Biological Bases of Behavior- AP PSYCHOLOGY UNIT 1

covers all 6 topics for unit 1 of AP psychology

Nature

Belief that heredity is a influential factor in the behavior and traits of a person

Nurture

belief that the environment (external factors) are what influences the behavior and the traits of a person.

Genetic predisposition

belief that some people are better at certain things because of their genetics. 

evolutionary perspective

explains behavior by looking at how natural selection and adaptation over time shaped mental processes to increase survival and reproduction. 

natural selection

process whereby organisms better adapted to their environment tend to survive and produce more offspring

which are examples of the evolutionary perspective?

fear of snakes and darkness (development of phobias)

Eugenics 

a discriminatory approach that uses genetic quality of human populations to support reproduction of certain individuals and discourage reproduction of those with “undesirable” traits. 

Twin studies

research method that compares identical twins to fraternal twins to see contributions of nature vs nurture to specific traits.

Family Studies

examining family members/dynamics to see how genetic inheritance and family environment interact to shape an individual

Adoption studies 

child is compared to adoptive/biological parents to see whether nature or nurture has a bigger effect on the childs behaviors and traits.

Central Nervous System (CNS)

• brain and spinal cord

• integrates information, processing sensory information

• spine connects the brain to the rest of the body

PNS (Peripheral Nervous System)

• consists of nerves that branch from CNS

• communication network that connects CNS to the rest of the body

Somatic Nervous System

• part of the PNS (Peripheral Nervous System) 

• includes skeletal muscle movements and the five senses 

• ex. going biking

Autonomic Nervous System

• part of the PNS (Peripheral Nervous System)

• controls involuntary activities like breathing and heart beating

• helps maintain homeostasis

Sympathetic Division

• part of the Autonomic Nervous System

• “fight or flight response”

• gets your body mobilized and ready for action

• heart beats faster, pupils dilate, increased breathing

Parasympathetic Division

• part of the Autonomic Nervous System

• “rest and digest”

• slows heartbeat, increases digestion, focus on saving and storing energy 

where is the Sympathetic Division in the nervous system?

Autonomic Nervous System, PNS

cell body/ soma

contains the nucleus, cytoplasm, and organelles

dendrites

branch like extensions that extend from the cell body

• receive incoming signals from the terminal branch of the dendrite (neurotransmitters) from other dendrites

• conduct electrical messages toward the cell body

• more dendrites = more ability to receive information

Axon

a long thin fiber that extends from the cell body, can be over a meter long in humans.

• Carries electrical impulses (action potentials) away from the cell body to other neurons, muscles, or glands.

• Often covered by a myelin sheath (a fatty layer made by Schwann cells or oligodendrocytes).

synapse

the place at which neurotransmitters are received - receptor sites on the dendrite of receiving neurons

neurons

Fundamental cells of the nervous system - responsible for processing, receiving, and transmitting signals through electrical and chemical signals.

afferent / sensory neurons

send signals from sensory receptors to the CNS

efferent / motor neurons

sends signals from the CNS to the peripheral nervous system

interneurons

neurons within the CNS that communicate INTERNALLY/ process information. 

Glial Cells

cells in the nervous system that support, nourish, and protect neurons and play a role in thinking, learning, and memory. more glial cells = better neurons

reflex arcs

involuntary, rapid response to a stimulus without direct brain involvement. basically, the pathway between the stimulus and brain is shortened. You act as soon as the information reaches your spinal cord, and process it only after it reaches your brain

which are examples of a reflex arc?

retracting a hand from a hot burner 

neural transmission

how neurons communicate- passing a signal across the synapse- a small gap between neural cells

resting potential

a neurons stable, electrically charged state when its not actually transmitting a signal.

action potential

brief, rapid electrical charge/ neural impulse that transmits information down a neuron’s axon, allowing for communication between neurons

threshold

minimum amount of stimulation required for a neuron to fire and send an action potential

depolarization

caused by an action potential, starts w/ depolarization, positive sodium ions flood into the neuron, making the inside of the cell more positive. this allows for an electrical charge to move along an axon.

all-or-nothing principle

neurons will only fire if the threshold is met.

refractory period

after a neuron fires a signal, brief period in which the neurons wait before firing again.

neurotransmitters 

chemical messengers which send messages through the nervous system.

reuptake

process where a pre-synaptic neuron reabsorbs neurotransmitters from the synaptic gap after they have been released to transmit a signal.

multiple sclerosis

when the myelin sheath is damaged, resulting in the disruption of the transmission of electrical signals, which can lead to muscle weakness, coordination problems, and fatigue.

Myasthenia gravis

affects communication between the nerve and the muscle. anitbodies block or destroy acetylcholine receptors preventing muscle contraction and causing muscle weakness and fatigue.

neurotransmitter

chemical signals in the nervous system that is used to relay information

excitatory neurotransmitters

increase likelihood that a neuron will fire an action potential ( electrical signal )

inhibhitory neurotransmitter 

decrease the likelihood that a neuron will fire a action potential

where are the actual systems that neurotransmitters and hormones lie in the body?

