Many thanks for the pointers to Pribram, Ray, and for getting the mental juices rolling on this. It does take me back to an interest I had in earlier years, and which I put aside for other curiosities. And again, thanks for the sharing of information.
Best regards, Lawry > -----Original Message----- > From: Ray Evans Harrell [mailto:[EMAIL PROTECTED]] > Sent: Sunday, August 18, 2002 6:33 PM > To: [EMAIL PROTECTED]; Keith Hudson > Cc: [EMAIL PROTECTED] > Subject: Re: Brain is not a holograph (RE: America in decline? (was Re: > What is Economics, Hudson? > > > The > > holographic idea only had flimsy evidence based on earlier > experiments on > > mice and rats which showed that a learned act seemed to be > scattered over > > the most of the perceptual processing areas of the brain, because > excisions > > of cortical tissue had to be very extensive indeed before the > learned act > > finally vanished from the repertoire. It was supposed, therefore, that > > originally there were multiple copies of the learned act scattered over > > large parts of the cortex and, even when very few remained (perhaps even > > only one!), then the full performance of the act could be resurrected in > > rather the same way that a holographic image can be resurrected > from very > > small parts of the whole. However, the mice experiments were > pretty crude. > > I'm way out of my league on this since I haven't done any work in it since > the late seventies and early eighties when I got my certification. > However if you type Karl H. Pribram into Amazon.com you will find > book being > written on it as late as 1994 and I believe there are three > including one of > those expensive types that usually means its too hard for the layman. So > you can find out for yourself. In the early stages they weren't only > talking about brain activity and as recent as last year there was in that > great scientific journal the New York Times Science section an article on > brain neurons found in the gut that weren't just wanderers. I > don't mean > to get into a tete with Keith on this since he obviously has a > lot more time > to donate to it than I but it was in the NYTimes and it did fit with my > experience. > > > > Parts of the learned act are indeed to be found in different > parts of the > > brain but only specialised aspects of it, and if a few of those > parts are > > excised then the other parts can still associate together and > perform the > > act (albeit less skilfully). Had the experimenters excised certain other > > very precise areas of the brain -- namely the motor strip that gathers > > together and synthesises all the specialised aspects of the act and > > instructs the muscles to perform the act as an integrated whole -- then > the > > learned act could not be performed at all. Indeed, over time, > because the > > specialised parts of the original memory of the learned act could never > > again "complete the circuit", as it were, the synapses would weaken and > the > > neuronal cells that were dedicated to the particular act would die from > > disuse. > > > > Here's another example based on the "grannie cell" approach. You and I > will > > have multiple instances of the concept of tomato scattered all over our > > cortex, each with varying proportions of perceptual speciality and at > > different levels of processing according to the inputs that are usually > > involved when faced with a tomato and eating it or even throwing it at > your > > least favourite politician (visual, taste, tactility, etc.) However, it > > would be possible that if either of us had a small stroke in a > > microscopically small area of the Wernicke's areas of the brain (perhaps > > only involving two or three cells perhaps) then the ability to utter the > > word "tomato" will have gone for good. You would be able to > remember that > a > > tomato was pleasant to eat. You would be able to choose a tomato from a > > pile of other fruit when asked to. But if you were asked the name of a > > tomato sitting on a plate in front of you would not be able to > answer. You > > would not even "know" the answer. You would shake your head in > puzzlement > > as though you'd never seen one before. However, if you were then > > instructed: "Pick up the tomato from the plate", you would be able to do > so > > instantly. (This is similar to experiences that occur to tens > of thousands > > of people every year when they have had minor strokes so it is not a > > fanciful example.) So this example is an attempt to describe the > phenomenon > > that some thought was holographic. > > Does the description of a unique synapse mean that the map for the human > being is not contained on a micro-level? I don't know, its not > my area of > expertise. On the other hand there are junction models found in > all kinds > of systems. I have no doubt that in the future there will be > some kind of > "miracle" healing of what Keith describes. It would have been wonderful > for my own mother, for example. However, I don't believe that > what he has > described is the be all and end all of this question. I also > figure that > Karl Pribram knows a great deal more than either of us will ever > know about > it as well. Things that seem simple to the amateurs become a great deal > more complicated as informational expertise is added and Pribram > is a World > Master on this stuff. Again I will mention that Pribram is very much > alive as is his theory. I typed his name into Google and found him > thriving which pleases me. I also scanned (in a very rudimentary manner) > the following http://www.acsa2000.net/bcngroup/jponkp/ which > seems to be > the comparison that Keith was making. One of the conclusions > said a simple > "ain't necessarily so" to Keith's tomato argument. > > But I will leave this now and recommend that you use the Google search > engine if you wish to examine this interesting theory further. > > Best > > Ray Evans Harrell > >
