Types of Memory Flashcards
What are the two types of memory
Short term and Long term
What is STM capacity
limited capacity
What did Joseph Jacobs say
STM
- Average digits- 9.3 items
- Average letter span-7.3 items
What did George Miller say
STM
- magic number 7(+2/-2)
- recall 5 letters as well as 5 words by chunking
What is LTM capacity
unlimited capacity
What is STM duration
short duration unless repeat items over and over
What did Peterson’s study?
STM
- gave students a consonant syllable and 3 digit number to count down from until told to stop
- each trial they stopped at different times;3,6,9,12,15,18 seconds)- retention interval
What did Peterson’s find
STM -on average: 90% correct after 3 seconds 20% correct after 9 seconds 2% correct after 18 seconds
What is LTM duration
potentially lasts forever
what was Bahricks study
LTM
- tested 392 ppts from 17-74
- recall tested by photo recognition and free call test
what did Bahrick find
LTM
- photo recognition- ppts within 15 years of graduation were around 90% accurate and after 48 years was around 70%
- free call-15 years around 60% accurate and drop to 40% after 48 years
what is encoding
info that we store has to be written in some form(code) and it can be held in form of sound(acoustic), images(visual) or meaning(semantic)
what does acoustic mean
sound
what does semantic mean
meaning
what was Baddeleys four groups
gave different lists of words to 4 groups of ppts3
- group 1-acoustically similar
- group2-acoustically different
- group 3-semantically similar
- group 4-semantically dissimilar
what was Baddelys findings for STM
STM recall was worse with acoustically similar words
what was Baddelys findings for LTM
LTM recall after 20 mins was worse with acoustically similar
Evaluation of STM duration(Peterson’s)
- low generalisability(all same age)
- reliable(in a lab)
- good application(reversal prevention)
Evaluation of research into Capacity
- support restricted capacity
- Cowan found it is most likely to be 4 chunks so lower end of Millers research
Evaluation of capacity
jacobs found digit span can increase with age
how is info encoded in STM
acoustically
how is info encoded in LTM
semantically
