MEMORY
Short + Long Term Memory (week of 15th Oct)
- Evidence for STM/LTM distinction
Glanzes + Cunitz
- Gave p.pants a list of neutral words verbally then asked them to recall them in any order immediately
- Found earlier words were better recalled (Primary effect) they’d been rehearsed. Later words were also better recalled (Recency effect) still fresh in the STM
- Continued study having new p.pants, list of words verbally + 30 second distraction task to delay recall
- Primary effect still intake, but recency effect no longer existed = most recent words in STM were displaced by the distractor task
- Suggests STM + LTM are different stores as one can be destroyed without the other
Capacity of STM
- Capacity – how much info memory can hold
- Miller – ‘The magical number 7 +/- 2’
- Jacobs – ‘Digit Span Technique (1887)’
- P.pants recall strings of digits in presentation order. Numbers of digits increase until p.pants can no longer recall them correctly (this may measure STM)
- RESULTS:
- Average no. of numbers recalled = 9.3
- Average no. of letters recalled = 7.3
- Info is lost from STM by displacement (full STM + new info pushes oldest info out)
Capacity of LTM
- Unlimited. There’s no way of testing this so it’s believed to be unlimited
Duration of STM
- Duration – how long info will remain without rehearsal
- Peterson & Peterson – tested on duration of STM using trigrams (3 consonants in a triangle)
- P.pants were shown these briefly then given a distraction task lasting 3-18 seconds before recall
- P.pants could recall about 80% of trigrams after 3 seconds
- By 18 seconds less than 10% trigrams were correctly recalled
Duration of LTM
- Bahrick et al – tested 400 people aged 17-74 asked them identify names of classmates from photos/year book
- RESULTS:
- P.pants tested within 15 years of graduating had a 90% recall
- After 48 years it was 70%
- In a free recall task (without photos/names)
- 60% effective after 15 years, but only 30% after 48 years
- Suggests recall is easier with retrieval cues
- Suggests LTM distraction is indefinite but more than 48 years on average (info hasn’t faded away, but just harder to retrieve)
Coding in STM (week of 19th Oct)
- Coding – the format information is stored in
- Conrad – gave p.pants either a list of acoustically similar letters or acoustically dissimilar letters. Then asked for immediate serial recall
- Recall was significantly worse for the group with acoustically similar letters
- Suggests STM codes mainly acoustically
Coding in LTM
- Baddeley – created pools of acoustically similar & dissimilar words, semantically similar & dissimilar words
- STM – gave 1 of 4 lists, asked for immediate recall
- RESULTS = only acoustically similar words were confused = supports Conrad
- LTM – p.pants given 1 of 4 lists of 10 words then distracted, then repeated task another 3 times. Asked for serial recall 20 mins later
- RESULTS = only semantically similar words were affected
- Suggests LTM codes mainly semantically
(AO3) EVALUATION OF RESEARCH INTO STM + LTM
- Capacity
- Cowan + other psychologists argue STM capacity may be less than 7 +/- 2
- Capacity of STM can be increased through ‘chunking’
- Individual differences
- Duration
- Testing STM was artificial – lacks mundane realism
- STM results may be caused by displacement
- Coding
- Baddelely may not have tested LTM at all – what is the definition of long term, 20 mins?
