Neuroscience and Behavior Flashcards
Neuroscience and Behavior
> many factors create why people function
>a mix of biology and psych
The Brain
> source of all thoughts, emotions, anxieties, fears, goals, and attitudes
all conscious experience in 2-3 lbs.
rest of body is life-support
neurons pass info to others
size: 100 billion neurons (connects to hundreds-of-thousands of others)
capacity: 100 trillion to 280 quintillion bits (DNA equals 5 billion bits)
The Nervous System
> processes information to make personality
neurons are found in brain, nerves, and senses
nerves: spinal cord, senses: passes info back to brain
some sensor receptors are modified neurons
Neural Network
> thousands of connections between each neuron
experiences change brain at neuro-circutry level
no two brains exactly alike
The Neuron
> basic brain cell (all shapes/sizes)
make up nerves & sensory cells
info flows as electrical signal (only out/down)
Dendrites
> passes info to other neurons (branch-like)
Axons
> takes messages away from cell body to other neurons, muscles, or glands
Multiple Sclerosis- caused by degeneration of axons
Cell Body
> the cell’s life-support center
Neural Impulse
> electrical signal traveling down axon
Terminal Branches of Axon
> form junctions with other cells
Myelin Sheath
> “Schwann Cells”
speeds up/maintains neural impulses’ info
like insulators on wires (covers some neuron’s axon)
Synapse
> synapse/synaptic gap- space between one neuron and next (axon tip->dendrite/cell body)
1) vesicles contain neurotransmitters/electrical signals
2) neurotransmitters- allow chemical electrical signals to jump gap
3) receptor sites capture neurotransmitters
Action Potential
> when brain reacts and sends electrical signal(s)/nerve impulses
negative ions rush out, positive ions rush in
units: mV is 1/1000 of a volt
Resting Potential
> when neuron has no activity (result is negative number)
Refractory Period
> recharge stage of neuron after firing
>NEURON WON’T FIRE
Repolarization
> neuron restores negative charge with Na-K pump
Action Potential Properties
> all-or-none response (either fires or does not)
strong stimulus can change firing rate, but not fire strength or speed
changes pattern/rate/frequency to differ messages
intensity remains same throughout axon (always same size/shape/speed)
Neurotransmitters
> transport info across synaptic gap
>types: ACh, Dopamine, Serotonin
Acetylcholine
> deals with movement/learning/memory
Cholinesterase
> Cholinesterase (enzyme) breaks down ACh
cleans/recycles ACh
enzymes end in “-ase”
Dopamine
> deals with movement/learning/attention
>too much/too little causes problems
Serotonin
> regulation of mood/hunger/sleep/arousal (awakeness)
Parkinson’s Disease
Neurotransmitters & Diseases
> Parkinson’s- lose ability to move (low dopamine)
neuro-mottor condition
signals aren’t generated
treatment 1: artificially create LDope (raw component of dopamine), but does not cure disease
treatment 2: Deep Brain Stimulation- plant electro/battery pack (sends electric signals to stimulate cells)
Schizophrenia
> moderate/severe psychological disturbance/random hallucinations (too much dopamine)
Alzheimer’s
> cells that produce ACh die (lack ACh)
>person becomes forgetful, gets progressively worse
Depression
> 10% struggle with (low serotonin)
Brainstem
> upper level of brain more easily damaged
>braindead- no brain activity, but Medulla works
Medulla
> controls heartbeat, blood pressure, blood flow, breathing, and some reflexes (sneeze, cough, swallow)
base of brainstem, attaches to spinal cord
not conscious and doesn’t sleep
Cerebellum
> controls voluntary coordinated movements/balance
helps motor skills & sequential memory
can get by without cerebellum
striped looking, attached to rear of brainstem
Thalamus
> sensory switchboard, directs/transmits info to other parts
helps identify/discern
top of brainstem
Hypothalamus
> controls basic functions/drives (urges)/motives
>ex. hunger, thirst, emotions, body temps
Simon LeVay
> studied hetero males, hetero females, and homo males
looked at hypothalamus nucleus
found 2x size in hetero males than heater females
realized homo males about same size as hetero females
Rats Testosterone Experiment
> exposed unborn rat pups to testosterone
later, females tried to mate w/ females
found females subjects had enlarged hypothalamus
The Limbic System
> plays role in emotions (emotion inhibition)
helps with learning/memory
includes hippocampus, amygdala, hypothalamus
most well developed in mammals, primates, humans
Emotion Inhibition
> tries to shut down emotions created by other parts of brain
>allows for flexible emotions
Limbic System and Aggression
> lacking -> act mechanically
ex. Put plastic fish w/red bellies in Stickleback fish tank
(taking away limbic system -> attack mode)
Hippocampus
> connection between short term & long term memory
also referred to as “N.A.”
STM- short term memory
LTM- long term memory
Hippocampus Damage Examples
> N.A. was stabbed while fencing roommate (unable to form new memories)
British musician got virus, damaged N.A.
(wrote in journal “I AM ALIVE”)
H.M had same problem
(father died, eventually remembered after kept finding note)
Cerebral Cortex
> controls higher mental processes
wrinkled outside (adaptation increases amount of cortex)
2/3 of brain’s mass/weight
when looking at brain, mostly see cerebral cortex
Grey Matter
> cell bodies, dendrites, neurons
White Matter
> myelin & axons make lighter color
Brain Ventricles
> fluid filled “gaps”, adds protection
Fissure
> deep division, separates left and right hemisphere
Rosenzweig’s Experiment
> rats raised in normal vs. enriched environment
“enriched” rats: more cortex, ACh, dendrites/synapse/neurotransmitters (quick learners with lever/maze)
result: brain changes based on experience
MIT Role of Environment Study
> Mackey studied 60 eighth-graders through MRI test
found grey matter & cortex thickness significantly greater in high income subjects
cortical thickness could account for 44% of income achievement gap (means low income does worse)
Motor & Sensory Cortex
> two motor cortex strips control/indicate movements
proportional to number of neurons allocated
can be changed by experience
ex. MRI before/after piano lessons (change in motor cortex)
Visual Cortex
> aids in seeing/recognizing visuals/responding to motion
located at back of brain
damage results in Visual Agnosia
ex. British man recognizes wife by voice instead
(some can describe, but not recognize objects)
Auditory Cortex
> aids in recognizing objects based on sound/helps with language
active in patients who hallucinate
Broca’s Area
> controls speech production/turns thoughts into spoken words
Broca’s Aphegia- damage causes people to struggle speaking (cognitive, but can’t speak)
ex. Military person could remember, but not speak well
Wernicke’s Area
> processes/understands spoken language
>Wernicke’s Aphegia- damage causes people to not understand what others say (not cognitive, but can speak)
Language & Aphagia
> most have Broca’s and Wernicke’s only on left hemisphere (near auditory cortex)
brain doesn’t heal well
other areas can sorta pick up functions
Association Cortex
> not as specialized, several complex functions (memory, recognition, problem solving, etc.)
combines info from several areas
Frontal Association Area/Frontal Cortex
> plans actions & movements, foresight
inhibition, emotional control
personality
STM functions
matures in late teens
incorrect myth: use on 10% of brain (could not multitask in were true)
Uses of the Brain (Percentages)
50% -> speech
40% -> visual
Uses of Stimulants
> ADD & ADHD kids given stimulants to “wake up” other parts of brain
creates a balance
Left & Right Hemispheres
> largely independent
Protective Membrane
> grey outside part of brain
Brain Size & Intelligence
> not connected within adult human species
>brain is like crunched up paper, not like intestines folded (flat paper vs. tubes)
