Lecture 9 + 10 + 11: Memory Flashcards
Memory in daily life
Routines and habits
* Brushing teeth, Riding bike
The sense of self
* The facts you have about yourself develop from your experiences
Solving problems
* You recall similar experience to solve a current problem
Social functions
* You might recall a funny story to connect with a person
Memory is not one thing
Clive Wearing
- Profound case of amnesia
*Clive Wearing’s memory was impaired, not other cognitive functions. Selective defecits to memory. - Not all aspects of Clive’s memory were impaired
* Knew his wife
* Could play the piano - There are various kinds of memory
* Distinct capacity, duration, and relation to consciousness
Memory processing stages
Encoding
Creating separate memory traces to represent experiences
- inputing information into memory
- creating memory traces (pattern for past event) for experiences you want to remember
Storage
Retaining encoded memory traces
- With time, we can consolidate some experience to make it stay in memory
encoding –> storage is memory consolidation
Retrieval
A memory is recovered when a cue activates part of a stored memory trace
- Can be external = cue causes memory trace to be active
- or internal = thinking
- when you recover the memory stored, enters conscious awareness
Forming and Retrieving a memory
- When you encode a memory, what you do essentially is you’re breaking apart that experience in different details from a memory and you store that memory as a pattern of these pieces.
- You are engaging in pattern seperation to form a memory trace and then overtime memory consilidatiion will form a ling term lasting memory as this pattern.
- At retrieval, what happens is part of the memory trace might be in your environment (queue) and trigger the activation of the entire memory trace (the rest of the pattern) and that is when you have a memory.
What happens when you are forming and retrieving a memory… in the brain?
Encoding: A memory trace is formed as a hippocampal-cortical activity pattern. The hippocampus is important for encoding new memories. It encodes our memory as a pattern of brain activity across the cortex.
Storage: Via consolidation, a memory is transformed into a stable cortical pattern. The particular areas of the cortex that are involved depends on the memory. Ex: If it is very visual = very visual cortex.
Retrieval: Part of a memory trace is activated by a cue that triggers pattern completion. The cue overlaps with part of storage pattern and then you remember it. Through consolidation, the memory trace becomes independent of the hippocampus.
Memory systems
What is the pathway of of an input to LTM?
- Memory systems are very information processing.
- There are different systems that information is passing through.
1) Sensory input: You take a quick scan of your environment with one of your senses.
2) Sensory memory: the important information is transferred here.
3) STM: Holds information for 30 secs
4) LTM: Important information that is rehearsed is encoded into LTM.
Further describe sensory memory, short term memory and long term memory
STM:
- has a limited capacity store
- can only attend to something for 30 secs
- Working memory = manipulatee information in STM.
Sensory memory
- Sensory memory is information that is presented to you in its most unprocessed form. Make quick decisions based on what’s in our environment.
- The first and a “temporary” stage of memory. Requires no conscious effort.
Different senses:- Gustatory memory
- Olfactory memory
- Echoic memory
- Sound-byte held for ~ 3 seconds
- Brief memory of sound, helps us seperate streams of sound very rapidly
- Ex: distinguish when one person vs another is talking
- Haptic memory
- Very brief memory of a touch
- Useful for gripping and grasping
- Iconic memory
-Millisecond visual memory
-A ‘persistence of vision’
Iconic Memory: Afterimages
Positive afterimage
* A visual memory that represents the perceived image
* Original image you saw it perceived in your memory
Negative afterimage
* A visual memory is the inverse of the perceived image
- Both of these examples you see for a very brief period
- You see the same image colours are inverted due to receptors being over used.
- Negative afterimage
How long does [sensory] memory last?
- Sperling (1960)
- Participants briefly (.05 seconds) viewed a visual display (3*4 letters)
- They showed a visual display very quickly
- Recalled the letters
- Whole report: reported letters from the whole display
- Partial report: reported only one row of letters at a time over trials
Whole report
Report any and all of the letters that they saw from a brief flash of display
* people could remember about 4 or 5 out of 12.
Partial Report
They heard one of 3 beeps.
* Before the xperiment started, they learned that each beep was associated with one of the 3 rows.
* They did not know what letters they would have to recall.
* He played different tones at different delays.
What was the result of the whole report vs partial report condition?
How long does [sensory] memory last?
