Memory Flashcards
What are the stages in memory?
REGISTRATION: Input from our senses into the memory system
ENCODING: processing and combining of received information (e.g. through repetition)
STORAGE: holding of that input in the memory system (a process of consolidation)
RETRIEVAL: recovering stored information from the memory system (remembering)
Multistore model of memory
SENSORY REGISTER: this can last just seconds
WORKING/SHORT TERM MEMORY: this lasts for a few minutes
LONG TERM MEMORY: this lasts for an indefinite period of time and has an infinite capacity
- Information that we attend to is transferred to our working (short-term) memory
- Not everything passes from our sensory experiences into working memory (just bits we attend to)
- If we rehearse something, this increases the change of transfer into working memory
- Memories can then be stored, to put them into long-term memory
What is retrieval?
The process by which memories in our long-term storage are taken out to be processed by our working memory. Retrieval is an active process. Working memory allows the active retrieval process
Types of long term memory and branches
DECLARATIVE: this memory is available to conscious retrieval, and can be declared (propositional)
- What did I eat for breakfast? (Episodic)
- What is the capital of Spain? (Semantic)
NON-DECLARATIVE: causes experience-induced change in behaviour, and canât be declared (procedural)
- How to ride a bike? (Skills)
- Phobias (Conditioning)
- Sublimal advertisement (The use by advertisers of images and sounds to influence consumersâ responses without their being consciously aware of it) (Priming)
Questions that can be asked to check episodic memory
âWhat did you have for dinner last night?â
âWhat are some of the headlines in the news?â
âHow is your team doing at the moment?â
âWhat is going on in your favourite soap?â
âHow did you get here?â
Questions to ask in clinical situations relating to memory
Do you or s/he have difficulties with remembering conversations?
Do you or s/he have difficulties with losing track of conversations
Do you or s/he have difficulties with repeating questions or information
Do you or s/he have difficulties with finding your way in familiar areas
Patient HM
- Underwent surgery for uncontrollable epileptic seizures
- He had specific lesions in the medio-temporal lobes â his hippocampi were removed
- After his surgery, he developed significant anterograde amnesia (some retrograde too)
- His seizures vanished, but so did his ability to develop memories
- He could learn new skills and recall general aspects of his life, but couldnât remember new experience
Which parts of the brain are involved in episodic memory?
Involves the medial temporal lobes including the hippocampus, entorhinal cortex, mammillary bodies, and parahippocampal cortex.
âŚ..
- Hippocampus is really important in new memory formation
- However, there are other brain regions involved as well (areas in medio-temporal lobes)
- The cerebellum plays a key role in learning motor tasks (this was preserved in HM)
- Parts of the temporal lobe are important in semantic memory
- Working memory seems to depend on the pre-frontal cortex
Hemispheric lateralisation
- Left hemisphere: Mainly concerned with verbal information processing
- Right hemisphere: Mainly concerned with non-verbal information
- People with lesions in the left hemisphere are more likely to experience difficulties with verbal memory
- People with lesions in the right hemisphere are more likely to experience non-verbal memory deficits
Formation of a memory
- There is a theory to suggest that the hippocampus is important for processing new information
- Information migrates to areas in the brain
- We can declare certain aspects of an experience, which forms a network of memory
- This network can be activated by any of the nodes within it
What is the mutiple trace theory?
- This theory states that, as well as being important in the formation of new memories, the hippocampus is also important in the activationof memory
- Therefore, when we remember something, we are also drawing on the hippocampi
Serial position effect
- We can do a âword listâ test where we call out many words, and ask them to be repeated back
- The order of repeating back does not matter â we are seeing how many we can remember
- We tend to follow the serial position effect
- This is where we tend to remember the words towards the beginning and end of the list
What does the probability of recalling a word from a list depend on?
- Order in the list
- Personal salience of words
- Number of words
- Chunking or other encoding strategy
- Delay time
- Distraction
Clinical value of serial position effect
In consultations, we give large amounts of information to patient
In order to get them to remember the key things, we can adopt these strategies:
- Give important information at the beginning and end of a consultation (e.g. take home messages)
- Emphasise and repeat important information a few times
- Make the information salient to the person (link information to their problem specifically)
- Chunk information into meaningful categories
- Avoid overloading with information
What are schemas?
- A mental structure that represents some aspect of the world
- Used to organise current knowledge and provide a framework for future understanding
- Automatic not effortful thought e.g. stereotypes
- Acquired through learning and experience
- Schemas themselves can dictate how we remember bits of information
What are associative networks and their importance in remembering?
- The information that weâve encoded and stored gets stored in a special way
- It is stored in such a way that it links to other bits of information
- Stored ideas are connected by links of meaning, strengthened through rehearsal and elaboration
- Multiple links to a given concept in memory make it easier to retrieve because of many alternative routes to locate it
How easily is memory distorted?
