Brain and Behavior CH 12

UCS unconditioned stimulus

thing that can already elicit a response

UCR unconditioned response

thing that is already elicited by a stimulus

unconditioned relationship

existing stimulus-response connecton

conditioning stimulus

a new stimulus we deliver the same time we give the old stimulus (UCS)

operant (instrumental) conditioning

behavior is followed by reinforcement or punishment

engram

physical representation of learning

Karl Lashley’s work

cortical lesions led him to propose Equipotentiality and Mass action

equipotentiality

all parts of the cortex contribute equally to complex behaviors like learning

• any part of the cortex can substitute for any other

All cortical areas can substitute for each other as far as learning is concerned

mass action

the cortex works as a whole, and the more cortex the better

• the reduction in learning is proportional to the amount of tissue destroyed

• the more complex a learning task, the more disruptive lesions are

what was Lashey’s assumption?

the cerebral cortex was the best place to search for an engram, and that all memories are physiologically the same

• neither assumptions were true!

lateral interpositus nucleus (LIP)

an area essential for learning

• damage to this area of the cerebellum leads to permanent loss of a classically conditioned eyeblink response in rabbits

• temporary suppression of the area led to zero effectiveness of classical conditioning training

Richard F. Thompson located an engram of memory where?

in the cerebellum

people with damage to the cerebullum exhibit:

• no conditioned eyeblinks, or only weak inaccurately timed ones

• impairs a learned response ONLY if the response needs to be made with precise timing

sound → _________ → lateral pontine region → both the Interpositus nucleus (IP), and directly to the ______ via the mossy fibers

cochlear nucleus / cerebellar cortex

the somatic information (air pressure) → _________ → inferior olive → __________ via the climbing fibers

trigeminal nucleus / IP and the cerebellar cortex

Cerebellar cortex → IP → ________ → cranial motor nuclei→ muscles including the eye lid.

red nucleus

reversible lesions of the ________ (using injections of the GABA agonist muscimol) during learning do NOT block the association

lesions of the red nucleus

where is the site of association from the red nucleus?

the site of association is upstream from the red nucleus

reversible lesions of ____ by cooling during learning DO block the association

lesions of the IP

short term memories can hold how many items

can hold up to 7 items

many STM (short term) are not simply temporary stores on their way to being LTM

STM dont simply turn into LTM

what hormones activate the amygdala and hippocampus to form memories?

epineprhine and cortisol

• enhances the storage and consolidation of recent experiences

what do emotional experiences activate?

the locus coeruleus is activated

• dopamine releases in the hippocampus

consolidated memories are ______ permanent

not always permanent

if a reminder is followed by a similar experience, the memory is _________ and requires protein synthesis

reconsolidated

• new experiences can modify the memory

flashbulb memories

slight incidents followed by dramatic incident are remembered together

• can prevent you from linking events that happen too far apart, such as the next day

• slippery patch → fall accident

STM process

sensory stimuli → _________ → held for a fraction of a second → pays attention to the sensory input for about _______ seconds to encode stimulus into short-term memory → STM loop established

cerebral cortex / eight, uninterrupted

once a complete loop is made, three things can happen:

1. info can be repeated silently or aloud, which will provide auditory cues

2. info goes into long term memory

3. or info is lost

Donald Hebb theory

any memory that stayed in short term storage long enough will gradually be strengthened into long term memory

what chemical produced by the brain interferes with consolidation?

protein phosphatase

• declines when experience is repeated and allows for consolidation

why are emotional infos more likely to be consolidated?

because of stimulation to the amygdala

working memory

temporary storage of memories about a task that one is attending to at the moment

phonological loop

process which stores auditory info (including words)

visuospatial sketchpad

stores visual info

central executive

directs attention towards one sitmulus or another and determines what info will be stored in working memory

• is dependant on the prefrontal cortex

what is the central executive dependent on?

dependant on the prefrontal cortex

delayed response task

memory task in which subject is geiven a signal to which it must give a learned response after a delay

• a common test for working memory

• increased acivity in prefrontal cortex

during any type of working memory task, a _________ holds the info

a reverberating circuit

cells holding an item in working memory ______ simply repeat the stimulus

do not

reverberating circuit is?

self-exciting positive loop

flashbulb memories are what? (short answer)

meaningful and emotional

reflexive memory relies on:

• cerebellum and amygdala

formative memory relies on:

the hippocampus and temporal lobes

how does amnesia happen

damage to the hippocampus produces powerful amnesia

covid brain fog

covid virus causes huge reaction by immune system

• this reaction impairs blood flow to the brain

• shrinkage of gray matter in cerebral cortex and decreased levels of myelin

people with alzheimer’s disease have better _______ than declarative memory and better ______ than explicit memory

procedural / implicit

where is the gene linked with alzheimers disease located?

on chromosome 21

• only accounts for 1% of cases however

true or false: people with down syndrome that survive into middle age tend to get alzheimer’s disease

true

what causes tangles? (neuronal degeneration)

• accumulation of amyloid beta deposits in brain

• tau protein accumulation

why do we not remember our time as a baby?

the rapid learning in early childhood displaces memories formed in infancy

a patient H.M. has his hippocampus and surrounding brain tissue removed from both hemispheres in 1953 to treat his severe epilepsy

• afterwards, he had great difficulty forming new long term memories, although his ________ working memory remained in tact

short-term

anterograde and retrograde amnesia caused by

result of the bilateral hippocampus removal

retrograde amnesia

loss of memory for events that occurred shortly before brain damage

anterograde amnesia

loss of long term memories for events that happened After brain damage

intact working memory (H.M)

