Long Term Memory Part 1 Flashcards
What is memory?
Processes, Types, Systems, & Tasks
* (Method: lesions & double dissociation)
* Short-term & long-term memory
* Implicit & explicit long-term memory
Implicit long-term memory
Non-associative
* Conditioning
* Skill learning
* Priming
Explicit long-term memory
Semantic
* Episodic
* Consolidation & reconsolidation
Examples of memory:
breakfast.
How my breakfast this morning tasted
- What I had for breakfast this morning
- What I usually eat for breakfast
- Examples of typical breakfast foods
- What breakfast is
- How to eat breakfast
- The coffee stain on my pants?
Long-term
memory
(LTM) Problem:
How to acquire information from experience,
maintain it over time, and use it when relevant to
guide behavior and plan future actions.
Long-term
memory
(LTM) Importance:
emphasizes that progress relies on memory and continuity rather than mere change. Without retaining past experiences, no true improvement can occur, as there is no stable foundation to build upon. If history and lessons from the past are forgotten, people will continuously repeat mistakes, remaining in a state of perpetual infancy, unable to grow or advance.
LTM Processes
Encoding
Consolidation
Storage
Retrieval
Reconsolidation
Are STM and LTM separate systems?
Single Dissociation: One task impaired, another spared (not proof of separate systems).
Double Dissociation: Opposite impairments in two tasks → strong evidence for distinct brain systems.
Short-term memory task
Memory span
* Hear three words:
“time base offer”
* Immediately recall in same
order:
“time base offer”
Long-term memory task
List learning
* Hear ten words:
“hand cook laugh …”
* Immediately recall in any
order:
“cook train hand …”
* Repeat until all 10 recalled in
any order
Patient K.F.
Brain Damage: Left parietal lobe lesion.
Impairment: Poor short-term memory (verbal).
Spared Ability: Intact long-term memory.
Significance: Supports double dissociation between short-term and long-term memory, suggesting they rely on separate systems.
Problem: Two alternative explanations.
Partial Damage Argument:
One system supports both STM & LTM.
STM tasks are harder, so partial damage affects STM more.
Compensation Argument:
One system supports both STM & LTM.
If fully damaged, the brain compensates for LTM but not STM.
Patient H.M
Brain Damage: Bilateral removal of the hippocampus.
Impairment: Severe anterograde amnesia (couldn’t form new long-term memories).
Spared Abilities: Intact short-term memory & procedural memory.
Significance: Supports double dissociation between STM and LTM, showing the hippocampus is crucial for forming new explicit memories.
Double dissociation
When two cognitive functions are shown to be independent because damage affects one but not the other, and vice versa.
Implicit memory task
Perceptual identification
* Study phase:
- 24 words presented for 2 sec each
- Test phase:
- 24 old (studied) and 24 new words flashed extremely briefly
(priming effect) - Identify word
Explicit memory task
Word recognition
* Study phase:
- 24 words presented for 2 sec each’
- Test phase:
- 24 old (studied) and 24 new words presented until
response - Respond “yes” or “no” if words
from study phase
Patient M.S.
Brain Damage: Lesions in the occipital cortex, specifically in the area responsible for visual processing.
Impairment: Unable to form new visual memories (visual agnosia).
Spared Abilities: Intact ability to form verbal and other non-visual memories.
Significance: Supports the idea that different types of memory (e.g., visual vs. verbal) rely on distinct brain regions
Amnesia patients
Amnesia Patients (e.g., H.M.) → Impaired explicit memory (unable to form new episodic memories) but intact implicit memory (able to learn motor skills like mirror tracing).
Double dissociation of
Implicit & Explicit LTM( example)
Patient 1 (e.g., H.M.) → Impaired explicit memory (cannot form new facts or events) but intact implicit memory (can learn motor skills).
Patient 2 (e.g., K.C.) → Impaired implicit memory (unable to learn new motor skills) but intact explicit memory (can recall past events).
Non-associative memory
Habituation: A reduced response to a repeated stimulus over time
* E.g., you stop noticing the ticking of a clock after a few mins.
- Sensitization: An increased response to a repeated stimulus
- E.g., rubbing your arm hurts more the longer you do it.
Habituation:
A decrease in response to a repeated, harmless stimulus over time.
Sensitization
An increased response to a stimulus after repeated exposure, particularly when the stimulus is intense or threatening.
Short term Changes, Long-term Changes.
Short-term” changes
* Last for minutes
* Changes in amount of neurotransmitter released
- “Long-term” changes
- Last for hours, days, weeks
- Changes in number of synapses
Short-term” habituation/sensitization
≠ short-term memory
Classical Conditioning Pavlov? Unconditional/Unconditional response
Unconditioned stimulus (US) = food
- Unconditional response (UR) = salivation
Neutral stimulus/ Pavlov
NS) = bell (before pairing)
Pavlov Conditional Stimulus / Conditional response
Conditioned stimulus (CS) = bell
- Conditioned response (CR) = salivation
Classical Condition Pavlov/ An Initially/ After pairing
US (food) —) UR (salivation)
* After pairing, the CS (bell) —) CR (salivation
Fear conditioning
Fear conditioning
- US = shock
- UR = freezing
- CS = tone
- CR = freezing
Motor Skill learning
Motor adaptation
* Cerebellar loops
- Motor sequence learning
- Cortico-basal ganglia-
thalamocortical loops
Skill learning: Motor adaptation
Task: Throwing darts with prism glasses
* Eye-hand coordination
- Prism glasses shift visual field to side
- Control participants adapt to distortion
- Patients w/cerebellar lesions fail to
adapt
Cerebellum
Uses forward model to predict results of
motor commands
- Uses differences between actual results
and predicted results for: - Online error correction
- Motor learning
Skill Learning: Motor sequence learning
Serial reaction time (SRT) Task
- Each light turns on in a certain order. Your job is to hit the appropriate buttons in that order.
- R = random order, S = repeating sequence
Depends on basal ganglia & reinforcement learning:
Select Action: Choose an action based on expected reward.
Perform Action: Carry out the chosen action.
Compare Rewards: Compare the actual reward to the expected reward.
Prediction Error: Prediction Error = Actual Reward – Predicted Reward.
Update Expectations: Use the prediction error to adjust future expectations.
Repeat: Continuously refine actions based on updated expectations.
Dopamine’s Role:
Dopamine signals from the substantia nigra pars
compacta (SNc) represent prediction errors.
Larger response = reward better than expected.
Smaller response = reward worse than expected.
Basal ganglia & Reinforcement learning
Unexpected rewards → Dopamine signals from SNc.
Excites direct pathway (D1) & inhibits indirect pathway (D2).
Modifies behavior based on reward.
