Long Term and Short term Memory

Long Term and Short term Memory

1. Memory Encoding

   • When information comes into our memory system (from sensory input), it needs to be changed into a form that the system can cope with, so that it can be stored
     • There are three main ways in which information can be encoded (changed): 1. Visual (picture) 2. Acoustic (sound) 3. Semantic (meaning)
       • Evidence suggests that this is the principle coding system in short term memory (STM) is acoustic coding. When a person is presented with a list of numbers and letters, they will try to hold them in STM by rehearsing them (verbally)
       • The principle encoding system in long term memory (LTM) appears to be semantic coding (by meaning). However, information in LTM can also be coded both visually and acoustically.

2. Memory Storage

   • Most adults can store between 5 and 9 items in their short-term memory. Miller (1956) put this idea forward and he called it the magic number 7. He though that short-term memory capacity was 7 (plus or minus 2) items because it only had a certain number of “slots” in which items could be stored.
     • In contrast the capacity of LTM is thought to be unlimited.
   • Information can only be stored for a brief duration in STM (0-30 seconds), but LTM can last a lifetime.

3. Memory Retrieval

   • STM is stored and retrieved sequentially.
   • LTM is stored and retrieved by association
   • Organizing information can help aid retrieval. You can organize information in sequences (such as alphabetically, by size or by time).

4. Criticisms of Memory Experiments

   • Many experiments designed to investigate memory have been criticized for having low ecological validity. First, the laboratory is an artificial situation. People are removed from their normal social settings and asked to take part in a psychological experiment.
   • Often, the tasks participants are asked to perform can appear artificial and meaningless