- There is a time delay between the visual display and the tone indicating what people should recall. The delay goes from 0 - 1sec.
- People can recall almost all the letters in the row when the tone is presented shortly after the visual display.
- For the whole report condition, participants are recalling very few words.
- These findings tell us that the sensory capacity is quite large. People can remember or recall a lot of information from sensory memory but only for a short period of time. People’s memory significantly decreased when the delay was increased to one second.
Short term memory
- Attended information moves from sensory to short term memory. Intermediate between sensory and long term memory.
- The prefrontal cortex
- Limited time capacity: ~ 20 to 30 seconds (lasts longer than sensory).
- Limited capacity: “magical number seven plus or minus two” –> this is why phone numbers used to be 7 digits.
Serial Position effects
- We do not forget information equally.
- The order that you learn it in will affect how you learn it and forget it.
Primacy effects
Rehearsal –> long term memory
* You remember the first item/items presented early on the list because they often have the most rehearsal and can benefit from long term memory; accessing early words are supported by short term and long term memory.
Recency effect
- If the study-recall delay duration > 30s, this effect is eliminated. If you go over the capacity of short term memory, the recency effect dissapears.
- The final items on the list are remembered very well by people.
- The recency affect is based only on short term memory processes.
*
How can one enhance short term memory?
- Chunking
- Grouping items together in a meaningful way so more
information to be represented at one time (free up some space) - With chunking, you need to use some kind of knowledge.
- Remember these letters:
HEN CAT DOG PIG COW
Chunking Effect
Chess study
- Chunking increases with knowledge
- Expert chess players recall more pieces on a chess board than new chess players. This only works when the pieces are arranged as an actual game in chess because they use their knowledge of chess moves.
- Experts use knowledge of moves to ‘chunk’ pieces together
- This effect is not present if the pieces are on the board randomly
Working memory model
- How we hold information in the short term
Central executive:
* Manages and manipulates information in your short term.
* Moves us from the idea that short term memory is static to something that is actually very dynamic. We can process information and manipulate it online.
Seperate short term memory stores
Neuroimaging studies
* Different areas of the brain are active for visual and verbal short term memory tasks
ex: if you hold an image or a song in your brain, when we scan your brain, we would fid different activity patterns. Visual and verbal short term memory stores must rely on distinct neural processes.
Double dissociation in neuropsychological cases
* Patient ELD has problems recalling visual-spatial but not verbal material in the short term. Can hold verbal but not not an image.
* Patient PV has problems recalling verbal but not visual material in the short term. Opposite of above.
Neuropsychological cases have found a dissociation between these forms of short term memory storage in cases of brain damage. Damage in the brain can lead to selective problems in the brain.
Verbal Working memory: Phonological loop
** Phonological store:** Passive store for verbal information
* “The inner ear”
* Holds verbal information online
Articulatory control loop: Active rehearsal of verbal information
* “The inner voice”
* Helps you rehearse verbal information.
* Used to convert written material into sounds (reading)
* A specialized role in language
Visuospatial sketchpad
The visual cache
* information about visual features (form, color and other)
Ex: remembering the color of someones dress in an episode in STM.
The inner scribe
* information about spatial location, movement and sequences
Ex: Holding in mind the sequence of the person dancing in STM.
You can dissociate these types of information: visual, verbal in working memory. This means that there can be a lot of variation and individual differences in people’s working memory system. Some people might be very good at holding visual information (visual catche) whereas others are very good at holding verbal information (inner scribe).
The working memory model: The
episodic buffer
Integrates information from short and long term memory
* Researchers added another element to this model called the episodic buffer.
* It is taking the informattion that is brought to you by sensory memory but you also have to bring information from your long term memory store. It helps explain how we can bring information from not only long term memory and sensory memory but also we can bring information together from these differentt storehouses.
* Without a episodic buffer it is hard to understand how something occurred.
* These models are not staic. We always update and change them.
Moving information to the long term
Encoding = when info from STM goes to LTM
Retrieval = A cue activates a memory. Something activates our patterrn of memory so that it is brought to our attention.
Ebbinghaus
- Tested how encoded nonsense syllables were retained and forgotten from memory over time
- He was testing how he himself could remember sets of these nonsense syllables which were in triplets of two consonants and a vowel, so they had no meaning so he could not access or use any knowledge.
- he had to remember these, no chunking.
