5- Memory Flashcards
What is prospective memory?
Prospective memory is remembering to do something. Involves linking an external stimulus (time point/location) to an action plan.
How is prospective memory linked to executive function?
Inhibition (e.g. impulse control) shifting from one task to another, planning, strategizing, generating ideas.
What conditions are associated with impaired prospective memory?
TBI
Multiple Sclerosis
Dementia
ADHD
Autism
What is the model for retrospective memory?
The Tulving Model
We divide retrospective memory into:
1. Duration i.e. Short-term vs long-term
2. Explicit (under voluntary control, amenable to conscious reflection) vs implicit (not under voluntary control)
All memory systems are prone to interference. What does this mean?
There is competition between “similar” information.
What is episodic memory?
Memory for “lived experience”. Involves detailed representation e.g. the taste of your breakfast this morning. Episodic memories is triggered by sensations.
Episodic memory is often characterised by autonoetic consciousness, what does this mean?
Autonoetic consciousness- as well as remembering events you have the sense that you were actually there. It involves projecting yourself in time.
What is semantic memory?
General world knowledge i.e. word meanings, concepts, facts, memory of word forms, voices, faces.
Compare/contrast episodic and semantic memory
Episodic memory= detailed representation of lived experience (1st person perspective) and involves autonoetic consciousness.
Whereas, semantic memory is more abstract.
Episodic memory more prone to forgetting, information may be transferred to semantic memory, but loses some rich detail e.g. For a child “dog” may refer to the family’s pet dog (strongly episodic representation)
Over time a more abstract meaning of “dog” is stored in semantic memory
What is the evidence for episodic/semantic distinction?
Patients with damage to medial temporal lobes have no ability to acquire new episodic memories (anterograde episodic memory) and have poor premorbid episodic memory (retrograde episodic memory) but semantic memory is relatively spared.
What is procedural memory?
Procedural memory= long term and implicit. It is automatic and unconscious and mainly motor tasks e.g. putting a code in a door, typing. (had to learn where keys were first and this is now in procedural memory)
Patient HM (procedural-declarative distinction). + Procedural memory difficulty with DLD children
Pre-surgery retrograde episodic and semantic memory partially effected, post surgery anterograde memory substantially effected but procedural memory spared. E.G. he learnt how to mirror write but could not recall training sessions.
DLD- difficulties with procedural memory which will affect sentence structure, syntax, morphology.
What is working memory?
Working memory is a limited capacity system that is capable of briefly storing and manipulating information involved in the performance of complex cognitive tasks e.g. reasoning, comprehension.
How do working memory and STM differ?
Working memory assumes both storage AND manipulation/processing of information. Whereas short term memory is purely storage of information. STM is involved in serial recall (remembering things in correct order).
Baddeley and Hitch- multicomponent model for working memory.
The central executive
The episodic buffer (for episodic LTM)
The visuospatial sketchpad (concerned with visual storage and processing/visual semantics) +
The phonological loop (acoustic equivalent for language).
What is the phonological loop?
Two parts. A short-term PHONOLOGICAL STORE that maintains info in that store
+ An ARTICULATORY CONTROL PROCESS where we sub-vocally repeat the info in order to retain it (silent repetition of stimulus). Measured by non-word repetition.
Evidence for phonological loop?
Strongly correlated with word-learning in children aged 4-5
We need to store new words for a sufficient length of time in order to “extract phonological regularities”
Very poor non-word repetition in children with DLD.
Evidence of phonological store= the phonological similarity effect, whereby people are less accurate in repeating back sequences of similar-sounding words such as MAN CAP CAT MAT CAN, than dissimilar words such as PIT DAY COW PEN TOP.
Evidence for the importance of rehearsal/ articulatory control = the word length effect, whereby immediate recall of long words (e.g. REFRIGERATOR UNIVERSITY TUBERCULOSIS OPPORTUNITY HIPPOPOTAMUS) is much more error-prone than for short words.
How does the phonological loop support acquisition of language?
Provides temporary means of storing new words while they are consolidated in phonological LTM
SLI impaired children deficit in…
Repeating non words due to impaired phonological STM
What is the episodic buffer?
Storage system It accounts for story recall in patients with anterograde amnesia (could not form new memories)
What is the visuospatial sketchpad?
Visual working memory designed to support any task that involves short-term maintenance of visual information. It creates and maintains a visuospatial representation that we can use when attempting to answer questions such as describe the route you take home.
Where is the Visuospatial sketch pad suspected to be located?
Right hemisphere- visual occipital and parietal (spatial aspects)
What is the central executive?
An attentional control system that has the role of controlling action. Does not have storage capacity itself.
