Long-Term Memory

Long-Term Memory

1. Capacity- possibly unlimited

2. Duration- measured in hours, days and years

   • Shepard (1967)
     • showed ppt 612 memorable pictures, one at a time
       • an hour later, they were shown some of these pictures among a set of others
         • showed almost perfect recognition
     • 4 months later, they were still able to recognise 50% of the photographs
   • Bahrick (1975)
     • asked people of various ages to put names to the faces from their high school year books
       • free recall accuracy dropped from 50% at 3 months to 20% at 40+ years
       • recognition of names and pictures and matching of names and pictures remained high (85-90%) for all retention intervals
         • dropping sharply to about 75% in the eldest age group
       • in picture-naming condition- about 70% accuracy at 3 months after graduation, 60% after 5 years and 20% after 40+ years

3. Encoding- semantic

   • Baddeley (1966a and 1966b)
     • tested effects of acoustic and semantic similarity on short-term and long-term recall
       • gave ppts list of words that were acoustically similar and dissimilar and semantically similar and dissimilar
         • found ppts found it harder to remember acoustically similar words for STM semantically similar words in LTM whereas it was easier the other way around
           • suggesting LTM stores information semantically
   • encoding in LTM may not just be semantic
     • Frost (1972)
       • showed LT recall was related to visual and well as semantic categories
     • Nelson and Rothbart (1972)
       • found evidence of acoustic encoding