PSYC midterm 3 Flashcards
Problem with LTM
How to acquire information from experience, maintain it over time,
and use it when relevant to guide behavior and plan future actions
Importance of LTM
In Order to change in a meaningful way we have to remember the past
Challenge of LTM
Out of all of experience, what to remember, and how to retrieve it when needed
Is learning the same thing as memory
yes
Processes involved in LTM
encoding, storage, retrieval,
Some types of LTM
semantic (facts), episodic (past experiences), procedural (how to do things)
Systems involved in LTM?
hippocampus, cortex, amygdala, ..
Tasks to study LTM:
free recall, stem completion, motor sequence learning, …
What does memory require in the nervous system
physical change
What part of the nervous system is involved in memory?
Memory is pervasive (almost every part is involved)
common underlying representation of all forms of memory?
number & strength of synaptic connections between neurons
How is STM, working memory, and sensory memory represented differently than LTM?
represented by which neurons are active at that moment and if they stop firing memory gets lost
require active maintenance
Can long term memories be passively stored
yes
Whereis the organization of storage and processing in memory located?
location of memory storage and processing coincide
How does interpretation of representations occur in LTM?
Interpretation of a synaptic weight depends on its location in nervous system (e.g. a synapse in V1 represents something visual) → where memory is is part of its meaning
What are memories accesses based on?
content (e.g. “What do you know about pandas?”) not location
What is encoding of memory in LTM?
Initial creation of memory traces in brain from incoming information → making memories
What is storage of memory in LTM?
Retention of memory traces over time
What is retrieval of memory in LTM?
Accessing/using stored information from memory traces
What is memory consolidation?
Continued organization and stabilization of memory traces over time → the way memories are initially stored may be different than how they are eventually stored
What is memory reconsolidating in LTM?
Possible reorganization and restabilization of memory traces after retrieval
after retrieval the memory can change
What are other words for short-term memory?
Working memory
Sensory memory
What are the two types of long-term memory?
Explicit (declarative)
Implicit (non-declarative)
what are the 4 types of implicit memory?
Procedural memory
Perceptual memory (priming)
Classical conditioning
Non-associative learning
What are the two types of explicit memory?
episodic memory (events)
Semantic memory (facts)
What is the Memory span test and what is it used for?
Used to test short-term memory
You hear three words and are asked to recall them in the same order
What is the list learning task and what is it used for?
Used to assess LTM
Hear ten words: “hand cook laugh …”
Immediately recall in any order: “cook train hand …”
Repeat until all 10 recalled in any order
What occurs in the list learning and memory span test for a patient with damage to the left temporoparietal cortex?
Impaired on the short-term memory task (memory span) and good at the LTM task (list learning)
What is a dissociation?
Performance differs across two task in an experiment
Can we use single dissociations to prove an argument?
NO
What is a single dissociation?
dissociated the performance on two tasks → can perform one task but not the other
What are we tempted to conclude based on single association about temporal parietal junction? Can we say this?
Short-term memory task depends on temporoparietal junction but long-term memory task does not
Therefore short-term and long-term memory are separable systems that depend on different brain regions and distinct cognitive processes
Can’t say this!!!!
What are the two alternative explanations for the results seen in the patient with damage to the left temporoparietal cortex?
- Partial damage argument
- Compensation argument
What is the partial damage argument?
Perhaps there is one system for both short-term AND long-term memory
But the short-term memory task is harder than the long-term memory task
So when this system is partially damaged the short- term memory task suffers more than the long-term memory task
What is the compensation argument?
Perhaps there is one system for both short-term AND long-term memory
But the short-term memory task is harder than the long-term memory task
So when this system is completely damaged, the brain can compensate for the long-term memory task (easier task) but not the short-term memory task
Does a single dissociation demonstrate that LTM and STM are separable systems? What do we need to determine this?
A single dissociation does not necessarily demonstrate separable systems, different brain regions, or distinct cognitive processes
A single dissociation might mean this, but to rule out alternative explanations 1 and 2, we need a double dissociation.
What is seen in a single dissociation of a patient with damage to the bilateral medial temporal lobes?
Patient can perform the memory span test (STM) but can’t perform the list learning test (LTM)
What is a double dissociation?
Two patients, Two different areas of damage
Two opposing single dissociations
What does a double dissociation show and why?
A double dissociation provides strong evidence for separable systems that depend on different brain regions and distinct cognitive processes
Suggests that short-term and long-term memory are separable systems
Short-term memory task cannot be both harder and easier than long-term memory task!
What is the timescale, capacity, and neural basis of STM?
Timescale: seconds
Capacity: extremely limited
Neural basis: sustained activation of neurons → current activation of neurons → if they stop firing the memory is gone
What is the timescale, capacity, and neural basis of LTM?
Timescale: minutes, hours, days, years
Capacity: massive
Neural basis: number & strength of synapses –> physical connections
How many words on average can a person remember in the memory span (short-term) task?
7
How many words on average does a person have in their vocabulary (LTM)?
20000
What is the perceptual identification task and what does it measure? What does it show?
