4.1.3 Memory - Duration of Memory Flashcards
What is Duration in memory?
The length of time that information can be held for
Who did research into STM?
Peterson and Peterson (1959)
Who did research into LTM?
Bahrick et al (1975)
Peterson and Peterson’s Procedure
. Tested 24 students in 8 trials
. Each was given a trigram (EGS GRQ etc)
. They were asked to count backwards in 3’s to prevent mental rehearsal
. Asked to recall the trigram after different intervals of 3,6,9,12,15,18 etc seconds
What did Peterson and Peterson find?
After 3 seconds 80% recalled the trigram correctly, at 18 seconds it fell to 10%
What did Peterson and Peterson conclude?
STM has a duration of round 18-30 seconds and decays rapidly if it is not rehearsed
Strengths of the Peterson and Peterson study
. Lab setting which allows for high control over EVs allowing for better cause and effect
Weaknesses of Peterson and Peterson study
. Lacks mundane realism - trigrams are not rehearsed in real life
. Cannot be generalised
. Participants know they are being tested which could lead to demand characteristics
Bahrick et al Procedure
. Studied 392 17 - 74 year old’s
. Tested them on memory recall using their high school year books
Bahrick et al Findings
. Participants tested 15 years since graduation had 90% accurate recall
. Participants tested 48 years after graduation were 70% accurate with recall
Bahrick et al Conclusion
LTM duration is infinite and can last forever
Strengths of Bahrick et al research
. High in ecological validity as its not in a lab and is in the real world
. Reflective of real memory and emotions so high in validity
Weaknesses of Bahrick et al research
. Difficult to replicate
. EV’s much harder to control
. Results cannot be generalised