Behaviour that is routine and habitual is controlled automatically by a range of schemas, well-learned processes that allow us to respond appropriately to the environment. An experienced driver on a routine trip would be a good example of this, sometimes arriving at the destination with no memory of the journey. When such procedures are no longer adequate, for example finding the normal route blocked by an accident, a second system, the Supervisory Attentional System (SAS) comes into operation. This is capable of using long-term knowledge in order to set up possible solutions, and reflect on them before choosing the best. In the case of our interrupted journey, this might involve the central executive of working memory, probably in connection with LTM, the visuospatial sketchpad, and possibly the phonological loop
What is echoic memory?
Memory for sensory representations- decays very rapidly
What is autobiographical memory?
Memory of information/ events which are unique to us. Helps us to make sense of who we are. Information distributed across episodic and semantic memory system.
What is cultural memory?
Our personal memories are “entwined” with cultural memories e.g… What were you doing when X happened?
Distributed cognition = “offloading” our memories to external cultural artefacts.
What is “choking” in sports?
Choking is the explicit analysis of skills and routines which would typically be represented in procedural memory (in an implicit fashion).
It is when procedural memory fails- something that should be implicit becomes explicit due to stress/pressure.
Considering paradigms of memory, what is more difficult recall or recognition?
Recall- it establishes stronger memories
Tests for short-term memory
Complex span tasks (shown a complex figure then client must copy it from memory)
Nonword repetition
Digit recall + backwards digit recall
Tests for episodic memory
- Paired associate learning (the associations are completely random so have to use episodic rather than semantic)
- Picture sequence memory test (series of pictures with no obvious sequence so to remember must use episodic rather than semantic)
Tests for semantic memory
- Word fluency (but note influence of central executive)
- Picture naming
- Synonym judgements e.g. red/scarlett
- Conceptual tasks e.g. drawing from memory, providing word definitions, Pyramids and Palm Trees.
Tests of Procedural Memory
- Serial reaction time task
- Pursuit Rotor Task
- Tower of Hanoi (proceduralisation). Starts out being explicit task using working mem/central executive but overtime becomes proceduralised= faster reaction times.
Relating to memory, why is sentence repetition the best marker of language impairment?
People w language impairment will make changes to words and structure of the sentence. The issue lies with LTM not STM/Working memory. Working memory too fragile to support language processing. Have to reconstruct the sentence you heard from information in LTM.
What is the process called where you repeat previously heard structures?
STUCTURAL/ SYNTACTIC PRIMING. It involves representations in long-term memory, because short term memory is insufficient to support recall, sentence repetition involves the reconstruction of the sentence based on activated representations in long-term memory.
What is chunking?
The process of combining multiple items into a single item in order to facilitate processing and recall of information. It is a solution to the fragility of short term memory.
Long-term memory disorders- EPISODIC MEMORY DISORDERS
AMNESIA
Not dementia because its not progressive. Problems with memory for events, episodes in own life (autobiographical memory) and world at large (extra personal memory)
Location of lesions in AMNESIA
Associated with lesions in:
Diencephalon (thalamus, hypothalamus, mammillary nuclei)
Medial temporal lobes (hippocampus, amygdala)
Frontal Lobe
Medial temporal lobe structure
Hippocampus, amygdala and nearby cortical areas: entorhinal cortex, perirhinal cortex, and parahippocampal cortex
What is Anterograde Amnesia?
Poor recollection about events AFTER onset
Cannot retain NEW INFORMATION- novel addresses, word list, story content, faces
Recognition vs recall- have you seen/heard this before (easy) vs what did you see/hear before (difficult)
Poor SUBSEQUENT learning
How to assess anterograde amnesia
List, fact, address or story recall.
Route learning
Immediate vs delayed recall
Recounting day’s activities
Functional difficulties of people with anterograde amnesia:
Daily routine, meals, pills, visitors, appointments, time, can’t learn new routine
What is retrograde amnesia?
Poor recollection about events BEFORE onset about own life (autobiographical). Particular difficulty remembering if they happened and when they happened in relation to other events
Recognise famous people/events
Subsequent learning is fine- can relearn about their past
How is retrograde amnesia assessed?
Autobiographical memory interview
Recognition of time limited events
Ordering events in time
Long-term memory disorders- SEMANTIC MEMORY DISORDERS
SEMANTIC DEMENTIA:
Profound affect on language (spoken + written) and other aspects of communication (gesture, signing). Affects word meanings.
Semantic dementia is a subtype of primary progressive aphasia.
Rare “category specific” semantic deficits.
Location of lesions in SEMANTIC MEMORY DISORDERS/ SEMANTIC DEMENTIA
Anterior and inferior temporal lobe.
Particularly left infero-lateral temporal lobe.
What is echoing?
Repetition of what conversation partner has said. Common in semantic dementia as it bypasses the semantic system
Test for semantic memory. Super-ordinate, sub-ordinate conceptual test
Super-ordinate e.g. Which is the animal? (1 pic of a frog, 2 of vegetables) is the easiest.
