LTM

• LTM capacity is potentially unlimited
• LTM is minutes to years and could potentially last a lifetime
• It is difficult to test exact duration of LTM
• Bahrick did a study on LTM
• Bahrick aimed to establish the existence of very long-term memory (VLTM) to see whether there was any difference between recognition and recall
• Bahrick procedure involved investigators tracking down graduates from a particular high-school in America over a 50 year period
• Bahrick showed the graduates photos from their high school yearbook and the graduates were split into 2 groups - the recognition group and the recall group
• The recognition group in Bahrick's study were given a group of names for each photo and were asked to select the name that matched the person in the photo
• The recall group in Bahrick's study were asked to name the people in the photos without being given a list of possible names
• Bahrick found that in the recognition group the answers given were:

  ninety% correct after fourteen years

  eighty% correct after twenty five years

  sixty% correct after forty seven years
• Bahrick found that in the recall group the answers given were:

  sixty% accurate after seven years

  less than twenty% accurate after forty seven years
• Bahrick's conclusion was that people can remember certain types of information for almost a lifetime
• Bahrick's conclusion was the very long-term memory appears to be better when measured by recognition tests than by recall tests
• Bahrick's study had high levels of mundane realism. people asked to remember old friends or pictures, therefore his study is externally valid
• Bahrick's study was a lab study, participants will have displayed demand characteristics, so there is low internal validity
• Baddeley's aim was to explore the effects of acoustic and semantic coding in LTM
• In baddeleys study on LTM participants were divided into 4 groups and shown a list of 10 words drawn from 4 catagories
• Just like in Baddeley's STM procedures, Baddeley had the same 4 categories to learn about coding
• One of Baddeley's categories is acoustically similar words (man, mad, map)
• One of Baddeley's categories is acoustically dissimilar words (pen, day, few)
• One of Baddeley's categories is semantically similar words (great, big, large)
• One of Baddeley's categories is semantically dissimilar words (hot, old, late)
• In Baddeley's study, after an interval of 20 minutes, during which the participants were given another task to do, they were asked to recall the 10 words they had heard in the correct order
• Baddeley found that recall in LTM was much worse for semantically similar words than semantically dissimilar words
• Baddeley found that recall was the same for acoustically similar and acoustically dissimilar words in his LTM study
• Baddeley concluded that LTM primarily makes use of semantic coding, as shown by the difficulties participants had recalling the correct order of words that had similar meanings
• LTM uses semantic coding whereas STM uses acoustic coding
• One strength of LTM coding study by Baddeley is that LTM is said to encode semantically in other research

  Found LTM makes use of semantic coding

  Therefore, its reliable and high external validity
• One weakness of Baddeley's study on LTM is laboratory

  Participant's may have had demand characteristics

  Low external validity and mundane realism
• Multi store model of memory

  
• Baddeley found that information was coded semantically in LTM
• the LTM codes semantically
• The LTM has an unlimited capacity
• The LTM has a duration of almost a lifetime depending on how its tested