Unit 1 Part 1 My Version

Natue v Nurtue

are our human traits present at birth (nature) or do they develop through experience (nurture)

Evolutionary Psychology:

study of evolution of behavior & mind; uses principles of natural selection 

natural slection

Charles Darwin’s principle that inherited traits enable an organism to survive + reproduce in particular environment will most likely be passed onto succeeding generations

Behavior Genetics:

• study of relative power / limits of genetic + environmental influences on behavior (how genetics / environment influence behavior)

human nature

• Evolutionary psychologists use Darwin’s principle of natural selection to understand behavior + mental processes

• Organism’ varied offspring compete for survival --- mutation (random error in gene replication that leads to a change)

• Certain biological and behavioral variations increase organisms; reproductive & survival chances

• Offspring that survive more likely to pass on genes

Eugenics:

• aims to “eradicate” genetic defects & improve genetic makeup through selective human breeding 

Environment:

NONgenetic influence (i.e. prenatal nutrition, experiences of people and things around us)

Heredity:

genetic transfer of characteristics from parent → offspring; Ex: 2 people may have gene for high intelligence level, but individual with lack of stimulation to academically excel may not reach full potential, while individual constantly motivated intellectual will be more likely to intellectually excel

• Genes:

• biochemical units of heredity

genome

• entire set of DNA / genetic information found in organism 

  • humans + chimps ~96% the same genetically

twin & adoption studies

1of ways to study nature v nurture argument

Identical (monozygotic) twins:

individuals who developed from 1 fertilized egg that split in 2, creating 2 genetically identical organisms; may not always have equal number copies of genes repeated in genome

Fraternal (dizygotic) twins:

individuals who developed from separate fertilized eggs; genetically no closer than ordinary siblings but shared prenatal environment

Twin studies:

allow researchers to examine role of genes in development of trait or disorder; comparisons between monozygotic twins & dizygotic twins conducted to evaluate degree of genetic + environmental influence on specific trait

• Studies have shown that environment shared by a family’s children has little impact on their personality--- just because you’re raised in same environment does not mean you will have similar personality as your parents/siblings

Interaction:

interplay that occurs when effect of 1 factor (environment) depends on another factor (heredity)

Example: If you walk all summer barefoot your feet will become more callused. Your friend wears shoes and is tender-footed ---biological adaptation to environmental changes

Epigenetics:

study of molecular mechanisms by which environments can influence genetic expression

Example: If a child is sleep deprived or nutritionally deprived they might not reach their biological/genetic height

Nervous System:

body’s speedy electrochemical communication network, consisting of all nerve cells of peripheral & central nervous system

• Central nervous system (CNS):

• brain, spinal cord

Peripheral nervous system (PNS):

sensory & motor neurons connecting CNS to rest of body

Nerves:

bundle of axons that form neural cables connecting CNS with muscles, glands, sensory organs

Sensory (afferent) neurons:

carry incoming information from body’s tissues and sensory receptors to brain, spinal cord

Motor (efferent) neurons:

carry outgoing information from brain, spinal cord to muscles and glands

Interneurons:

within brain, spinal cord; communicate internally & process information between sensory inputs and motor outputs

Autonomic Nervous System:

division of PNS that controls glands, muscles of internal organs; involuntary (without conscious thought) — heart beating, lungs breathing

Sympathetic Nervous System:

division of

autonomic nervous system that arouses

body, mobilizing its energy; “fight or flight”

Parasympathetic Nervous System:

division of autonomic nervous system that calms body, conserving its energy; “rest and digest”; brings cody back to homeostasis

Somatic Nervous System (AKA Skeletal Nervous System):

division of PNS that controls body’s skeletal muscles

Brain:

controls most of 5 functions of body, including awareness, movement, thinking, speech, 5 senses

Spinal cord:

extension of brain; carries messages to / from brain to rest of body

Reflex:

simple, automatic response to sensory stimulus; Ex: knee-jerk stimulus

Neuron:

nerve cell; basic building block of nervous system

cell body

contains cell nucleus

dendrites

receive messages from terminal branches of sending neuron

Glial cells (“glue of Nervous System”): t

type of cell that provides physical + chemical support to neurons & maintains their environment

Multiple Sclerosis

Autoimmune disorder; body’s immune system attacks + destroys myelin sheath of neurons → disrupts signals nerves send to body; diminishes muscle control, can impair cognition

Myasthenia Gravis

Progressive autoimmune disease; body produces antibodies against / attacks acetylcholine receptors at neuromuscular junctions (connection point between motor neuron + muscle fiber); symptoms = muscle weakness in eyes, mouth, throat, limbs

