On Thu, Apr 05, 2007 at 11:34:09AM +0200, Shane Legg wrote: > The wiring is not determined by the genome, it's only a facility > envelope. > > Some wiring is genetic, and some is not. On a large scale genes
No, the wiring is not genetically determined. There is no specific gene telling cell 0x093785 to connect to cell 0x3464653, and a similiar gene for every other cell. In fact, there is no individual cell addressing, only cell type addressing and relatively diffuse addressing by diffusion gradients. > regulate > how one part of the neocortex is wired to another part (there are even > little I've heard of neuromorphogenesis in embryos, yes. > tiny crawler things that do the wiring up during the prenatal > development of > the brain that sound totally science fiction and very cool, though the > system > isn't exactly perfect as they kill quite a few neurons when they try > to craw > around the brain hooking all the wiring up). You don't know this is defect, and not by design. Apoptosis is is frequently a deliberate mechanism. > At a micro scale each of the different types of neurons have different > dendritic tree structures (which is genetic), and lie in particular Cell type, yes. Individual cell, no. > layers of > cortex (which is also genetic), and various other things. In short, > it's not > really genetic or due to adaption, it's a complex mixture of genetics > and > adaption that produces the wiring in the adult brain. I've never claimed anything otherwise. But the genome is not a noticeable source of complexity in the adult individual. The fertilized egg in the womb context maps to an embryo which maps to an fetus which maps to a neonate which is capable to directly extract information from an appropriately structured environment. There's no gene which tells you how to integrate or how to fix a flat tire. > The models are not complex. The emulation part is a standard > numerics > package. > > Heh. Come to Switzerland and talk to the Blue Brain guys at EPFL... > Their model is very complex and definitely not simply some standard I agree it's not off the shelf. It's still not anything you won't find in Biophysics of Computation, and primary literature. It's completely pedestrian physics, and rather unexciting (by the standars of AI folks, numerics is really complicated and somewhat of a black art) programming. > numerics package. They are working in collaboration with something > like 400 researchers all around the world and the project will be > going > for at least several decades. Simple it is not. It is not only simple, it is completely trivial in comparison to a hypothetical AI designed by people. The complexity in the behaviour comes from the neuroanatomy, not the code. The code is vanilla numerics. -- Eugen* Leitl <a href="http://leitl.org";>leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?list_id=303
