Memory Flashcards
Capacity
= the no. items a memory store can hold at any one time.
STM Study: Jacobs (1887) & Miller (1956) - study of immediate digit span.
-Participants recall random lists of digits/no. in correct order.
-List increases by one digit/no. each time.
-Digit span measured at the point where participants can no longer recall the digits in the correct sequence.
STM Findings: STM capacity limited to 5-9 items (7 items of info +/- 2)
LTM Study: N/A
LTM Findings: unlimited.
Duration
= the length of time a memory store can store/remember an item for.
STM Study: Peterson & Peterson (1959) trigram retention study.
-Participants briefly presented with a consonant trigram (e.g. WGP)
-They were asked to count backwards in 3s from a random no. (to prevent rehearsal).
-Participants were asked to recall trigrams at different time intervals ranging from 3-18 seconds.
STM Findings: STM duration is brief wen rehearsal is prevented - up to 30 seconds.
Participants could recall 80% trigrams correctly after 3 seconds but fewer than 10% after 18 seconds.
LTM study: Bahrick et al (1975) - high school yearbook study.
-Tested nearly 400 American high-school graduates on their memory of former school mates.
-Used a variety of recognition and name-matching tasks.
LTM Findings: 30 seconds-lifetime.
-Memory better on recognition than recall.
-Memory began to decline after 47 years.
Coding
= the form in which the store remembers the item e.g. visually, acoustically or semantically.
STM Study: Conrad (1964) study of acoustic confusion.
-Participants were shown a random sequence of 6 consonants briefly on a screen.
-Some sounded similar.
-Some sounded different.
-Participants were then asked to write down the consonants in the correct order.
STM Findings: Mainly acoustic.
Participants found it more difficult to recall & made more errors on the lists of similar sounding consonants.
LTM Study: Baddeley (1966) Acoustic/Semantic encoding.
-Participants presented with 10 words from each of 4 categories:
1.Words that sound similar
2.Do not sound similar
3.Mean the same
4.Do not mean the same
-Rehearsal was prevented (counting) & recall tested after 20 mins.
LTM Findings: Mainly semantic
-Participants performed well on words with similar meaning.
-Baddeley concluded that this was because LTM codes for meaning.
Multi-store model
Proposed by Atkinson & Schiffrin (1968) consisting of 3 main stores: Sensory, STM & LTM.
Explains how info flows from one storage system to another:
-Info received through senses enters sensory store, constantly receive info, most receives no attention.
-If attention is paid to it it is transferred & processed by STM, if not attended to it is forgotten.
-If rehearsed efficiently it is transferred to LTM.
Sensory register
Particular registers for different senses:
-Iconic (vision)
-Echoic (sound)
-Haptic (touch)
= passive stores -> cannot control what enters & its functioning.
Constantly bombarded with info, so has mechanism for selecting relevant & discarding rest.
Capacity: Very large
Duration: Limited
-iconic = 500 milliseconds
-echoic = 2 seconds
Coding:
-iconic = visually
-echoic = acoustically
Evaluation points for multi-store model
+ Supporting case studies:
-Clive Wearing contracted viral infection & left with brain damage & major memory disruption.
-Episodic severely impaired, had difficulty recalling events from past e.g. wedding day.
-Basic semantic memory = relatively unaffected e.g. meanings of words.
-Displayed procedural memories e.g. tie shoelaces, walking, talking, complex piano pieces
->Points to clear distinction between LTM & STM, supporting proposal they are separate stores. Clear that virus just attacked STM.
+ Support from Serial Position Effect:
-Murdock (1962) presented participants with list of words to recall any order.
-Found that words at beginning & end of list recalled better than middle = serial position effect.
-Words at beginning = primary effect - rehearsed - LTM.
-Words at end = recency effect - STM (can stay up to 30 seconds without rehearsal).
->Provides existence for separate stores.
x Mere rehearsal doesn’t ensure transfer from STM to LTM:
-Bekerian & Baddeley (1980) found people didn’t know of changes to BBC radio wavelengths despite hearing info on average over 1000 times.
->Questions role of transferring info from STM to LTM - according to MSM info should have been rehearsed sufficiently.
x Info which isn’t rehearsed can be stored in LTM:
-Jenkins (1974) demonstrated some info can be retained in LTM even when participants not warned about recalling = incidental learning.
-Occurs due to interest, funniness, or personal relevance.
-> MSM cannot account for recall of this info, proposes that STM must rehearse in order for transfer, may not always be true.
Types of LTM
Endel Tulving (1985) one of first cognitive psychologists to realise MSM view of LTM = too simplistic & inflexible & thus proposed 3 LTM stores.
Can be divided into 2 main types:
-Declarative = ‘knowing that’ e.g. facts, details, events.
-Procedural = ‘knowing how’ e.g. how to do things.
Episodic memory
= refers to our ability to recall events from our lives.
WWW criteria:
-What happened
-Where it happened
-When it happened
Likened to a diary - memories of a single episode will include several elements e.g. people, places, objects, behaviours - all interwoven to produce a single memory.
Time-stamped: Yes (can remember when happened)
Awareness: Conscious effort to recall memories.
Brain localisation:
Initial coding - prefrontal cortex
Consolidation & storage - neocortex.
Memories of different parts of events - different visual, auditory & olfactory areas but connected in hippocampus to create memory of event rather than collection of separate memories.
Semantic memory
= contains general knowledge - our knowledge of the world.
Includes facts but in broadest possible sense.
Likened to an encyclopaedia & dictionary.
Time-stamped: No - less personal knowledge & more facts we all share.
Awareness: Conscious effort to access.
Brain localisation: some disagreement:
-some evidence of involvement of hippocampus & related areas.