- STM may not be exclusively acoustic
- LTM may not be exclusively semantic
The Multi-store Model of Memory
- Atkinson + Shiffrin
- Information – processing approach (e.g. computer analogy, everything is saved in the same manner/format)
(AO3) EVALUATION OF MSM OF MEMORY
- Plenty of research support for separate STM + LTM
- Glazer + Cunitz = primary + recency effects
- Peterson + Peterson / Bahrick
- Physiological evidence: Beardsley – found pre-frontal cortex in brain activated during STM tasks, but not LTM tasks
- Squire – found hippocampus activates during LTM tasks, but not STM
- Supports MSM of memory
- Support from case studies
- ‘HM’ = had hippocampus removed to reduce epilepsy – STM intake, existing LTM intact, but unable to make new LTMs
- Supports MSM’s theory of there being separate stores
- Opposition from case studies
- ‘KF’ = motorcycle accident damaged STM, only left with capacity of 2, but still able to make new LTM
- MSM can’t explain this
- MSM is too simple
- LTM + STM aren’t unitary stores
- ‘KF’ case suggests selective disruption – some parts can be damaged while others remain intact
- Maintenance rehearsal isn’t the only/best rehearsal
- 3 types of LTM = semantic (knowledge = sometimes maintenance rehearsal) , episodic (events = not maintenance rehearsal), procedural (skills learnt = maintenance rehearsal)
- Craik + Lockhart – level of processing is more important for LTM
- STM/LTM distinction is unclear
- Many tasks use STM will use LTM as it possess info
- Ruchkin – gave one group real words and the other ‘pseudo’ words to recall
- ‘pseudo’ group only used STM, while ‘real word’ group used both STM and LTM parts simultaneously
- It’s possible that STM is a separately functioning part of LTM rather than a completely separate unit
The Working Memory Model (Week of 5th Nov)
- Baddeley + Hitch
- Two-way flow of information
- Replaces the too simplistic STM
- Accepts concepts of sensory memory and LTM
- Principle control through, Central Executive (uses two slave components when necessary)
(AO3) EVALUATION OF WMM (Week of 9th Nov)
- Can explain dual task performance
- Hitch & Baddeley – gave one group a difficult task and an easy task to complete simultaneously
- Another group had two difficult tasks
- 2nd task takes longer as it requires the CE for both, while 2st group could give easier task to PL
- Evidence from brain damage patients that STM is made up of separate stores
- KF (Shallice & Warrington) - STM was severely damaged but only in the case of auditory info. He could remember meaningful sounds
- Suggests that only PL was affected
- LH (Farah) – could complete spatial tasks better than visual ones after a road accident, VSS may need to be further split
- Supports the WMM’s STM split into many compartments
- CE is too vague
- May need to be further split, agreed to be our ‘attention’ and allocates resources to other compartments
- Eslinger & Damasio found EVR had tumour removed and showed good reasoning but poor decision making skills so CE may be partly damaged
- Suggests CE may need to be split more
- Evidence from brain damage patients may be unreliable
- The trauma of such events may affect or damage memory
- May affect attention span, so may not have affected memory but attention indirectly impacts their memory
- Brain damage patients may not be valid as it may not apply to the wider population
Types of Long Term Memory
Explicit/Declarative: Semantic and Episodic = ‘knowing that’
Implicit: Procedural = ‘knowing how’
Episodic Memory
- Explicit
- Personal memory of events
- Include contextual details (what, where, why, who, etc)
- Emotional details associated to event
Semantic Memory
- Explicit
- Facts and knowledge you know – shared by all = not personal experience
- May relate to – function of object, behaviour/customs, abstract concepts like maths/languages
- Links to episodic – all knowledge starts as episodic personal experience
- Link to particular event is lost as it becomes general semantic knowledge
Procedural Memory
- Memory of how to do things
- Automatic due to repetition & practice – become less aware so can do other tasks at the same time
(AO3) EVALUATION OFDIFFERENT TYPES OF LTM
- Support from neurological evidence that 3 different areas of LTM exist
- Brain scans have shown different areas activated when different LTM are utilised:
- Episodic = Hippocampus and parts of the Temporal Lobe
- Semantic = Temporal lobe
- Procedural = Cerebellum, Motor cortex, Basal ganglia & Limbic system
- Difference between procedural (implicit) and declarative (explicit) LTMs
-‘HM’ – could no longer create new declarative LTMs, but could learn new procedural skills
- Corkin – found he could learn mirror drawings, yet had no episodic memory or recollection of learning how
- Explicit memories both involve the temporal lobe, while implicit doesn’t, which supports them being separate
- Differentiating between episodic and semantic memories
- Hodges and Patterson - found Alzheimer’s patients who could form episodic memories but not semantic
- Irish et al – found Alzheimer’s patients who could form semantic memories but not episodic
- Use brain damage patients may not be reliable
- In cases like ‘HM’ its hard to be sure exactly what areas of the brain were damaged/removed
- Not sure if targeted brain areas are responsible for types of memory, or are just relay stations for other parts of the brain
Types of Forgetting: Interference
Interference = memories become mixed up/interfere with recall of other memories, more likely with memories similar to each other
Retroactive Interference: new info affects the recall of old info
Proactive Interference: old info affects the recall of new info
- Retroactive
- Muller and Pilzecker – identify the effects of RI
- gave p.pants list of nonsense syllables to learn for 6 mins
- after retention interval p.pants were to recall list
- performance poorer in p.pants that were given the task to describe 3 landscape paintings
- intervening task = RI as later task (paintings) interfered with earlier info learnt
- Proactive
- Benton Underwood
- gave p.pants series of words lists they don’t learn words encountered later as well as the 1st list of words
- 10+ lists after 24hrs – 20% remembered
- 1 list after 24hrs – 70% remembered
Real world Baddeley + Hitch
- Rugby players + recall of opposition teams over season
- Some players had played all games or some games due to injury (so played fewer games)
- More info = all games played = more interference = less recall
- Less info= some games played = less interference = better recall
Impact of similarity of test material/info
- McGeoch + McDonald
- Gave p.pants list of 10 adjectives followed by 10 min interval why they learnt 2nd word list, then recalled 1st list
- If 2nd list was synonyms (similar words) = recall was 12%
- If 2nd list was nonsense syllables = recall was 26%
- If 2nd list was numbers = recall was 37%
(AO3) EVALUATION OF INTERFERENCE
- Research is quite artificial
- Lab-based often using artificial word lists
- Underwood, Muller & Pilzecker – research can be said that it wouldn’t apply to real life situations
- P.pants may lack motivation due to a lack of consequentiality = stronger interference which is low in ecological validity
- Only explains some examples of forgetting
- Interference doesn’t happen in everyday life
- As really similar memories are required for interference
- Unimportant as its not regular
- RWA: Advertising
- Dancher et al – found that adverts run 30 times in a week are likely to be interfered with. So less likely to be remembered
- Suggests that ads are played a lot in a short period of time to prevent interference
- Accessibility vs. Availability
- Is interference causing memories to disappear or have temporary effects?
