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Studied by 4 people
Neuroscience of Memory
Neurons
Neurons are specialized cells for information transmission and retention.
Somas: Cell bodies containing the nucleus, genetic information, and directing protein synthesis.
Nucleus: Stores genetic information of the cell.
Dendrites: Projections from the cell body that are primary inputs; they receive signals from sensory cells or other neurons, collecting information for the neuron.
Dendritic Spines: Allow for increased synapses with terminal buttons of presynaptic axons.
Axon: Extends off the soma, splits several times; it is the main output that transmits information from the neuron.
Action Potential: Electrical current that travels down the axon when the membrane potential reaches the threshold of excitation.
Synapse: Junction between two neurons where communication occurs; axons can synapse with dendrites, cell bodies, or axons of subsequent neurons.
Myelin Sheath: Insulates axons, allowing faster transmission of signals.
Nodes of Ranvier: Gaps in myelin sheath that facilitate quicker transmission, allowing neural signals to jump between nodes instead of traversing the entire axon length.
Membrane Potential
During resting potential, the membrane is negatively charged (-70mV), with more negative ions inside.
Stimulation leads to depolarization of electrical potential in a positive direction.
When the stimulus threshold is met, sodium channels open, allowing positively charged sodium ions to rush in, resulting in +40mV action potential.
Subsequently, potassium channels open to return the membrane to resting potential after a refractory period.
Action potential can be compared to falling dominoes as sodium gates open sequentially.
All-or-None Principle: Action potentials are either generated or not—always the same intensity.
Synaptic Communication
Synapse: Chemical communication between neurons occurs here.
Terminal Button: End of the axon forming synapses with postsynaptic dendrites, axons, or somas; contains neurotransmitters.
Myelin sheath acts as an insulator to prevent signal loss or confusion in lengthy axons.
Formed by glial cells associated with neurons.
Synaptic Gap: At the synaptic end, action potentials cause vesicles to merge with the membrane, releasing neurotransmitters.
Neurotransmitters
Chemicals used for signaling between neurons:
Acetylcholine (Ach):
Excitatory: Enhances memory, suppresses memory when diminished.
Glutamate (Glu):
Excitatory: Vital for creating new memories.
Gamma-Amino Butyric Acid (GABA):
Inhibitory: Modification of glutamate, involved in new memory formation.
Norepinephrine:
Excitatory: Key in memory consolidation.
Dopamine:
Both excitatory and inhibitory: Involved in memory processing.
Synaptic Strength Changes
High Frequency Stimulation: Increases neuron firing; long-term potentiation (LTP) strengthens neuronal connections.
Long-Term Depression (LTD): Weakens neural connections, important for learning; low-frequency stimulation decreases neuron firing.
From Neurons to Tissue
Neuron cell bodies primarily found in the cortex (grey matter) with axons extending through white matter to other brain regions.
Neuroanatomy and their roles in memory:
Frontal Lobe: Controls action, emotion, thought, and memory coordination.
Parietal Lobe: Processes sensory information and spatial awareness.
Occipital Lobe: Responsible for vision.
Temporal Lobe: Critical for visual/auditory processing and retaining knowledge about the world.
Cerebellum and Brain Stem: Involved in coordination and basic life functions.
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Medial Temporal Lobe: Contains hippocampus (critical for memory) and subregions (Subiculum, CA1, CA2, CA3/4, DG).
Receives diverse information inputs via the entorhinal cortex (central to visual processing).
Frontal Lobe: Coordinates memory and aids prospective memory; organizes memory contextually.
Whole-brain Networks: Memory retrieval involves multiple interconnected regions even when at rest (Default Mode Network).
Measures of Structure
CT Scans: Cost-effective; used for bones and detecting blood clots/tumors through X-rays.
MRI: More accurate; used for soft tissue detection by measuring magnetic resonance.
Single-Cell Recording: Measures electrical activity of action potentials; invasive.
EEG: Non-invasive; measures electrical activities through scalp electrodes, providing high temporal resolution.
MEG: Non-invasive; measures subtle magnetic field changes with high temporal resolution.
PET: Invasive with radioactive isotopes; measures blood flow to the brain with lower temporal resolution.
fMRI: Non-invasive but shows changes in blood oxygen levels, provides good spatial resolution but lower temporal resolution than EEG and MEG.
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tDCS and TMS: Methods to induce/disrupt brain function using electrical or magnetic fields.
Patient Work/Special Cases:
An example is HM, with lesions in the hippocampus, affecting memory consolidation and retrieval.
Memory Processes:
Consolidation: Making memories stable; occurs during sleep which enhances memory retention (Ribot's Gradients).
Synaptic Consolidation: Forms enduring memories of recent experiences; occurs within seconds but can last for days or weeks.
Systems Consolidation: Process where long-term memories become independent of the hippocampus over time.
Reconsolidation: Memories become malleable and subject to change upon retrieval, relevant in therapies for PTSD.
Neurogenesis: May contribute to the formation of permanent memories.
ch 5 WORKING MEMORY
Involves the controlled use of information in STM
Baddeley's multicomponent model
Made up of the 1) phonological loop 2) visuospatial sketchpad 3) episodic buffer 4) central executive
Phonological loop: part of WM responsible for processing verbal and auditory information
Visuospatial sketchpad: responsible for processing visual and spatial knowledge
Episodic buffer: where multimodal information from different parts of WM are combined together. Binding creates a unified episodic memory of an experience that can be stored in LTM, such as an event model.
EB requires attention/executive resources.
Central executive: control centre, with the capacity to devote to a subsystem if needed. Regulates the flow of information in the current stream of thought as a supervisory attentional system.
Alpha higher if task is easier, lower if difficult.
Theta increased if task is difficult
Cross-system deficits are observed when executive controller processes are affected, such as when tasks involve large memory loads
What does WM do for you?
It allows you to maintain different types of content, manipulate it, and put it together to form new ideas and understandings.
Holds onto ideas as they are thought about, with multiple thoughts handled by different parts of WM
Phonological loop
Phonological store: temporary storehouse
Articulatory loop: for active rehearsal
Articulatory suppression: reduced verbal span when people speak, while simultaneously trying to remember a set of items
Lexicality effect: working memory is influenced by prior knowledge, and memory spans are larger for words than nonwords.
Evidence for phonological loop comes from word length effect, articulatory suppression, the irrelevant speech effect, phonological similarity effect, and lexicality effect.
Boundary extension: the operation of the visuospatial sketchpad depends on knowledge in LTM; if a picture does not activate this knowledge, then no boundary extension occurs.
Dynamic memory: objects in motion
Representational momentum: bias for people to misremember the location or orientation of an object further along its path than where it was the last time it was seen.