-usage of several areas.
-coding mainly associated with frontal & temporal lobes.
Procedural memory
= memory for actions, skills or how we do things.
e.g. driving a car - (eventually) change gear without realising.
Time-stamped: No - we don’t often recall when we learnt.
Awareness: Without conscious awareness or great deal of effort.
Brain localisation:
Motor skills - prefrontal cortex, parietal cortex & cerebellum all engaged.
-Cerebellum = coordinate flow & timing of movements.
-Damage to cerebellum & basal ganglia = affect on procedural.
-> 1977 study of Alzheimer patients - discovered procedural memory functions better than declarative as it is less dependent on affected regions of brain (cerebellum & basal ganglia).
Evaluation of types of LTM
+ Research from Clinical Case Studies:
-Patient HM & Clive Wearing - both episodic severely impaired from amnesia - difficulty recalling events from past.
-Semantic relatively unaffected e.g. meaning of words.
-Procedural intact - how to tie shoelaces, Clive could still read music and play piano (professional musician).
-> Supports Tulving’s view that there are many different stores in LTM - one store can be damaged but others remain unaffected - clear evidence of different types of memory & stored in different parts in brain.
+ Support from neuroimaging evidence:
-Brain scan studies for different stores in brain e.g. Tulving et al (1994) got participants to perform various memory tasks while scanned (PET).
-Found episodic & semantic both recalled from prefrontal cortex - area is divided one on each hemisphere of brain. (Left for semantic, right for episodic).
-> Supports view that there is physical reality to different types of LTM within brain.
+ Real-life applications:
-Being able to identify different aspects of LTM allows psychologists to target certain types of memory in order to better people’s lives.
-Belleville (2006) demonstrated episodic memories could be improved in older people who had a mild cognitive impairment.
-Trained participants performed better on test of episodic after training control group.
-> Episodic most affected by mild cognitive impairment highlighting benefit of being able to distinguish between types of LTM - enables specific treatments to be developed.
Explanations for forgetting:
Interference
= occurs when 2 pieces of info conflict with each other - results in forgetting of one or both items, or some distortion.
Proposed mainly as explanation in LTM - once memory reaches LTM its more or less permanent, therefore any forgetting is most likely because we can’t get access even though available.
-> Interference between memories makes it harder for us to locate them, and this is experienced as ‘forgetting’.
Types of interference:
Proactive = when older memory interferes with a newer one
e.g. teacher learned many names in past - difficulty remembering new ones.
Retroactive = when a newer memory interferes with a older one
e.g. teacher learned so many new names - cannot remember old names.
Evaluation for inference as an explanation for forgetting
+ Research Support:
-Interference is worse when the memories (or learning) are similar - McGeoch & McDonald (1931)
-Studied retroactive by changing amount of similarity between 2 sets of materials.
-Participants had to learn a new list of 10 words until they could remember with 100% accuracy. They then learnt a new list.
-6 groups of participants who had to learn different types of lists: synonyms, antonyms, unrelated words, nonsense syllables, 3-digit no. & no new list (rested).
-When recalling original list again, synonyms produced worst recall.
-> Shows interference is strongest wen materials are similar.
+ Evidence from lab studies:
-Most consistently demonstrated findings in psychology. 1000s lab experiments carried out e.g. McGeoch & McDonald.
-Most studies show both types are likely to be common ways of forgetting LTM.
-> Lab experiments control effects of irrelevant influences & thus give confidence that interference is a valid explanation for some forgetting.
x Problems using lab studies to test:
-Much greater chance interference demonstrated in lab than real-life situations for 1 good reason.
-Stimulus materials in most studies are list of words - completely different to learning things in everyday life e.g. faces, birthdays.
-> Use of artificial tasks makes interference much more likely in the lab. Interference may not be as likely as explanation for forgetting in everyday life as it is in lab.
Explanations for forgetting:
Retrieval failure
-Insufficient cues - when info is initially placed in memory, associated cues are stored at same time.
If cues are not available at time of recall, it may make it appear you have forgotten when really due to retrieval failure - not able to access memories there.
Two types:
Context-dependent forgetting:
-occurs with external retrieval cues - forgetting when external environment is different at recall from how it was at coding.
Research - Godden & Baddeley (1975):
-carried out study using deep-sea divers as participants.
-divers learnt list of words either underwater or on land then asked to recall in either environment - 4 conditions.
-when learning in different environment to recall = 40% lower recall than others.
-external cues at learning different from ones at recall - retrieval failure.
State-dependent forgetting:
-occurs when internal retrieval cues - forgetting occurs when internal environment is dissimilar to when coded i.e. mental state (e.g. recall drunk, learned sober).
Research - Goodwin et al (1969)
-asked male volunteers to remember list of words when either sober or drunk (those in drunk condition 3x over UK drink driving limit).
-participants asked to recall lists after 24hrs.
Evaluation for Retrieval Failure as an explanation for forgetting
+ Applications in real-life:
-Cognitive Interview uses research findings from retrieval failure to improve recall from witnesses.
-Aims to recreate conditions in which individual first seen event e.g. weather, time, mood = context reinstatement.
-thought that this increases number of cues available & helps to access info from variety of different sources.
-Found to have improved recall by 34% over standard interview technique.
-> Supports as when we increase number of cues then our memory will improve as a result.
x Questioning context effects:
-Baddeley (1977) argues context effects are not actually very strong, esp in real-life
e.g. hard to find an environment as different from land as underwater.
-in contrast learning something in one room & recalling in another is unlikely to result in much forgetting as environments are generally not different enough.
-> Limitation as means real-life applications of retrieval failure due to contextual cues don’t actually explain much forgetting.