Neuropsychology of Memory Flashcards
How long is short term / working memory?
up to 30 seconds
How big is the short term memory store?
Limited to around 7 chunks (+/-2)
How long is long term memory?
Up to many decades
How big is the long term memory store?
Supposedly unlimited
How do short term memories get lost?
Even just the slightest distraction can replace the information
How do memories get lost from long term memory?
Either through retrieval failure or interference (e.g. from new memories)
What are the three main influential models of memory?
▪️Baddeley’s Working Memory model (1974)
▪️The Multi-Store Model of Memory (modal model) (1968)
▪️The Long-Term Memory Model (1987)
What are the original three main components of the working memory model?
▪️Central executive
▪️Visuospatial sketchpad
▪️Phonological loop
What are the fluid systems of the working memory model?
▪️Visuospatial sketchpad
▪️Episodic buffer
▪️Phonological loop
What are the crystallised systems of the working memory model?
▪️Visual semantics
▪️Episodic LTM
▪️Language
What are the three main stores of the Multi-Store Model of Memory?
▪️Sensory memory
▪️Short term memory
▪️Long term memory
How does information move from sensory memory into short term memory?
Through attention
How is short term memory forgotten?
Through decay or displacement
How is long term memory forgotten?
Through interference or retrieval failure
How does information move from short term memory to long term memory according to the multi store model?
Elaborate rehearsal, particularly if information is contextualised/made relevant
What are the two main types of long term memory?
▪️Declarative (explicit)
▪️Non-declarative (implicit)
What are the two types of declarative memory and where are they mapped to in the brain?
▪️Semantic (facts)
▪️Episodic (events)
Medial temporal lobe and diencephalon
What are the four types of non-declarative memory?
▪️Procedural (skills, habits)
▪️Priming
▪️Simple classical conditioning
▪️Non-associate learning
What brain region is associated with procedural memory?
Striatum
What brain region is associated with priming memory?
Neocortex
What is non-associate learning related to?
The reflex pathway
What are the two types of simple classical conditioning and what are the neurological correlates?
▪️Emotional response - amygdala
▪️Skeletal musculature - cerebellum
What is episodic memory?
Unique memories located in a specific time and place. They last up to several decades, can be verbalised, and come with a sense of recollection
What is semantic memory?
Memory of facts, both general and personal. They can be verbalised although are not associated with a sense of recollection
What is amnesia?
A disorder of new learning (anterograde)
▪️Intellectual functioning intact
▪️Working memory intact
▪️May also have retrograde amnesia (inability to recall past events)
Lesions in which brain areas are most frequently associated with amnesia?
▪️Medial temporal lobes
▪️Hippocampus
What did the study of HM teach us about the medial temporal lobes?
They play a key role in the acquisition of new memories
What is consolidation?
The process through which memories become more stable over time, making them less vulnerable to loss after injury
What is hypothesised to be the neuroanatomical underpinning of consolidation?
A complex relationship between the hippocampus and neocortex
What is the Multiple Trace Theory of consolidation?
▪️Memories are encoded in hippocampal-neocortical networks
▪️More extensive memory traces are formed and dispersed over wider areas of the hippocampal complex over time with repeated retrieval
▪️This process protects older, more extensively represented memories from damage
What did Winocur, Moscovitch, and Bontempi (2010) add to the hippocampal-neocortical network theory of consolidation?
With time and experience, a hippocampal memory supports the development of a less integrated, schematic version in the neocortex, retaining the gist of the original but with few contextual details
What type of dementia is associated with bilateral hippocampal atrophy?
Alzheimer’s disease
What type of dementia is associated with unilateral onset of MTL/hippocampal atrophy?
Semantic dementia
What type of dementia initially presents with poor new learning, getting lost, and trouble finding things?
Alzheimer’s disease
What type of dementia initially presents with preserved new learning but forgetting words and concepts?
