Chapter 6 and 7 - Memory Flashcards
1- 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
Clive Wearing (worst case of amnesia)
* Clive Wearing’s memory was impaired, not other cognitive functions
* 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
2- Memory Processing Stages and Memory Systems
Memory Processing Stages:
- Encoding:
Creating separate memory traces to represent experiences
In the brain:
A memory trace is formed as
a hippocampal-cortical activity pattern
…memory consolidation… (with time)
- Storage:
Retaining encoded memory traces
In the brain:
Via consolidation, a memory is
transformed into a stable cortical pattern - Retrieval:
A memory is recovered when a cue activates part of a stored memory trace
In the brain:
Part of a memory trace is
activated by a cue that triggers pattern completion
Memory systems:
1. Sensory input
…goes to
2. Sensory memory (iconic, echoic, haptic)
A second!
…Information not transfered is lost
…goes to
3. Short term memory. Attentional control. (working memory)
30 seconds!
…rehearsal
…goes to
4. Long term memory (implicit/non-declarative/non-conscious= procedural and priming + explicit/declarative/conscious= episodic and semantic)
30 seconds to forever!
…retrieved to STM
3- Sensory memory
Sensory memory:
* The first and a “temporary” stage of memory
* Gustatory memory
* Olfactory memory
* Echoic memory
-Sound-byte held for ~ 3 seconds
* Haptic memory
-Very brief memory of a touch
* Iconic memory
-Millisecond visual memory
-A ‘persistence of vision’
Iconic memory: Afterimages
* Positive afterimage
- A visual memory that represents the perceived image (ex: cog dog in the sky)
* Negative afterimage
- A visual memory is the inverse of the perceived image (negative Mona Lisa…then see real Mona Lisa)
How long does [sensory] memory last?
* Sperling (1960)
* Participants briefly (.05 seconds) viewed a visual display (3*4 letters)
* Recalled the letters
1. Whole report: reported letters from the whole display
2. Partial report: reported only one row of letters at a time over trials
Results:
Whole report condition: remembered 5 items
Partial report:
delay of 0 seconds: 9 items
“ of 0.1 seconds: 7 items
“ 0.3 seconds: 6 items
“ 1 second: 5 items
In other words, sensory memory lasts for 1 second!!!
4- Short term memory and working memory
Short term memory:
* Attended information moves from sensory to short term memory
* Where? The prefrontal cortex
* Limited time capacity: ~ 20 to 30 seconds
* Limited capacity: “magical number seven plus or minus two” 7 +/- 2
Serial position effects
Primacy effects:
Remember first items on list
* Rehearsal to long term memory
Recency effects:
Remember last items on list
* If the study-recall delay duration > 30s, this effect is eliminated
Enhancing short term memory
* Chunking
* Grouping items together in a meaningful way so more
information to be represented at one time
* Remember these letters: HEN CAT DOG PIG COW
* Chunking increases with knowledge
- Expert chess players recall more
pieces on a chess board than new
chess players
- Experts use knowledge of moves to
‘chunk’ pieces together
* This effect is not present if the
pieces are on the board randomly
Game: experts recalled correctly a significantly higher number of pieces than novices
Random: The number of pieces correctly recalled does not differ between experts and novices
Working Memory Model:
Visuo-spacial sketch pad, central executive, phonological loop
Separate short term memory stores
* Neuroimaging studies
- Different areas of the brain are active for visual and verbal short term memory tasks
* Double dissociation in neuropsychological cases
- Patient ELD has problems recalling visual-spatial but not verbal material in the short term
- Patient PV has problems recalling verbal but not visual material in the short term
1. Verbal WM: The phonological loop
* Phonological store: Passive store for verbal information
Where: Broca’s and Wernicke’s
- “The inner ear”
* Articulatory control loop: Active rehearsal of verbal information
- “The inner voice”
- Used to convert written material into sounds (reading)
- A specialized role in language
2. The visuospatial sketchpad
Where: occipital lobe
* The visual cache
- information about visual
features
* The inner scribe
- information about spatial
location, movement and
sequences
3. The episodic buffer
Baddeley, 2012
Where: Parietal lobe
Integrates information from short and long term memory
ALL GO TO THE CENTRAL EXECUTIVE (SEE IMAGE)
Where: Prefrontal cortex
ACC= attention controller
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 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
5- Long term memory: Getting information into long term memory
Long term memory (implicit/non-declarative/non-conscious= procedural and priming + explicit/declarative/conscious= episodic and semantic)
Moving information to the long term
Short term memory —- encoding —- to long term explicit memory
—- retrieval —- to short term memory
Ebbinghaus
