109 Essays on Infinite Lifespans   William Sims Bainbridge best a third of a millimeter, still far too gross to record the fine structure of the neurons, but the methods could probably be improved greatly. Whether through a similar mechanical sec- tioning process or through an intensive application of brain scan techniques, destructive mapping of the brain could con- ceivably chart the connections between the neurons. Storage and analysis of the data are well beyond current information technology capabilities. Functional approaches have a different set of advantages and disadvantages, but they are ready today to make at least low fidelity copies of human personalities. While we can imagine many possibilities for the distant future, they will be of no value for the millions of people who will die before they can be developed. If I had to make a prediction, I would guess that everyone alive when this essay is published will have died before struc- tural methods of mind reading are perfected, and they will be of little value until a short time before then. This last point is based on the view that we will have to know very much about neural connections before we can deduce what meaning they represent. With functional mind reading, the meaning is attached to the data, so that even small fragments can be understood. A good metaphor is assembling a jigsaw puzzle when some parts of the image become perfectly clear long before we figure out what the whole picture is about. PROGRESS IN PERSONALITY CAPTURE Functional  mind  reading  is  already  possible  at  a  moder- ate level of fidelity, and concentrated research efforts could achieve  significant  progress  rapidly.  Both  traditional  psy- chological tests and more recent computerized methods can