Memory

Capacity: 7+/- 2 (5,7,9) 

MILLER:

• Investigated how much info can be stored in STM
• Found P's can cope reasonably well with 7 dots flashed on a screen but not many more
• Miller concluded the span of STM is 7 plus or minus 2

JACOBS:

• used the digit span technique to investigate how many digits (letters&numbers) could be stored in memory at any one time
• he read aloud lists of digits and added one every time
• jacobs stop reading when P's could recall them 50% of the time
• he found average for STM: numbers= 9 but letters= 7

Duration: 18 seconds

peterson and peterson:

• studied 24 university students
• P's were asked to remember nonsense trigrams
• Then count back in 3's from a number (eg: 303) until told to stop
• P's then had to recall the trigrams (the idea of counting back in 3's was to prevent rehearsal)
• on each trail the time spend counting back varied between 3 and 18 seconds
• P's remebered around 80% when there was a 3 seconds interval and about 18% when there was a 18second interval
• this shows P's can remember information for around 20seconds when rehearsal is prevented

Encoding: Haptic, echoic, and iconic

conrad:

• Presented people with visual data
• asked them to recall the letters they had seen (letters shown for 0.75 of a second)
• P's asked to recall in order they had be presented in
• letters sound more alike = more errors
• this shows info is encoded aqcounsitcally in STM

Baddeley:

• Gave P's 4 lists of words (acoustically similar, acounstically dissimilar, semantically similar and semantically dissimilar) 
• Halfs of P's were asked to recall words immediently whilst the other half recalled words after 12 minutes
• people who recalled straigt away = remeber semantically similar better but made more mistakes with acoustically similar
• this shows info in STM is stored acoustically