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Progress toward Cyberimmortality
links such as that gives requires someone in a giver relation-
ship and someone in a receiver relationship.
Nobody knows how many episodes an adult remembers, 
but the number 50,000 is sometimes mentioned in Cognitive 
Science discussions. If Shastri is right, then a computer model 
of the hippocampal system might not need to be very big. If 
concepts are addressed efficiently in other parts of the brain, 
then an episode like John gave Mary a book could be stored 
in fewer than a hundred bytes. This would imply the entire 
hippocampal system could get by with only 5 megabytes of 
memory, a tiny fraction of the memory of todays pocket com-
puters. Shastri notes that the human mind imaginatively fills 
in the missing details of memories, and each episodic memory 
really has very little information in it. We are not generally 
conscious of the yawning gaps in our memory, any more than 
we are conscious of the blind spot in the vision of each of our 
eyes. Shastri also notes that memories are generally stored in 
multiple copies, perhaps to guard against losing them through 
the death of any single neuron, but the redundancy in memory 
may have other functions as well, such as helping us combine 
facts from different sources by placing some copies of them 
nearer to each other. Computerized memories might not need 
that redundancy.
This very quick summary of the current state of AI suggests 
that we really cannot predict how soon computer and infor-
mation scientists will be able to simulate real human minds. 
Rapid progress is going on in other directions, and in a few 
years  a  renewed  interest  in  duplicating  human  intelligence 
could plausibly move forward very quickly by exploiting all 
the discoveries and inventions that are being made now for 
other purposes. Once we know how to duplicate a mind in a 
computer, then we will know far better how much informa-
tion of what kinds we will need. We do not currently have this 
knowledge, but such rapid progress is being made in several