Module 2- Memory L1-6 Flashcards
Define cognitive psychology
concerned with people’s thought processes and how these affect their behaviour
What is memory
process of retaining learned info, and accessing this info, when it is needed.
Why is memory important
important factor in how human beings process information.
Three processes in memory
Coding, Storage, Retrieval
What is coding
The way information is changed so that it can be stored in memory
What is storage
Keeping information within the memory system until it is needed.
What is retrieval
Recovering information stored in the memory system when it is
required.
What are the memory stores
Sensory registers, STM, LTM,
What is the sensory register
Contains unprocessed impressions of info received through the senses
-Separate sensory store for each sensory input. (Iconic, echoic)
What is STM
temporary store for information received from the SR.
What is LTM
permanent store holding limitless amounts of info for long periods of time, potentially a lifetime.
How do STM and LTM differ
terms of coding, capacity, duration, and how information is lost.
Define capacity
amount of info that can be held in memory before new incoming information displaces it.
Define duration
amount of time information can be held in a memory store before it is lost due to decay.
Coding in SR
-modality specific (each sensory store codes info differently)
Coding in STM ( Baddeley 1966, procedure and findings)
- Baddeley (1966)
- investigated coding in STM
- gave participants four lists of words to recall. (List A= sounded similar , List B= sounded dissimilar, List C= similar meanings, List D= dissimilar meanings)
- argued STM coded acoustically -> participants performed worse with A than B, but no difference between C and D.
Conclusion of Baddeley experiment (coding in STM)
- coded acoustically
- Theorised that as STM organises info based on how it sounds, similar sounding words can become muddled.
Coding in LTM (Baddeley 1966)
- repeated experiment to test coding of LTM.
- tested participant’s recall of lists after 20m delay to ensure info had passed into LTM. -Recall of C worse than D.
- No difference between A and B
Conclusion of Baddeley experiment (coding in LTM)
concluded LTM is coded semantically.
- LTM organises info based on its meaning, so words with similar meaning can become confused.
Evaluation of Baddeley (coding in LTM +STM)
+ strength- lab experiment= easy to replicate as variables have been closely controlled so reliability can be assessed
- weakness -lack ecological validity. The material (lists of unconnected words) which participants needed to recall was artificial, as was the laboratory setting.
Capacity of SR
Unlimited
Capacity of LTM
Unlimited
Capacity of STM (Jacobs 1887)
- digit span test- determine the capacity of STM.
- Gave participants several sequences of digits/ letters, asking them to repeat each sequence immediately after given , in correct order. Sequences got longer by one item each time.
- Jacobs found on average we can hold 9.3 digits and 7.3 letters.
Capacity of STM (Miller 1956)
- Miller (1956) reviewed psychological research studies and concluded that the span of STM is 7 (+/) 2.
- Try to recall more info than we have capacity for, new incoming info displaces old info.
- Found people can recall five words as easily as five letters, and so chunking can help us remember more.
Define chunking
Grouping large amounts of information into smaller groups
Evaluation of Capacity of STM (Jacobs)
+ strength- Jacob’s research= first to acknowledge that STM capacity
gradually improves with age.
- weakness - conducted a long time ago= may not been done to the same scientifically rigorous standard as research today = validity of the findings is in question.
Duration of SR
250 milliseconds
Duration of STM (Peterson and Peterson 1959)
- used nonsense trigram’s to test STM duration.
- to prevent participants keeping info in STM, maintenance rehearsal used, asked to count backwards from 100 in threes.
- After 3 seconds recall was accurate 90% of time
- After 9 seconds recall was accurate 20% of time
- After 18 seconds it was only accurate 2% of the time.
Conclusion of duration of STM (Peterson and Peterson)
info in STM lasts for 18-30 seconds without rehearsal, before lost due to decay.
Evaluation of duration of STM ( Peterson and Peterson 1959)
+ strength -high level of control (used standardised procedures to ensure all participants experienced same process)
- fixed timings for participants to count backwards from.