- Cambridge university students read a traditional native American tale)
- Reported that aspects were fantastical and didnât seem to follow logically
- Subjects asked to reproduce story to one another after a short period of time
- They changed the order, added rationalisations, and omitted parts â they normalised the story
- Most people donât realise that memory is susceptible to distortions
Memory experiment - car (smash, bump, collided, effect of leading questions)
A study showed participants a video of a collision, and they were asked how quickly the cars were going
All that happened was a change in words â they changed the word from âhitâ to âsmashâ
When they were asked how quickly the cars smashed into each other, they estimated a higher speed
The change of the word changed the perception of peopleâs memory of how fast the cars were going
EWT - factors affecting it
- If the police can use different words to ask questions during investigation, this can impact recall
- The police can influence memory of incidents
- When we activate memories from our long-term storage, we are actually changing them
- We remember the same events differently over time â we are influenced by other peopleâs recollection
- We have to take peopleâs memory recollection with a certain degree of caution
How to commit information to memory?
STEP 1: Rote
- Frequent repetition (verbal) of information
- Forms a separate schema, not closely linked to existing knowledge
- Least efficient (time consuming, and the information isnât processed very deeply)
- Less deep processing
STEP 2: Assimilation of information into existing networks
- Fitting new information into existing schema(s)
- Learning by comprehension of meaning
- Can only be used where there is link between old and new knowledge
- Deep processing aided by spaced retrieval
STEP 3: Mnemonic device
- Artificial structure for reorganising or encoding information to make it easier to remember
- Useful when info doesnât fit existing into schemas
PQRST - learning technique
> P = Preview the information to learn
> Q = Question, write down the questions that you want to be able to answer once finished
> R = Read through information that best relates to questions you want to answer
> S = Summary, summarise the information by writing, diagram, mnemonics, voice recording
> T = Test, try to answer the questions
Memory disorders
- Total amnesia is rare, especially isolated amnesia with otherwise preserved cognition
- Numerous neurological conditions can affect memory with varying lesion sites
- Lesions in the pre-frontal cortex can affect memory because of their affect on working memory
- E.g. episodic, semantic, anterograde, retrograde etc. are affected in different ways by different disorders
Alzheimerâs disease
- Disorientation for time (day, year, month) and difficulty in finding way around familiar places may be early features
- Disorientation often has both an anterograde and a retrograde component, as well as problem-solving, language and spatial components
- Memory for autobiographical or news events from the previous few years will generally show patchy impairment in the early stages, with more marked deficits as the disease progresses
- Longer-term autobiographical memory and personal factual knowledge (recognition of family members, etc.) is usually intact in the early stage
- Ability to perform overlearned skills, such as driving a car, swim, cook, etc., are usually preserved till late in the disease, but general memory, attention and executive difficulties may interfere with performance
- âImplicit memoryâ, such as the ability to learn a motor skill or react faster the second time something is seen, is usually spared till late in the disease process
What are the features of a memory disorder?
- Drop in recall after delay
- Recognition as well as recall affected
- Intrusions/false positive responses
Transient amnesia - global and epileptic
Transient global amnesia:
- 4-5 hrs
- episodes hardly recur
- after episode MRI is normal
- normally make a complete recovery
- memory gap for episode
- preceded by stress
- in 50s or 60s
- severe retrograde amnesia
Transient epileptic amnesia
- episodes less than 30 mins
- 24 hr EEG may be abnormal
- anti-epileptic meds will eliminate episodes
- some patchy recall of episode
- younger patients affected too
- outside of episode perform normally on standard memory test within 30 min delay with evidence of accelerated forgetting and remote memory impairment
What is transient global amnesia?
Transient global amnesia is a sudden, temporary episode of memory loss that canât be attributed to a more common neurological condition, such as epilepsy or stroke
What is transient epileptic amnesia?
Transient epileptic amnesia has been considered a syndrome of temporal lobe epilepsy characterized by recurrent episodes of isolated memory impairment of epileptic cause
Retrograde amnesia
- Here, there is a loss of personal identity, and intact new learning is unusual
- This may suggest a psychiatric cause for memory loss
- Psychiatric history more likely to be present
- May be precipitated by stressful personal event
- Loss of remote memory may persist for days, weeks, or months
- These patients perform normally on a memory test but can suffer from remote memory loss
- Recovery may be sudden and triggered by emotional event
Rehabilitation for memory loss
- We want to try to restore peopleâs memories to what they were/are
- In reality, we have to try to compensate for the sorts of memory difficulties that they have
- There are some aspects that promote restoration
- However, for the vast majority of people, we are looking at compensation memory aids
- People have stable memory deficits â so we need to support their memory
- To support these patients, we need to consider the nature of the memory difficulty they have
- We also need to think about the aspect of memory that is affected
- We also need to consider what the patient is required to do
- Only then, can we design effective rehabilitation strategies
Brain training and its effectiveness
- Six-week online study in which 11,430 participants trained several times each week on cognitive tasks
- The aim was to improve reasoning, memory, planning, visuo-spatial skills and attention
- Improvements were observed in every one of the cognitive tasks that were trained
- However, no evidence was found for transfer effects to untrained tasks, even when those tasks were cognitively closely related
- Brain training makes you good at doing the brain training tasks, but it doesnât seem to generalise into other, day-to-day cognitive abilities.
