PSYC 2200 Week 14

localizationists

believed that you can identify one area in the brain where learning occurs

-Pavlov believed that the connection within 1 part got stronger with conditioning

equipotentialityists

believe that you cannot identify one area in the brain where learning occurs but rather that it is integrated within different structures

Karl lashley

disagreed with pavlov. first to do mouse maze

mass action principle

the efficiency of neural processing is decreased proportional to the amount of damage to the entire brain

theory of equipotentiality

all of the brain is equal in its ability to code for behavior

why is the aplysia a good animal to study to learn about learning?

1. small NS, series of ganglia, no CNS

2. some really big neurons, easy electrode insertion

3. identifiable neurons (recording from R52 - communicate)

habituation

decrease in responding to a repeated stimulus

-psychological (not receptor) level

-light tap on face causes contraction. the response lessens over time

habituation causes a decrease in ________ released

quanta of neurotransmitters

sensitization

habituate then shock then play the tone again and you'll startle the subject because they are now more aroused

-interferes with the circuit of the habituation response (lass less than 1 hour)

how sensitization works

axoaxonic serotonergic inputs make the K+ channels sticky. they open a little slower so the Na+ continues flooding out (voltage inc) for longer. taller AP longer depolarization so the second cell gets more neurotransmitters

long term potentiation (LTP)

long-lasting alteration to specific afferent synapses in the hippocampus when stimulated with a high frequency stimulus; possible biological mechanism for some forms of memory

-stimulate a bunch quickly in a pathway. then later only small stimulation will elicit larger response

3 components of LTP

specificity (only trained synapses affected)

cooperativity (costimulation strengthens both)

associativity (pairing weak and strong strengthens both)

Donald hebb

convergent activity strengths synapses and vice versa

carla shatz

said that cells that fire together wire together and cells that don't sync don't link

mechanisms behind LTP

NMDA and AMPA are glutamate receptors. there are 2 conditions for them to respond to glutamate.

1. postsynaptic cell already depolarized: AMPA open, Na+ entering. There's a Mg2+ in the NMDA receptor (blocking it) and Na+ influx removes the Mg2+ and opens NMDA to Na+ and Ca2+ which can make a lot of changes in the cell

2. glutamate present (can only bind to NMDA when Mg2+ removed)

hebbian synapse theory of learning

the basic idea, proposed by Donald Hebb, that nerve cell circuits are established, strengthened, and modified by the learning and memory formation that accompany changes in behavior

place cells

cells that become activated when rats are located in specific locations, or places, in a maze

direction cells

cells (similar to place cells) that fire in the subiculum, near the hippocampus, when a rat points its head in a specific direction

grid cells

cells, likely in the entorhinal cortex surrounding the hippocampus, that fire as a rat crosses compartments of an imagined coordinate system grid over a spatial area, allowing the rat to determine cumulative distance traveled

subiculum

area near the hippocampus where direction cells fire when a rat points its head in a specific direction

activity-mediated spine enlargement

a possible mechanism of synaptic restructuring in which aspects of long-term potentiation change the shape of dendritic spines, specifically the bulbous head at the end of the spine, prompting the emergence of new dendritic spines nearby

filopodia

dendritic sprouts, appearing around day 16 of a neuron's life, that seek out existing synaptic terminals on other neurons to incorporate an existing circuit into the neuron's infrastructure

feeding trained planaria to untrained planaria to see if they would do better in the maze

they did not because everything is broken down in digestion

phonological loop

repeating a number to remember it for a few seconds

visuospatial sketchpad

seeing an image as you repeat info short term

rule of thumb for short term memory

7 +-2 things can be remembered

-hints don't help

consolidation

short --> long term memory

retrieval

long --> short term memory

state dependent learning

you'll remember stuff learned in a state when you're back in that state

-drugs, alcohol, room/time

one trial passive avoidance

animal in cage with electrified floor. they're on flower pot, they jump off, they'll never do that again.