Representational gravity: distorted objects toward the earth in memory.
Representational friction: moving objects slow down when moving along another object
Overall, people are unconsciously predicting outcomes of events using the visuospatial sketchpad.
Dysexecutive syndrome: people lose some executive functions. Damage to medial frontal lobes.
Perseveration: when people have been doing a task in one way and need to do it in another way, but the switch is not made. With swan to cat they cannot detect it quickly.
Distraction: focus toward a task is gone, toward irrelevant environmental stimuli.
Cowan's Embedded processes model: says working memory is a portion of long-term memory that is in an activated state
What does WM do for you?
It is a spotlight, focusing your attention on ideas. Active use of knowledge either from the past or present.
LT WM: a way to coordinate large amounts of information. Set of retrieval cues held in working memory that reference information in LTM.
Engle's controlled attention model
WM contents are the information that is currently activated. Important how much cognitive control one has.
2 components of control 1) the scope of attention (# of items) and 2) the control of attention (effectiveness)
Measures of WM span reflect how much control people have in processing information in working memory.
WM is disrupted by unexpected tactile stimulation.
Greater WM control reduces interference effects
What does WM do for you?
It makes you intelligent. The better you control the flow of thoughts, the better you can think about things.
SPAN TESTS
In simple span tasks, not much mental work is being done.
Complex span tests - have at least two components, one retention and the other active.
Reading span: sentence span is a good predictor of language processing. Remember the last word from each sentence; 2-6 sentences
Comprehension span: people make sensibility judgements.
Operation span: math operation-word combos given in set sizes from 2-6, then the largest set size that can be accurately recalled is the operation span score.
Spatial span: initially indicate whether letters are normal, mirrored, reversed, which is active processing component. Then people do retention component.
n-back test: does the current item match the one n items ago?
NON-DECLARATIVE MEMORY - Jan 22, 2025.
Ch 6 p175-201
Classical conditioning/Pavlovian: organism learns that certain stimuli are reliable predictors of the onset of another important stimuli.
Unconditioned
Conditioned
Response
Stimulus
Stimulus-response association or stimulus-stimulus?
Abstract: unconditioned stimulus met with neutral stimulus that learns response. Then a conditioned stimulus results in CR.
Concrete: bell rang and dogs associated it with meat, so they started salivating (CR) when they heard bell (CS)
PHOBIAS:
Example with human memory: people have initial negative experiences. Then they begin to avoid those situations, creating a phobia. Also, emotionally charged negative memories are better remembered. Emotional remnants are there. US is public speaking and CS is lecture hall it happened in.
Systematic desensitization: classical conditioning to get rid of phobias. Show them pictures of the fear gradually more real.
Blocking: the prior learning of an association blocks the acquisition of any new associations for subsequent info that might occur at the same time.
Stimulus-response association: CS is directly associated with the CR, causing it to occur.
Stimulus-stimulus association: CS predicts the onset of the US, eliciting a CR in preparation for the US.
Ring the bell to make no clear causal conditioning, so not just about contiguity it is more contingency, the link has to be there.
Contiguity learning: learning occurs when an NS and US occur near each other in time. Learning is driven by some cause-effect relationship
Contingency learning: sensitivity to the underlying causal structure rather than simply relying on things happening. More important when aware of CS.
Important phenomenon:
Learning curves occur, dogs take time to obtain associations.
Extinction can occur with responses too. Contingency means associations can be broken. Probably never complete.
Spontaneous recovery: after extinction there is a delay and then the CS is presented again. Weaker CR emerges. e.g. bell elicits salivation again.
Savings: after extinction, when relearning occurs, less time is needed to learn than the first time.
Mere-exposure effects: people prefer things they have been exposed to before. Involve the right lateral frontal lobe, which is not observed with standard memory judgments.
Classic example of French painter who featured some and not others. People rated the ones on left more than ones on right. Children without exposures did not show favourability.
If you have seen something a lot and not historically tied to negative things, it will make you like it more.
i.e. top 40 music at a certain point too many exposures makes you dislike things.
Instrumental/Operant conditioning: acting on the environment and then remembering and evaluating the consequences of those actions. Not passive association. Mouse lever example, food is reinforcer, shock is a punisher.
Can train the behaviours by rewarding after observing a desired action
Thorndike's Law of Effect: the time and energy that we have available can be directed toward activities that benefit ourselves and away from activities that either provide no benefit or may cause harm.
Causal learning: people draw inferences, and is more effective when people can interact with a system, but can occur through passive observation.
Procedural and motor memory
Motor memory: memories for skills/ skilled movements behave like other memories
Must be consolidated, benefits from sleep even more than episodic or declarative
Recently learned can be disrupted by new learning
Variable practise strats are better approach than same-strategy repetition
Motor skills temporarily increase brain size
Verbal overshadowing
Declarative memory can interfere with n-declarative memory
Derails performance for higher skilled athletes, to point where nearly equated with lower skilled.
Negative transfer: prior procedural knowledge impedes the ability to learn new things. The amount experienced is a function of the degree of overlap between the old and new skills.
Tennis vs squash harder but baseball is different enough. Reactivating tennis memories.
3 stages of skill acquisition:
Cognitive stage: consciously and deliberately perform the actions of the task.
Associative stage: some effort, memories are directly associated with different aspects of the skill. Quicker.
Autonomous stage: nondeclarative, unconscious execution of actions.
s
Arduous/clumsy easier/fluid
Mutually exclusive stages^
Might use multiple at the same time v
Triarchic theory of skill learning: grounded in neurophysiological evidence.
Metacognitive system: most engaged when first learn a skill. Conscious, deliberative thought and action, devoted to processing more novel information. Involves the anterior prefrontal cortex (BA 10) and anterior temporal lobe (semantic knowledge) to reconfigure pathways and processing for brain to adapt to new skill. Acts quickly but results are not immediately long lasting.
Cognitive control network: manages process of the skill and makes execution more automatic. Brain regions involve dorsolateral prefrontal cortex (Bas 9+46), anterior cingulate cortex (Bas 24, 32, & 33), inferior frontal junction and posterior parietal cortex (BA 7). More enduring than metacognitive. Domain independent.
Representation system: dominates when skill is more practiced, cells are wired together. Memory traces are the direct mental instructions for how to do the skill, other systems less involved. Brain areas depend on the task. Domain dependent = transfer to other domains is unlikely. Automatic and enduring. Like riding a bike.
Choking under pressure: conscious thoughts compete with nondeclarative ones and reduces performance. Novices do better if focus on accuracy and experts if focus on speed.
Monitoring pressure: primarily when task involves nondeclarative memory, focuses on how they are doing the skill (e.g. being video taped).
