Features of memory

• define capacity


  it is a measure of how much information can be held in memory.
• supporting evidence regarding capacity

  -> Jacobs (1887) first developed the digit span test- participants had to recall an ever increasing list of digits (the first 4 digits, then 5, then 6). their digits pan was the maximum number of digits they could recall

  -> Miller (1956) noted that most people have a STM capacity of 7+/-2 items. he also noted that this could be increased by chunking (grouping sets of info together)
• what is the capacity of the STM?

  7+/-2
• what is duration?

  it simply refers to the length of time we can remember something for
• what is the duration of the LTM?

  considered infinite (potentially forever)
• who tested the duration of the STM?

  Peterson& Peterson
• How did Peterson&Peterson test the duration of the STM? (supporting evidence)

  -> each participant was given 3 consonants and 3 digits to remember

  -> they were then asked to recall what they'd been given during intervals of 3-18 seconds (e.g recall after 3,6,9 seconds and so on)

  -> most participants correctly remembered their letters and numbers when recalling after the shortest amount of time; showing that the STM isn't very long
• more supporting evidence for duration(LTM)

  -> Bahrick et al (1975) tested over 400 people of varying ages on their memory of classmates from their past.

  -> people were given photos of their classmates from yearbooks and were asked to name as many as they could. Participants who have graduated within the past 15 years could remember more names than those who had been graduated longer (48)
• what is the duration of the STM

  between 18-30 seconds
• define coding

  it is also known as encoding- it is the way in which things are 'written' into our memory
• what are the three types of codes that we use to remember things?

  -> visual- processing information in terms of what it looks like

  -> acoustic- processing information in terms of what it sounds like

  -> semantic- processing information in terms of what it means
• supporting evidence of coding

  ->Baddeley (1966) gave participants lists of words to learn that we are either acoustically similar or dissimilar or semantically similar or dissimilar

  ->they found out that when participants had to recall words immediately after presentation (test for STM) they performed worst on acoustically similar words.

  -> when participants had to recall words after a delay of 20 minutes (a test of LTM) they performed worst on semantically similar words.
• what did the supporting evidence that Baddely did suggest on how info is coded in our STM and LTM?


  -> info is coded acoustically in STM and semantically in LTM
• define LTM

  Long Term Memory- a permanent store that holds unlimited amounts of information for long periods of time
• define STM

  Short Term Memory- a temporary store that holds limited amounts of information for a short period of time
• what is a strength of the studies done into the short and long term memory?


  ->there is a lot of supporting evidence and these findings have been replicated many times

  ->for example, Miller (1956) noted that most people have a STM capacity of 7+/2 items, and that this could be increased through 'chunking'-> grouping sets of info together
• why is the plentiful supporting evidence around the studies done into the short and long term memory a strength?


  ->because it increases the validity of coding, capacity and the duration theory
• what is a weakness of the studies done into the studies done around coding, duration and capacity?

  ->it lacks ecological validity, that is; they do not represent how the STM/LTM work in everyday life

  ->for example; Peterson & Peterson conducted a study in a laboratory where each participants was given 3 consonants and 3 digits remember and they were asked to recall what they were given from 3-18 seconds
• why is the lack of ecological validity concerning the studies done around coding, duration and capacity a limitation?


  this is an issue because in order to understand how memory works, we need to be testing it in a way that is similar to everyday life
• give a counterpoint on the lack of ecological validity surrounding the studies done around coding, capacity and duration


  Bahrick's study involved asking participants about real-life memories so has higher external validity
• what is another limitation of Miller's research done around the STM?


  ->he may have overestimated the capacity of our STM

  ->E.g Cowan (2001) reviewed other research and concluded that the capacity of STM was only about 4 chunks

  ->so this suggests that Miller's estimate of 5 items is more appropriate than 7