Memory Flashcards
Coding
-the format in which info is stored in various memory stores
Capacity
-the amount of info that can be held in a memory store
Duration
-the length of time info can be held in a memory store
STM summary
- coding
- capacity
- duration
- coding = acoustic
- capacity = 7 (+/- 2)
- duration = 18-30secs
LTM summary
- coding
- capacity
- duration
- coding = semantic
- capacity = unknown
- duration = unlimited (lasting a lifetime)
Baddeley (1966) - Coding in STM & LTM, acoustic/semantic
- procedure
- findings
- limitation
- acoustically similar words (e.g. cat, cab) or dissimilar (e.g. pit, few)
- semantically similar words (e.g. large, big) or dissimilar (e.g. good, hot)
- immediate recall worse with acoustically similar words; therefore STM codes acoustically
- recall after 20 mins worse with semantically similar words; therefore LTM codes semantically
- limitation, words used in study had no personal meaning to participants, however when processing meaningful info people may use semantic coding even for STM; therefore results cannot be generalised so low ecological validity
Jacobs (1887) - Capacity of STM
- procedure
- findings
- limitations
- digit span, researcher reads 4 digits and increases until participant cannot recall order correctly
- on average, participants repeated back 9.3 numbers & 7.3 letters in correct order immediately after presented
- capacity of STM = 7 (+/-2)
- used in real world for car registration plates & postcodes
- limitation, early research lacked adequate control of extraneous variables (e.g. some participants may have been distracted & so didn’t perform as well), results not valid as there were confounding variables that weren’t controlled
- limitation, lacks ecological validity (cannot be easily generalised to real-life situations)
Wilder Penfield Casestudy (1891-1976) - Capacity of LTM
- procedure
- findings
- limitation
- wanted to locate source of seizure activity in brain, by opening patients’ skulls & stimulating temporal lobes of brain with electricity
- could elicit meaningful, integrated responses (e.g. memory including sound, movement & colour)
- found capacity of memory bigger than believed, could be unlimited
- limitation, unethical as patients signed up to have seizures looked at, but due to experiment may have had to remember traumatic memories; psychological trauma
Peterson & Peterson (1959) - Duration of STM
- procedure
- findings
- limitation
- tested length of time items could be held in STM when rehearsal was prevented
- 24 students each given a trigram (e.g. YCG) to remember & a 3 digit number to count backwards from in 3s
- after 3sec interval, average recall 80% correctly
- after 18sec interval, average recall 3% correctly
- suggests duration of STM without rehearsal is approx 18-30secs
- limitation, lacks mundane realism, as remembering trigrams isn’t meaningful, study lacked external validity; however study not totally irrelevant as we sometimes remember meaningless things like phone numbers
Bahrick et al. (1975) - Duration of LTM
- procedure
- findings
- limitation
- strength
- 392 American participants
- recognition test, 50 photos from participants’ high school yearbook
- free recall test, participants listed names of their graduating class
- after 15 years, 90% accurate at photo recognition; 60% at free recall
- after 48 years, 70% accurate at photo recognition, 30% at free recall
- free recall less accurate due to no memory trigger
- limitation, confounding variables not controlled (e.g. participants may have looked at yearbook photos & rehearsed memories over the years)
- strength, real-life meaningful memories studied (faces & names), so more ecological validity
Episodic memory - Types of LTM
- summary
- strength
- limitation
- stores personal events (episodes) from our lives
- memories of occurrences, the people, places, objects & behaviours involved
- memories retrieved consciously & with effort
- e.g. last visit to dentist, favourite food being pizza
- strength, supported by Clive Wearing case study (had difficulty recalling past events), however procedural memories unaffected (could remember how to play piano), supports view of different memory stores in LTM as one store can be damaged while others are unaffected
- limitation, evidence based on clinical cases (one off events) when memory is damaged, so difficult to generalise findings of how LTM works in all people
Semantic memory - Types of LTM
-summary
stores our knowledge of the world
- less personal
- includes facts, & knowledge of what words & concepts mean
- need to be recalled deliberately
- e.g. the taste of an orange, capital of France being Paris
Procedural memory - Types of LTM
-summary
- stores memories for actions and skills (how we do things - muscle memory)
- recall occurs without conscious awareness or effort
- e.g. driving a car, riding a bike
Multi-store Model (MSM)
-diagram
…
Multi-store Model (MSM)
- summary
- strength
- limitations
- MSM describes how info flows through memory system (made of 3 stores linked by processing)
- research supporting it (Peterson & Peterson/Jacobs studies), increases validity
- has been repeated, so is reliable, increases scientific credibility
- limitation, doesn’t say why people have flashbulb memories (meaningful memories that haven’t been rehearsed but can still be remembered)
- limitation, only suggests 1 type of LTM when actually there are 3 types
- limitation, suggests STM has limited capacity & doesn’t explain that STM can ‘multi-task’ doing 2 things at once, as model is over-simplified
Working Memory Model (WMM)
-diagram
…
Working Memory Model (WMM)
- summary
- strength
- limitations
- WMM explanation of how STM is organised & how it functions (model of STM)
- strength, supported by KF case study, suffered damage to brain, verbal memory impaired with difficulty recalling sounds, but visual info processing normal as could recall letter/digits; suggests damage to phonological loop, but visuo-spatial sketchpad still intact, therefore supports existence of separate visual and acoustic store slave systems
