SHORT TERM MEMORY

SHORT TERM MEMORY

1. Capacity

   • Jacobs- Jacobs studied digit spans and concluded letter recall was 7 and number recall was 9 because there are more letters than numbers so it's harder to remember.
     • Miller- Miller suggested that the magical number was 7, plus or minus 2. He said that we chunk words or numbers together as it helps to remember them, for example a phone number.
       • This can be affected by individual differences- as many people have different abilities-, reading aloud- as digit span studies are better if numbers are read aloud-, and length of word- short words are more likely to be remembered.

2. Duration

   • Peterson+Peterson- They did an experiment where they gave a random trigram and then made the participants count backwards from a number in three's. They found that duration of short term memory is around 20-30 seconds.
     • Trigrams are artificial and may not be a good way to test how we remember things in everyday life, so it lacks ecological validity. They may have tested capacity rather than duration.Trigrams in earlier trials that were presented may have confused participants.

3. Encoding

   • Conrad showed participants a random sequence of six consonants in two different conditions, either acoustically similar or acoustically dissimilar. Conrad found errors when the participants were given acoustically similar words so STM is mainly acoustic.
     • Low ecological validity, he used students as his participants so maybe not representative of population. Controlled lab experiment