coding in memory

• Information that we store has to be ‘written’ in memory in some form. It is described as a ‘code’ in which it held in the form of sounds (acoustic), images (visual) or sound (semantic). For example, these words are acoustically similar but semantically different: cat, cab, can, man. These words are the opposite, so semantically similar, but acoustically different: great, large, big, huge.
• . Alan Baddeley used words like those above to test the effects of acoustic and semantic similarity on STM and LTM. He found that participants had difficulty remembering acoustically similar words in STM, but not in LTM, whereas semantically similar words didn’t cause a problem from STM but made muddled LTMs. This suggests that STM is largely encoded acoustically, and LTM is largely encoded semantically.
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  Baddeley’s study has been criticised for its methodology.

  In the study, STM was tested by asking participants to recall a word immediately after hearing it. LTM was tested by waiting 20 minuets then recalling the list. It is questioned if 20 minutes really tests LTM.

  This casts doubt therefore, on Baddeley’s results as he didn’t seem to be tested LTM at all.
• In general, LTM appears to be semantic, but not always.

  Frost showed that long-term recall was related to visual as well as semantic categories, and other researchers found evidence of acoustic coding in LTM.

  Therefore, it seems that coding in LTM is not simply sematic but can vary according to circumstances.
• Some experiments have shown that visual codes are also used in STM.

  For example, Brandimote found that participants used visual coding in STM if they were given a visual task. When given a visual task, if they were prevented from doing any verbal rehearsal, eg saying ‘la la la’ in a retention interval. When verbal rehearsal was prevented, participants used visual codes.

  This suggests that STM is not entirely acoustic.