- limitations, evidence from case study may not be reliable as concerns unique cases with traumatic experiences
- limitation, lack of clarity over CE suggesting that WMM hasn’t been fully explained
Working Memory Model (WMM)
- central executive (CE)
- strength
- CE moniters incoming data/info
- allocates slave systems to tasks
- limited storage/processing capacity
- strength, support for brain scanning studies, Braver et al’s (1997) participants did tasks involving CE while having a brain scan, activity seen in area known as prefrontal cortex, activity in this area increased as task became more difficult, makes sense in terms of WMM as demands on CE increase it has to work harder to fulfil its function; study provides evidence that CE may have a physical reality in the brain
Working Memory Model (WMM)
- phonological loop (PL)
- strength
- PL is 1st slave system, preserves order in which info arrives
- consists of phonological store (stores words you hear)
- consists of articulatory process allowing maintenance rehearsal (repeats sounds in loop to keep in WM while they are needed, capacity of ‘loop’ approx 2 secs)
- strength, Baddeley et al. (1975) word length effect supports PL, people have more difficulty remembering a list of long words (e.g. association) than short words, due to limited space for rehearsal in articulatory process (approx 2 secs); word length effect disappears if person is given a repetitive task tying up articulatory process, demonstrating the process at work
Working Memory Model (WMM)
- visuo-spatial sketchpad (VSS)
- strength
- VSS is 2nd slave system, stores visual & spatial info when required
- limited capacity (according to Baddeley (2003) approx 3-4 objects)
- subdivided into, visual cache (stores visual data e.g. shape & colour)
- subdivided into, inner scribe (records arrangement of objects in visual field & transfers info to CE)
- strength, dual task performance supports VSS, demonstrates ability to complete 2 tasks simultaneously if using different slave systems
- e.g. pat head (visuo-spatial) & say alphabet (phonological) is easier as from different slave systems
- e.g. pat head (visuo-spatial) & rub belly (visuo-spatial) is more difficult as from same slave system
Working Memory Model (WMM)
-episodic buffer (EB)
- EB is 3rd slave system, added in 2000 as temporary store for info
- integrates visual, spatial & verbal info from other stores
- maintains sense of time sequencing
- links to LTM
Interference Theory
- interference
- explanation for forgetting: no1
- when 2 pieces of info are in conflict, resulting in forgetting one or both
- proposed as an explanation for forgetting in LTM, as we can’t access memories even though they are available
Interference Theory
-proactive interference (PI)
- when old memories interfere with new
- e.g. a teacher has learnt many names of pupils in past, but can’t remember the names of her current class
Interference Theory
-retroactive interference (RI)
- when new memories interfere with old
- e.g. a teacher learns many names of pupils THIS year, but can’t remember names of her current class
Interference Theory
-when is interference worse?
- interference is worse when memories are similar
- in PI, previously stored info makes new info more difficult to store
- in RI, new info overwrites previous memories which are similar
McGeoch & McDonald (1931) - Effects of similarity in memories
-procedure
- participants asked to learn a list of words to 100% accuracy (could recall them perfectly)
- given a new list to learn, new material varied in degree pf similarity to old list
McGeoch & McDonald (1931) - Effects of similarity in memories
-procedure GROUPS
- group 1, synonyms
- group 2, antonyms
- group 3, unrelated
- group 4, consonant syllables
- group 5, three-digit numbers
- group 6, no new list (participants rested, so control condition)
McGeoch & McDonald (1931) - Effects of similarity in memories
-findings
- performance depended on the nature of 2nd list
- most similar material (synonyms) produced worst recall
- when given different material (e.g. three-digit numbers) the mean number of items recalled increased
McGeoch & McDonald (1931) - Effects of similarity in memories
-conclusions
- shows that interference is strongest when memories are similar
- in group 1 its likely that the words with the same meanings as original list blocked access, or that the new material became confused with old material
McGeoch & McDonald (1931) - Effects of similarity in memories
-strengths
- many lab studies carried out into interference, consistently demonstrating both types of interference as causes of forgetting in LTM
- lab experiments controls effects of extraneous variables; gives confidence that interference is valid explanation
- real-life studies have supported interference explanation; Baddley & Hitch (1977) asked rugby players to recall names of teams they had played so far in that season, accurate recall did not depend on how long ago the match took place, as more important was number of games played in the meantime; shows interference explanations can apply to some everyday situations
McGeoch & McDonald (1931) - Effects of similarity in memories
-limitations
- use of artificial materials, makes interference much more likely in lab, but may not be likely cause of ‘everyday’ forgetting, lacks mundane realism
- time allowed between learning & recall is very short in lab, so does not reflect real life, so conclusions generated cannot be generalised outside lab (role of interference may be exaggerated)
Retrieval Failure
-explanation for forgetting: no2
-memory available but not accessible
Encoding Specificity Principle (ESP)
- Tulving (1983) recall is better when cues present at learning are also present at recall
- helps retrieval
Cues
- a trigger that enables access to memories
- lack of cues can cause retrieval failure
Meaningful Cues
-cues linked to material to be accessed in a meaningful way