Measures implicit (non declarative) memory
Study phase: 24 words presented for 2 sec each on screen
Test phase: 24 old (studied) and 24 new words flashed extremely briefly
Identify word
The words that you have been recently exposed to, you are faster at identifying
What is the word recognition task and what does it measure? What does it show?
Measures explicit (declarative memory)
Study phase: 24 words presented for 2 sec each
Test phase: 24 old (studied) and 24 new words presented until response → don’t disappear
Respond “yes” or “no” if words from study phase → explicitly asked
Can detect the words that were seen
What does the single dissociation of implicit & explicit Long-Term memory show for patients with damage to right occipital lobe?
impaired on perceptual identification task (implicit) but can do the word recognition task (explicit)
What does the single dissociation of implicit & explicit Long-Term memory show for patients with amnesia, Korsokoff’s syndrome and epilepsy?
Impaired on word recognition task (explicit) but can do perceptual identification task
Are regular people generally better at perceptual identification task or word recognition task
Word recognition
What does the double dissociation of explicit and implicit LTM suggest?
Suggest that implicit and explicit memory are distinct types of memory that depend on separate parts of the brain
What are the characteristics of implicit LTM. Is it declarative or non-declarative? Conscious awareness? Types of of implicit LTM? Timescale?
Capacity?
Neural basis?
Non-declarative → memory that you can’t describe if asked about them
Independent of conscious awareness
Procedural, conditioning, nonassociative, or priming
Timescale: minutes, hours, days, years
Capacity: massive (e.g. ~1,000s of skilled motor sequences)
Neural basis: number & strength of synapses → connections between neurons
What are the characteristics of explicit LTM. Is it declarative or non-declarative? Conscious awareness? Types of explicit LTM? Timescale?
Capacity?
Neural basis?
Declarative
Available to conscious awareness
Semantic or episodic
Timescale: minutes, hours, days, years
Capacity: massive (e.g. ~20,000 word families in adult vocabulary)
Neural basis: number & strength of synapses → connections between neurons
What does declarative mean>
if you are asked “what did you do last night” you can them
What is the difference between semantic and episodic LTM? Give an example of each.
Semantic: know facts “what is the capital of BC”
Episodic: about your own experiences “what did you do last night”
Is non-associative learning implicit or explicit?
Implicit
What is non-associative memory
A change in response to an unchanging stimulus
What are the two types of non-associative memory?
Habituation
Sensitization
What is habituation? Give an example?
Reduced response to an unchanging stimulus?
You stop noticing the busy street outside your new apartment after a while
What is sensitization?
Increased response to an unchanging stimulus
E.g.: Rubbing your arm hurts more the longer you do it
What does habituation and sensitization primarily involve?
sensory-motor reflex pathway → don’t involve higher processing in the brain
What organism was used to determine the first evidence of neural basis of memory>
sea slug Aplysia
What is a syphon?
used to pull in water and nutrients from ocean
How is the neural circuitry connecting the syphon and the gills organized inn a sea slug?
sensory neurons that are detecting touch on syphon synapse directly on motor neurons that signal the gill to contract
For habituation, what happened upon repeated siphon stimulation?
less withdrawal
What was seen regarding EPSP and AP in a sea slug experiencing habituation?
The AP from the syphon is the same
For the EPSP (excitatory postsynaptic potential) in the motor neuron of the gill were large in response to the syphon touch initially then decreased
Initially a large gill withdrawal then less
What is Pre-synaptic depression? Where is it seen?
Seen in habituation. After learning/habituation there is less neurotransmitter released for the same AP → smaller EPSP –> less gill withdrawal
For sensitization, what happens to the sea slug after it is shocked?
More withdrawal –> sensitizes the animal
What was seen regarding EPSP and AP in a sea slug experiencing sensitization?
AP are the same in the sensory neurons
EPSPs in the motor neuron are larger after
What is presynaptic facilitation? Where is it seen?
In sensitization
same action potential leading to more neurotransmitter release → larger EPSP
What did the sea slug study on habituation and sensitization show?
Showed that we can connect behavioral changes due to memory to neural changes in the brain.
Changes for habituation and sensitization happens at the synapse.
less or more release of neurotransmitter in presynaptic neuron
What are the short-term changes for habituation and sensitization? and how long do they last?
Last for minutes
Changes in amount of neurotransmitter released
What are the long-term changes for habituation and sensitization? and how long to they last
Last for hours, days, weeks
Changes in number of synapses
What happens to the # of synapses in habituation and sensitization?
More when sensitized
Less when habituated
What does conditioning involve and is it more or less complex than sensitization and habituation?
Involves the association between stimuli
More complex
What is the main study that showed classical conditioning and what did it find?
Pavlov noticed that a dog learned to salivate in response to a bell that predicted food
What happens in the classical conditioning experiment involving pavlov’s dogs?
An initially neutral conditioned stimulus (CS) comes to elicit a conditioned response (CR) due to pairing with an appetitive or aversive unconditioned stimulus (US) which reflexively elicits an unconditioned response (UR)
what is the US, CS, UR, CR in the pavlov experiment?