Ebbinghaus result
- Created over 2000 cards of nonsense syllables
- Learned and relearned sets of the syllables under strict testing conditions
- Read the syllables without any inflection (read them very slowly to himself)
- Read them at a consistently fast pace: 2.5 items per second
- He did nothing else while running these experiments (Remove any sort of confounds)
The forgetting curve
- Forgetting is exponential
- Memory loss is largest early on and slows down
- This is the result from Ebbinghaus but was also replicated so many times with animals.
- Rate of forgetting is really fast initially.
- The initial strenght of the memory is very strong if you encode it very well and then you see a steep drop off in the strenght of the memory meaning a lot of information is forgotten early on and then it sort of flattens out. Memory loss is bigger ealry on
The spacing effect
- Memory is better when the same amount of learning is spread out over time.
- You are most likely to remember information, if you learn it at different time periods rather than all at once.
- You need to take breaks between encoding information.
- It is also important that there is variations between the sessions, it is not always the same time.
Theories of forgetting
Decay Theory
* Forgetting from time
* We forget information simply from the passing of time. Information is just going to fade away.
Interference Theory
* Forgetting from interfering information
* Information that is processed between or before encoding and retrieval effects what we can remember
Interference Theory
Retroactive interference (‘backward in time’)
* Newly learned information interferes with old
information
* E.g., Trouble remembering your old phone number
Proactive interference (‘forward in time’)
* Previously learned material interferes with new
information.
* Trouble learning something new because you keep remembering a new one.
* E.g., Trouble learning a new phone number
Proactive interference
*Previously learned material interferes with new material
* I lived by Parc Lafontaine and took my dog there
* After moving near Parc Marquette, someone asks me at which park I now walk my dog, and I say “ Lafontaine!”
Retroactive Interference
- New information interferes with the recall of old information
- I take my dog to Parc Marquette
- Someone asks me which park I first walked my dog, I say ‘Parc Marquette’ and not ‘Parc Lafontaine’!
- I take my dog to Parc Marquette
Getting Information into memory
- Levels of processing: the strength of a memory depends on the depth of processing when encoding
- The approach that you take to form a memory trace will depend on how well it can be activated later on
- Memories can be processed at different levels
* Focus on sensory information (shallow processing) à integrate higher-level knowledge (things we know/ figuring out the meaning; deep processing) - Memory is stronger with deep processing
Deep and Shallow encoding of faces
When you have to think about something in terms of the meaning, you have to evaluate it and link it to prior knowledge.
Shallow condition: people decided if the face was upright or inverted.
Deep condition: The person presented to them looked more like an actor or politician –> forced to think about that person at a deep, meaningful level.
Result: people recognized the faces in the deep encoding condition more than in that shallow encoding condition.
People are much better at remembering faces in the upright orientation then when its inverted. You process the face as one sort of unitized object. Inverted faces do not have that priveledge so its harder to recognize those faces.
The depth of processing an item will determine how well you can remember it.
Mnemonics
*Organizational strategies that help encode to-be-remembered information
* Often involves chunking
* Naming mnemonic: “ROY G. BIV” for the colors of the rainbow
* Story mnemonic: Create a story out of a list of words
* Method of Loci: Associate pieces of information with a location or a visual image
‘Method of Loci’ in non-experts
Three participant groups
* Mnemonic training group
* Active control group
* Passive control group
Memory assessed with word lists at
* 20 minutes, 24 hour and 4 months
* Measured the change in the number of words remembered at these timepoints
They were all given a memory test in which they had to learn and remember a list of 72 words and they had to remember this at different time points.
The group that learned the method of Loci actually had improvements in their ability to retain words from the list.
There were different neural connections in the people who werre trained with the method of loci. If you engage in different strategiess for your memory that it can really have lasting effectss and leave a neural imprint.
Implications for studying
- Review your work regularly at shorter sessions (spacing effect)
- Focus on important material at the beginning and end
of sessions (primacy and recency effects) - Link what you are learning to what you know (depth of
processing)
What’s important about working memory?
- It has a limited capacity and duration
- It is where incoming information can relate to prior knowledge and be manipulated
- It is where information enters consciousness and awareness
- It is critical for long-term memory formation
Working memory model
- Working memory components are dissociable in the brain.
- They are processed in their respective processing areas.
