Biology and Behavior/Sensation and Perception/Consciousness

dendrites

fiber-like cells that come out of the cell body; take information and pass it on to the soma (cell body)
[part of neuron]

cell body

provides the energy for the nerve cell and houses the nucleus; power plant

axon

carries information away from the cell; consists of myelin sheaths, nodes of Ranvier, and Schwann's cells

myelin sheath

acts as insulation; allows signal to run fast and uninterrupted from cell body to axon terminals; protects axon from damage; each bubble has a cell called Schwann's cell

node of Ranvier

where action potential occurs; in between two myelin sheaths

Schwann's cell

produces and maintains the myelin shell

axon terminal

where information is released from the nerve cell

synapse

gap between two nerve cells; makes you who you are

input of information

handled by afferent (aka sensory) neurons that bring information to the brain
[one of the three functions of neurons]

interneuron

process information; all in the brain and spinal cord (central nervous system)
[one of the three functions of neurons]

output of information

efferent (aka motor) neurons neurons that handle information sent from the brain to the body
[one of the three functions of neurons]

threshold

minimum amount of stimuli needed to trigger a neural impulse; genetic; referred to as tolerances
ex | pain tolerances

ascending track

afferent neurons sending information from the body to the brain
(northbound on I-95)

descending track

efferent neurons sending information from the brain to the body
(southbound on I-95)

excitatory response

nervous system fires at faster than normal rate
[one of two events that occurs when a reflex is triggered]

inhibitory response

nervous system fires at slower than normal rate
[one of two events that occurs when a reflex is triggered]

excitatory overrules inhibitory

ex | Thursday night - party, Friday morning - major test
- lie to yourself and say you'll study until you have to leave; too busy thinking about party
- lie to yourself and say you'll only stay a little while, flash forward to 3 am and you're still there
- say you'll study in the morning but end up sleeping through alarm and rushing to class

action potential

neural signal moving down the axon from node of Ranvier to node of Ranvier; caused by positive and negative ions rubbing against each other

neurotransmitters

communicators of the nervous system; talk through chemicals

Goldilocks principle

"just right"; perfect amount of neurotransmitters equals normal behavior

abnormal behavior

oversupply/undersupply of neurotransmitters

illicit drugs

temporarily create an undersupply or oversupply of neurotransmitters

lock and key

type of relationship between neurotransmitters and receptor sites; if all receptor sites are used, then the message is received

characteristics of a neurotransmitter

- work quickly
- serve a specific function
- released next to an adjacent nerve cell

ACh

primary neurotransmitter for memory and learning
undersupply - Alzheimer's

serotonin

primary neurotransmitter with mood, hunger, and sleep
undersupply - depression
oversupply - mania

dopamine

primary neurotransmitter with muscle movement and mood
undersupply - Parkinson's
oversupply - Schizophrenia

glutamate

primary neurotransmitter for excitatory responses; speeds up nervous system
oversupply - migraines

GABA

inhibitory neurotransmitter; slows down nervous system

PEA

what causes people to find other people attractive; breathing and heart beat accelerate, pupils dilate; only lasts between 90 days and 6 months
(works with oxytocin)

oxytocin

produces feelings of love
(works with PEA)

reuptake

releases more neurotransmitters than we have receptor sites for; extra unused neurotransmitters are recycled to the axon terminal to be used later; makes sure you always have enough to keep things moving; replenishing now doesn't have to occur constantly

undersupply of neurotransmitters

reuptake didn't happen, and all these molecules are sitting there, waiting to be used

oversupply of neurotransmitters

reuptake was too quick and the message wasn't fully received
to fix: you want to block reuptake

central nervous system

where interneurons are located and process information
- spinal cord is protected by vertebrae, disks, and spinal fluid
- brain is protected by skull and spinal cerebral fluid

peripheral nervous system

brings information to brain and allows the brain to send information back to the body
- SNS
- ANS

SNS

controls voluntary muscle movement; you have to think to do it
ex | running, walking, talking, writing

ANS

controls smooth muscles and heart; everything that your body does unconsciously
ex | breathing, blinking, heart beating
- sympathetic
- parasympathetic

sympathetic

uses energy; runs fight/flight responses; helps release adrenaline

parasympathetic

makes sure you're never burning more energy than necessary so you have energy for fight/flight

lesion

permanently destroys part of the brain so you can understand what it controls
ex | Phineas Gage - railroad pipe through the frontal lobe; changed his personality completely

lobotomy

probe shoved through eye and hammer hits it against frontal lobe, it gets wiggled around and supposedly cures mental illnesses

EEG

captures electrical activity in the brain
Strength: shows brain activity; non-invasive
Weakness: cannot show detail such as structure

CT scan

slice by slice 3D X-ray
Strength: shows detail
Weaknesses: doesn't show activity; uses radiation, invasive

PET Scan

measures brain activity by looking at blood flow
Strength: shows higher level of activity
Weaknesses: requires radioactive isotopes, invasive; cannot show structure, no good picture; doesn't last long

MRI

uses radio waves that produce an image once sent back
Strengths: highly detailed image, shows soft tissues; non-invasive; can spend hours in the machine
Weaknesses: can't show activity; cannot have reactive metal

fMRI

first machine to show both activity and structure; looks at how oxygen moves through body

