Psych Unit 3: Brain

phrenology

a pseudoscience; phrenologists feel the size and shape of your brain

myelin sheath

layer of fatty tissue that insulates and builds along the axon to speed up axon impulses; more myelin=more efficient

anterograde amnesia

an inability to form new memories(dory)

retrograde amnesia

cant remember past memories

declarative memories

get processed through the hippocampus; memories of our experiences, facts, knowledge, and information

declarative- semantic memories

memories of facts and knowledge

declarative- episodic memories

memories of our own previous experiences

non-declarative memories

implicit unconscious memories that you have; motor skills like typing-procesed through cerebellum
as the neurons get more myelinated, it makes it more implicit(the signal/motion happens faster)

hypothalamus

pleasure/reward center of the brain; hunger, thirst, sex drive, sleep wake cycle, body temperature are all regulated by it;helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward

superchiasmatic nucleus

group of neurons in hypothalamus that regulate circadian rhythm

circadian rhythm

approx 24 hour cycle; light helps regulate it; artificial light has reduced the quality of sleep because they are disruptive to the superchiasmatic nucleus

melatonin

a hormone that helps with sleep

ventromedial hypothalamus

makes you feel full

lateral hypothalamus

makes you feel hungry

cerebral cortex

part of the brain that makes us human and different from other species; most mass and density in the brain; sits on top of brain stem and limbic system

prospagnosia

face blindness

Wernicke's area

language comprehension

Broca's area

helps with the production of speech

aphasia

an issue with language or speech

Wernicke's aphasia

struggle comprehending language; production of speech is also hard because you struggle to comprehend; you physically can speak but it is hard to know what to say

Broca's aphasia

trouble producing speech; you know what you want to say but it is hard to physically say it

neuron

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

cell body

the part of a neuron that contains the nucleus; the cells life support center

dendrites

receive and integrate information/impulses, conducting it toward the cell body; often bushy
dendrites listen, axons speak

axon fiber

neuron extension that passes the message through its terminal branches to other neurons or to muscles or glands; may be very long(several feet)

multiple sclerosis

if myelin sheath degenerates, communication to muscles slows, with eventual loss of muscle control

glial cells

cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, information transmission, and memory; more complex brains have more glial cells

neurons transmit messages when...

stimulated by our senses or neighboring neurons

resting potential

positive inside/negative outside

action potential

temporary inflow of positive ions

how does a neuron fire?

the first section of the axon opens its gates, and positively charged sodium ions(attracted to the negative interior) flood in through the now open channels to open, and then the next, like falling dominoes

excitatory signals

most neurons are excitatory; like pushing a neuron's gas pedal

inhibitory signal

like pushing a neurons brake pedal

when is the action potential triggered?

if excitatory signals exceed inhibitory signals by a certain minimum threshold

threshold

the level of stimulation required to trigger a neural impulse

refractory period

a resting pause during which action potentials cannot occur until the axon returns to its resting state, and then the neuron can fire again

a strong stimulus can...

trigger more neurons to fire, and to fire more often but it does not affect the neuron's strength or speed

all or none response

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

synapse

the meeting point between neurons; the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; the tiny gap at this junction is called the synaptic cleft

neurotransmitter

chemical messengers that cross the synaptic gaps between neurons; when released by the sending neuron, neurotransmitters travel across the synapse and bind to the receptor sites on the receiving neuron, influencing whether or not an impulse will occur

reuptake

a neurotransmitter's reabsorption by the sending neuron

neurotransmitter: serotonin

feelings of happiness, focus, and calm; undersupply linked to depression; some drugs that raise serotonin levels are used to treat depression

neurotransmitter: dopamine

feelings of reward, motivation, being productive;oversupply linked to schizophrenia, undersupply linked to tremors and decreased mobility in parkinson's disease

neurotransmitter: acetylcholine

enables muscle action, learning, and memory; with Alzheimer's disease, ACh producing neurons deteriorate;

neurotransmitter: Norepinephrine

helps control alertness and arousal; undersupply can depress mood

neurotransmitter: GABA

a major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia

neurotransmitter: glutamate

a major excitatory neurotransmitter; involved in memory; oversupply can overstimulate the brain, producing migraines or seizures

neurotransmitter: endorphins

neurotransmitters that influence the perception of pain or pleasure; oversupply with opiate drugs can suppress the body's natural endorphin supply

agonist

increase a neurotransmitter's action

antagonist

decrease a neurotransmitter's action by blocking production or release

nervous system

made up of neurons communicating with neurotransmitters; a communication network that takes in information from the world and the body's tissues, makes decisions, and sends back information and orders to the body's tissues

