AP Psychology Unit 1 pt. 1

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Evolutionary psychology

the study of the evolution of behavior and the mind, using principles of natural selection
Applies Darwins principles of natural selection

• changes in genetics to match environment

HOW ARE WE ALIKE

Mutation

a random error in gene replication that leads to a change

Naturally occurring selection

Historical genes give us a great capacity to learn and adapt in varied environments
adaptive flexibility contributes to fitness

• biologically prepared for a world that no longer exists

Behavioural genetics

The study of the relative power and limits of genetic and environmental influences on behaviour
Heredity: genetic transfer from parent to offspring
vs
Environment: every non-genetic influence, from prevatal nutrition to the people and things around us

HOW DO WE INDIVIDUALLY DIFFER

The human genome

• Many more similarities than there are differences in human genetics -> ~95% of genetic variation exists within populations

• developed over natural selection
  -genetics predispose to particular behaviour

Monozygotic twins

A single fertilized egg splits in 2 -> 2 genetically identical organisms

identical twins

Dizygotic twins

Seperate fertilized eggs share maternal prenatal environment, but no more alike than normal siblings

fraternal twins

Twin study

A study in which the behavioral similarity of identical twins is compared with the behavioral similarity of fraternal twins.

Adoption study

analysis of how traits vary in individuals raised apart from their biological relatives

• creates 2 types of relatives (biological, environmental) -> find that environment shared by a family's children has virtually no discernible impact on their personalities

Gene-environment interaction

Seeking to discover how genes + environment interact to predict physical/mental health outcomes

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change

-Genes can be active (expressed) or inactive
-> study the molecular mechanisms by which environments can trigger/block genetic expression

Epigenetic marks

chemical modifications to DNA that can turn genes on or off

• created by experiences

-> possible mechanism to explain life-long effects of environmental factors (childhood trauma, poverty, malnutrition, etc.)

Nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

• made up of neurons that communicate using neurotransmitters

Nerves

bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs

types:

• sensory neurons (in to the CNS)

• motor neurons (out from the CNS)

• interneurons (connecting)

Central nervous system (CNS)

Brain, spinal cord

• coordinate incoming sensory messages, outgoing motor messages

Brain: neurons cluster to form neural networks
Spinal cord: controls reflec pathways in the reflex arc

Reflex arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.

eg. Immediately dropping a hot pan out of reflex

Peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

2 components:

• somatic nervous system

• autonomic nervous system

Somatic nervous system

Voluntary skeletal muscle control

Autonomic nervous system

Involuntary control of glands + muscles of internal organs

Sympathetic:

• Arouses body, mobilize energy

• pupils dilate, heartbeat accelerates

• digestions inhibited, bladder relaxes

• adrenal glands -> epinephrine, norepinephrine
  FIGHT, FLIGHT, FREEZE

Parasympathetic:

• Calms body, conserving energy

• pupils contract, heartbeat slows

• digestion stimulates, bladder contracts
  REST, DIGEST

Neuron

a nerve cell; the basic building block of the nervous system

parts:

• cell body (soma)

• axon

• dendrites

• terminal branch of axon

• myelin sheath

Cell body (soma)

contains the nucleus (genetic info, direct protein synthesis) and other parts of the cell needed to sustain its life

Dendrites

Branchlike parts of a neuron that are specialized to receive information, conducting impulses toward cell body

Axon

Attached to cell body
Neuron extension that passes messages through to other neurons, glands, muscles

Myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons

• enables vastly greater transmission speed of neural impulses

• provides insulation to prevent impulse from interfering with others

• MYELINATION

Myelination

the formation of a fatty sheath around the axons of a neuron

• not complete until age 25

• behaviour, movement, thought

• deterioration -> motor impairments (multiple sclerosis)

Terminal Branches

Ends of axon that hold synaptic vesicles that store neurotransmitters

• communication across synapse

Glial cells

cells in the nervous system that support, nourish, and protect neurons

• learning, memory, thinking

Resting potential

The resting state of the neuron

• charge is more positive outside the membrane and more negative inside

Neural Signals

Excitatory signal : signals trigger actions (gas pedal)
Inhibitory signal : signals depress action (brake pedal)

when excitatory impulses outnumber inhibitory impulses, the THRESHOLD has been reached -> ACTION POTENTIAL occurs

Threshold

the level of stimulation required to trigger a neural impulse

• neurotransmitters recieved by dendrites build up to initiate action potential

All-or-none response

a neuron's reaction of either firing (with a full-strength response) or not firing.

eg. gun -> squeezing trigger harder wont make bullet go faster

Action potential

1. first section of semipermeable axon opens once threshold met -> positive (Na+) ions flood in to balance internal negative charge

2. leads to depolarization

3. depolarization changes electrical charge of next part of axon -> gates in second area open, more Na+ ions flood in.