DTI

studies blood flow on a microscopic level

TMS

uses electromagnetic waves to create temporary lesion in the brain

hindbrain

back, bottom part; most primitive part of the brain; takes care of the most basic functions; consists of medulla, pons, cerebellum, and reticular formation

medulla

controls breathing, heart rate, pulse and reflexes; essential function

pons

regulates sleep; bridge connecting lower and upper brain

cerebellum

posture, balance, memory, ability to perform controlled activities

reticular formation

controls alertness and arousal; like alarm system in house; active while sleeping, only inactive when in coma or death; brain processes unimportant information while sleeping by dumping it in dreams

midbrain

integrates and coordinates sensory information; helps tie it together and make it work together
ex | hear a noise and turn your head to try to find out where it came from

forebrain

where complexities start; higher order operations

limbic system

inner core of the brain; second oldest part of the brain; control motivation and emotion

thalamus

sensory switchboard; all incoming sensory information goes here, and it directs it to the correct part of the brain to be processed; except for smell

hypothalamus

the brain's pleasure center; runs human pleasures and directs pituitary gland
four human pleasures: food, drinks, body heat, sex

hippocampus

in charge of memory, helps coordinate it; Function 1A - make short-term memory long-term and Function 2B - long-term memory short-term

retrograde amnesia

forget everything; entire life is erased and have to start over

antrograde amnesia

cannot make any new memories; stuck in time only remembering events that occurred prior to event causing the brain damage (50 First Dates)

amygdala

in charge of fear, anger, and impulsive thinking; makes decisions during fight/flight; makes decisions because it seems fun at the time, without thinking of consquences; if all your friends jump off a cliff, you would too

singular cortex

bridge between thoughts and emotions

cerebrum

upper part of the brain; right and left hemisphere, same four lobes on each hemisphere; functions can be hemisphere-specific

left hemisphere

language, analytical thinking, and controls right side of the body

right hemisphere

creativity, spatial thinking, holistic, and left side of the body

corpus callosum

connects hemispheres together; allows information to go back and forth between them
- females have larger ones, which is believed to make them better at empathy and nonverbal communication/language

cerebral cortex

upper covering of brain; where all higher order learning occurs and where personality is; makes you who you are; part of the brain that becomes "brain dead"; the higher your level of education, the thicker this will be

occipital lobe

smallest of the lobes; where visual information is processed; 70% of brain's energy is used for it

parietal lobe

where body senses (touch and taste) are; larger part because it codes a large area

temporal lobe

hearing, language, emotions, memory, and human faces

frontal lobe

takes 22 to 23 years to develop; where organization and planning occurs; most sophisticated part of us is the cerebral cortex on our frontal lobe (pre-frontal cortex)

somatosensory cortex

very front of parietal lobe; where all incoming touch information goes; hands and mouth are most sensitive

motor cortex

back of the frontal lobe; controls movement

association areas

neural cluster/network that performs a unique and specific function

Broca's area

left frontal lobe; controls speech production; if damaged, Broca's aphasia will occur - know what you want to say but are unable to physically communicate it

Wernicke's area

understanding; if damaged, you could speak but it wouldn't make sense

split-brain operation

cut the corpus callosum in half; right brain and left brain that don't that don't talk to each other anymore; treats fatal epilepsy

hemispherectomy

done when right side is having seizure activity that is life-threatening; cuts out right hemisphere

hormones

messengers of the endocrine system
- very slow
- carried by bloodstream
- last longer and affect a much broader area of the body

pituitary gland

master gland; controls other glands and tells them to start secreting hormones; right under hypothalamus

pineal gland

produces/secretes melatonin (sleep)

thyroid gland

produces/secretes thyroxine

hypothyroidism

too little thyroxine is used; weight gain

hyperthyroidism

too much thyroxine is used; weight loss

adrenal gland

makes three hormones: adrenaline (opens up airways and rushes blood to muscles), noradrenaline (brings body's functioning back to normal), and cortisol (retains energy for fight/flight; stores calories; also releases from stress and causes weight gain)

ovary

produces estrogen and progesterone; regulates fertility cycle; develop secondary sex characteristics in females (puberty); retain and shave fat; cycles sync when females cohabitate; these characteristics start at puberty and run up until menopause

testes

testosterone is regulated within 28 seconds; can be made higher by having women treat him rudely and can be made lower by handing him a baby; drives sexual behavior and creates secondary sex characteristics (facial hair and deepening of voice)

sensation

raw information/stimuli taken in by senses; governed by sensory system

perception

how sensation is organized into something meaningful; governed by interneurons
experiences - memory
expectations - what you think will be there

accessory structure

anything that modifies or enhances incoming stimuli
ex | lens of eye - focuses image on retina
ear - funnels sound into the ear canal

transduction

all about brain and its function; turns outside stimuli into electrical activity so the brain can enhance it

receptors

specialized cells in which transduction is caused

adaptation

when an incoming stimuli is constant and unchanging, we stop responding to it
positive: weight of clothes
negative: when it occurs in the eye
ex | driving down a long country road and hit a cow because you don't see it

absolute threshold

minimum amount of stimuli you can accurately detect 50% of the time

Signal Detection Theory

at or near the absolute threshold, there are two or more competing stimuli and you have to to tell the difference between them
ex | thinking someone in a crowd looks like someone you know from far away but as you get closer you realize it's not them
competing stimuli - the faces in the crowd vs. the face of the person you know

Just Noticeable Difference

the smallest amount of distance needed to detect a difference

sight

dominant sense; overrules every sense except smell

sight

dominant sense; overrules every sense except smell