Lecture 7: Memory Flashcards
Memory
Memory: the retention of information over time
- reflects different abilities (it’s not one thing)
- consists of different sub-systems that lets us remember different things over time
- Memory is actively reconstructed, not passively reproduced
- We don’t reproduce memories as we live them
- We reconstruct/rebuild memories
- You dont reproduce memories exactly as they happen
- Memory is very fluid
- Memories change everytime you remember them and you rebuild them
- Photographic memory doesn’t exist?
3 General Systems of Memory
1) Sensory memory
2) Short-term memory
3) Long-term memory
- each system differs in capacity and duration
Sensory Memory
Sensory Memory: holds sensory information (very briefly) so it can be transferred to short-term memory
- short duration
- each sense has its own system:
Iconic: vision, 1/2 a second
Echoic: hearing, 2-4 seconds
- allows more elaborate perceptual processing
- duration is short but capacity is large
Short-term Memory
Short-term Memory: holds information in your mind
- aka working memory
- duration of information lasts 20-30 seconds (without rehearsal) (because you’re constantly refreshing what you’re thinking about from moment to moment)
- capacity is limited to 5-9 items
Long-term Memory
Long-term Memory: information acquired across lifespan
- perhaps unlimited (?) duration and capacity
- different types:
Explicit/ Declarative
Implicit/ Non-Declarative
Types of Long Term Memory
Explicit/ Declarative Long-term Memory: memory that is consciously recalled
Episodic: events in our lives we’ve consciously experienced (events you’ve consciously lived through first-hand) (e.g. remembering what you wore yesterday)
Semantic: facts of the world (knowledge and concepts) (e.g. 9/11)
- These two divisions exist in different parts of the brain because you can have one and not the other
- episodic memories can turn into semantic memories
Implicit/ Non-Declarative Long-term Memory: memory that does not require conscious though
Procedural: habits and how to do things (skills and actions) (e.g. playing piano without thinking about it) (e.g. tying your shoes)
Priming: exposure to a stimulus influences future response to a different stimulus (information you’re exposed to earlier influences what information you recall later on) (e.g. imagining the colour yellow so you think of banana)
Primacy & Recency
- Tendency to remember different words based on where they are on the list (beginning or end) because of short and long term memory
Primacy: remembering things at the start of a list well (long-term affects?)
Recency: remembering things at the end of a list well (short-term effects?)
3 Memory Processes/ Stages
- Encoding
- Storage
- Retrieval
Encoding
Encoding: process of getting information into our memory
Attention
- Unless you pay attention, it won’t be encoded (it won’t encode to long-term memory) (e.g. what direction does the sail face on a dime?)
**Mnemonics** Learning aids/strategies that enhance later recall (e.g. BEDMAS)
Storage
Storage: maintaining information over time in memory
**Engrams** - Physical basis of memory (the memory itself) - Structural + functional changes in our CNS as a result of experience **Consolidation** - Stabilizes memory traces in CNS **Schemas**: Mental models or knowledge structures (e.g. what a sofia is, how to order at a restaurant) - Gained through experience (the general idea of an object is encoded in your CNS) (e.g. you know what a car deos even though you dont remember every single car you’ve ever seen) - Frames of reference for interpreting new situations (knowledge you have for the new observation of an object)
Retrieval
Retrieval: accessing information when you need it
- Whatever circumstance you’re in when encoding, that’s the best circumstance to be in for retrieval
- Reactivation or reconstruction of memories from storage
- 2 types:
Recall: generating remembered information on your own (e.g. generating the correct response on short answer)
Recognition: selecting previously remembered information from several options (e.g. recognizing the correct multiple choice option)
Retrieval cues: hints that make it easier for us to recall information
Encoding & Retrieval
- encoding specificity
Context dependent memory: best when physical/external context between encoding and retrieval are similar
e.g. where you learn information is where you’ll retrieve it best
e.g. divers encode on load, recall best on land, encode underwater, recall best underwater
State-dependent memory: match in internal/mental context between encoding and retrieval
e.g. learning sober/drunk vs recalling sober/drunk
Mood-dependent memory: match in mood between encoding and retrieval
e.g. if you learn it happy then your best recall is when youre happy
Engram
physical changes in our brain as a result of experience (memory traces)
Karl Lashley
- Tried to find where engrams are stored
- Trained rats to run mazes
- Create lesions in the brain
- No one area when lesioned created memory problems
- Engrams are not stored in a single place, but they’re distributed in the brain
Donald Hebb (Lashley’s Student)
“neurons that fire together, wire together”
- neurons that activate at the same time become associated
Long-Term Potentiation
- strengthening connections between 2 neurons after they are both activated
Long-Term Depression
- weakening of connections between 2 neurons after low or no activation between them
Nerouns that fire together lead to an increase in vesicles containing neurotransmitter, and more receptors on the post synaptic dendrite
- increases in neurotransmitter in vesicles & more receptors on post synaptic dendrite
