Some Pyshcological Properties of Memories
   - As a firing CA is the neural correlate of a short-term memory,
       it should behave like a memory.
 
   - One property of short-term memories is that they decay over
       time.
 
   - That is, they become less active.
 
   - This is inconsistent with our earlier simulation results.
 
   - How can we make these CAs decay over a short period of time (seconds).
   
 
   - Other issues include reactivation of memory.
 
   - Associative memories.
 
   - Number of items in memory.
 
   - Note that we assume that the activity of a memory is a consequence
       of the number of neurons firing in the CA that represents 
       that memory.