US = food
UR = salivation
CS = bell
CR = salivation
How does fear conditioning in a mouse work and what are the US, UR, CS, CR?
Mouse walking around in cage. Initially when you play a tone the animal doesn’t respond. After repeated pairing the tone with a shock to the animal → now if you play the tone the animal will freeze as if it is anticipating the shock
US = shock
UR = freezing
CS = tone
CR = freezing
Where does the CS and the US converge in fear conditioning? And what does the output lead to?
lateral nucleus of amygdala –> leads to fear
What does the neural circuit in fear conditioning involve?
Circuitry is between thalamus, amygdala and cortex
Thalamus is a way station that sends info up to the cortex or directly to the amygdala
What happens to the EPSP to the tone in the lateral nucleusof the amygdala after pairing it with a shock?
After conditioning, there is an increase of EPSP in the lateral nucleus of amygdala –> changes in connections between neurons
What does the dip in the graph for fear conditioning mean?
= dip in this graph of extracellular potential, since positive ions enter post-synaptic cells while leaving extracellular space → lower because we are recording outside of cells
What are the 2 types of motor skill learning (procedural memory)?
Motor adaptation
Motor sequence learning
What part of the brain is involved in motor adaptation in motor skill learning
Cerebellar loops
What part of the brain is involved in motor sequence learning in motor skill learning
Cortico-basal ganglia-thalamocortical loops
What does motor skill learning depend on?
motor system
What is the throwing darts with prism glasses measuring and what does it show?
Eye-hand coordination
Prism glasses shift visual field to side
Control participants adapt to distortion
- if they take glasses off it takes time to adjust
Patients w/cerebellar lesions fail to adapt
- if they take glasses off they can do it immediately again because they didn’t adapt
Shows that the cerebellum is required to fine tune the action based on errors → can still do the action as you know it
What model does the cerebellum use and why?
Uses forward model to predict results of motor commands
What does the cerebellum use the feedforward model for? What happens if this system is damaged?
Uses differences between actual results and predicted results for:
Online error correction
Motor learning
Feedback control
If this system is damaged, you can’t make these adaptations based on errors
What is the Serial reaction time task? and why does it measure?
Measures motor sequence learning
Sequence of light appears and you push button associated with each light → record how long it takes to press each button
Initially you are kinda slow, but if the same sequence is repeated again, you get faster
If you switch to a new sequence you are slower again
What does motor sequence learning depend on?
basal ganglia & reinforcement learning:
What occurs in reinforcement learning for motor sequence learning?
Select action expected to lead to maximum reward
Perform action
Compare actual reward to expected reward
What is prediction error?
Prediction error = actual reward – predicted reward (determines if we did worse of better than expected)
If we did better than expected then you are more likely to do that action again
What do we use prediction error for
update actions based on what will give the best reward
What represents prediction error? What occurs when something better or worse than expected occurs?
Dopamine signal from substantia nigra pars compacta (SN c) represents prediction error
Larger response (more dopamine) = better than expected
Smaller response (less dopamine) = worse than expected
What happens in the basal ganglia during reinforcement learning?
Unexpected rewards generate dopamine signals from the substantia nigra pars compacta (SNc)
This excites the direct pathway (via D1 receptors) and inhibits the indirect pathway (via D 2 receptors)
More likely that you will do the same action in the same contex
This allows modification of behavior based on reward
What is priming (perceptual representation system) and what type of memory is it?
Implicit
Change in stimulus processing due to prior exposure to same or related stimulus without conscious awareness
Exposure to a stimulus affects your later response to that stimulus
What are the three types of priming?
Perceptual priming:
Conceptual priming:
Semantic priming:
What is perceptual priming based off
How a stimulus looks
What is conceptual and semantic priming based on
meaning
You are shown the word “envelope” then asked to come up with a word that has the letters EVLP, then you will be able to come up with the envelop quickly
What type of priming is this?
Perceptual
you are shown the word envelope, then you’re asked to think of a word related to stationary → more likely to say envelope since we were recently primed with it
What type of priming is this and why?
Conceptual
Conceptual relationship between stationary and envelope → meanings are related
Having recently seen the word envelope makes up quicker to think of a related word
What type of priming is this?
Semantic priming
What is the difference between conceptual and semantic priming?
The different from conceptual priming is that the thing we are thinking of is not the same as the prime but it is related
Explain the perceptual priming experiment that uses Gollin pictures and what was found in patients with Korsakoff’s syndrome
Show fragmented pictures (Gollin figures)
Identify object in as few frames as possible
Participants improved day to day, despite not remembering the previous day’s training → how evidence of perceptual priming although they don’t have any explicit memory of doing the task
What is Korsakoff’s syndrome
Amnesia (memory deficit) due to severe alcoholism
What does the hierarchial organization of language allow for?
Allows language to have a limited numbers of phonemes but be able to have an almost limitless number of possible structures → combinatorially
What is deep structure in this picture?
Deep structure is the same but the assertion/annotation is different
What type of ambiguity is this?
They are cooking apples.