Central Nervous System

brain and spinal cord; the body's decision maker

Peripheral Nervous System

responsible for gathering information and for transmitting CNS decisions to other parts of the body

nerves

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

sensory(afferent)neurons

carry messages from the body's tissues and sensory receptors inward to the brain and spinal cord for processing

motor(efferent) neurons

carry instructions from the central nervous system outward to the body's muscles and glands

interneurons

neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs

somatic nervous system

enables voluntary control of our skeletal muscles

autonomic nervous system

controls our glands and our internal organ muscles; may be consciously overridden but usually operates on its own(autonomously)

sympathetic division of autonomic nervous system

arouses and expends energy(fight or flight)

parasympathetic division of autonomic nervous system

calms and conserves energy(rest and digest)

neural networks

like people networking with people, neurons network with nearby neurons with which they can have short, fast connections

spinal cord

two way information highway connecting the peripheral nervous system and the brain

reflexes

simple automatic responses to stimuli

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 endocrine glands, travel through the bloodstream, and affect other tissues(influence our interest in sex, food, and aggression)

nervous vs endocrine system

nervous system is fast, takes a fraction fo a second to send message
endocrine system is slow, takes several seconds to send message, but effects last longer than nervous system

adrenal glands

a pair of endocrine glands on top of the kidneys that secrete hormones(ad and noradrenaline) that help arouse the body in times of stress

pituitary gland

pea sized structure in the core of the brain; the endocrine's system's most influential gland; controlled by the hypothalaus; regulates growth and controls other endocrine glands

lesion

tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue

optogenetics

uses light to control the activity of individual neurons

EEG

an amplified recording of the waves of electrical activity sweeping across the brain's surface; these waves are measured by electrodes places on the scalp

MEG

a brain imaging technique that measures magnetic fields from the brain's natural activity

CT Scan

examines the brain by taking x ray photographs that can reveal brain damage

PET Scan

depicts brain activity by showing each brain area's consumption of its chemical fuel, the sugar glucose

Brain body weight vs calorie intake

makes up 2% of our body weight but takes up 20% of our caloric intake

MRI

a technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue; show brain anatomy

fMRI(functional MRI)

a technique for revealing blood flow and, therefore brain activity by comparing successive MRI scans

brainstem

the oldest and innermost region; responsible for auomatic survival functions; a crossover point, where most nerves to and from each side of the brain connect with the body's opposite side

medulla

the base of the brainstem; controls heartbeat and breathing

pons

sits just above the medulla and helps coordinate movements and control sleep

thalamus

a pair of egg shaped structures that act as the brain's sensory control center; directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

reticular formation

a neuron network extending from the spinal cord right up through the thalamus and plays an important role in multitasking and controlling arousal from sleep

cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory;
helps us judge time, modulate our emotions, and discriminate sounds and textures; with help from the pons

cerebral hemispheres

the brains newest and highest regions

limbic system

neural system including the amygdala, hypothalamus, and hippocampus, located below the cerebral hemispheres; associated with emotions and drives

amygdala

two lima bean sized neural clusters in the limbic system; linked to aggression and fear(emotions)

hippocampus

a seahorse shaped brain structure that processes conscious, explicit memories and decreases in size and function as we grow older; give you your ability to form new memories of facts and events

corpus callosum

the wide band of axon fibers connecting the two hemispheres and carrying messages between them

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the connecting fibers

information from the left half of your field of vision goes to...

you right hemisphere and vice versa

information received by either hemisphere is...

quickly transmitted to the other across the corpus callosum

the brain often runs on autopilot...

it acts first and then explains itself

when a person performs a perceptual task activity increases in...

the right hemiphere

when a person speaks or does a math calculation activity increases in...

left hemisphere

left hemisphere

quick literal interpretations of language

right hemiphere

makes inferences, modulating our speech, and orchestrating our self awareness

consciousness

our subjective awareness of ourselves and our environment

cognitive neuroscience

the interdisciplinary study of the brain activity linked with our mental processes including perception, thinking, memory, and language

high vs low roas

high road-conscious, deliberate, reflective
low road- unconscious, automatic, intuitive