- Ceraso – found that when memory was tested 24hrs later, recognition improved while recall stayed the same
- Suggests = memories are temporarily not accessible rather than not available
- Individual differences
- Interference occurs but doesn’t take into account individual differences
- Kane and Eagle – proactive interference is less likely to occur in individuals with a greater working memory span
Types of Forgetting: Retrieval Failure
Retrieval Failure = the lack of accessibility rather than availability to a memory. The failure to retrieve a memory/piece of info due to the lack of sufficient cues/clues
Cues = things that work to be a reminder, with some kind of link to what you are trying to remember. Meaningful link to material or not meaningful (e.g. environmental cues or mental state – being drunk, sad)
- Retrieval failure vs. Interference
- Interference is info getting in the way of info/memory you want to remember
- Retrieval failure is when info is present but there is a lack of cues making the info hard to recall/access
- Retrieval cues : The encoding specificity principle
- Tulving and Thomson - proposed memory is more effective if info at encoding is oresent at recall/retrieval
- Closer the cue is to the original item = more useful
- Tulving and Pearlstone – p.pants to learn 48 words belonging to 12 categories
- 2 different conditions: free recall vs. cued recall (category name)
- Free recall = 40% recall
- Cued recall = 60% recall
- Cues : Meaningful link = cues that have been explicitly/implicitly encoded at time of learning vs. cues not relating to learning material = environmental context/emotional state
- Context : Context dependant forgetting
- Ethel and Abernathy – students tested before a course and tested weekly
- some students tested with usual instructor + teaching room
- others tested with usual instructor + different room
- others tested with different instructor + teaching room
- others tested with different instructor + different room
- RESULTS:
- Same instructor and same room condition = students performed BEST
- Superior students – least affected by changes
- Godden and Baddeley – effect of contextual cues
- Scuba divers given set of words to learn either on land or underwater
- Tested either on land/underwater = 4 conditions in total
- RESULTS:
- Recall best when initial context matched recall environment (e.g. learnt & recall underwater)
- State : State dependant forgetting
- Godwin et al – male p.pants to remember word lists either being drunk or sober
- P.pants asked for recall after 24hrs some sober, some drink again = 4 conditions in total
- RESULTS:
- Recall highest when state at learning matched state at recall (e.g drunk @learnt and @recall)
(AO3) EVALUATION OF RETREIVAL FAILURE
- Lots of research support
- E.g. Tulving and Pearlstone, Abernethy, etc
- Research successfully supports theory of the value of cues in the role of retrieval failure
- RWA: Schools
- Abernethy - if context aids recall then having exams in the same room where it was learnt should lead to better results in exams.
- Just imagining the room during the exam should also help
- Also used in cognitive techniques of police interviews
- Retrieval cues doesn’t always work
- Research is focused on simple words related to cues and context
- In real life we deal with more complex info which is more in depth so less easily triggered by cues + context
- Smith + Vela – context effects = largely eliminated when learning meaningful material
- Retrieval failure explains interference effects (Interefernce-wise) (Retrieval failure)
- Tulving and Psotka
- Gave groups varying no.s of lists to learn and immediate recall
- Each list = 24 words divides into 6 categories
- Recall after each list got progressively worse with more lists due to proactive interference
- After completing allocated lists all p.pants given the categories and asked for cued recall
- RESULTS:
- Recall approx. 70% regardless of how many lists learnt
- Suggests: RF is more important than interference as the presence of cues can remove the impact of interference