* Tested how encoded nonsense syllables were retained and forgotten from memory over time. Ex: HEF, VRA, MAG…
* 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 at a consistently fast pace: 2.5 items per second
- He did nothing else while running these experiments
The forgetting curve
* Forgetting is exponential
* Memory loss is largest early on and slows down (like U but doesn’t go back up)
The spacing effect
* Memory is better when the same amount of learning is spread out over time (first learned, then reviewed, reviewed, reviewed on spaced out days)
And better if alternating…like sometimes 30 minutes, sometimes an hour (I think)*** double check
Theories of forgetting
* Decay Theory
- Forgetting from time
* Interference Theory
- Forgetting from interfering
information
Interference theory:
* Retroactive interference (‘backward in time’)
- Newly learned information interferes with old information
- E.g., Trouble remembering your old phone number when you get a new one
- Ex: used to walk at parc lafontaine but now parc marquette, but someone asks you where you USED to walk and you say parc marquette
* Proactive interference (‘forward in time’)
- Previously learned material interferes with new information
- E.g., Trouble learning a new phone number because you remember your old one better
- Ex: used to walk at parc lafontaine but now parc marquette, but when someone asks you say parc lafontaine
Getting information into memory
* Levels of processing: the strength of a memory depends on the depth of processing when encoding
* Memories can be processed at different levels
- Focus on sensory information (shallow processing) — integrate
higher-level knowledge (things we know; deep processing)
* Memory is stronger with deep processing
Task: deep and shallow encoding of faces (one upright, one upside down)
Easier to remember upright than upside down in both conditions (shallow and deep encoding), but both easier to memorize in deep encoding
actor/politician…… see results explained in lecture cause idgi
Go deep for the long term
* Meaningful encoding is best for forming lasting memories
* Self-reference effect
1. Do these adjectives describe you? Happy, Talkative
2. Are these common words? Happy, Talkative
- The first condition led to better memory (Leshikar et al., 2015)
* Generation effect
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)
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 (memory palace)
‘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
Results: mnemonic group remembered much better than active (2nd) and passive (3rd)
6- Encoding specificity hypothesis
The encoding specificity hypothesis
* Memory retrieval is better when there is overlap with
encoding 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
24 hour delay
Sober (encoding)-sober (retrieval)
Sober (enc.) -drunk (ret.)
Drunk (enc.) -sober (ret.)
Drunk (enc.) -drunk (ret.)
Results:
Best performances:
sober-sober!
drunk-drunk!
Basically, remembered better when in the same state
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
Results:
best performance:
land-land
water-water
7- Long term explicit memory: The distinction between episodic and semantic memory
Episodic and semantic memory
- Episodic memory: specific events and episodes
- Retrieve encoding context (what, where and
when) - “Dancing at my high school prom”
- Semantic memory: facts and general information
- No retrieval of context of learning
- “Proms occur at the end of high school”
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
Semantic dementia
* Relatively spared at episodic
memory tasks
* Impaired at word naming and
picture matching tasks
Patient K.C
Episodic memory
Can remember semantic memory (facts), but not episodic memory (his own life…)
It may be a matter of consciousness
Long-term Memory:
-Anoetic Consciousness
Implicit Memory
No awareness or personal
engagement
-Noetic Consciousness
Semantic Memory
Awareness but no personal
engagement
-Autonoetic Consciousness
Episodic Memory
Awareness AND personal
engagement
Mental time travel
An intermediary: Personal semantics
Episodic and semantic memory might lie on a continuum rather than be separate systems
1. General facts (semantic memory)
2. Autobiographical facts (part of personal semantics… in between semantic and episodic). Ex: My brother’s name is Nicolas
3. Repeated events (part of personal semantics… in between semantic and episodic). Ex: I brought my brother to school
every day
4. Unique events (episodic memory)
Blurring the lines of retrieval
* Semantic knowledge can affect the ability to retrieve detailed instances
(like how a bike looks)
8- A special type of explicit memory: Flashbulb memories
Episodic memory: The reappearance
hypothesis
* An episodic memory trace is recalled the same way at each retrieval
- It is reproduced, not reconstructed
* Based on clinical observations that recurrent memories are unchanged from the original event in cases like PTSD
- Does this happen for highly emotional memories?
