MEMORY
MULTI-STORE MODEL- ATKINSON & SHIFFRIN
proposed as a cognitive explanation of memory. Made up of 3 components: sensory register, STM and LTM
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WORKING MEMORY MODEL- BADDELEY & HITCH
TYPES OF LONG TERM MEMORY- Tulving proposed there are three LTM stores. All LTM memories are categorised as either explicit ( declarative) or implicit (not declarative)
SENSORY REGISTER- coding= echoic/iconic (from all 5 senses) capacity= high duration duration= limited 250 ms
STM- coding= acoustic capacity= limited 7+/- 2 items duration= 18-30 sec
LTM- coding= semantically capacity= infinite duration= infinite
sensory register --attention--> STM --retrieval (maintenance rehearsal)--> LTM
DECAY- info lost in time
DISPLACEMENT- new information overrides existing information
MAINTENANCE REHEARSAL- when info is repeated over and over
RETRIEVAL FAILURE- failure to recall a memory due to missing stimuli or cues that were present at the same time the memory was enclosed
INTERFERENCE- new info and existing info interfere
PETERSON & PETERSON~ tested duration, showed ppts trigrams asking them to recall them every 3,6,9,12,15,18 secs; during pause they had to count backwards in 3's (interference task which prevents the repetition of the trigram by the ppt), after 3 secs- 80% correct recollection, after 18 secs- 10% correct recollection, longer the interval = less accurate the recall
STRENGTH- lab (reliable)
LIM- artificial task so lacks ecological validity
CONCLUSION~ STM has limited duration of approx 18 sec. If we're unable to rehearse information it will not be passed to LTM, providing further support for the MSM and the idea of seperate components
BAHRICK~ tested duration of LTM. 392 ppl from American high school to list the names of their ex-classmates (free-call test). Then they were shown images of each classmate to recall names (photo recognition). Or given names to math with photo (photo-recognition) Ppts recognised about 90% of faces - 90% accurate = free-call - After 30 years it declined 30% accuracy - After 48 years 80% accurate = facial-recognition - 40% = photo-recognition
EVIDENCE of very long term memories in real setting
STR= high ecological validity, field experiment
LIM= hard to control variables, less reliable
OVERALL EVALUATION OF MSM
STRENGTH- one strength of the MSM is research support. Baddeley found that we tend to mix up words that sound similar when using STM but mix up words that have similar meanings using LTM. Shows that coding for STM & LTM are different. Shows they are independent stores
LIMITATION- one limitation is that evidence suggests that there is more than one type of STM. for example, evidence from people suffering with amnesia shows that this cannot be true. Shallice and Warrington found that KF's STM recall for digits were poor when read aloud to him but was much better when he could read them to himself. this is a limitation because research shows that at the very least there must be one short-term sore to process visual information and another one to process auditory info
LIMITATION- one limitation to the MSM is that it only explains one type of rehearsal. for example, Craig & Watkins found that rehearsal type is what matters. they discovered that there are two types of rehearsal: maintenance rehearsal which is described in MSM and elaborative rehearsal which is needed for LTM. this occurs when you link the info to existing knowledge
SEMANTIC- contains facts and knowledge, long term memory store, no conscious effort, general knowledge, not personal, explicit (declarative) e.g. London is the capital of England
PROCEDURAL- non conscious effort, long term memory, skills, performed tasks, automatic actions, implicit (non-declarative) e.g. swimming
EPISODIC- time-stamped, details, context, emotions, long term memory, requires efforts, personal events, explicit (declarative) e.g. your wedding day
THE CASE OF CLIVE WEARING- suffers a severe form of amnesia from an infection that spread to the brain damaging his hippocampus and associated areas. before his accident he was a musician, he can still play the piano and remember some life before. knows he has children but cannot remember their names
EVALUATION OF TYPES OF LTM
Brain scans provide support for the different types of LTM. episodic memory has been associated with the hippocampus and temporal lobe. procedural memory has been associated with the temporal lobe and procedural is associated with the cerebellum and motor cortex
Focus on STM- concerned with the part of the mind that is active when we are temporarily storing and manipulating information
4 components: central executive, phonological loop, visuo spatial sketchpad, episodic buffer
EPSODIC BUFFER- 3rd slave system, brings together info from other slave systems into a single memory rather than separate strands, binds and integrates info from all other components and passes info to LTM, limited capacity, modality free coding
CENTRAL EXECUTIVE- main store, controls attention and directs info to slave systems, attentional process that monitors incoming data, makes decisions, allocates tasks to slave systems, limited capacity, modality free- not dependent on a particular sense, codes from all 5 senses
PHNONOLOGICAL LOOP- inner voice, 1st slave system, auditory info, preserves order of how info arrived, phono~ words you can hear, articulatory~ maintenance rehearsal, temporary storage space for storing acoustic info, 2 seconds capacity
VISUO-SPATIAL SKETCHPAD- inner eye, 2nd slave system, stores visual and spatial info, visual cache~ visual data, inner scribe~ manipulation of mental images, records the arrangement of objects in visual field. 3/4 objects capacity, codes visually than spatially
EVALUATIONS OF THE WMM
SUPPORTING EVIDENCE- Shallice & Warrington's 1970's case of KF who was injured in motorcycle accident. KF had suffered with brain damage resulting in his STM being poor for verbal info but could still process visual information presented visually. (difficulty with sounds but could recall all letters and digits. suggests that his phonological loop had been damaged leaving the other areas intact. supports the existence of a separate visual and acoustic store.
COUNTER- CASE STUDY (GENERALISABILITY)
LACK OF CLARITY OVER CENTRAL EXECUTIVE- For example, Eslinger & Damasio studied a patient who after the removal of a brain tumour could still perform well on tasks requiring reasoning but not tasks requiring decision- making. this suggests that there is more than one component in the central executive which isnt accounted for by the WMM
DUAL-TASK PERFORMANCE- Baddeley & Hitch, requires ppt to do two tasks at once. showed that ppts had more difficulty doing two visual tasks than doing both a visual and verbal task at the same time. the increased difficulty is because both visual tasks compete for the same slave system whereas, when doing a verbal and visual tasks simultaneously there is no competition =. this is a strength because it means there must be a separate slave system (the VSS) that processes visual input