Outcome pressure: primarily when task involves declarative memory (GPA depends on this exam) anxiety fills working memory with irrelevant information.
Multifactor gene-environment interaction model (MGIM): assumes that there are several factors that influence the achievement of expertise. Several of these factors work together.
High levels of skill with a task depend on our going through a process of moving our motor memories from a slow, deliberate process, to a quicker, more automatic process.
IMPLICIT MEMORY
Unconscious, without awareness. Might be unaware that memory is being used.
Déjà vu; intuition; savings; mimicking.
Incidental learning: we are not consciously aware of knowledge being stored in our memory.
EEG recordings show information that is remembered later involves increased theta band and decreased alpha band synchronization
Indirect tests of memory:
Priming: faster at getting target info that was facilitated by an earlier prime trial (cue).
Repetition priming: people better respond to an item that was encountered recently. Larger when the info is presented in the same way as it was encountered earlier. Even seemingly irrelevant details can influence memory later. Associated with decreased brain activity in visual cortex. Lower amount of work needed to be done because memory engrams are already at a heightened level of availability based on the recent experience.
Applies to reading, if one reads for conceptual understanding, repetition priming transfers to other texts. However, if just surface characteristics then derailed by changes in those characteristics.
Effects last a long time: reading upside down passage means you'd do it faster a year from now, even if you don't explicitly remember this moment.
Memory is compartmentalized:
Word-stem completion task: if info is already active in memory, reconstruction is facilitated. people are given the first few letters of a word and must complete the word with the first few letters that come to mind. People are likely to use words they saw recently. Inclusion and exclusion.
Word fragment completion: people are asked to complete words with missing letters. Do better if saw the words more recently. Ability remains stable even after long delay. Illustrates enduring influence of implicit memory processes on behaviour.
HM lost ability to do declarative tasks but maintained implicit memory capabilities.
Decisions/naming
Naming: quicker to name something if "primed" by related concept. "read the word aloud". Doctor nurse
Lexical decision task: quicker to decide if something is a word if PRIMED "is this a word". By activating concept, you gain fluency with that and related words
Primacy effect is small, but consistent.
Diagnose, treat, heal. "are these words related" in logical order, or swap into less logical order. Faster to respond words are related in logical event order.
Visual judgments
Priming also applies in visual stimuli: which direction is the figure facing? Then make possible vs impossible decisions, faster for ones you have seen before but only the possible shapes. Understanding of the object as a whole rather than just the parts.
Statistical learning
Sensitivity to regularities in our environment
The participant is passively presented with a stream of stimuli, sometimes with a cover task that is unrelated to the structure of the sequence.
Sets of three syllables that are regular, show to infant and they have preference for syllables they haven't seen together, showing reaction to novel
Sequence learning: sensitivity to regularities in environment. If there's a sequence, people are faster and do not actually notice sequence.
Artificial grammars: implicit memory has the ability to accept valid sequences that were never seen before and accept new sequences that used different letter sets following the same rules. Memory is better if we have an overarching structure of the artificial grammar.
Neural mechanisms
Our brains build associations we are not explicitly aware of. People get faster at processing second item in a pair because they expect to see it with the first one.
Similar brain activity: hippocampus shows A and B item have similar brain activity even though arbitrarily associated.
Implicit memory more data driven (environmental stimuli), while explicit is more conceptual (prior knowledge, expectations, and goals).
Perceptual match and original presentation vs
COOL: your brain is always tracking your experiences to try to understand the world. It does this without you having to devote conscious effort. Moreover, memory draws upon this knowledge and influences your behaviour. This is the realm of implicit memory. Because these memories operate below the radar screen of awareness, several indirect methods are needed to assess how this important part of your memory is involved in your life (201).
Ch 7 p207- 235 EPISODIC MEMORY
episodic memories: of experiences (last movie I saw)
Also subject to primacy effect (reflects novelty, better remember first item) and recency effect (more recent words better remembered than older events). Start/end less interference.
Mental models include experiential details, and are remembered over time.
Supported by the posterior medial (PM) brain network including parahippocampal cortex, retrosplenal cortex, and precuneus, angular gyrus, posterior cingulate cortex, and mPFC. Gives it flexibility.
Cueing: recall easily but need a prompt
Self-reference effect: if you can relate things to who you are, then memory will be better.
The fewer memories a cue responds to, the more likely remembering will be successful.
Context:
External contexts- hippocampus binds info together to form episodic memories. Anterior inputs correspond to content information and posterior correspond to contextual information.
Encoding specificity: ability to remember when the retrieval context matches the encoding context. Not need to be identical but similar, and can be thought about not just present.
Mood-congruent memory: it is easier to think of things that are consistent with one's current mood.
Transfer appropriate processing: memory is better when retrieval uses mental processes that are more in tune with those used at learning.
Repetition and practice
Repetition effect: more we are exposed to information, the more likely it will be remembered.
Study-phase retrieval account: when we have subsequent study sessions, this reminds us of prior sessions, allowing connections to be made between them.
Distributed practice reactivates prior memory traces, strengthening them and boosting resistance to forgetting. More connections = more elaborate memory traces.
Relational processing improves memory for info that is unclear how it relates to what is known already.
Item-specific processing improves memory when people already have well-developed organization, helping make knowledge stand out and be less affected by interference.
Prospective memory: can be focal (WM processes and medial temporal lobe) or non-focal (not part of the ongoing task, frontal lobe activity) which affects the ease with which it is done.
Episodic future thinking - draws on past episodic memories as a guide to thinking about the future
Semantic memory: of general world knowledge (what is a movie)
Mental time travel: autonoetic consciousness, replay events from the past or think about the future. Involves DMN.
This week's demo
Distinctive/bizarre stimulus seemed to pop out
Objects were overlaid on backgrounds
Some cases only one object per background, other backgrounds were associated with many objects.
Many with telephone booth for example. Had to make judgments about how well objects went together, had to process more deeply by rating (keep focused) and can see whether perceived similarity affects likelihood of remembering.
Hit rate: successfully indicating old item was old
False alarm rate: times you said new item was old that you hadn't encountered before.
Accuracy: difference of hit rate and false alarm
Many condition: objects only associated with unique background better memory.
Cue specificity is demonstrated. If there's only one cue memory is better than if cue has multiple objects associated with it.
Retrieval: same context initially studied in or different background. Better memory when context is repeated.
Context reinstatement effect ^
Can also look at interaction between these things: if there's only 1:1 mapping is the effect larger than if many objects (cue specificity). Not quite significant but numbers show small interaction.
Fit rating and memory performance: weak positive correlation, something we can look at as an exploratory analysis.