Flashbulb memories
* Where were you when you learned that ….
- Donald Trump was elected?
- Kobe Byrant died?
* Vivid memories of significant events that are:
- Emotionally arousing or shocking events
- Retrieve specific details about the time and place when hearing about the event
Are flashbulb memories special?
* 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
After 1 week, 6 weeks and 32 weeks
* Scored detailed descriptions across retrievals for
- details that didn’t change over time (consistent details)
- details that changed over time (inconsistent details)
Results:
No detail difference between flashbulb
and everyday memories
Flashbulb memories ratings of belief and
recollection (vividness) increased over time
Flashbulb memories change
* The 1997 verdict for the O.J. Simpson murder trial
* Participants recalled the verdict and rated emotional reaction initially and then 15 months and 32 months delay
* From initial to 15 months, 50% recollections changed (inaccurate)
* From initial to 32 months, 70% recollections changed (inaccurate); 40% major distortions
Forming flashbulb memories
* New Yorkers recalled memories of 9/11
* Half of the participants has a flashbulb-like
memory for this event predicted by distance
to the World Trade Center
Results:
closer to WTC, better recollection
**I think??
Flashbulb memories do not reappear
* Flashbulb memories are not recurrent recordings of events
* Flashbulb memory retrieval changes over time and are not resistant to memory distortion, even though memory feels strong for these events
- Distinction subjective and objective memory
* Accept the theory that memories are reconstructed
9- Distortions in explicit memory
Constructing an episodic memory trace
Remember different parts and put together. Ex: the music, the food, the people, the location, the emotions, etc.
Memory consolidation
* Experiences are encoded and then consolidated into a long term memory
trace
* The formation of stable cortical representations of memories
Memory re-consolidation
* When a trace representation becomes activated, it becomes de-stable
* Cortical connections can be strengthened and modified during this time,
which alters how the memory trace is reconsolidated
* Retrieval changes a memory trace
Application of re-consolidation
PTSD, phobias
Period of time where memories are unstable, fragile (10 minutes to an hour): rewrite it, update it or erase it: present safe information
Memory reconstruction
* Reconstructing memories at retrieval open them up to distortion
* We may infer the way things “must have been” in a recalled memory based on our schemas (interplay with semantic memory)
* We may include new and false information in the underlying memory trace
Schemas distort memories
* Schemas organize and categorize information, provide expectations
about how things should occur
* Bartlett (1932)
* The War of Ghosts experiments
- Participants read an unfamiliar Native American folk story
- Content: young men hunting seals in a river with unfamiliar supernatural details
- Did not match Western folk story structure (schema)
- Examined how the story changed with repeated retrievals
Results:
* Participants remembered a simplified version of the story and it became more conventional with repeated retrievals
* Engaged in assimilation: changing new, learned information to match our schemas
* Omissions and alterations to match Western schema
* Excluded uncommon details; “a black thing rushed out of his mouth”
* Changed uncommon activities to conventional activities, according to
their schemas: Hunting seals became fishing
Schemas can lead to false memories
* Study scenes associated with schema-consistent items removed
- Classroom without a chalkboard
* Auditory word recognition test for items
from the scenes
- Studied items: “Desks”
- Schema-related lures: “Chalkboard”
- Non-schema-related items: “Ball”
Results:
50% thought there was a chalkboard
Other example: words like sugar, chocolate, candy, pie, nice…
When asked if the word “sweet” was in it, people often said yes even though it wasn’t
Deese, Roediger, McDermott (DRM)
* Participants tend to falsely
remember semantically related lure words (Sweet) more than unrelated words
* Illustrates the influence of semantic memory
(expectations) on episodic memory
False memories
1. A familiar feeling can lead to incorrect associations
2. Details can be added to memories during retrieval
The misattribution effect
* Retrieving familiar information from the wrong source (place)
* A failure in source monitoring (not remembering the where or when accurately)
Ex: Oh I know you, you bagged my groceries the other day! (but it’s actually your professor)
The misinformation effect
* Leading questions can cause false memory
formation
* Participants viewed a simulated car crash and after, asked:
* “how fast were the cars going when they
CONTACTED each other?”
* “how fast were the cars going when they
SMASHED into each other?”
