Lecture 4: Working Memory Flashcards
Learning objectives:
Part 1: The information processing approach to cognition.
Part 2: The development of working memory.
Part 3: Individual differences in working memory.
- Explain what working memory is.
- Describe the information processing approach to cognition.
- Discuss what processes drive the development of working memory.
- Discuss the impact having a poor working memory might have on a child.
Part 1: The information processing approach to cognition.
What is working memory?
- The small amount of information that can be held in mind and used in the execution of cognitive tasks (Cowan, 2014).
- This is in contrast to long-term memory which is the vast amount of information saved over one’s life.
Part 1: The information processing approach to cognition.
Brief history of working memory…
John Locke (1690)- distinguished between contemplation (holding an idea in mind) and memory (the power to revive an idea after it has disappeared from the mind)
William James (1890) - wrote about a distinction between primary memory (the items in consciousness and the trailing edge of what is perceived in the world) and secondary memory (the items in storage but not currently in consciousness)
Ebbinghaus (1885/1913) was one of the first to run memory experiments, used self as subject - tried to memorise lists of nonsense syllables. Found it easy to recall lists of 7, harder to recall lists of 12. Also tested the effect of delays between memorising and recall - found he forgot most words in first 20 minutes –> Ebbinghaus forgetting curve
Part 1: The information processing approach to cognition.
Information processing approach to cognition: context
Approach to explaining how cognitive development occurs was developed in the 1950s as an alternative to behaviourism (behaviour is a result of conditioning, not thought).
The central idea is humans are seen as processing systems: we encode, store and retrieve information and then produce a behavioural output (action)
Essentially a computer metaphor
Part 1: The information processing approach to cognition.
Assumptions of the I.P.A to cognition
- Info moves through a series of stores
- Info moves serially (the product for one stage of processing is the input for the next stage of processing and so on…)
- Cognitive system has a limited capacity, so, tasks and mental processes can be placed on a continuum relative to how much capacity they require –> varies from an automatic process to an effortful process
E.g., most of us have enough processing ability to walk and chew gum at the same time. But add in a maths task as well and a change in our rate of walking or gum chewing will be noticeable. Once other things are added that we need to do, different tasks will start to interfere with one another.
Part 1: The information processing approach to cognition.
Information processing approach to cognition: Origins
- Atkinson and Schiffrin (1968) devised one of the first information processing models of memory
- They proposed that we don’t just have one system or process for storing information in memory. Memory actually consists of several stores
- Therefore, memory is made up of a series of parts that work together as a process
Part 1: The information processing approach to cognition.
IPA: First Model
At A-level –> Multistore model
(Atkinson and Schiffrin)
Draw from ppt onto mindmap
- The sensory register processes information attended by our senses – provided it is processed in the short period before decay/being overwritten by other information.
- Short term memory is the space where information you have attended to is stored; it’s also where information is placed when its retrieved from LTM. How efficient this process of storage and retrieval is, is dependent on how proficient we are at attending to the right information in the first place; what strategies we use to store information and can be dependent on retrieval cues.
- Long-term memory is where things are stored permanently.
Part 1: The information processing approach to cognition.
IPA: Current model
(Baddeley and Hitch)
Draw from ppt onto mindmap
Over many years, research most notably by Baddeley, Hitch + Gatherole has added to this model.
- STM is replaced by WM which is both a short-term memory store and a place where information is actively processed.
- Working memory is where we live, mentally speaking. It’s the system that stores information long enough for us to evaluate it. It’s where information is processed and transformed.
So if you imagine you are going shopping with a mental shopping list, this would be where you have your list and when you buy something you would update your memory and knock that item off your list.
- Its capacity is limited and if something is not done to the information contained within it, it is lost. But if some operation is done on it e.g., verbal rehearsal, it will be transferred to long-term memory.
Part 1: The information processing approach to cognition.
Memory in Development
Cognitive development involves changes in:
- “Hardware” like the capacity of memory and speed of information processing
- “Software” like children’s ability to use strategy
Part 2: The development of working memory
Processing limitations - name them
Brainerd 1983:
- Encoding limitations
- Retrieval limitations
- Storage/capacity limitations
- Metacognitive limitations
Part 2: The development of working memory
Processing limitations: Encoding limitations
The crucial part about a task or experience might not be encoded. This may be driven by a failure to attend to the right information or failure to use an encoding strategy.
Attention:
- young kids have diff atteding to only important bits of tasks - poor selective attention
- older children attend to the right aspects initially so perform better in tasks
Encoding strategies
Rehearsal:
- The repetition of information
- kids under 10 were intitially thought not to use rehearsal, now we know they can use it but in a more/less effective way than adults (kids repeat words in order, adults group by theme)
Evidence rehearsal helps:
- With age, kids can say words faster and memory span increases accordingly
- bilingual studies - welsh kids have better number memory for english numbers than welsh because they can be articulated quicker
Organisation:
- kids <10 don’t organise items into categories for easier memorisation
Elaboration:
- like adults, kids remember pairs of words better if provided with an association between them, but kids seem unable to form associations themselves, or if they can they are less effective (distinctive) elaborations
Part 2: The development of working memory
Processing limitations: Retrieval limitations
Children may know the retrieval strategy they need to apply, but retrieve the wrong one from memory (retrieve rules for division rather than multiplication).
- reflects a lack of knowledge and experience using retrieval strategies
Adults are good at coming up with retrieval strategies e.g retrace steps to find keys. While 10y/os can name at least 1 strategy, half of 5y/os can
Part 2: The development of working memory
Processing limitations: Storage/ Capacity limitations
This limits the amount of information a child can store and thus remember.
Storage is typically measured by giving a randomly ordered selection of unrelated items (numbers or words) that need to be recalled in the exact order.
Storage capacity increases with age
But… Experience can affect storage ability - when tested on chess positions child chess experts outperformed non-expert adults, but adults outperformed kids on digits - it is experience of specific domains that affects storage limits
Span tests only measure STM. A more sensitive test of memory storage limits is when info is transformed as well as stored. Taps into storage and processing side of WM.
Working memory span is usually two items less than a child’s short-term memory span
Part 2: The development of working memory
Processing limitations: Metacognitive limitations
Metacognition - thinking about thinking
Due to poor metacognitive skills and limited experience, kids may not be aware they have memory limitations so they may not make an effort to encode something properly.
- children overestimate their own memory
- v young children possess too limited WM capacity so that use of strategies would impair, rather than improve recall.
- children don‘t realise how useful strategies are
- children have less world knowledge that other information can be integrated with to store it better (the chess player study). But…
More knowledge can also sometimes lead to more errors in recall, such as:
- “Recalling“ details that had never been mentioned
- Overgeneralising facts to situations in which they don‘t apply
- Adding facts that fit in with previous knowledge but did not apply to a specific situation
Part 3: Individual differences in Working Memory
Working memory and language
Working memory supports other developing skills:
- Language
- Academic skills (particularly maths)
- General school readiness
Working memory is important for vocab acquisition before children start school
- 3- to 4-year-olds with better working memory learned novel labels for toys significantly faster than children with poor working memory.
Working memory is also important for language comprehension. This helps when processing complex sentences.
However, because this is a correlational relationship it is possible that children with better language ability are able to use better strategies on working memory tasks…
