Short- term memory

Short- term memory

1. Badderley (1964) Encoding

   • Gave different lists of words to four groups of participants to remember
     • Group 1 - acoustically similar
       • group 2 - acoustically dissimilar
         • Group 3 - semantically similar
           • Group 4 - semantically dissimilar
           • remembered most
       • remembered least
     • The more you rehearse something the more likely something is likely to transfer from short term memory to long term
     • After 20 mins they had to recall the words in the correct order - Long term recall was a lot worse for semantically similar words compared to dissimilar ones

2. Conrad

   • Presented participants with the visual list of six consonants that they had to write down.
     • Recall errors were mainly related to a letters sound, not the visual appearance. For example V instead of B not F instead of E
       • The visually presented information must have been encoded acoustically STM is primarily encoded on the basis of sound

3. Mr. & Mrs Peterson Duration of STM

   • Procedure
     • 1. They asked the subjects to remember a single nonsense syllable of three consonants
       • 2. They then gave them a distractor task to stop them from rehearsing the trigram that they had already seen - for example counting backwards from 100 in 3's
         • 3. They were then tested on their recall after 3,6,9,12,15 or 18 seconds - the recall had to be perfect and in the correct order in order to count
   • Findings
     • Progressively fewer trigrams were recalled as time intervals lengthened
     • After 18 seconds fewer than 10% of trigrams were correctively recalled
   • Evaluations
     • Trigrams are rather artificial and do not reflect modern memory interference (conclusions of other trigrams) and not deccay caused the poor recall
     • Lacks ecological validity
     • STM duration is less than 18 seconds