X-Message-Number: 32877 From: Daniel Crevier <> References: <> Subject: thought experiment on progressive uploading Date: Mon, 27 Sep 2010 12:51:14 -0400 Greetings. Given the recent rush of postings about uploading, now may be the time to submit some considerations I've entertained for a while about the thought experiment where a person 's brain is gradually replaced by artificial components. Since we, uploaders and opponents, are all materialists here, we are agreed that the procedure should not bring about any observable change in the behavior of the patient, since his or her "input-output function" remains unchanged. During and after the procedure, the person should keep on reacting to the environment and report on his or her internal states in the same way. In particular, the patient should keep on insisting that he or she is still conscious. Uploaders claim that this shows that the person effectively remains conscious throughout, and is thus "the same" in the uploaded state as before. Anti-uploaders claim that since non-biological material cannot be conscious, the person in fact gradually loses consciousnous and becomes, in philosophical parlance, a zombie: a being with all the outwards appearances of consciousness, but effectively dead inside. But for this last interpretation to be true we have, imho, to accept that some pretty weird things happen during the transformation. To be precise, let us assume that the person has had the V5 section in the back of the brain converted, and nothing else. To the rest of the brain (ROB), the input from the digitized V5 "feels" exactly the same as before, and therefore ROB's behavior should be unaffected. It so happens that V5 processes visual input from the optic nerve, and makes this information explicitly available to the rest of the brain. By the anti-uploading assumption, since the digitized version of V5 lacks whatever magic is required to generate consciousness, then the person should not be conscious of what he or she sees. Hower, as per our assumptions, the person should report that he or she is still conscious of visual input. But wait a minute! Remember, ROB is still intact. In particular, the monitoring and command areas in the neocortex, the centers that control what the patient says, and the auditory centers that interpret what the patient hears, are still biological. So how can the patient's mouth be activated to say something that is to him or her patently untrue (that he or she is still conscious of visual input), hear his or her mouth spout this nonsense, and not react? If you believe in the zombie interpretation, what's going on here? (And in case you're wondering, it's not anything like blindsight: patients with a damaged V5 are perfectly aware of their partial blindness, even if other areas of the brain keep on processing part of the visual infrmation). Daniel Crevier Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=32877