memory - studies - peterson & peterson 1959 Flashcards
1
Q
Aims
A
- To test the true duration of STM
- to see if retention of items was affected by
interference during recall intervals - second part of their study, they investigated
whether silent or vocal rehearsal would affect recall of items.
2
Q
sample
A
- 24 students from an introductory psychology course at Indiana University, USA were selected.
- As part of their course, the students were required to take part in
research experiments.
3
Q
procedure
A
- The green light meant that the trial was ready to begin.
- The red light meant to stop counting & recall the trigram (three-letter consonant.)
- Each participant was tested eight times at each of the following six recall intervals: 3s, 6s, 9s, 12s, 15s, 18s
- 2 practice trials to ensure the instructions had been fully
understood. - Beginning of each trial, the experimenter would spell out a trigram followed by a number from which the participant had to count backwards in either 3’s or 4’s
e.g BFP 709, 707 - In half the trials, participants counted backwards in 3’s
- in the other half they counted backwards in 4’s
- Participants counted backwards in time with the ticking of a metronome. This was a task that would minimise rehearsal behaviour between presentation and recall.
- In 2nd experiment, experiment asked participants to do same tasks, but given time to repeat trigram.
4
Q
results
A
- longer each student had to count backwards, less they’re able to accurately recall the trigam.
- when asked to count backwards after 3s = remembered 80% of trigram
- 18s = less then 10%
2nd experiment - extra time increased frequency of recall = able to consolidate info little more
- showed similar decline over time
5
Q
conclusion
A
- participants unable to rehearse trigrams
- info in our STM fades rapidly, only 10% recalled after 18s
- stm has limited duration
- Only in conditions where the repetition was vocal and controlled did accuracy of recall improve.
- The rate of forgetting from short-term memory depends on the amount of rehearsal undertaken.
6
Q
strengths
A
- Reliable → Extraneous variables like noise eliminated. Situational variables controlled. Study can be replicated, findings can be checked to make sure they weren’t one-off result.
- Standardized procedure → Fixed timings used - scientific.
- Explains how verbal distraction (interference) affects retention of info.
7
Q
weaknesses
A
- Lacks mundane realism → recalling trigrams not realistic use of memory.
- Reductionist → biological factors not considered.
- Trigrams may have personal meaning to participant → extraneous variable participant variable.