H.M.’s short term memory remained intact

• remembered a number after 15 minutes without distraction

• when distracted, memory was gone in seconds

impaired storage of long term memory (H.M)

• couldn’t form long term memories

• words like jacuzzi and granola were regarded as nonsense

• did not recognized self in a photo, but in a mirror

severe impairment of episodic memory (H.M)

• could not form episodic memories (personal events)

• could describe facts learned before operation, but not personal events

• retained ability to weakly retain factual memories

  • affected ability to describe the future

nearly all patients with amnesia show better _____ memory

better implicit memory

implicit memory is:

influence of a recent experience on behavior even if one does not realize that they are using memory at all

explicit memory (declarative memory)

deliberate recall of info that one recognizes as a memory

procedural memory

the development of motor skills and habits

• a special kind of implicit memory

people with amnesia have ____ working memory, severe anterograde amnesia for ______ memory, and some retrograde amnesia

• do they have better implicit or explicit memory?

normal / declarative

• people with amnesia have better implicit memory!

delayed matching to sample task:

task used to measure declarative memory in animals

• animal see an object → a delay → choose between two objects, one of which matches the sample

delayed nonmatching to sample task

same as delayed matching, except that the animal must choose a Different object from the sample

the hippocampus relates most strongly to episodic memories

• episodic memories always include _____

• acts as a coordinator, tying together representations from various cortical areas

always includes context

when people retrieve an episodic memory, activity in what area synchronizes with activity in several cortical areas?

activity in the hippocampus synchronizes

memory represenations develop in ______ in the hippocampus and _____ fro the start

parallel / cortex

hippocampus stores ______ and the cortex stores ________ information

details / semantic

as time passes, ______ representation weakens while the representation in the ______ remains

hippocampal / cortex

how are memories reactivated?

the hippocampus and cerebral cortex bounce messages back and forth with sharp-wave ripples (SWR)

• ripples help reexperience an event and resemble the waves formed during the initial event

research of the function of the hippocampus suggests it is important for what?

• critical for declarative memory functioning (episodic)

• spatial memory

• contextual learning and binding of info

delayed matching to sample tasks measure what?

measures declarative memory in animals

• animal sees object and must choose the one matches the object after the delay

________ damage impairs both delayed matching sample and delayed nonmatching sample

hippocampus damage impairs both

in rats, many hippocampal neurons are tuned to _________

particular spatial locations

in human cab drivers, imaging data have shown that the hippocampus is activated when answering spatial questions

• they have a larger what?

a larger than normal posterior hippocampus

radial maze

maze with eight or more arms

• tests spatial memory in animal

• damage to hippocampus impairs performance on this task

Morris Water Maze

animal has to find a hidden platform under murky water

• tests spatial memory in animals

• hippocampus damage impairs ability to find

in birds, the larger the hippocampus…

the better their performance on spatial memory tasks

May-Britt Moser, Edvard Moser, and John O’Keefe in 2014 earned noble prizes for?

discovered the cells responsible for spatial memory

place cells

hippocampal neurons tuned to particular spatial locations, responding best when an animal is in a particular place and looking in a particular direction

• anticipate the next places it will go

time cells

response at a particular point in a sequence of time

from where do place cells receive input?

from cells in the entorhinal cortex

recorded cells in the ___________ (grid cells) become active at location separated from one another in a hexagonal grid

• responds to the animals ________ instead of its location or direction

entorhinal cortex / speed of locomotion

at a given level within the entorhinal cortex, different cells respond to different sets of locations, but Always in what shape?

in a hexagon

any _______ refers to events that occurred in a particular place, with a particular sequence of events over time

any episodic memory

loss of place and time cells leads to?

disruption in many types of memory formation

episodic memory, dependant on the hippocampus, develops after how many experiences?

after a SINGLE experience

if you learn “when you hear a chime, turn towards the clock”, what structure does that rely on?

relies on the hippocampus

if you learn “when you hear a chime, turn to the right”, what structure does that rely on?

relies on the striatum

“Will it Rain?” example

1. multiple strats. for guessing yes/no with different probabilities

2. with more trials, you gain more accuracy, even if strategy is unexplainable by self

3. gradual probabilistic learning depends on the [Basal Ganglia]

almost all cortical and subcoritcal structures are involved in some aspect of memory

• what is important for fear learning?

the amygdala is important for fear learning

parietal lobe damage affects what ability?

affects ability to associate one type of info with another, piecing info together

damage to the anterior and inferior temporal lobes results in _______ dementia, in which semantic memories are impaired

results in semantic dementia

damage to prefrontal cortex impairs the ability to learn about ______ and punishments

rewards and punishments

damage to orbitofrontal cortex results in people opting for..?

opting for immediate reward as opposed to slowburn

Penfield

each neuron stored a specific memory, which could be elicited through stimulation but! → dreamlike experiences that may or may not have been part of the patient’s past

Horridge demonstrated what?

headless cockroaches could learn via conditioning, but results varied widely and occurred slowly over time

researchers pursued the possibility of transfering memories from one person to another through injecting What?

injecting proteins from one brain into another

• inconsistent results, abandoned study

Hebbian synapse

• synapse the increases in effectiveness because of simultaneous activity in the presynaptic and postsynaptic neurons

• cells that fire together, wire together

• may be critical for many kinds of associative learning

aplysia slugs as an experimental animal Why?

fewer neurons, large and easy to study

• gill withdrawal response