Semantic dementia
What are the signs of left-dominant semantic dementia?
Poorer performance on naming and verbal comprehension
What are the signs of right-dominant semantic dementia?
Poorer performance with visual stimuli (e.g. faces, pictures, models)
What did Maguire (2000) find in London taxi drivers?
Greater grey matter volume in posterior hippocampi and less in the anterior - spatial memory?
What memory impairments might be seen with frontal lobe injury?
Executive impairments in retrieval strategies, attention and working memory
What brain areas, aside from the medial temporal lobes, might result in memory impairments if damaged and why?
Frontal lobes and subcortical structures such as the basal ganglia, due to complex circuitry and feedback loops
What brain area is thought to map onto the central executive?
Prefrontal cortex
What brain areas are thought to map onto the phonological loop?
Broca’s and Wernicke’s areas
What brain area is thought to map onto the episodic buffer?
Parietal lobe
What brain area is thought to map onto the visuospatial sketchpad?
Occipital lobe
What are signs of functional amnesia?
▪️Lack of organic injury (psychogenic)
▪️Variable presentation
▪️Retrograde amnesia but not so much anterograde
▪️Loss of identity
▪️Psychiatric history/comorbidity
What is the main principle of the Multiple Trace Theory of consolidation?
The more widely dispersed a memory trace is through the brain, the less vulnerable it is to degradation
What executive functions are involved in prospective memory?
Planning, initiation, and goal maintenance
What roles does executive function play in retrieval of memories?
▪️Strategic information search (shown by ability to recall with prompts)
▪️Verification of memories
What signs might indicate impairment of the role of executive function in retrieval?
▪️Confabulation - filling in the gaps when retrieval fails
▪️Intrusions - inability to filter so lots retrieved unnecessarily
How do you assess posttraumatic amnesia?
Specific tools such as the Galveston Orientation and Amnesia Test (GOAT) or the Westmead PTA scale
What are the four main processes of memory?
- Attention
- Encoding
- Storage
- Retrieval
Find where in this process it’s breaking down!
What is the first step of a memory assessment?
Clinical interview
▪️Ask about specific situations, what’s usually forgotten and what’s not affected
▪️Questions about recent events
What other neuropsychiatric factors might influence memory?
▪️Depression (concentration, effort, speed)
▪️Anxiety (WM)
▪️Fatigue
▪️Substance abuse
How might you interpret poor immediate and delayed recall but good recognition?
▪️Initial attention and retrieval issues
▪️Some encoding intact
▪️Severe depression, anxiety, or frontal lobe inefficiency
How might you interpret some immediate recall but severely impaired delayed recall and poor recognition?
▪️Clear forgetting over time
▪️Medical temporal dysfunction - early AD or other conditions affecting this area
How might you interpret reasonable immediate recall, normal recognition but poor delayed recall?
▪️Retrieval difficulties
▪️More likely frontal than medial temporal
▪️Pattern commonly seen in vascular dementia
How might you interpret very poor recognition, but relatively better immediate and delayed recall?
▪️Non-neurological?
▪️Possibly anxiety, performance anxiety, or related to motivational factors
What are the two main routes to rehabilitation?
▪️Repair and restore (e.g. medication, brain training)
▪️Compensation
What are the three main compensatory techniques used in memory rehabilitation?
- Enhanced learning
- Modifying environment
- External aids
What are the five main methods of enhanced learning?
▪️Chunking
▪️Mnemonics
▪️Elaboration
▪️Repetition - spaced retrieval
▪️Errorless learning
What is elaboration?
An enhanced learning technique that involves connecting information to something familiar, creating a story, or adding meaning to something with the aim of achieving deeper semantic processing
What is errorless learning?
An enhanced technique that involves prompting the individual after a question so that they get it right. Prompts are reduced until they don’t need it.
Aim to reduce errors in acquisition phase of memory
What group have shown the best response to errorless learning?
Those with severe memory impairment