neurotransmitters: nervous system

Hormones: endocrine system

Hormones

chemical messenger released by endocrine glands

adrenaline 

hormone, helps with the body’s response to high emotional situations and helps form memories, expands air passages, redistributes blood, involved in fight or flight response 

leptin

hormone, helps balance energy by inhibhiting hunger

ghrelin

hormone, often called the hunger hormone because it increases appetite and promotes the release of growth hormones

melatonin

hormone, regulates sleep- wake cycles and circadian rhythm

Oxytocin

love hormone, causes feelings of affection

Agonist

drug or substance that binds to a receptor and causes it to activate

agonist

a drug or substance that blocks a receptor and prevents the natural substance from being an agonist

reuptake inhibhitors

drug that prevents the reuptake of a neurotransmitter from the synpatic cleft back into the pre synaptic neuron

acetylcholine 

Function: enables muscle action, learning, and helps with memory

effect of deficit: 

• memory problems 

• Alzheimers like symptoms 

• Muscle weaknesses

effect of surplus:

• muscle spasms 

• excessive salivation 

• depression

Dopamine

Function: movement, learning, attention, emotion

effect of deficit:

• parkinsons disease

• poor focus

• low motivation

• depression

effect of surplus:

• schizophrenia

• impulsivity

• addiction

• hallucinations

Serotonin

Function:

Impacts hunger, sleep, arousal, mood

effect of deficit:

• depression

• anxiety

• sleep issues

• OCD

effect of surplus:

• serotonin syndrome (confusion, sweating, tremors)

Norepinephrine 

Function:

increases blood pressure, heart rate, alertness, flight/fight response 

effect of deficit:

• depression

• low energy 

• lack of focus

effect of surplus:

• mania

• anxiety 

• high blood pressure 

GABA

Function:

helps with sleep, movement, slows down nervous system

effect of deficit:

• anxiety

• seizures

• tremors

• insomnia

effect of surplus:

• excessive sedation 

• impacted memory

• sleepiness

endorphins

Function:

helps with pain control and impacts individuals pain tolerance

effect of deficit:

• increased pain sensitivity

• sadness

• low stress tolerance

effect of surplus:

• insensitivity to pain

• euphoria

• risk of addiction

Substance P

Function:

helps with transmitting pain signals from sensory nerves to the CNS

effect of deficit:

• Reduced pain perception

• numbness

effect of surplus:

• excess pain perception

• chronic pain syndromes

Glutamate

Function:

helps with long term memory and learning

effect of deficit:

• poor memory 

• psychosis risk

• low synaptic plasticity 

effect of surplus:

• excitotoxicity (neuron death) 

• migraines

• seizures

psychoactive drugs

psychoactive substances that purposefully alter an individuals perception, concious, and mood

stimulants 

excite and promote neural activity - gives energy, decreases appetite, causes irritability

Depressants

reduce neural activity - causing drowsiness, muscle relaxation, lowered breathing, and if abused, death

Hallucinogens

drugs that cause and individual to sense things that are not actually there

Opiods 

functions as a depressant but has its own category because it is more addictive in nature. 

cocaine

• stimulant, causes euphoria and energy boost, increases heart rate, dilates pupils and causes heightened perception.

• cocaine impacts dopamine, and acts as a reuptake inhibhitor which forces dopamine to remain in the synaptic cleft and bind over and over again

Alcohol

• depressant

• enchances GABA, which slows brain activity and surpresses glutamate that keeps you awake, also increases dopamine

• Impacts the

a) prefrontal cortex: decision making, impulse control

b) amygdala: emotional regulation

Marijuana 

• hallucinogen 

• causes Euphoria, blloodshot eyes, reduced coordination, hallucinations

Heroin

• endorphins- mimics endorphins and binds to receptors to increase pain relief and suppress pain signals before they reach higher brain centers

• tolerance, dependence, reduced endorphin functions

tolerance 

as you consume more of a drug more often, you need a higher quantity of the drug to acheive the same effect. 

addiction

craving or dependence on a drug

withdrawal

craving the drug after stopping using it.

Brainstem

• handles all the basic functions a person needs to survive

• sends information between the brain and the rest of the body

Medulla

• bottom of brainstem

• control center for vital involuntary functions

Reticular Formation (RAS)

• network of nerve pathways that extends through the brainstem

• regulates wakefulness, consciousness, and attention

• acts as a filter for sensory information

• arouses the brain and maintains alertness

cerebellum

• hindbrains “little brain” 

• smooth coordination, precision, accurate timing, 

• helps with balance, posture, and motor learning

limbic system

• group of structures within the brain involved in emotion, memory, and motivation

• emotional brain

thalamus

• sensory control center

• directs messages to sensory receiving areas and transmits replies to cerebellum and medulla

• DOESNT INCLUDE SMELL

Hypothalamus 

• directs maintenance activities (eating, drinking, body temp) 

• governs endocrine system

pituitary gland

controls other glands and regulates natural bodily functions

hippocampus

a neural center in the limbic system that processes CONCIOUS memories

amygdala 

• helps process emotions 

• forming vivid, emotion charged memories

Cerebral cortex

• outermost layer of the brain

• divided into frontal, parietal, occipital, and temporal loves

• what gives us our HUMAN cognitive abilities

Corpus callosum

large band of neural fibers connecting both brain hemisphered and exchanging messages between them

occipital lobes

portion of cerebral cortex at back of head 

recieves information from visual fields 

temporal lobes 

includes auditory areas, and enables language processing

parietal lobes

recieves sensory input for touch and body positions

somatosensory cortex

• in parietal lobes

• registers body touch, and movement sensations

wernicke’s area

language processing and memory processing

frontal lobes 

• linguistic processing, muscle movements, higher order thinking, executive function

motor cortex

• in frontal lobe

• controls voluntary movement

Broca’s area

• in frontal lobe

• Speech PRODUCTION/ motor planning for speech