Action potential:

neural impulse; brief electrical charge that travels down axon (neurotransmitter transported from dendrites → terminal branches of axon → next neuron); will only be generated when excitatory impulses > inhibitory impulses

threshols

level of stimulation required to trigger action potential

refractory period

brief resting pause after neuron has fired / initiated action potential (more difficult / impossible for neuron to produce another action potential during this time); subsequent action potentials cannot occur until axon returns to resting state; neuron cannot “re-fire” until it reaches refractory period; prevents action potential from happening too quickly again + signal moving backwards

all-or-nothing response

neuron’s reaction of either firing or not firing depending on whether threshold is met (no partial responses); for a certain neuron, action potential stays the same regardless of strength of stimulus

synapse

•  (a.k.a. Synaptic gap, synaptic cleft): junction between axon tip of sending neuron + dendrite / cell body of receiving neuron 

neurotranmsitters

chemical messengers that cross synaptic gap between neurons; released by sending neuron → neurotransmitters travel across synapse → bind to receptor sites of receiving neuron (influence whether receiving neuron will generate a neural impulse)

reuptake

neurotransmitters reabsorption by sending / presynaptic neuron (prevent accumulation of neurotransmitters in synapse → excessive / prolonged stimulation of postsynaptic neuron, terminates signaling by neurotransmitter once signal has been transmitted to postsynaptic neuron, allows neurons to recycle neurotransmitters)

Acetylcholine

excites skeletal muscles; inhibits heart action; memory

• malfunction: Alzheimer’s disease

dopamine

movement; learning: attention; motivation, reward

Parkinson's disease (too little); Schizophrenia (too much); Substance abuse

s

serotonin

sleep; arousal / alertness; mood; eating; pain perception

Depression; Obsessive Compulsive Disorder; Some eating disorders; Chronic pain

Norepinephrine

sleep; arousal / alertness; mood

Depression

GABA

chief inhibitor; regulates arousal / alertness

some anxiety disorders; some seizure disorders

g;utamate

chief excitatory neurotransmitter;

many diverse functions

Neural death following head injuries

endorphines

pain suppression

Some indication of link to mood

substance p

carries pain signals

Some indication of a link to depression

Agonist:

molecule that ↑ action of neurotransmitter; usually has very similar structure to neurotransmitter allowing it to mimic actions of neurotransmitter by binding to specific brain receptors

Ex: morphine binds to neurons to heighten pleasure / decrease pain

Antagonist:

molecule that inhibits or blocks action of neurotransmitter

Ex: memantine blocks glutamate receptors in brain, helping reduce excitotoxicity (neuronal damage; associated with neurodegenerative diseases)

endocrine system

• Body’s “slow” chemical communication system; set of glands, fat tissue that secrete hormones into bloodstream

hormones

chemical messengers manufactured by endocrine glands that travel through bloodstream + affect other tissues

hypothalamus

• secretes hormones that stimulate / suppress release of hormones in pituitary gland

arenaline

hormone / neurotransmitter secreted by adrenal glands typically during stressful, exciting, or highly emotional situations

leptin

hormone released by fat cells; works together with ghrelin to regulate appetite

Ghrelin

hormone produced primarily by gastrointestinal tract; helps to regulate appetite

Melatonin

hormone released primarily by brain’s pineal

gland; regulates body’s sleep-wake cycle

Oxytocin

produced by hypothalamus, released by pituitary gland; known as “love hormone”; plays key role in socializing, romantic relationships, parent-child bonding

Psychoactive Drug:

chemical substance that alters brain, causing changes in perceptions + moods (i.e. seeing things that aren’t there, hearing things that aren’t there, distance / depth perception)

Substance Use Disorder:

disorder characterized by continued substance use despite resulting life disruption; Ex: someone who continuously uses alcohol even if it may cost them their family, job, money etc.

Near-death experience:

altered state of consciousness reported after “close brush with death”; often similar to drug-induced hallucination

Tolerance:

diminishing effect with regular use of same dose of drug → forces user to UP DOSAGE in order to experience drug’s effect; can also be built up with medication

Addiction:

compulsive substance use that continues despite harmful consequences; considered psychological disorder

Withdraw:

discomfort and distress that follows discontinuing an addictive drug / behavior; physical / psychological symptoms after coming off a drug

Depressants:

drugs that reduce neural activity and slow body functions

Alcohol

Initial high followed by relaxation + disinhibition; may not be able to do certain things after using

Depression, memory loss, organ damage, impaired reactions

Barbiturates (tranquilizers)

Reduce anxiety, can be used to help other disorders

Depress NS activity, can be prescribed to induce sleep / reduce anxiety, in large doses can impair memory & judgment

Opiates (Heroin)

Rush of euphoria, relief from pain, mimics effects of endorphins / norepinephrine

Depressed physiology, slows down NS (slower cognitively, reduced memory), agonizing withdrawal once you come off it & don’t have another supply