Memory Flashcards
What is memory
The way the mind stores and resembles info
What is the duration of sensory memory
Less than half a second
What is the coding of sensory memory
Iconic- visual
Echoic- acoustic
What is the capacity of short term memory
Between 5 and 9
What is the coding in short term memory
Acoustic
What is the duration of short term memory
18-30 seconds
What is the coding for long term memory
Semantic
What is the capacity of long term memory
Unlimited
What is the duration of long term memory
Up to a life time
Procedure
Sperling 1960
Presented a grid of letters for less than a second.
Then participants were asked to recall immediately
Sperling 1960
Results
Capacity- recalled on average 4 letters
Duration- info decays in around 2 seconds
Encoding- visual
who did research on digit span and what was the research on
jacobs 1887
research on capacity of stm
how was capacity of stm investigated
participants would be asked to recall 4 digits in order out loud then 5 digits the 6 and so on until the participant cannot recall in the correct order.
was found that the mean span for digits was 9.3 and for letters was 7.3.
explain millers observations of span of memory and chunking
he observed that thing usual come in sevens. this suggests that the span of stm is 7 plus or minus 2.
he also noted that people can recall 5 words as well as 5 letters. they do this by chunking.
who did research on the duration of stm
peterson and peterson 1959
peterson and peterson procedure
24 undergraduate students. took part in eight trials. each trial the student was given a trigram to remember and a 3 digit number. they had to count backwards from that number in threes or fours until told to stop. this was to prevent rehearsal.recall was tested after 3,6,9,12 and 18 seconds. know as retention interval.
peterson and peterson findings
longer the retention interval the lower the percentage of correct responses. suggests stm has a very low duration
who did research on the duration of ltm
bahrick et al 1975
bahrick et al procedure
392 pp’s aged between 17 and 74. recall was tested in various ways such as photo recognition consisting of 50 photos , and free recall where pps recalled names of people from their graduating class.
bahrick et al findings
those tested within 15 years of graduation were 90% accurate on photo recognition. after 48 years recall declined to about 70% for photo recognition. free recall was worse than photo recognition. after 15 years it was about 60% and after 48 years it dropped to 30%. suggests ltm can last very long.
limitation of baddeleys research on coding
used artificial stimuli, the word lists had no meaning to the pp’s. means we should be cautious about generalising findings to different kinds of memory tasks. so has limited application
limitation if jacobs research on the capacity of stm.
it was conducted a long time ago ad so lacks external validity. early research often lacked adequate control. but results from other research has confirmed the findings so supports its validity.
limitation of millers research on capacity of stm
may have overestimated the capacity . cowan 2001 reviewed other research and concluded the capacity is actually only 4 the lower end of millers estimate may be more appropriate.
limitation of peterson and peterson
stimulus was artificial. trying to remember trigrams does not reflect most real life memory activities where what we are trying to remember is more meaningful. so lacked external validity.
strength of bahrick et al
used real life meaningful memories. when research with meaningless stimuli was used the results were lower. this increases the external validity.
who proposed the multi store model of memory
atkinson and shriffin 1968/71
how is information transferred from sensory register to stm
by paying attention
how is information transferred from stm to ltm
maintenance rehearsal
how is information transferred from ltm back to stm
retrieval
strength of the multi store model of memory
supported by research to show ltm and stm are qualitatively differently. baddeley found they are coded differently so supports the multi store model.
weaknesses of the multi store model of memory
suggests that ltm and stm are unitary store however research into amnesia patients suggests there are more than one type of long term and short term memory.
Craik and Watkins 1973 also suggested that maintenance rehearsal does not transfer information into ltm. Only maintains information in stm
Explain episodic memory
Refers to ability to recall events. It has been likened to a diary. For example your recent visit to the dentist and so on. Memories are time stamped. You have to make a conscious effort to recall episodic memories.