Sound Matters in short-term memory.
Conrad used strings of letters to investigate short-term memory. A typical string has to be letters of irrelevance for Example; BBQ or BBC Would not be in the string of letters.
These letters were shown on screen for approximatley three quaters of a second.
The errors in recall were very interesting; The letters V, B and P were mixed up quite frequently. Conrad claimed it was the sound of the letters that mattered in encoding in the STM. Eventhough they were shown on a screen, the visual information must have been changed into sound on the way to the subjects' memory for such errors to occur.
The capacity of short-term memory is limited
'The magic number 7 +/-2'
Used letters which didn't have more than one syllable (For example; would not use 7 or W because they have two syllables). By using a metronome, he showed an item every half a second.
He found that:
- The average digit span was just over nine.
- The average digit span for letters was seven.
- As we get older, we get better at remembering both digits and numbers.
- The Capacity of STM is Limited.