SHORT -TERM, LONG-TERM AND WORKING MEMORY Flashcards
What did ebbinghaus do?
First to study on memory around 1885 using himself as a participant
Findings shown highly reliable and still used today
Used lists of cvc trigrams
- meaningless consonant - vowel-consonant syllables
To the sound of a metronome, would read out syllables and attempt to recall them after delay
What did ebbinghaus find?
• Measured time required to re-learn a
list of trigrams after an interval of time
• In this figure, the interval is 24 h
• Time taken to relearn the list
significantly decreased based on the
number of repetitions in training
Whats the index of retention?
• trials to learn minus trials to fully re-learn (e.g. 20-15 = 5)
• Express value as a percentage of original trials (e.g. 5/20 = 25%
Explain the forgetting curve?
- • Exponential loss of information
• Sharpest decline in memory in
the first 20 minutes, and fast
decay continues through the
first hour.
• But not everything is forgotten
in this time.
• The curve begins to completely
level off at an hour, and levels
off after about one day
• This pattern suggests the
existence of short-term and
long-term memories that are
differentially sensitive to
forgetting
What did Atkinson and shift in look into?
Multi store model of memory
Explain the multi store model of memory?
Memory is formed from three linked storage sub-systems
The duration is memories and the storage capacity of the sub-systems increase from left to right
Stimuli - sensory memory - short term memory - long term memory
Short term memory can lead to a response
Explain sensory memory?
Sensory memory
• Stimuli in the environment that are detected are initially encoded in
sensory memory.
• Iconic = visual
• Echoic = Auditory
• Haptic = touch
Explain short term memory?
• Information that is attended to in the sensory register (i.e. it is task
relevant) enters short-term memory.
• Rehearsal of information increases duration of short-term memory and
the likelihood that information will be transferred to long-term memory
• Information from the long-term store can be retrieved to help with current
decisions in order to generate behavioural responses
Explain long term memory?
A permanent memory store
Information can only get inot long term memory if its is rehearsed in short term memory
Explain the multi store model of memory by Atkinson and shiffrin?
Information registered in sensory memory.
• It is task relevant, so enters short term memory
• Rehearsal in STM leads to storage in LTM
• When we want to call Jane, information
retrieved from LTM into STM
• This information is used for the behavioural
response (dialling the number)
What did the reasrch on sensory store originally focus on?
Iconic -visual- memory
Originally thought that the sensory store had a very limited duration and storage capacity
Brief presentation of visual patterns
Partipants were then required to recall the letters presented in particular trial
What was the performance like in the sensory store?
Very poor
- particpants were able to recall about 4 letters
- many couldn’t rember past the first line of letters on display
What did they conclude about the sensory store?
The iconic memory as very limited in terms of capacity and duration
- only few elements are retained for an very short period of time.
What did sperling suspect about iconic memory?
Capacity was seriously underestimated
Explain spellings partial report procedure?
- particpants again presented with an array of 12 letters
- only had to report part of stimulus
- high tone = top
Medium tone = middle
Low tone= bottom
Varied in delay in presentation of stimulus and the tone that indicated recall
Explain the serial position curve?
Imagine an experiment where you give particpants a list of words to memorise
Then ask them to recall in full
Plot the percentage of words recalled based on the position of the word in the original list
What kind of partipants does the serial position curve tend to find?
Remember the first items on the list
Remember few in middle
Most of the last items
Whats it called when particpants can remember most of the first items on the list?
Primary effect
Whats it called when they can remember most of the last times on the list?
Recency effect
What dies primary effect depend on?
Rehearsal of first items in stm
What happens with the middle items in the list in STM?
The middle items of the list enter STM
• But STM has a limited capacity (~7 items)
• The middle items are therefore displaced
from STM by items from later in the list.
• If the items are not in STM, they cannot be
rehearsed and transferred to LTM
What does recency effect depend on?
Recall of the last items from stm
Explain baddeleys working memory model?
• Atkinson and Shiffrin’s model contained a
unitary short term memory store with
limited capacity and duration.
• If it is a unitary store, any kind of info
processed in STM should cause
interference – we should not be able to
multi-task.
• To test this, Baddeley & Hitch (1974) had
2 groups of participants
• Some participants had to memorise a
list of words presented sequentially
• Other has to memorise a list of words
while counting backwar
What was the recalling like in baddeleys working memory model?
• The number of words recalled by
participants was similar in both the
single and dual task groups.
• Participants performed similarly,
despite the supposed limited capacity
of the short-term store in Atkinson and
Shiffrin’s model
• These results suggest that short-term
memory must be broken down into
separate components