- Central executive: manuipulating and processing of information
Working memory components work together
- How many windows are in your house?
-
Episodic buffer – access information
from long-term memory -
Visuospatial sketchpad – imagine the
layout - Phonological loop - count the number of windows
- Central executive - guide the process (coordinate processes together)
Go deep for the long term
- Attaching information to prior knowledge within working memory will help form lasting memories.
- Meaningful encoding iss best for forming lasting memories.
Deep encoding
- Self-reference effect (link itt to prior knowledge)
1. Do these adjectives describe you? Happy, Talkative
2. Are these common words? Happy, Talkative - The first condition led to better memor (Leshikar et al., 2015)
- Generation effect (when you generate content rather than read content, you will remember it better)
1. Read these pairs: king – crown; horse - saddle
2. Generate the word: K___g – crown; H___e-saddle - The second led to better memory (Norman et al., 1978)
The encoding specificity hypothesis
- Memory retrieval is better when there is overlap with encoding context (overlap with encoding and retrieval context)
- Context can act as a retrieval cue
- Context can be:
- Internal state (e.g., mood)
- External environment (e.g., room)
State-dependent learning
Alcohol dependent learning
* Memory was better for individuals that were sober at learning and recall
* Drunk at both was better than mistmatch. Stronger match between state at learning and recall will facilitate learning.
External Context
- Participants: Deep sea divers
- Encoded/retrieved words
- Encode: On land ; Recall: On land
- Encode: Underwater; Recall: Underwater
- Encode: On land ; Recall: Underwater
- Encode: Underwater ; Recall: On land
- Encode: On land ; Recall: On land
Long term memory
Semantic: culturally shared general knowledge
Episodic memory: spatial and context
Episodic memory and the hippocampus
- Children with hippocampal damage
- Episodic memory impairment: Cannot copy images after a delay
- Semantic memory preservation: Normal factual knowledge
- Episodic is dependent on the hippocampus
- Amnesia is often regarded as a condition where episodic memory is impaired - damage to hippocampus
Semantic Dementia
- Different from Alzeihmer’s
- Relatively spared at episodic memory tasks
- Impaired at word naming and picture matching tasks –> cannot access facts
Long term memory may be a matter of consciousness?
implicit memory: us doing procedures - not consciously aware in remembering how to engage in these processes.
Episodic memories: by nature these memories are self reflective (what makes us human)
An intermediary (between episodic and semantic): Personal semantics
- Facts we have about ourselves or general workings about autobiographical events.
- Now, this idea that we have personal semantics, or maybe there’s some blurring between episodic and semantic memory, comes from early case studies of people with amnesia.
Semantic and episodic neural overlap
- Episodic and semantic memory might lie on a continuum rather than be separate systems.
- They overlap quite a bit: you are often not remembering a semantic memory vs an episodic memory - they are very interconnected.
- These results have prompted researchers to think that maybe episodic and semantic memories are not separate systems but are actually on a continuum.
- Recent fMRI studies have found a lot of overlap in activity when people engage in episodic and semantic memory tasks.
- Looked at the common areas among the semantic tasks and episodic tasks within the default mode network: important for forming internal representations or thinking about knowledge.
Blurring the lines of retrieval
- Semantic knowledge can affect the ability to retrieve detailed instances.
- If you are really at one end of the continuum you might have trouble accessing info from the other end.
- Draw a bicycle from memory -artist then created structures from drawing - people forgot a lot of aspects of the bike.
Are flashbulb memories special?
- Collected memories from event and random autobiographical events
- Recall 9/11 (flashbulb) and other autobiographical events at these
delays: - Dependent variables:
- details used to describe these events
- ratings on vividness of the recollection
- belief and confidence in their memory
Asked the people to rate their experience for remembering the even through many different scales.
Are flashbulb memories special?
- Scored detailed descriptions across retrievals for
- details that didn’t change over time (consistent details) = events consistently remembered at every time point.
- details that changed over time (inconsistent details) = switch an aspect of your recollection/memory.
Are flashbulb memories special?
- Objectively the memories are changing.
- What you find is that people rated their experience of remembering flashbulb memories as more vividly recollected and with more belief and confidence overtime.
- So there was no diminish in the vivid recollection or the belief that what they were saying was accurate for flashbulb memories, but you do see those ratings declined for every day events
