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Flashcards in Cognitive psychology Deck (26):

series of storage systems in multi store model

sensory register, short term memory and long term memory


who discovered multi store model

atkinson and shiffrin 1968



the form in which information is stored



how much information can be stored



how long information can be stored for


multi store model

- sensory memory from senses, loses through decay
- short term memory from SM through attention, lost through displacement and decay
- ltm from stm through rehearsal, lost through interference decay or retrieval failure
- goes from ltm to stm from retrieval


how does the multi store model work experience

- info gathered from sense to SR
- only small amount paid attention to passes to short term memory for further processing, rest decayed
- information in STM that is actively processed (thought about) through rehearsed goes into LTM


coding in the SR

- sr is modality specific (stored in form it arrives in) so is stored in the form it arrives in. each sense has its own sensory store
- visual information stored in the iconic store and sound in the echoic


crowder coding in sr

found that SR only holds information in the iconic store for a few milliseconds but for 2-3 seconds in the echoic -> sensory information is coded into different sensory stores with different durations


capacity of SR sperling 1960

flashed a 3x4 grid of letters onto a screen for 1/20th of a second and asked ppts to recall letters of one row
capacity quite large
recall of letters of indicated row was hugh


duration of SR walsh and thompson

have limited duration 0.5 seconds
- found iconic sensory store has average duration of 0.5 seconds which decreases as you get older
- limited and age dependent


short term memory encoded (baddeley)

acoustically. we encode information being transferred from sensory to atm by verbalising it either saying it out loud to ourselves or repeating mentally
- presented words that were acoustically similar and dissimilar and semantically similar and semantically dissimilar
- random sequence of 5 words and asked them to write down immediately
- words that sounded similar were hardest to remember
- stm codes acoustically


miller stm capacity

- immediate digit span test
- number of digits to recall was increased until able to recall accurately
- 7 plus or minus 2
- capacity limited to 5-9 chunks of info
- could be increased by chunking (eg combining numbers to remember phone numbers)


duration stm peterson and peterson

limited to maximum of about 30 seconds
- tested 24 undergraduate students, given trigrams
- counted backwards to prevent rehearsal
- each trial they were told to stop counting after different amounts of time - retention interval
- suggests stm may have a very short duration unless we rehearse


capacity of ltm

Linton kept a daily diary of events on cards and gave each day a key word. 7 years later she could give 70% accuracy of a given key word
estimated 11,000 items recorded, huge capacity


duration of ltm bahrick

can last a life time
- bahrick tested 733 adults who had taken or were taking a high school or uni course in spanish.
- first 3 years after completing 30-40% lost
- after this a lot of words remained in ltm and didn’t decline much more


Aims of Baddeley 1966

- to investigate the influence of acoustic and semantic word similarity on learning and recall in stm and ltm


how is baddeley aim done

by giving participants word lists that are similar in sound (acoustic) or meaning (semantic). if the participants struggled to recall word order it suggests ltm is confused by the similarity which means that’s how LTM tends to encode


procedure for baddeley 1966

- a laboratory experiment to test sequence recall of acoustically and semantically similar word lists.
- 72 male and female volunteers from Applied Psychology research unit at his university
- 15-20 words in each condition
- four lists of 10 words given
List A 10 acoustically similar words
List B 10 acoustically dissimilar words
List C 10 semantically similar words
List D 10 semantically dissimilar words
Lists B and D acted as baseline control groups
- assigned one of the 4 lists conditions as independent groups design.
- presented via protector 1 word every 3 seconds
- interference task presented 8 numbers at one second intervals to prevent rehearsal to block effect of STM as LTM was tested
- recall word list in 1 minute by writing down the sequence over 4 learning trials
- word list in random order made visible on card in the room, then given a 15 minute interference task again before getting another retest


results of baddeley experiment 3

- recall in acoustically similar condition (list A) and acoustically dissimilar (list B) very similar including at retest
- in LTM acoustic similarity did not affect recall
- recall of semantically similar list (list C) was much worse than in the semantically dissimilar words (list D)
- semantic similarity affected recall in LTM


conclusions of baddeley 1966

- findings from his other 2 experiments suggested STM is affected by acoustic coding whereas this study suggests the LTM is affected by semantic coding but not exclusively
- the fact that participants found it more difficult to recall list A in initial phase of learning suggests STM is largely acoustic so acoustically similar words more difficulty to encode
- concluded ltm encodes semantically


aim of schmolck et al 2002

wanted to compare hm to other patients with similar brain damage to see if a precise link could be made between brain structure and semantic memory, especially whether medial temporal lobe damage had an effect on semantic memory


procedure of schmolck et al 2002

- 14 patients in total, 6 had severe damage to MTL compared to 8 controls with no brain damage - healthy volunteers
- match with the pairs in terms of age and education
- 3 of 6 had amnesia (including HM) and had brain damage to hippocampus (part of MTL) from surgery or other injuries and the other 3 had brain damage from widespread viral infections
- these latter 3 fell under category of MTL+ as they suffered large MTL and anterolateral temporal cortex damage
- 9 tests designed to measure semantic long term memory functioning based on 48 drawings, half animals half objects and further divided into 8 groups of 6:
6 domestic land animals, 6 foreign land animals, 6 water creatures, 6 birds, 6 electrical household items, 6 non electrical household items, 6 vehicles and 6 musical instruments
- category fluency and sorting - asked to name or sort into categories such as living or man made without a picture clue
- definitions - definite picture by theme it fitted into
- object/ non object discrimination task - whether real or not
- pointing to or naming picture - given name or description


how was schmolck checked for reliability

tape recorded and responses transcribed, checked for reliability and looked at grammar/syntax errors when participants spoke


results of schmolck

- controls got all the answers right when asked to point to the picture of a named object, as did those with the hippocampus damage only
HM got 98% for living creatures and 100% for objects
- MTL+ patients performed worse getting an average of 85% for creatures and 90% for non living
- MTL+ patients performed badly in most tests including when participants shown a picture and asked to name it, given a verbal description and asked to name and asked yes or no questions
- direct relationship with amount of brain damage and number of mistakes made. MTL+ made most mistakes followed by Gj then the theee hippocampus damage only patients
- when hippocampus only patients did better than controls schmolck suggested age was a factor - they were younger


conclusions of schmolck et al

- clear relationship between how well a participant did and the damage to the lateral temporal cortex, particularly for HM and 3 MTL+ patients
- clear link between damage to lateral temporal cortex generally and the loss of semantic LTM. only applicable to MRL+ damage patients not MTL only