Episodic
Memory for recent or past events and experiences
Mentally 'reliving' past events
Typically what is referred as "memory"
Endel Tulving
Proposed distinction between semantic and episodic
Recognized adaptive role of EM for future planning in particular
EM and "mental time travel": allows us to recall past events and think of future plans. Useful for navigation. Important for sense of self, reflect on past events, and not unique to humans.
Autonoetic consciousness: noetic = thinking
Memory has several subcomponents that handle different elements
Mental time travel in rats
Trained rat on a maze and recorded activity In hippocampus
Replay of sequences of neural activity during exploration = during low wave sleep
Hippocampus "plays back" encoded events
Consolidation process to transfer information from hippocampus —> neocortex
Systems consolidation
During sleep, activity in the hippocampus engaged in a place specific
activity (maze) had the same structure of the representations of that
location
Wilson & McNaughton 1994
Levels of representation
We process what we experience at multiple levels
Each level encodes into a separate memory trace
Verbatim words and syntax in the text: surface form
Abstraction over the text, independent of the word and syntax used: text base
Representation of what is being described by the text : event model
Mental models
Contain information in the text and involve inferences we make based on prior knowledge and experience
Can use mental models to make decisions based on past experiences.
More easily remembered than surface level
DMN
MM supported by posterior medial brain network
DMN contributes to episodic memory (past and future) and also mind wandering
This integration and coordination gives EM its flexibility
CUEING
Cueing aids in memory retrieval by accessing memory traces with the same info
Takes 1-2 seconds
Feature cues: components of the memory, some features better than others. Self-reference effect
Context cues: context in which memory is formed, can be external or internal.
Cues are more effective if they correspond to fewer memories.
Context
Can be place, time, mental state, physiological
Binding features and context
Hippocampus integrates info from inferior (features) and posterior inputs (context based)
In demo, objects presented within the unique context so easier to recall when matched.
Encoding specificity:
Environment can provide context to memory]
Memory is improved when retrieval context matches encoding context.
SCUBA DIVING
Subjects remember more when tested in the original learning environment. If learned on land and were tested on land, memory was better than if under water.
- Can also provide our own context cues (i.e can mimic this effect by mentally reinstating the context)
- Can be useful to vary learning contexts
State dependent memory
Internal contexts physiological states
Memory is better when state during learning matches state during recall,
Mood dependent memory
Mood can be a memory context
Mood-congruent memory
Learning mood matches mood during recall. Orbitofrontal regions.
Regions activated during retrieval of emotional context associated with regions that play a role in EM retrieval.
The repetition effect
More likely to remember information if exposed to it more than once
Type of practice also impacts memory
Massed and distributed practice
Massed (4 hours)
Distributed (spread out over many sessions)
Distributed practice
Better for memory
The spacing effect or lag effect: longer spacing between practice improves memory
Effect as short as few seconds up to 1 week.
Why?
Consolidation account: mass does not allow time for consolidation, which happens during sleep
Deficient processing account: mass reflects processing deficiency. Become habituated so attend to novel info less. Less effort is required to retrieve info when studying.
Study-phase retrieval account: can remind us of prior study sessions and allow us to make connections between them. Can help to have same information across time.
Contextual variability account: distributed allows for varied context and cueing effects, environment and time change. More retrieval pathways.
Context and practice
Study gave people different contexts and mass and distributed conditions. Found distributed outperformed mass but mass benefitted from contextual variability.
Schedules of practice
Uniform: learn, practice equal spacing between
Expanding: start off with shorter delays, then increase
Contracting: start with bigger delays, then decrease as closer to test. Might be best for students.
Overlearning and permastore:
Possible to overlearn info and make it resistant to forgetting
Up to 3 years later
Memories in permastore are less likely to be forgotten
e.g. studied spanish language, advance and moderate students retained. Actors and musicians often do not need prompts
Study or test?
Learning is better if tested after studying
"testing effect" or "retrieval practice effect"
Testing increases memory consolidation
Effect not found for learning verbal information
ORGANIZATION AND DISTINCTIVENESS
Organization
Helps improve episodic memory
Via chunking info into broader categories
Reduces load on working memory
Cueing based on groups.
Segment (like phone numbers)
If we expect to use the memory later, it will impact how you engage with the info.
Distinctiveness
Separates competing memories and reduces interference
Retrieval is better for distinct information
Context can contribute to distinctiveness
VON RESTROFF effect
Emotional events, particularly negative emotional events are typically better remembered
Bizarre imagery effect
Using bizarre imagery aids in memory via distinctive processing
Only works if some of the information is “bizarre”
Unexpected events increase neural processing
Fuzzy trace memory
Different memory traces work together during retrieval
EM involves both details and gist (fuzzy info). Do not want to over-remember things.
Can help explain formation of false memories
MEMORY FOR THE FUTURE
Prospective memory:
For the future. Distinct from retrospective memory
More important the task, more likely it will be done
We are more conscious of prospective memory errors
Monitor for cues, recall what to do, retrieve memory, execute task.
Event-based:
Event signal actions that need to be done
e.g. remembering to deliver a message when you see your friend
Time-based:
Remember to do something a specific time
e.g. birthdays
Activity-based:
Complete task after another specific task is completed
e.g. send an email after a meeting
Location-based:
remember to do something when at a particular location
e.g. remember to get milk when at the grocery store
Episodic future thinking
"mental time travel"
Similar processes as episodic retrospective memory
"constructive episodic simulation hypothesis"
Easier to imagine situations we have already experienced
More difficult and less vivid than retrospective EM
MNEMICITY
Putting it all together - memory and learning
Build mental models to give information more context (draw during studying)
Relate information you're learning to something personal
Vary the context you practice in
Very schedules of practice for more consolidation
Categorize info and engage with material on a deeper level.
Faster in 1 vs many condition
Forgetting (CH 8)
Seven sins (Schacter):
Transience: memories forgotten with passage of time.
Absent-mindedness: people are not paying attention so not encoded
Blocking: people struggle accessing a desired memory because others get in the way, interference
Misattribution: forgetting the nature of a memory, not its content.
Suggestibility: memories are implanted from outside sources, possibly causing incorrect info to be forgotten
Bias: memory can be distorted toward what is currently known
Persistence: memory compromised by incorrect knowledge that should be forgotten. Failure to forget.
Can be helpful though- efficient to lose information
The forgetting curve
Can help identify neurological disorders
Linear forgetting
By knowing the pattern of forgetting, we can predict how much a person will likely remember after a given period of time
Forgetting through decay and disuse
McGeoch: events that occur between learning and testing are what causes forgetting.
New theory of disuse preserves the idea that disuse leads to poorer performance and incorporates interference and inhibition
Forgetting through interference
Proactive interference: older memories impair the ability to access newer memories
Retroactive interference: new memories impair the ability to access older memories
Associative interference: general overlap among memory traces makes it harder to recall. Fan effect = the more links "fanning" off a concept, the greater the interference from the competing associations, and retrieval time increases accordingly.
