Stm Duration, Capacity and Encoding Essay
Outline and evaluate research into the duration, capacity, and encoding of information in short term memory’.
-12 marks ;gt;;gt;;gt;PLAN;lt;;lt;;lt; CAPACITY .(George miller1956) seven +/- 2 immediate memory. Chunking, . (simon 1974) shorter chunks much easier to remember .
(cown 2001) found that the STM is likely only 4 chunks .(vogel et al. 2001) agrees ENCODING .(Bradely 1966a and 1966b) tested effects of acoustic and semantic similarity on short and long term recall. Gave participants words that were acoustically and semantically similar and dissimilar. Participants difficulty in remembering acoustically in STM but not LTM.Semantically similar words easily remembered in short term recall but not so in long term recall .
(Brandimote et al. 1992) found participants used visual coding in STM if given a visual task, as no verbal task took place visual encoding stayed instead of acoustic coding . (wickens et al. 1976) showed Semantic coding sometimes used in STM . LTM encoding not entirely semantic .
(frost 1972) longterm recall related to semantic and visual meaning . (nelson and rothbart 1972) found evidence of acoustic coding in LTM . in general STM is acoustic and visual DURATION . ;gt;;gt;;gt;END PLAN;lt;;lt;;lt;In a very early psychology experiment: in 1887 Joseph Jacobs used the digit span technique to assess the capacity of participants STM. His findings were that the capacity for short term memory was roughly 9 digits and roughly 7 letters.
Jacobs suggested that a STM could remember digits easier as there are only 9 digits and 26 letters, so with digits you theoretically had to remember less. In 1956 George Miller wrote an article called ‘The magic number: seven plus or minus 2’ in which he came to a conclusion that the human capacity for the STM was 7 items +/- 2 and that we “chunked” items or etters together to help us remember them by giving them semantic meaning. And in 1974 Simon discovered that the longer the chunk the more difficult it was to remember However contrary to Miller, in 2001 cowan found that the limit of chunks was actually about 4 after viewing a variety of studies on capacity of STM. And in 2001 Vogel et al. Concluded also that the chunking limit for visual cosing in the STM is about 4, same as acoustically. Thus probably disproving Miller. In 1966 Bradely conducted 2 tests (1966a and 1966b) and tested effects of acoustic and semantic similarity on short and long term recall.
He gave participants words that were acoustically and semantically similar and dissimilar. Participant’s difficulty in remembering acoustically in STM but not LTM. However Semantically similar words were easily remembered in short term recall but not so easily in long term recall In 1992 Brandimote et al. found participants used visual coding in STM if given a visual task, and no verbal task took place when the test was being conducted so visual encoding stayed instead of acoustic encoding showing that memory wasn’t only kept acoustically in the STM In 1976 Wickens et al.
howed Semantic coding sometimes used in STM. However in general STM is encoded mainly acoustically and visually. In 1959 Peterson and Peterson conducted research into STM, they devised a test where non-sensical consonants were being remembered, however in-between remembering participants were prevented rehearsal of the consonant by counting back in 3’s, with a interval of 3 seconds participants remembered 90% and with an interval of 18 seconds the participants remembered 2% suggesting that without rehearsal STM lasts 20 seconds at most.However in 1999 Naire et al. Found items could be recalled after as long as 96 seconds by through various tests remembering the same item to avoid inconsistencies. The test results suggested that items can stay in the STM for a long while unless replaced or overwritten thus providing substantial evidence to Dispute Peterson and Peterson