CONCLUSION: how a question is framed can affect how information is remembered
Implanting memories
* Participants recalled childhood experiences recounted by their parents over three experimental sessions
* A false memory was added to the list of experiences by the experimenter
“An overnight stay in a hospital”
* 20% of people had a false memory of this event by the end of the third
session
Virtues of reconstructive memory
* The same processes that help us construct the past help us imagine the future and plan for our lives
* These are processes of the hippocampal episodic memory system
You need your past to imagine
your future
Mental simulation of novel events
A benefit to prior knowledge
* Schemas can lead to distorted memories (War of the Ghosts experiment) and false retreival (DRM studies)
* Memory integration: related memories become interconnected via medial prefrontal cortex (prior knowledge) – hippocampal
(episodic) processes to form generalized knowledge
* Generalize knowledge requires to make inferences about the world and think flexibly
10- Implicit Memory
- Procedural memory
* Learned abilities to perform an automatic behavior/action
* The brain has encoded patterns of movements
- BASAL GANGLIA – motor sequence; Prefrontal cortex - organization
Striatum
* More immune to forgetting compared to other types of memory
Ex: walking, swimming, bicycling…
Habits: Deliberate actions become routine
* Initially rely on explicit memory; with training and or exposure then rely on implicit memory
* Motor action sequences (e.g., remember your phone’s password by just moving your fingers over the pad)
* Repetitive thoughts and emotions [Obsessive Compulsive Disorder (OCD)]
* Basis of some addictions
Forming and breaking habits
Habit Formation:
* Rats trained on a T-shaped maze with tones to signal reward (chocolate milk; sugar water) at left or right end
* Required the striatum
Breaking Habits:
* Removing a reward at one end, or making one reward gross (non-rewarding) did not break the habit
* Required inhibiting prefrontal cortex, region that monitors habit - Priming (neocortex)
* Prior exposure facilitates information processing without awareness
* Word-fragment completion test
- First, participants shown a list of words
- Then, they are asked to complete word fragments
- Result: likely to use prior words to complete the fragments - Implicit emotional responses (amygdala)
* Conditioned emotional responses
- Fear response to snakes, the dark and other scary stimuli
* Amygdala critical for implicit emotional memory (as well as modulating explicit memory … recall emotional enhancement
effect on memory)
No fear and no amygdala response: video of guy who climbed mountains with no equipment
11- Semantic Memory
Explicit memory= medial temporal lobe, diencephalon
How semantic memory stores concepts
General to Specific
Spreading activation in the semantic network
* Spreading activation
- Automatic activation spreads from an activated concept to other interconnected aspects
- Thinking about a canary will trigger activation in related bird concepts
- Spreading activation to features
* Semantic priming
- Related ideas triggered at retrieval
* Trains of thought that might seem nonsensical
Ex: might think of canary, can sing, Celine Dion
The structure of semantic representations
* Modality-specific representational forms of concepts
- E.g., Action, sound, emotion, color
*Evidence for abstracted representations
in “convergence zones”
* inferior and lateral temporal lobes
* inferior parietal cortex
12- Amnesia and Dementia
Dissociations in long term memory:
Amnesia
H.M. patient
* Experimental neurosurgery to
reduce seizure activity
* Bilateral medial temporal lobe,
including the hippocampus,
removed
* Selective episodic memory loss
* Intact short-term memory
- Can remember a short list of word for 30
seconds
* Intact procedural memory
- Could learn new skill-based tasks
* Intact semantic memory
- Could recall major historic events of childhood
* Profound episodic memory loss
- He couldn’t learn new information and recalled his past in sparse detail
* He could not remember the people, places,
and objects he saw, even after repeated
encounters
* He forgot conversations
* He could not remember what he had eaten
that day, or if he ate at all
* He had difficulty describing experiences that
had occurred from his life
He was like in a permanent present tense
Anterograde amnesia:
the inability to form NEW episodic
memories (after brain injury or psychological trauma)
* Clive Wearing
Retrograde amnesia:
* The loss of memories from BEFORE the onset of amnesia
* Temporally graded, according to Ribot’s law
- Remote memories are less affected than recent memories
Dissociative amnesia
* A very rare psychiatric disorder
* Commonly retrograde amnesia for episodic memories and autobiographical knowledge
* Leads to shifts in lifestyle such as moving to a new place, assuming a new identity
* Usually, a response to psychological or physical trauma
- Not from brain injury or malingering
* Hypometabolism in the lateral