Paradox of the expert: experts have more info than novices with no deficit in the speed of remembering
Walking through doorways causes forgetting:
General interference and consolidation:
Avoiding interference through resting:
Forgetting and inhibition
Part-set cuing: people who are given part of a set of information find it harder to retrieve the rest of the set, compared to if no cue is provided, like in a simple recall test.
Negative priming: memories that were just previously sources of interference are responded to more slowly.
Retrieval practice: repeatedly retrieving part of a set of items can make the rest of a set harder to recall later.
Intentional forgetting
Directed forgetting: people are told to forget some things and remember others. TBF info is remembered worse, TBR info is remembered better. List-based is alleviated by a night's sleep, lifting memory inhibition.
Retraction: learn info and then find out it is incorrect. CIE - continued influence effect, information part of the larger event continues to influence our thinking. May not believe new info, and could be a backfire effect where they cling more strongly to the original, incorrect information. ECHO CHAMBERS.
Knowledge Revision Components framework (KReC): there are five mental processes that can affect memory change. Overtime, our misunderstandings can be corrected.
Social influences
Collaborative inhibition: people recall less in a group than as individuals. Occurs both for retrospective and prospective memory tasks. The testing effect may guard against collaborative inhibition at retrieval; shifting where the memory problems are originating from.
Collaborative facilitation: recognition is better in groups, pool resources to arrive at a consensus about what happened, although better at accepting old items than rejecting new ones.
Other people's memories: consensus bias = we assume other people know what we know, so if we have an idea we implicitly expect others to know this too. Also, people expect others to do better when the pressure is on to remember.
Drugs and alcohol
Benzodiazepines (Valium and Halcion) depressants, increase GABA-related processes which inhibit neural firing. People taking these drugs have trouble acquiring new memories. Drug-induced anterograde amnesia, impairing the ability to encode new knowledge and disrupt amygdala processing. Declarative memories mostly compromised. Diminished retroactive interference effects (no new memories).
Lecture jan 29
Autobiographical memories (ABMs)
A form of episodic memory that covers events, situations, and other knowledge about yourself that spans entire life.
Differ from episodic which is just a single event. ABM is constructive, integrative, spanning multiple events sometimes.
Vicarious ABMs: from stories we hear, which are like the memories we create for ourselves.
Can get distorted over time, and vicariously lived through (Sturniolo triplets think they were the one that a memory happened to)
Richness of autobiographical memories
Many different kinds of information encoded (sounds, emotions,
Because of their complexity, they often take longer to retrieve (2-15s) than episodic or semantic memory (1-2s)
Gender and age differences in how details are recalled.
"probably bc it was steep" - semantic
"we were at the grand canyon" - episodic
"I remember…" - narrative.
Looking at people across age groups and who had/did not have a concussion
Mostly episodic details in young adults vs semantic. Older group has fewer episodic and more semantic. No diff between older adults. Younger adults who have had concussion (>1 year after) have less episodic memory.
Barriers to study
Can be complicated, messy, and labour-intensive
Out of lab vs in lab -> clear objective reality of what is learned. But autobiographical memories are real-world so learning takes place outside of lab. Time passes where there can be decay, interference from other events, and then tested in lab without ground truth. Long time frame, years to decades.
Methods to study one's personal past
Galton-Crovitz cue word method - uses words as cues to generate the first memory that comes to mind (e.g. tree, dog, truck)
Cue phrases for life events
Diary studies - send home with diary and they keep track of the events in their life (keep track of their accounts, but is longitudinal so takes effort and investment)
Over time, retention decreases linearly, not characteristic forgetting curve.
Alternatives to diary approach
Sensecam- wear a camera, case study using a patient with amnesia. Now called a memory prosthetic, see whether it preserves their memory vs no memory aids. Tried to keep protocol similar - wrote in diary as much as pictures were taken.
Within 5 days, patient with memory problems forgot almost everything, if diary = some preservation, and Sensecam had best preservation of detail 3 months down the line. Using repetition to bypass hippocampus system the person doesn't have.
HippoCamera - 'memory prosthetic' designed as an app at UofT. Can annotate memories, create audio narrative, and then can replay memory. Had people use this for 2 weeks, then remove for at least a week. Advantage for replayed memories after 3 months. They also got ratings of quality of life, and it seemed helpful therapeutically.
1secondeveryday - social app where user's record 1s of video everyday: scanned brains in fMRI and saw how changed depending on age of memory, whether yours or someone else's and significance to you of the memory. medial parietal lobe stronger for your own, older, and more significant.
For functions of ABM
What is it for?
Reflective function - understand and define yourself
Social function - positive, but other-focused leading to interpersonal
Ruminative function - future threats and losses (risk-aversion) least used
Generative function- focused on trying to create legacy, teach others, develop achievements and connect with people and events from our past.
3 levels of ABM
"lifetime periods" - broad, theme-based portion of a person's life. (work and education)
We have different memories depending on period we are asked about. Middle school memories are more educationally oriented, and high school more socially oriented. Priorities shift. Tone of memory, details, depend on period.
"general events" - extended sequences or repeated series
Unifying smaller events into one memory (first day on the job, psyc 100 class, first exam period)
But also a class you took last semester (every Tuesday)
These require integration and interpretation - because different events must be brought together into a common memory, and people must understand how the sub-events go together.
"event-specific" - individual events
Closest to a basic, episodic memory
Contains details from diff modalities, features, emotions, space and time.
Forgotten at much higher rate than two others because more specific.
4 ways event specific memories endure:
Cause later goal-relevant memories
Turning points in a life plan is redirected
Events that become a basis for a major belief system
Anomalous events that can guide future behaviour
Taxonomy of ABMs - three categories for memory, but the lines are blurred (more of a heuristic)
Taxonomies are useful because they help us to talk about abms
Evidence for hierarchy - CUES
Different types of memories elicited by diff cues (life period, theme, valence)
"high school, achievement, positive" OR in-depth example.
Instructions social (talk about the memory as if explaining to a friend)/standard.
What details do they come up with and how does cueing differ?
Look for both general and specific details.
When they get the narrative, they have fair amount of specific details. When social condition, less specific detail (could be bc talking to a friend, shorthand). Social instruction, produce more general than specific. Standard had no difference.
Amnesiacs
Different lesions elicit different patterns of ABMs
Patient SS - left hemisphere damage. Preserved memory for general and lifetime but not specifics.
Patient KC - frontal-parietal/parietal-occipital. No autobiographical memory but personal and general semantics intact (facts).