Sub-ordinate e.g. Which is the insect? (1 pic of insect, 2 of fish) more difficulty
Which is the largest? (3 animals that look same size on pictures) is most difficult as have to use your semantic knowledge.
Semantic memory DEFINING WORDS TEST
Better at defining abstract words than concrete words.
Low frequency words worse than high frequency in both categories.
In people with semantic memory disorders, schemas can be relatively intact- what are schemas?
Part of semantic memory, over learnt routines for example eating.
A well integrated chunk of knowledge about the world, events, people or actions.
- Scripts: knowledge about events and consequences of events e.g. know not to put hand on candle.
- Frames: knowledge structures referring to some aspects of the world (e.g. building) containing fixed structural information.
Is Alzheimer’s disease impaired episodic or impaired semantic memory?
BOTH. Impaired semantic memory is a common feature but is invariably overshadowed by episodic memory deficit.
Give examples of assessment for semantic memory
Must measure performance across a range of modalities since tasks can yield sub-normal performance sue to impairments in other processes that must interact with semantic knowledge, such as visual perception or speech production. CONSISTENTLY POOR PERFORMANCE across tests
Tests: 1) Category fluency e.g. tell me the names of as many animals you can think of in one minute
2) Confrontation naming
3) Naming to description
4) Picture Sorting at superordinate, category and sub-ordinate levels
5) Verification of semantic attribute questions: does an elephant lay eggs?
6) Word-picture matching
7) Generation of verbal definitions
8) Tests of associative semantics: the patient is asked to match a target item (e.g. an elephant) with one of two alter-native response choices (e.g. a circus tent or a farm).
Category fluency often impaired in early course of AD, explain this pattern.
AD patients are significantly more impaired
in category than letter fluency, although both of these tasks require the adequate functions of attention, working memory, etc. Patients with other forms of dementia involving mainly subcortical structures (Huntington’s disease,
Parkinson’s disease, progressive supranuclear palsy, etc.) show the opposite pattern (more correct responses to categories than to letters)‘“.
What is Herpes Simplex encephalitis
HSVE is a brain infection. Results in category specific loss of semantic memory. Disproportionate loss of knowledge about “natural kinds” (living things such as animals, fruits, vegetables) with relative preservation of knowledge about artefacts (inanimate objects such as house-hold items or tools).
Neuroanatomically, this aligns with HSVE damage typically being in ventral temporal structures, distinct from the inferior parietal region damaged in strokes that don’t usually cause this category effect. This suggests separate brain areas for these types of knowledge. Functional imaging (PET) studies further back this up, showing different temporal vs. parietal activation for tasks involving living things vs. objects
Short -term memory disorders: what is the sentence superiority effect?
Being able to repeat sentences rather than random words. Means involvement in LTM rather than short term. SO THERE IS DOUBLE DISSOCIATION BETWEEN LISTS AND SENTENCES
Short-term memory disorders: auditory repetition span (serial recall)
Auditory-verbal and auditory-pointing showed same pattern, repetition of one item okay, worse as number of items increased.
What is semantic dementia?
Deterioration of semantic memory. Decline in both ability to understand and express language as well as recognise familiar objects and people.
Spontaneous speech categorised as “empty” with word finding difficulties and occasional semantic errors, but is fluent with normal articulation and phonology.
Despite the widespread loss of conceptual knowledge, other cognitive functions like visuospatial skills, executive functions, short-term memory, and nonverbal problem-solving abilities are generally preserved in semantic dementia. This distinguishes it from conditions like Alzheimer’s disease, where multiple cognitive domains are affected.
Unlike AD, preserved episodic memory.
Brain imaging studies reveal focal atrophy in the anterior and infero-lateral temporal lobes.
What brain regions are crucial for semantic memory function?
Infero-lateral regions of the temporal lobes.
Left infero-lateral temporal lobe.
Additionally, some evidence suggests that the antero-lateral right temporal lobe may be specifically involved in the representation of person-specific knowledge. difficulty in face recognition (prosopagnosia),
What research supports a double dissociation between word lists and sentences?
STM disorder- showed sentence superiority effect, better able to repeat sentences with many words rather than a list of random words. Due to involvement of LTM, rather than STM for sentence recall.
What are the features of phonological versus semantic short-term memory disorders?
Martin & Allen (2008)
Phonological STM impairment= better performance in semantic probe than rhyme probe task. Better performance with short words than long words. Better performance in span-tasks with words rather than non-words.
Semantic STM impairment= better performance in rhyme probe than semantic prove tasks. NO length effect, similar performance between word/non-word tasks.
“Complex” working memory task= COMPLEX SPAN TASK, what is this?
Simultaneously processing sentences (with verification questions) and remembering the last word of each. High correlation between performance on this task and reading comprehension of complex sentences