4. Gates open in first part of axon allowing positive (K+) ions to flow out -> repolarizes section

DEPOLARIZATION (action potential) -> REPOLARIZATION

Refractory period

a period of inactivity after a neuron has fired -> action potentials cannot occur until axon returns to resting state, only then can the neuron fire again

• reestablishing negative charge inside

REPOLARIZATION

Neuron communication

Sending neuron releases neurotransmitters across a synapse to receiving neuron

• action potential reaches axon's terminal branch -> stimulates release of neurotransmitters
• cross synaptic gap to bind to receptor sites of other neuron -> will either excite/inhibit new action potential

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

tiny gap at this junction -> synaptic gap/synaptic cleft

Neurotransmitter

chemical messengers that cross the synaptic gaps between neurons

• bind to receptor sites on receiving neuron -> influence whether that neuron will generate neural impulse

Reuptake

a neurotransmitter's reabsorption by the sending neuron

• SSRI's (selective serotonin reuptake inhibitors) are antidepressants -> relieve depression by blocking reuptake of serotonin

Acetylcholine (ACh)

FUNCTION:

• enables learning and memory
• acts as a messenger between motor neurons and skeletal muscles (released = contracts, blocked = cannot contract, paralyzed)

MALFUNCTIONS:

• Alzheimer's -> ACh-producing neurons deteriorate
• MYASTHENIA GRAVIS = neuromuscular disorder in which body produces antibodies against ACh receptors = fatigued muscles, temporary paralysis

Dopamine

FUNCTION:

• Movement, learning, attention, emotion

MALFUNCTIONS:

• Oversupply = schizophrenia
• Undersupply = tremors, decreased mobility in Parkinson's disease

Serotonin

FUNCTION:

• mood, hunger, sleep, arousal

MALFUNCTION

• Undersupply: depression

Norepinephrine

FUNCTION:

• Control alertness and arousal

MALFUNCTIONS:

• Undersupply = depress mood

BOTH A HORMONE AND A NEUROTRANSMITTER

GABA (gamma-aminobutyric acid)

FUNCTION:

• major inhibitory neurotransmitter

MALFUNCTION:

• undersupply linked to seizures, tremors, and insomnia

Glutamate

FUNCTION:

• excitatory neurotransmitter

MALFUNCTION:

• Undersupply = overstimulate brain, migraines, seizures

Endorphins

"morphine within"--natural, opiatelike neurotransmitters

FUNCTION:

• linked to pain control and to pleasure.

MALFUNCTION:

• Oversupply = (opiod drugs) suppress body's natural endorphin supply

Substance P

FUNCTION:

• Pain perception, immune response

MALFUNCTION:

• Oversupply = chronic pain

Agonists

Increases neurotransmitters action

• increase production of neurotransmitters
• increase release of neurotransmitters
• block reuptake
• similar enough to neurotransmitters to bind to receptor + mimic its effects

Antagonists

drugs that block the function of a neurotransmitter

• block production of neurotransmitters
• block release of neurotransmitters

Endocrine system

the body's "slow" chemical communication system

• a set of glands that secrete hormones into the bloodstream

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues

eg. adrenaline, melatonin

Adrenaline

A hormone released into the bloodstream in response to physical or mental stress

• increases heart rate, blood pressure, blood sugar (part of parasympathetic response)

Melatonin

• regulate sleep-wake cycle

• influence body's circadian rhythm

adrenal glands

a pair of endocrine glands that sit just above the kidneys

• secrete epinephrine and norepinephrine that help arouse the body in times of stress when sympathetic nervous system is activated

Pituitary gland

The endocrine system's most influential gland.

• Under the influence of the hypothalamus

• regulates growth and controls other endocrine glands.

• part of CNA and endocrine system

Psychoactive drugs

Chemical substances that effect consciousness by altering perceptions and mood

1. Depressants (downers -> calm neural activity, slow body functions
2. Stimulants (uppers) -> temporarily excite neural activity, arouse body functions
3. Hallucinogens -> distort perceptions, evoke sensory images in absense of sensory input

Tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect

• experience neuro-adaptation (brain's counteracting disruption to normal functioning)

Withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug

• symptoms : physiological, behavioural, cognitive manifestations

Substance use disorder

continued substance craving and use despite significant life disruption and/or physical risk (addiction)

addiction: diminished control + social functioning, hazardous use, drug action (tolerance/withdrawal)

• despite adverse consequence, ppl want the drug more than they like the drug

Depressants

• Calm neural activity
• slow bodily functions

Alcohol, opiods

Alcohol

Depressant
Slows brains activity -> judgement, inhibitions, memory, processing of experiences, reduces self awareness, decreases sexual inhibitions

• Brain shrinkage with alcohol use disorder

Opiods

Opium + derivatives

• Morphine, heroin depress neural functioning
  pupils constrict, breathing slows, lethargic, lessens pain (does not last long and effects are worse)