Patient KS - right anterior temporal lobe. Preserved specific but no gen/lifetime. Most semantic is housed in front part of brain. Lacking time period/who was there.
Patient PS - thalamic damage. No personal but intact general semantics. Forgot his wedding and details but could recognize famous faces. ABM damage.
Past the acute stage, recovered.
Life narrative
Accessing narrative elements (people, places, activities, thematic info)
ABMs are life narrative memories, organized in stories, cued by their elements
Can be cued by anything, but most prominently sounds and odors.
Fresh coffee and Vicks VapoRub used as cues. Looked at how detailed the autobiographical memory was (childhood and adulthood). Remembered better when scent was used.
Odors are more memorable than others, and elicit rarer memories. Also tend to be more emotional.
Olfactory bulb is close to hippocampus and amygdala (smell, emotionality and memory are deeply interwoven).
Clustering, common elements, order, narrative, structure
Temporal contiguity effects: ABMs retrieved in temporal clusters of events.
People recall ABMs in linear order of time. Go forward in order as recounting.
Patterns of brain activity in hippocampus are similar if closer in time
Memories that are causally related are retrieved one after the other
Memories that share a person, place, or activity
People fill out their memories with semantic details
Snapshots are bad cues (poor memory for order)
Field perspective (1st person) vs observer (3rd person)
Field: newer, more emotional, less self-aware.
Observer: older, less emotional, more self-aware
Schema-copy-plus-tag model
Schemas: used to reconstruct incomplete memories
Older memories more likely to be schematized.
Tags: exceptions to that schema or rule.
Schema-copy-plus-tag model: first activate schemas as a basis, then denote important schema-inconsistent details (tags). Helps reduce the need to actively think about every little detail.
Consequently, students' memories for what happened during class are often better for unusual things that happened compared to lecture content.
Cultural differences
Schemas are deeply rooted in our culture and lifetime experiences
Japan vs America - collectivist vs individual role in event.
German more elaborative than India.
However, multiculturally, positive memories are central in defining who we are and are most important parts of life stories.
Emotion
Positivity bias/the polyanna principle: over time remember pleasant events more than negative ones.
The role of emotionality in retention
Tend to remember emotional events more than neutral ones
The emotionality of negative effects fades faster (fading affect bias)
Emotional memories more likely to have eye movements and imagery involved
Tunnel memory: increased focus on central over peripheral details in autobiographical memory. These are less likely to exhibit boundary extension and are more common for negative events.
Mental health and ABMs
Negative memories have higher staying power in anxiety
Overgeneral memories in people with depression. More schema driven, fewer details. Abms can trigger rumination that brings in persona concerns and prevents consolidation of details
Not all involuntary memories are rumination
Reducing emotionality?
Some evidence of selective interference with emotional memories
Negative and neutral information presented -> info taken away -> time passes (consolidation) -> info reactivated (or not) - either reconsolidate or administer a beta-blocker. Then information is tested.
In placebo, advantage for negative memories (no intervention). For b-blockers, reactivated memories that were negative were shown to be forgotten.
Prevents the reconsolidation. Emotionality of memory tanks in some other memories, trickled into PTSD treatment.
Electroconvulsive therapy works in the same way.
Flashbulb memories: a highly detailed and vivid memory of and emotionally significant or surprising event
1963 kennedy assassination
1986 spacecraft explosion (challenger disaster): asked undergrad students to recount their memory of when the explosion happened. Documented actual experience initially. 24 hours after the event: in class and people walked in and started talking about it, then went to room. 2.5 years later: sitting in dorm room and watching tv with roommate.
2001 9/11. Bush had a different story of where he was when he found out (in classroom)
Emotional, detailed, and confident but inaccurate.
Flashbulb memories
Novel, important event
Novelty can lead to surprise
These precipitate an emotional response
Affective attitudes shape
Reminiscence bump: more autobiographical memory around age 20
Similar trajectory to other forms of memory, with an important exception
People given list of words
Transition theory: major transitions in our lives serve as landmarks that organize how we think about and remember our lives (moving, start at new school, make new relationships)
Look at people who had major transitions after age 20, centre memories around the age they were when had major transition, transition as opposed to specific age.
Neurological explanation: brains fully developed, memory most efficient
Identity formation
Cultural drivers - used as a guide when retrieving
Children show reminiscence bump in predictions - ABM richer during them.
Ch 12
Transience
Advantage for drawing over writing in both weeks, this week there was a drop-off. General trend is downward but some exceptions. Proportional memory loss was about the same
Context reinstatement demo and cue specificity.
Right-most yellow bar barely decreased (reinstated one). Highest forgetting is when there is no cue specificity. Forgetting is lowest when cue is reinstated and only one object associated with scene.
Retrieval-induced forgetting: encode a list of categorized word (fruits: lemon). 8 categories, 4 were randomly assigned in retrieval practice, and 4 were NRP. Non-retrieval practice. Notably, none of the two-letter cues were of the fruits we studied, then final cues were.
Extra-list retrieval practice vs non-retrieval practice. See slight disadvantage for retrieval practice. So slightly impaired memory performance. Common compared to normal retrieval practice.
Natasha - guest lecture
William Utermohlen - diagnosed with Alzheimer's in 1990s
Created self-portraits throughout, become more distorted, forgetting what he looks like.
Common forgetting experience: parking spot in big mall
What would happen if you remembered every single parking spot? Remembering a lot more than normal = ppl with highly superior ABM
Endless memory video: she feels fluent in a language nobody else speaks, can overwhelm her though.
Makes way for newer, more accurate 'engrams' (neural rep of memory)
Perception of environment rat example. Initial formation of engram which can then be used to predict future events, can adapt behaviour, imagine initially met a cat that was cowardly and runs away. If prediction was slightly off, it can update and change some features. Violation of previous engram triggers reversible features/weakens connections to memory and adapts behaviour to new type of cat.
Predictions can be correct or wrong.
Schacter's seven sins of memory
Things that may lead to flaws or degradation in one's memory can be useful
Transience- overtime memories are forgotten. Adaptive because you cannot remember all details of every single day. Abstract over the memories we have and can generalize certain events. Schemas of events are based on prior knowledge. Less reproductive and more reconstructive.
In demo, memory showed transience.
Absentmindedness - not paying attention, do not encode information, same for multitasking. Taking a photograph of something makes us more likely to forget it (paying more attention to the action of photographing). Typing vs writing - typing interacts with content less. If choosing not to pay attention to something, you probably do not care about it (adaptive)
Blocking - in cuing, there can be cue overload (too many things associated with that cue so makes it less effective). Effort it takes to get to memory pushes down and makes easier to remember later on.
Misattribution - forgetting the nature/source of a memory. Common in ABM. Vivid stories may forget where they came from. Like elephant in demo.