-active avoidance would be if they had to do something in order to avoid the aversive stimulus

electroconvulsive shock

like a computer restart. 2 electrodes on sides of head, run current to reset brain electrical activity

short term memory is stored in the brain as _____. how do we know?

electrical activity

animals do one trial passive avoidance then get an electric shock and we see if this interferes with their memory that the floor is electric. the answer is that it does, and the closer that the shock is to the trial, the higher the chance that they won't remember learning it

retrograde amnesia

can't remember past memories

anterograde amnesia

can't make new long-term memories

H.M.

intractable epilepsy, anterograde amnesia

-aura in temporal lobe, took out both hippocampi. he could not make new memories and thought that he was always in the 1950s

Korsakoff's syndrome

severe alcoholics with nutrient deficit; lack thymine/B1

-anterograde amnesia

Solomon shereshevsky

cannot forget anything

hemorrhagic stroke

weakened/disrupted blood vessels rupture and blood leaks into brain tissue

ischemic stroke

blood clots stop the flow of blood to an area of the brain

acronym for stroke warning signs

Face drooping

Arm weakness

Speech difficulty

Time to call 911

treatment for strokes

TPA (tissue plasminogen activator): effective for ischemic stroke within 3 hours

TBI categories: how long consciousness was lost

mild: <30 min

moderate: 30 min-24 hours

severe: >24 hours

-you can also have a TBI without ever losing consciousness

what type of scan do they do for head injury?

CT because it is faster than an MRI and it tells you if there is bleeding or swelling

a mild TBI means

you can get back to homeostasis

CTE

form of dementia caused by repeated head trauma

neural basis of dementia

microtubules are highways down axons that provide structure and a mechanism of transport. a protein called tau holds them together, but tau gets tangled in dementia and prevents the microtubule from transporting

-extracellular beta amyloid plaque

declarative memory

information that can be consciously recalled for further processing or use

episodic memory

a form of autobiographical memory

semantic memory

a memory for word meanings and concept-based knowledge

memory engram

memory traces in the brain

procedural memory (implicit)

memories of how to perform certain actions

delayed matching-to-sample task

a laboratory method for assessing memory formation, initially designed for monkeys, in which a single stimulus is presented ("sample phase") followed by a timed delay, after which two stimuli-- one similar to the sample stimulus and one different-- are presented ("choice phase"). The monkey must choose the stimulus that matches the sample stimulus to be rewarded

delayed nonmatching-to-sample task

a laboratory method for assessing memory formation, initially designed for monkeys, in which a single stimulus is presented ("sample phase") followed by a timed delay, after which two stimuli-- one similar to the sample stimulus and one different-- are presented ("choice phase"). The monkey must choose the unfamiliar stimulus to be rewarded

Morris water maze

one of the most commonly used tasks in behavioral neuroscience. Measures spatial memory in rats using tracings of spatial paths to a goal, plus the amount of time required to locate it

radial arm maze

a task used in behavioral neuroscience that tests an animal's memory of recent experiences to solve a problem

working memory

keeping information readily accessible while working on a problem (as opposed to merely being able to remember recent events); associated with the prefrontal cortex

eye-blink reflex conditioning

a classical conditioning model, used in rabbits, in which a tone is used as a conditioned stimulus and paired with a puff of air (an unconditioned stimulus) delivered to the eye to investigate procedural memory

purkinje cells

the principle inhibitory cells of the cerebellar cortex

pontine nuclei

deep cerebellar nuclei that contain excitatory climbing mossy fibers and project to the granule cells in the cerebellar cortex

granule cells

cells in the cerebellar cortex that receive signals from the pontine nuclei within the cerebellum

interpositus nucleus

a deep nucleus in the cerebellum that experiences lengthening of the synapse surface following conditioning

paramedian lobule

an area in the cerebellar cortex that specifically regulates limb movement

cortical-hippocampal system

a memory network underlying declarative memory, composed of the hippocampus, the parahippocampal region, and the more recently evolved neocortex

orbitofrontal cortex

prefrontal cortex region of the brain; associative area required for effective memory processing and learning

processing-based memory system

a proposed memory system consisting of three processing modes that vary across three variables: fast versus slow encoding, single-item versus associative encoding, and flexible versus rigid representation

reconsolidating

restructuring (said of long-term memories that may change during formation, augmentation, storage, or retrieval)

postretrieval liability

instability of memories

confabulation

the rewriting of memories by inventing stories to fill in gaps, typically including bits of true information with fabricated segments, to seem fully believable as honest recollection

inattention blindness

a cognitive illusion whereby a selectively focused attention to one detail results in the failure to notice other details

Nash equilibrium

in a noncooperative game, the point at which each player finds the best response by considering the strategies of the other players during the decision-making process

neuroeconomics

the discipline that investigates the neural computations accompanying value-based decisions, or the ways in which the brain makes choices among various options

lateral intraparietal area (LIP)

a cortical area involved in decision making that integrates relevant sensory, motor, and cognitive information to determine the most optimal outcome of various response choices

dorsolateral prefrontal cortex (DLPFC)

a brain area involved in the computations associated with the decision-making process

action-outcome associations

the probable relationships between specific actions and outcomes and various rewards that are computed by the brain during decision-making challenges