Repeated use -> brain stops producing its own endorphines (morphine within) -> withdrawal can be VERY severe, may cause death

Stimulants

Speed up body functions

• increase heart + breathing rates, pupils dilate, appetite diminishes, energy increases, self confidence increases
• can be addictive, withdrawal symptoms severe
• to stay awake, lose weight, boost mood/athletic performance

1. Nicotine
2. Caffeine
3. Amphetamines
4. Cocaine
5. Methamphetamine

Nicotine

a stimulating and highly addictive psychoactive drug in tobacco

• reaches brain within 7 seconds, faster than heroin
• signals to CNS to release flood of neurotransmitters

Cocaine

a powerful and addictive stimulant, derived from the coca plant, producing temporarily increased alertness and euphoria

• enters bloodstream quickly -> rush of euphoria that depletes dopamine, serotonin, norepinephrine
• crash follows

Hallucinogens

psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

• LSD (Lysergic Acid Diethylamide) -synthetic
• MDMA (ecstasy) -synthetic
• Acid
  -Marijuana
• Ketamine (valium)

Marijuana (cannabis)

Mild hallucinogen -> amplifies sensitivity to colours, sounds, taste, smell

• relaxes, disinhibits, may produce euphoric high

leaves + flowers contain THC (delta-9-tetrahydrocannabinol) -> psychoactive ingredient

• hallucinations, delusions, anxiety

Cerebrum

• 2 central hemispheres in forebrain
• covered by cerebral cortex

Cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

• tightly packed wrinkles to increase surface area = more nerve cells, synaptic connections

lobes: (deep grooves)

1. frontal
2. temporal
3. parietal
4. occipital

Frontal lobes

• linguistic processing
• muscle movements
• higher-order thinking
• executive functioning

Parietal lobes

Receives, processes sensory input (touch, body position)

Temporal lobes

Auditory information
Language processing

Occipital lobes

visual information from opposite visual field

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

• integration (sensory info integration)
• perception (analyze sensory info)
• memory/learning (storage/retrieval of memories, acquiring new ones)
• language (speech, reading, writing)
• decision making (higher-level cognitive process)

cannot be neatly mapped

Motor cortex

an area at the rear of the frontal lobes that controls voluntary movements

Somatosensory cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Visual cortex

The visual processing areas of cortex in the occipital and temporal lobes.
receives info from eyes

Auditory cortex

Receives info from ears

Wernicke's area

a brain area involved in language comprehension and expression

• usually in the left temporal lobe

Broca's area

Controls language expression

• left frontal lobe

Functional connectivity

Communication among distinct brain areas + neural networks

• social skills, language, memory come from functional connectivity

• lack functional connectivity = more prone to mental disorders

Lateralization

left and right hemispheres have different functions

left:

• reading, writing, speaking, math

right: ("minor" right hemisphere)

• emotion

Split brain

Corpus callosum (connects left/right hemispheres) severed

• cross transference does not occur

Split brain research

-study of patients with severed corpus callosum
-involves sending messages to only one side of the brain
-demonstrates right and left brain specialization

HE . ART

• ART = right visual field -> left hemisphere w/ Broca's and Wernicke's area
  -> can VERBALIZE it

• HE = left visual field -> right hemisphere
  -> can DRAW it
  -> after they draw it out, they can verbalize it

Forebrain

The largest and most complicated region of the brain, includes:

• thalamus

• hypothalamus

• limbic system

• cerebrum.

Midbrain

Connect brainstem + cerebellum to cortex

Hindbrain

medulla, pons, cerebellum, reticular formation

Brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull

• responsible for automatic survival functions (very basic)

MEDULLA, PONS

Medulla

Base of spinal cord

• controls breathing, heartbeat (BASIC)
• can sustain life alone w/o higher brain functions

Pons

Just above medulla

• sleep/wake cycle

• coordinate movement

• relay sensory input

Reticular formation

Nerve network that travels through brainstem into the thalamus

• regulates level of consciousness

• filters incoming sensory input

Thalamus

Sensory control center

• top of the brainstem

• transmits incoming/outgoing sensory info for all senses EXCLUDING SMELL

Cerebellum

A large structure of the hindbrain that controls fine motor skills.

• rear of the brainstem

• movement + balance

• nonverbal learning, memory

Amygdala

2 almond shaped neural clusters in limbic system

• emotion

• memory (link emotion to memory)

• aggression, fear

Limbic system

Neural system located mostly in forebrain, below cerebral hemispheres

• emotions, drives

AMYGDALA
HYPOTHALAMUS
THALAMUS
HIPPOCAMPUS
PITUITARY GLAND

Hypothalamus

Below the halamus (hypo)

• eating, drinking, body temp
• emotion + reward
• govern endocrine system via pituitary gland

part of BOTH endocrine and nervous system

Hippocampus

A neural center located in the limbic system that helps process explicit (conscious) memories for storage.

Corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them