Suggestibility - outside sources can lead to memories changing or false memories. Someone asked if you've ever been locked in grocery store (common experience) you may create details of memory that doesn’t exist. Leading questions. "hit" or "crash" cars wording changes someone's thoughts about memory.
Bias - memories can be distorted toward what you already know, leading to forgetting useful or true information. War of the ghosts story example, people removed Indigenous language and altered to be more
Persistence - false information is not forgotten:
Forgetting curves
Used as a diagnostic tool
Ebbinghaus forgetting curves. When people were testing for memory, they used it as a tool for patients with complaints about memory issues. Maybe accelerated forgetting. Controls and patients similar until 30 mins and 1 week (patient pop performed worse than control).
Forgetting of ABM is more linear. Forgetting same amount of information but proportion over time is more.
Some evidence to suggest that forgetting can be linear
Shapes can be broken down into 3 different features (shape, colour, orientation), one can act as a cue. Different features have different rates of decay.
Time/disuse alone are not enough: forgetting is linked to interference
Storage strength: how much we've learnt something. Is it there?
Retrieval strength: where interference comes in. can I get it?
Study tested participants on faces on same vs varied background. Better memory for constant background, made path to that memory quite clear and strong. But at final test, deficit in memory in constant group vs varied. Challenge of remembering made more resistant to forgetting.
Interference
Over days/weeks/months/years there may be different memories in the way so we need to clear the path to gain access to memory
Proactive interference: older memories impair retrieval of similar new memories. Left DLpfc associated.
Decreased similarity releases proactive interference. New category of stimuli improves memory, and further categories better than closer subjects (fruits vs professions)
Interleaving instead of massed studying.
Testing - shifts internal context you have from learning info. Integrate different memories so fewer competitors, more monitoring.
Sleep-dependent consolidation - differentiate old from new info.
Retroactive interference: newer memories impair retrieval of old memories especially when they are similar.
During sleep no new experiences, or memories formed.
Drugs (benzodiazepines) and alcohol.
More severe in recall than recognition (what did you see? vs did you see this?)
Associative interference: interference based on the amount of associated information
If you meet a new person, more likely to remember one fact about them than 5.
Fan effect, other memories competing with ability to do so.
Experts
Chunk info together. 5 objects associated with one place (object/background) can act as cues to help remember.
Event boundaries in memory
Doorways, scene changes, and transitions. We do this on a day-to-day basis. Change in spatio-temporal info, jump in time, walk into another room and forget what you need. Memory within event is better than memory across events.
Angular gyrus/retrosplenial cortex: when moving through an event there is a shift in activity. Peaks right before an event boundary
Parahippocampal cortex: navigationally salient landmarks (desk in space)
Hippocampus: same time as AG, a prediction error signal follows this change in cortical activity. 'whatever is happening now is different from before'
Entorhinal cortex: detects regularities in environment based on context
When error signal goes up, pattern similarity goes down.
Scene change and music change
People see variety of videos with music in background. When event boundary happens, change in music. People were tested either between event boundary or across. Within EB, memory is better.
Inhibition: one way to counteract interference
Can cause forgetting because weaken memory for one item over another (negative priming)
Forgetting
Two groups of words to study
Retrieval-induced forgetting: fruit- ap____. During test fruit- ____.
Makes apple easier to retrieve and related items harder to retrieve. Baseline is worse memory than what is practiced, but better than related words. Forgetting of related items.
Retrieval induced forgetting
Weakened memory for info closely related but unretrieved
Practice category best memory, unpracticed and similar items same level, NRP better than middle two.
In demo, with retrieval practice we used a whole new list of words. "extra-list" so may be why results did not come out as strongly.
Extensions and boundary conditions
Observed in:
Recall and recognition
Sentences that are conceptually similar
Autobiographical memories
Prospective memory
Prose
Often weaker, or non existent
When no interference to inhibit (distinctive or integrated info)
After delays
Part-set cuing: participants cued with first a portion of a list.
Memory worse.. Why?
Retrieval plan disrupted. Have an idea of how you will retrieve that information.
Retrieval competition. Cued items can bring to mind and block uncued words
Inhibition. Now cues are inhibiting activation of other memories.
Impairment due to prior exposure to related information
Negative priming: slowed response to previously seen stimuli
Retrieval induced forgetting:
Part-set cuing:
Intentional forgetting
Directed forgetting: explicitly told not to remember something. Two ways to test this. One is item method (forget these items and remember x items). Do not encode the info in their brain. Inhibited dlPFC with TMS and prevents top-down inhibition. Same as interference (inhibit activation limits ability to forget what was told to be forgotten)
List method: told to forget after shown entire list so have to use effortful inhibition (choose to inhibit memory of entire list). Stimulated dlPFC and saw more forgetting. Can do by
Social influences
Social info is a determinant of memory performance
Different reports depending on audience
"social pressures" increase memory - Queen's students.
Better memory for information heard from people relative to computer screens
We remember faces better with directed eye contact
Amnesia
Retrograde: loss of long-term memories that were previously accessible
Caused by damage to consolidation, usually a blow to the head or cardiovascular incident (a stroke). Disruption in oxygen and nutrient flow to neurons. Lasts long enough, neurons die
Loss of ABM
Nondeclarative memories generally preserved, intact semantic, public events, language, new visual/verbal memory.
Ribot's gradient: more recent memories are recently disrupted, whereas older memories are more firmly established and difficult to disrupt. When damage happens, the old ones have diversified out to cortex.
When there has not been permanent brain damage
There is a time just prior to the trauma where memories are never recovered. Permanently destroyed because disruption hits when in fragile state.
Seems like paradox but normal forgetting shows more over time and Ribot's is less. Memories around this stave are firmly consolidated.
Older memories (ribot) are more likely to bounce back as the brain heals. Newest memories will likely never recover.
Case studies:
P.S trapped in time (1940s)- stroke targeted thalamus. Thought to help organize and integrate memories. WWII vet from Britain. Profound memory loss for everything except for wartime. Interpreted through the lens of 1940s. Able to remember new famous faces but situated them in 40s.
M.L. and DR - had closed head injuries and retrograde amnesia. In time just before injury they have almost no memory, whereas they have massive amounts of memory after injury. Isolated preceding injury.
Electroconvulsive therapy ECT
Done as a therapeutic treatment often and induces amnesia, alleviates depression symptoms and leads to brief anterograde amnesia and sustained retrograde amnesia just before the procedure.
Electrodes are placed on the head, patient is strapped to table, and series of electrical pulses are passed through the brain. Unless anticonvulsants administered, shocks can cause body to convulse violently.
People lose memories of recent past, lose ABM and community-shared public memories, implicit is unaffected.
