Memory

~ Multi-store model ~

Proposed by Atkinson and Schifrin – information is passed between the stores in a linear way.

Sensory register > Short term memory > Long term memory 

Sensory register receives information from a stimulus. This information would come from environment. 

Two main stores = iconic memory – visual information is coded – echoic memory – sound information 

If the information is paid attention to then it gets passed onto the short-term memory. If any information is not important then the information is decays or disappears. Or if there is not enough rehearsal then the information is displaced or decays. Maintained rehearsal – when repeating material to ourselves over and over again. Long enough to pass into the long-term memory. 

Once in the short-term memory informed can be rehearsed and some information is rehearsed and the passed into the long term memory.

Memory is stored in the long-term memory however to retrieve it when recalling information it is transferred to the short-term memory = retrieval. 

Each has its own characteristics – encoding, capacity, duration. 

Sensory register 

Encoded = all sensory experience

Duration = 500 milliseconds// half a second 

Capacity = very huge 

Short term memory 

Encoded = mainly acoustic 

Duration = 30 seconds 

Capacity = 5-9 chunks 

Long term memory 

Encoded = mainly semantic – can be visual and acoustic 

Duration = unlimited 

Capacity = unlimited

ü Multistore model is that it gives us a good understanding of the structure and process of STM. Allows researchers to expand the model further. 

×     Short term memory and long term memory is more complex than the multistore model makes out. Supporting research from Baddeley and Hitch show that the short term memory store and long term is not a unitary store – compromising of different stores e.g. central executive, Visio-spatial.

×     Model suggests that rehearsal helps transfer information were we able that the 

ü Supported by research studies STM and LTM indeed qualitatively different. Baddeley, found we mix up words that sound the same when using STM. We mix upwards with similar meaning in LTM. Strength of study use acoustic coding in STM and LTM use semantic coding. Generated a lot of research.

Research:

     Coding = Baddeley // given four groups // acoustically similar and dissimilar // semantically similar and dissimilar // asked to recall after hearing it (STM recall) tend to do worse with acoustically similar words. When asked to recall after 20 minutes (LTM recall) they did worse in semantically similar words. 

     Capacity = Jacobs 1887 // digit span // 4 digits give to participants asked to recall these in correct order out loud. // if correct asked to read out 5 digits so on until the participants cannot recall order correctly // Jacob found the mean span to be 9.3 items and 7.3 letters. 

George Miller 1956 – span for short term memory is 7 items (+ or – 2) // also noted that through chunking people can recall 5 words as well as 5 recalling 5 letters. 

     Duration = Peterson and Peterson // 24 undergraduate students tested // took part in 8 trials // trial = 1 test. // given a consonant syllable (trigram i.e. YCG) also given 3 digits // made to count backwards to prevent mental rehearsal of consonant syllable. // each trial told to stop after different amounts of time 3,6,7,9,12,15 or 18 seconds. = retential interval. // STM has short duration. // repeating = verbal rehearsal. 

Bahrick and colleagues 1975 – 392 participants American sstate ohio 17-74 // high school yearkbooks collected . recall was tested by 1) photo recognition – 50 photos from year book 2) free recall – recalled names of their graduating class 

Those tested within 15 years of graduation recalled 90% accurately in photo-recognition // 48 years recall decline to 70% for photo recognition. Free recall for 15 years after graduation 60% dropping 30% after 48 years. (LTM supportive evidence