Short And Long Term Memory Flashcards
Define duration?
How long a memory last
How do STM and LTM differ?
In capacity, duration and encoding
Define capacity?
How much can be held In the memory.
What are the differences between capacity of STM and LTM?
STM has limited capacity, LTM has potentially unlimited capacity.
Define encoding?
Transferring information into code, it is the way information is stored in your memory.
What are the differences between duration of STM and LTM?
STM has limited capacity, LTM has potentially unlimited capacity.
What did Peterson and Peterson investigate?
The duration of STM.
What type of encoding does STM and LTM have?
LTM is encoded semantically (meanings).
STM is encoded acoustically.
What was the method that Peterson and Peterson used?
Participants were shown nonsense trigrams and were asked to recall them after either 3,6,9,12,15 and 18 seconds. During the pause they were asked to count backwards in threes from a given number. This prevented them from rehearsal.
What were the results of Peterson and Peterson’s experiment?
After 3 seconds participants could recall 80% of trigrams correctly. After 18 seconds only about 10% were recalled correctly.
What was the concluding of Peterson’s and Peterson’s experiment?
When rehearsal is prevented very little can stay in STM for longer than 18 seconds.
Evaluation of Peterson and Peterson
It’s a laboratory experiment therefore the variables are controlled, there will be no extraneous variables. For example they controlled the trigrams, they were nonsense and therefore won’t mean anything to the participants. However this then means that the task and setting are artificial so it lacks ecological validity. They therefore may act differently because they are under pressure.
What did Bahrick et al. Investigate?
LTM
What was Bahrick et al’s method?
392 people were asked to list the names of their ex classmates. This is the free recall test. They were then shown photographs and asked to recall the names of the people shown, this was the photo recognition test. They were given names and asked to match them to a photo of the classmate, this is the name recognition test.
What were the results of the study?
Within 15 years of leaving school participants could recognise about 90% of names and faces, they were about 60% accurate on free recall. After 30 years free recall had declined to about 30% accuracy. After 48 years name recognition was about 80% accurate, and photo recognition was about 40% correct.