Electroconvulsive shock ECS
When used to study memory not treatment.
Rats with platform shocks - if longer delay between shock and ECS, info was stored in their brains and more resistant to ECS. Certain parts of cage associated with small foot shock so learned to follow tones associated. Controls were really good at avoiding this but those with ECS initially do not consolidate well. More consolidation more stable memories.
Anterograde amnesia
Inability to store new memories after an incident. Become frozen in time.
Damage to either medial temporal lobes and hippocampus or diencephalon.
H.M. Henry Molaison - medial temporal lobe and hippocampus. He had brain surgery in 1953 to relieve epilepsy that impaired daily functioning. Surgeons removed much of his hippocampus. He was not able to learn new things despite reduction in seizures. Damage beyond hippocampus; also uncus, amygdala and entorhinal cortex.
Normal intelligence, language ability, semantic
Partial picture completion - did not need explicit memory to do that task.
Mirror drawing - he could get better at it over time.
Beyond hippocampus
Diencephalon (above brainstem)
Thalamus, hypothalamus and mammillary bodies, connections with frontal lobe
Can be damaged via Korsakoff's syndrome - B1 deficiency related to alcoholism. Because of frontal-thalamic connections.
Thalamus has strong connections with frontal regions relevant to memory
Diencephalon anterograde amnesia: includes thalamus, hypothalamus, and mammillary bodies. Korsakoff's syndrome which occurs in chronic alcoholics. Due to deficiency in thiamine (vitamin B1) from alcoholism.
Confabulate (fabricate false memories to make up for loss), may have decline in coordinating information, and difficult to retrieve old information.
Diencephalic amnesia leads to confabulation - spontaneously producing false (or distorted/misinterpreted) memories
No intent to deceive.
Round-up of additional effects
Conscious, declarative memory is most affected by a.a. do not show distinctiveness and novelty effects, like von Restorff effect. Because cannot keep track of context. Shift in language use reflects changes in availability of info in memory. Difficulty making decisions because they have a hard time tracking how events have unfolded in the past.
More recall with recall than recognition since recognition can happen unconsciously. Indirect tasks with environmental cues rather than retrieval.
Sheila Mokes also encephalitis example could tutor on only one lesson but couldn't teach linear over time. Same with TV shows - had to be individual episodes rather than building off plot.
Clair - encephalitis and got anterograde amnesia which progressively improved over time. She keeps detailed notes and checks things off as completed. Keeps schedule and has a job but keeps pictures of coworkers and their names underneath. Some people recover entirely but usually takes minimum 18 months post trauma
Highly specific deficits
AB - hematoma causing damage to posterolateral frontal lobe, adjacent parietal lobe
Could not retain lists of words, bjut could maintain complex narratives in memory
TR - Cerebral anoxia after heart failure, likely hippocampal damage
- Remembered events, but not who was there
Other ways of acquiring anterograde amnesia are loss of oxygen to brain, brain tumours, neurological disorders such as epilepsy, or viral attacks like herpes simplex encephalitis.
It is rare to find cases of only retrograde/anterograde amnesia occurring without the other.
Transient global amnesia TGA
Cause is organic but duration is brief. Transient because lasts short time only, global = both retrograde and anterograde components. Unusual and difficult to study. 0.005% ppl experience this.
Episodes last 3-8 hours typically. Have no memories of recent past, from hours to decades although usually a few months. Even traumatic and emotional memories disrupted.
Working memory, semantic and procedural knowledge are fine. Episodic is off. No clear indicator of cause. 50-70 years old usually and once in lifetime.
May be caused by ischemia (temporary disruptions of blood flow), most likely causes are emotional/anxiety in women, and physical activity in men
Damage to CA1 subfields during TGA. Temporary impact on CA1 might be causing this.
Semantic amnesia/dementia
Deficit in the ability to retrieve semantic knowledge as a result of damage to temporal lobes.
Unlikely to be damaged by stroke because this part of brain is well supported by two major arteries
Makes it hard to retrieve word meanings
Patient MN brain has damage or missing tissue on right temporal lobe, "black holes". Interior temporal lobe damage
Difficulty remembering public events, facts and concepts. Unable to draw common items. Regression to superordinate categories.
ANOMIA -what is the object
APRAXIA - how objects are used/what movements can I do with it? Bat example baseball
Reversal of ribot's gradient with semantic amnesia as they remember episodic ABMs but not semantic facts.
Other selective deficits
Aphasia
Losing the ability to use language, generally a result of damage to left hemisphere of the brain.
Broca's aphasia - speech production difficulties but comprehension is better preserved (TMS wand where guy was targeting this area). Occurs when damage to caudal part of frontal lobe and adjoining portions of temporal lobe.
Wernicke's aphasia - speech comprehension difficulties caused by damage to posterior temporal lobe and adjoining parts of parietal lobe (BA 22). Have difficulty monitoring their own language so produce utterances that are semantically anomalous.
Amusia - difficulty comprehending or producing music
Prosopagnosia - face recognition failure. Can occur after damage to the fusiform gyrus (BA 37).
Short-term deficits: damage often in supramarginal gyrus.
Serial position curve is not shown - primacy yes but no recency. Some are verbal processing deficits, some are visuo-spatial
Damage moved over a cm or two can cause vastly different outcomes.
Not traceable to physical damage = psychogenic amnesia
No measurable physical damage, but driven psychologically. Memory loss associated with traumatic event, such as death of parent. Loss of episodic or ABM.
Repression
- Suppression of traumatic or threatening experiences, BUT limited evidence. Plant false memories so can be unempirical. Could be undetected physical trauma but harder to pick up on in basic scans.
Dissociative amnesia
- People cannot remember segments of their lives; distressing. Caused car crash for example. Troubled by the memory loss unlike repression.
Systematized: amnesia for information related to specific event
Localized: amnesia for a block of time (hours or weeks)
Generalized: nearly one's entire life is forgotten
Dissociative fugue (extremely rare)
- People forget fundamental parts of their identity (e.g. where they live)
Fugue and flight: change in identity and location
Memory fugue: loss of memories but identity is intact
Regression fugue: reversion to earlier life state, memory loss after that period.
- Dissociative identity disorder (DID)
Alternative identities, each with its own autobiographical history
Often with amnesia for the other identity's experiences that differs across identities
Wrap-up:
The distinction between short- and long-term memories is reinforced by the finding that people can have either short- or long-term amnesias.
Distinction between declarative and non-declarative memories is highlighted by the loss of declarative memories in amnesics, with largely preserved nondeclarative memories.
Amnesia- lose underlying neural tissue used to store memories
Varying degrees of accuracy in films about amnesia
Organic amnesia - resulting from a physical cause (brain damage/resection)
