what is long term memory
continual storage of info which is largely outside of our awareness but can be used into working memory when needed
-lasts from 2 mins-100yrs
-unlimited capacity + duration
what is short term memory
-the info we are currently aware of or thinking about.
-The info comes from paying attention to sensory memories
-memory is measured in seconds + mins
-limited capacity short duration
what is capacity
the measure measure of how much can be held in memory
what is duration
a measure of how long memory lasts
how can the capacity of STM be assessed and who assessed it
by using a digit span
-assessed by Joseph Jacobs
what did jospeh Jacobs find about his assessment of the capacity of STM
he found that the average span of digits was 9.3 items and 7.3 for letters
what was joseph jacobs explanation for why it was easier to recall digits
there was 9 digits whereas 26 letters
what was millers research on human memory- CAPACITY OF STM
-the span of immediate memory is 7+-2
-he noted people cope well with counting 7 flashing dots on screen but not many more
-the same is true if you are asked to recall music notes, letters and words
- he found that people recall 5 words as well as they can 5 letters
-came up with chunking to help us remember more
who studied the duration of STM
Peterson and peterson
what was Peterson + Peterson research to study the duration of STM
- used 24 students
-each pps were tested over 8 trials - on each trial a pps was given a constant syllable and a 3 digit retention interval
- during their retention interval they had to count backwards from their 3 digit number
what did peterson and peterson find on his research
pps on average:
-90% correct over 3 secs
_20% after 9 secs
-2% after 18 secs
-suggests that STM has a very short duration less than 18 secs
who studied the duration of LTM
Harry Bahrick
what was Harry Bahrick research on LTM
- tested 400 people of various ages 17-74 on their memory of classmates
-a photo recognition test consisted of 50 photos some from high school book
-in a free recall test pps were list the names they could remember of their class
what did Harry Bahrick find on his study on duration of LTM
- pps who were tested within 15 yrs of graduation was 90% accurate at identifying faces of class
-after 48 yrs it was 70%
free recall: - 60% accurate after 15 yrs
-30% accurate after 48 yrs
what is coding
the way info is changed so it can be stored in memor.it can be stored visually ,acoustically and semantically
what is visual coding
memories stored visually ie pictures
what is acoustic coding
memories stored due to sound
what is semantic coding
memories with similar meaning
who studied the effects of acoustic and semantic similarity on STM and LTM
Alan Baddeley
what was Alan Baddeley research on the effects on acoustic and semantic similarity on LTM + STM
- used word lists to test the effects
- he found that pps had difficulty remembering acoustically similar words in STM then LTM
-yet semantically similar words posed little problem for STM but muddled in LTM
what did Alan Baddeley conclude in his study
STM is largely encoded acoustically
LTM is largely encoded semantically
millers research AO3- capacity of STM
millers original findings have not been replicated.
-Cowan reviewed a variety of studies on capacity of STM
-concluded that STM is limited to 4 chunks
- research on capacity of STM for visual info- the limit is 4 items per chunk
-shows that the lower end of miller research is more appropriate so STM is not as extensive as thought
cowan{2001} concluded what
magic number=4
AO3- capacity of STM
size of the chunk affects how many chunks u can remember
-simon found that people had a shorter memory span of larger chunks than smaller chunks
-supports the view that STM had a limited capacity + refines understanding