- eliminated noise and other factors that could have had an influence on memory.
- weakness - possibly caused by interference rather than by STM having short duration = Possible earlier learnt trigrams became confused with later ones.
Duration of LTM (Bahrick 1979)
400 participants given photo recognition test = shown 50 photos, deciding if they belonged to their classmates or not.
- In free recall test participants asked to list names they could remember from class-
- free recall of identifying FACES of school friends
- 90% accurate after 15 years
- 70% accurate after 48 years (decline)
- Free recall of NAMES of classmates
- 60% accurate after 15 years
- 30% accurate after 48 years (decline)
Conclusion of duration of LTM (Bahrick 1979)
duration is potentially a lifetime BUT sometimes we have retrieval failure and need retrieval cues to access this information.
Evaluation of duration of LTM (Bahrick 1979)
+ strength- higher ecological validity than Peterson and Peterson (duration of STM 1959) as the material was more relevant to everyday life.
- weakness- problematic to control for extraneous variables, e.g. people staying in touch after left school or how many participants have looked in their yearbook since leaving school.
What is the multi store model of memory (MSM)
- developed by Atkinson and Shiffrin (1968)
- attempts to explain how info flows from one memory store to another.
- 3 permanent structures in memory system: SR, STM, LTM.
- Each memory store differs in capacity, duration, coding and how information is lost from them.
What enters the SR
Environmental stimuli received through senses
What is the SR
- short duration store retaining unprocessed impressions of information received through the senses
- has separate sensory store for each sensory input
Examples of sensory stores in the SR
Iconic store = visual info
Echoic store= auditory info
How does info move from SR to STM
Attention - attended to and acoustically coded into STM
Selected for further processing in STM, or lost due to decay
Why can similar sounding info in STM be confused
STM is coded acoustically
What is the STM (MSM)
- temporary store for information received from the SR before it is transferred to LTM.
- info may be recalled at this point and then forgotten before it is transferred to LTM
Why is STM limited capacity (7+-2)
So info can be displaces by new incoming info
Why does info decay quick from STM
Due to short duration (18-30s), needs rehearsal info
What is maintenance rehearsal
repeatedly verbalising or thinking about the info
What is elaborative rehearsal
where info is organised in a meaningful way
How is info kept in the STM
Maintenance rehearsal
How does info move from STM to LTM
Elaborative rehearsal ( for more permanent storage) - if rehearsed enough, semantically coded into LTM
What is the LTM
permanent store holding vast amounts of information for long periods of time.
How is info recalled from LTM
Retrieved by STM (STM
Why can we sometimes not access info from LTM
Due to retrieval failure, may need retrieval cues to help access
Draw MSM
draw MSM
Evaluation of MSM
Neurobiological evidence, Laboratory experiments, General evaluation
Neurobiological evidence to support MSM (Scoville 1957)
+ Scoville (1957) treated patients (HM) epilepsy by removing hippocampus.
- HM unable to code new LTM memories
- STM unaffected
- supports the idea of separate STM and LTM.
Neurobiological evidence to support and criticise MSM (Shallice and Warrington (1970)
- Shallice and Warrington (1970) reported case of KF
- support -motorbike accident = reduced STM capacity of 1/2 digits, normal LTM .
- supports the idea of a separate STM and LTM
- criticise- Poor STM for verbal tasks, not visual tasks= suggests more than one type of STM, contradicts MSM
- Criticise- MSM states LTM retrieved by STM, therefore STM damaged, difficult to retrieve LTM but KF access LTM without any difficulty.
Laboratory experiment to support MSM (Murdock 1962)
+Murdock (1962) gave participants long list of words to recall in any order (free recall experiment).
- Words at beginning and end were recalled better than middle (serial position effect) -beginning = constantly rehearsed and transferred to LTM (the primacy effect)
- end = recalled as still in STM (the recency effect).
- This supports the idea of separate and distinct STM and LTM.
General evaluation of MSM (oversimplified)
- over simplified= assumes one type of STM and LTM.
