 2

• Apgar test

  • heart

  • respiratory

  • muscle

  • colour

  • reflex irritability

• protective factors

  • personal resources

  • supportive postnatal environment -family and community based

Endocrine system

• Pituitary gland

• thyroid gland

• testes/ovaries

• hand in hand with the nervous system

Pituitary gland

• controlled by the hypothalamus

• produces growth hormones

• triggers release of hormones in other endocrine glands

Thyroid gland

• key role in physical growth and development

Testes

Endocrine system triggers the prenatal development of the testes

secrete testosterone

than trigger the growth

Ovaries

produce oestrogen and progesterone

Oestrogen

growth and secondary sexual characterisitic

Progesterone

bodily changes that allow conception

Nervous system

Neuron is a basic unit of the nervous

Myellenation

process of depositing fatty sheath around the neural axons to speed up transmission of neural impulses

rapid growth early on

Principles of growth

Cephalocaudal

proximodistal

orthogenetic

Cephalocaudal principle

growth occurs in a head to tail direction

proximodistal principle

growing and developing muscles from the centre outward to the extremities

Orthogentic principle

developent starts globally and unidifferentiated to increase differentiation and hieracal integration general to specific

life span developmental model of health

health is a state of complete physical, mental and social well being and no merely the absence of disease

Infants physical growth

grow in fits and starts gain on average 30 gram a day, 2.5 cm a months, at 2 they are half their potential adult size

Synaptogenesis

formulation of synapses the connections between neurons

Synaptic pruning

removal of unescessary synapses brain is highly adaptable

Newborn capabilities

Reflexes

functioning senses

a capacity to learn

organised, individualised patterns of walking and sleeping

already respond to their environment in adaptive ways

Reflexes

unlearnt responses

primitive, postural, locomotor

primitive reflexes

help for survival ad are controlled by the brain stem emerge at birth e.g. suck reflex

Postural reflexes

automatic responses to changes in body position and gravity, essential for developing balance and coordination and posture emerge after birth

locomotor reflexes

automatic movements that prepare them for future mobility apears after birth

Classification of infant states

• regular sleep

• irregular sleep

• drowsiness

• alert inactivity

• walking activity

• crying

Irregular or rapid eye movement sleep (REM)

• characterised by eyes darting beneath the eyelid, uneven heart rate, blood pressure, and breathing

Regular sleep (non-REM)

• characterised by almost motionless body, heart rate, breathing, and brain wave activity are slow and regular

Infant sleep

spend much time in irregular sleep a way the brain stimulates itself

Motor skills at birth

• sucking, looking, grasping, breathing, and crying

  • milestones emerge in a regular sequence

Motor skills

gross, fine, pincer grasp

Gross motor skills

involves large muscles and whole body or limb movement

fine motor skills

involves precise movements of hands and fingers or feet and toes

pincer grasp

thumb and another finger

Dynamic system perspective

• nature (maturation of the nervous system) and nurture (sensory and motor experience) are both essential and inseparable

• integration of action and though

• Voluntary movement softly assembled rather than hard wired

Dynamic system theory

• motor development takes place through a self organising process

  • C uses sensory feedback they receive when they try different movements to modify their motor behaviour (adaptive)

• the inherent mechanism that constrained the degrees of freedom in the infant to make walking possible

• preferred configuration of the cooperating muscles needed for walking changed as biological factors developed or as environmental conditions were altered

• walking on sand different to concrete

basic sensory neurological processes

• vision

• Vestibular system

  • internal stimuli

  • balance

  • situation our body is in

• Kinaesthesis

  • body limb position

Integrative perceptual process

• recognition of sensory information

• inter sensory matching

• crossmodal transfer

  • the ability to use knowledge from one sensory modality to perform tasks in another

• recognising with vision alone

cognitive processes

• memory

  • with age, children get better at remembering events after a delay

• Higher order processes and executive function

  • metacognition

    • internal voice

  • Executive function mental processes behind goal directed behaviour and self control

Cerebral cortex

largest brain structure, surrounds the rest of the brain

cortical regions develop as capacities emerge

• first year: auditory and visual; body movement areas

• Infancy through preschool: language areas

Prefrontal cortex

• responsible for compile thought

• functions more effectively from age 2 months on

Infant motor capabilities

• gains in basic gross motor skills

• Major physical accomplishments

  • many motor skills become more fluid and rhythmic accurate and faster

  • children can increasingly integrate multiple body movements

  • children learn to modify movements to adapt to changes in environment as well as changes in their own bodies as they grow bigger

  • children’s eye-hand coordination and control of the small muscles improve to allow more sophisticated use in their hands

Adolescent growth spurt

triggered by increase in growth hormones

Adrenarche

• period of increase production of adrenal hormones

  • starting around 6-8

  • precedes production of gonadal hormones associated with puberty

Menarche

females first menstrual period

Semanarche

a males first ejaculation

Early pubertal timing in adolescent girls

• early maturing

  • more likely to report body dissatisfaction

  • more likely to report psychosomatic symptoms

  • earlier puberty girls report higher levels of anxiety and depression than their peers

  • can alter girls social environment

• life maturing

  • do not seem to be at a disadvantage

Puberty in boys

• less understood in boys than girls

• three interrelated measurement issues

  • shortage of visible markers of boys maturation

    • could mask early maturation

  • many pubertal events lack a single gold standard measurement tool

    • e.g. pubertal hormones continue to rise long after the physical markers of puberty

  • there is no objective event in boys life as a proxy of pubertal timing

    • contrast with menarach as a discrete measurable life event

Adolescent brain

• inverted u shape pattern across adolescence for grey matter

  • increase synaptogenesis before puberty

  • followed by heightened pruning of synapses

• white matter: increase in a linear fashion

• Is there a link between adolescent risky behaviour and their brain development

• part of the brain that regulate self control has not yet matured

• has a greater need for reward seeking behaviour

  • nucleus accumbens

  • the neurons serving the frontal lobes are among the last to become myelinated

    • thinking without emotions

Sleep in the adolescent brain

• Changes in sleep patterns

• experience sleep phase delay

Young adult

• peek physical health

• minor changes in physical appearance

Middle age

• noticeable signs of ageing; wrinkles, hair grey and loss, extra weight

• some loss of physical functioning

Older age

• loss of weight (muscle and bone)

• Loss in physical/physiological function

Adult brain

• Capable of neurogenesis - the process of generating new neurons across the life span

• Brain can change in response to physical and mental exercise

• Brain weight and volume decrease over the adult years

• Neuron loss greater in areas that control sensory and motor activities

• both degeneration and plasticity

• scaffolding theory of ageing and compensation

  • brain may adapt to losses by reviving up in other areas

Sensation

process by which the sense organs pick up information from the environment and transmit it to the brain for initial process

Perception

the process by which the brain makes sense of these sensations (organises, interprets, recognises and identifies)

Nativist position

infant comes capable of perceiving forms and patterns

Empiricists

only through experience can the infant develop the ability to construct forms out of the pieces of visual information coming from the environment

Ethologist/Gibsonian position

the child’s environment is rich in information that can guide accurate perception

Cognitive position

thinking and reasoning affect perception