prefrontal cortex
* Impaired executive processes
* A retrieval deficit, not a storage
deficit issue
Dementia
* Progressive cognitive and functional
impairments due to neuronal death
* 63% of all dementia cases are Alzheimer’s
disease
* Earliest symptom is a deficit in episodic memory (Collie & Maruff, 2000)
* Medial temporal lobe (MTL) regions are the first to be by AD pathology (Braak & Braak,
1991)
Probably don’t need to know all the details but:
First symptoms: memory loss (hippocampus and entorhinal cortex (medial temporal lobe)
Mild Alzheimer’s Disease: reading problems, poor object recognition, poor direction sense (spreads to lateral temporal and parietal lobes)
Moderate AD: poor judgment, impulsivity, short attention (spreads to frontal lobe)
Severe AD: loss of language and basic motor skills, function problems (widespread brain atrophy)
Alzheimer’s disease and music
* AD patients can learn and play songs (Fornazzari, et al., 2006)
* Recognition of familiar songs intact in AD (Vanstone et al., 2009)
* Music creates an alternate procedural memory pathway
* Music improves mood, reduces stress ~ improves cognition
Semantic dementia
* Neurodegeneration begins in the left
anterior temporal lobe
* Convergence zone for semantic concept
representations
* Deficits recognizing faces of friends, words,
and uses of objects
* A loss of word meaning and finding (anomia)
* Calls common objects ‘thingys’
* Impairments naming function of objects
* Problems accessing fine-grained information about concepts
Ex:
- All four-legged animals are considered dogs
- Will draw a camel without atypical features
13- Differences in memory: Aging and individual differences
Healthy aging
* Volume loss ~ 5% per decade after age of 40
* Not all areas affected equally
* Implicit memory is intact
* Semantic memory intact
* Episodic memory (and
working memory) is
impaired
Domain-general cognitive aging theories
* Older adults have deficits in general executive cognitive processes from frontal lobe atrophy
- Slower at processing information
- Can’t inhibit irrelevant information
- Ex: Older adults will have trouble focusing on one picture and ignore all other pictures on a busy wall
The associative deficit hypothesis
* Older adults have problems encoding and retrieving associations in memory due to hippocampal atrophy
* Familiarity or single items: recognizing a face (non-hippocampal)
- I know I know you from somewhere …
* Recollection: remembering a face and place (hippocampal)
- I know you from the dog park and we met yesterday morning
Older adults worse at face-name recognition: pick the correct face for the name
Adaptive cognitive aging
* Young adults (YA)
* High memory performing old adults (Old-high)
* Low memory performing old adults (Old-low)
* Memory test in the scanner showed that YA and Old-low recruited the right PFC
but Old-high recruited the bilateral PFC
* Evidence of neural compensation
Cases of extreme memory: Taxi drivers
* Memory and space are intimately linked
* ‘The knowledge’: memorize a labyrinth of 25,000 streets within a 10- kilometer radius
London taxi drivers
* Taxi drivers performed better on tests of spatial memory than bus drivers, due to greater posterior hippocampus grey matter volumes
* The volume of the posterior hippocampus in taxi drivers is related to years of experience as a taxi driver (more experience, bigger volume)
* The posterior hippocampal section is important for spatial navigation
* A larger posterior hippocampus in taxi drivers comes with a reduced anterior
hippocampus
Highly Superior Autobiographical
Memory
* HSAM people can remember every single day from their lives in detail
* Enhanced Autobiographical memory
* Recalling very detailed daily memories
* HSAM does not involve mnemonic strategies
* These are not memory athletes
* This is not photographic memory
* HSAM people do not remember a word list any better than the average person
* HSAM is specific to autobiographical memory
Downsides of superior memory:
Consistency in recalling memories (not forgetting details of the past) relates to OCD symptoms
* A case studied by Luria who had a perfect detailed memory
* Recalled conversations word for word
* Recalled detailed events from years ago
* Could reproduce 70 digits without error
* Problems with accessing general concept knowledge
* E.g., recognizing items if there a slight change in detail
This perfect “pathological memory interfered with his ability to hold a regular job, enjoy literature, or even seemingly to think in the abstract without being distracted by sensory association.” Luria, 1968
Individual differences in remembering
* Episodic remembering
- Retrieve vivid details and rich images
Remembering contextual details
and images “When I remember events, in
general I can recall people, what
they looked like, or what they were
wearing”
* Semantic remembering
- Retrieve the associated facts and
thematic links
Remembering facts or knowledge
about oneself and events
“I can learn and repeat facts easily
even if I don’t remember where I
learned them from”