- Research studies indicate several types of STM (phonological loop, visuo-spatial sketchpad).
- Research indicate several types of LTM (episodic memory, semantic memory, procedural memory)
General evaluation of MSM (Baddeley and Hitch 1974)
- Baddeley and Hitch (1974) claimed MSM cannot explain multitasking
- If one type of STM then multi-tasking not possible, but ppl multitask all the time e.g. radio while driving
Who developed the Working Memory Model
Baddeley and Hitch (1974)
Why did Baddeley and Hitch develop the WMM
- questioned MSM (one type of STM and LTM and inability to multitask)
- believed STM was more complex
How did STM and LTM differ in MSM and WMM
- WMM= STM seen as active store holding several pieces of info while they are being worked on
- WMM= LTM seen as passive store, only holding previously stored info to be used by STM when needed
Components of WMM
- Central executive
- phonological loop (phonological store, articulatory loop)
- Visuo-spatial sketchpad (visual cache, inner scribe)
- Episodic buffer
What does the Central executive do
- drives WMM, allocates data to the slave systems.
- Manages cognitive tasks (mental arithmetic, reasoning and problem solving)
Why can people multitask
People have limited attentional capacity
- automated tasks make less attentional demands on central executive and leave us free to perform other tasks
E,g, driving with radio
Why can an old driver listen to the radio and a new driver may not be able to?
Old driver, driving has become automated task that doesn’t make many attentional demands, so can listen to radio
What is the phonological loop?
component of WMM , deals with spoken and written material. It has two sub-components - phonological store and articulatory loop
What is the phonological store?
- Inner ear
- linked to speech perception and holds info in speech-based form (i.e. spoken words) for 1-2 seconds.
What is the articulatory loop?
- inner voice
- linked to speech production, used to rehearse and store verbal information from phonological store. allows for maintenance rehearsal.
What does the Visuo- spatial sketchpad do?
- inner eye
- stores and processes info in a visual or spatial form. (Used for navigation)
- has 2 sub components - visual cache and inner scribe
What does the visual cache do?
stores visual material about form and colour.
What does the inner scribe do?
handles spatial relationships
What is the episodic buffer?
limited capacity store, integrating info from all other WMM components and LTM.
Why did Baddeley add the episodic buffer?
- realised model needed a general storage component to operate properly
- slave systems =processing and temporary storage of specific types of info
- central executive = no storage capacity
Evaluation of the WMM
Neurobiological evidence, laboratory evidence, general evidence
Neurobiological Evidence supporting WMM (Shallice and Warrington 1970)
+ Shallice and Warrington (1970) reported case of KF
- motorbike accident = poor STM for verbally presented words but not visually presented words.
- suggests more than one type of STM, as WMM states (phonological loop, visuo-spatial sketchpad).
Laboratory Experiments supporting WMM (Baddeley and Hitch)
+ Baddeley and Hitch (1974) gave participants dual task.
- Complete reasoning task (uses central executive) and at same time, reading aloud task (uses phonological loop).
- Participants could do both tasks simultaneously very well, supporting the idea of separate components in STM.
Laboratory Experiments supporting WMM ( Baddeley et al 1975)
+ Baddeley et al. (1975) participants given brief visual presentations of lists of words.
-Lists made of short words or long words. -asked to recall list immediately in correct order, found participants recall more short words than long ones (word length effect) -supports idea that phonological loop can hold as many as can be said in 1.5 to 2 s rather than 7 (+/- 2) (MSM)
General evaluation of WMM (practical applications)
+ WMM has practical applications- has improved understanding of how people learn to read and so helped psychologists to assist Dyslexic
General evaluation of WMM (CE vague)
- criticised WMM as idea of a central executive is vague and untestable.
- Damasio (1985) case of EVR, cerebral tumour removed.
- good reasoning skills, suggested central executive intact, but couldn’t make decisions, suggests his central executive was damaged.
- case study strongly indicates that the central executive is more complicated than the WMM claims.
