sandip@oddjob.UUCP (Sandip Chakra) (06/13/85)
For some days the following question is bothering me. If the evolution
theory is right, then why the human brain evolved to about six times
as that of an orung-otung and yet human uses only about 5 percent of the
brain cells? If the other cells were not needed then why produce them? Does
any of you have an answer? I thought that may be since brain cells
do not multiply nature has provided us enough at a time to protect against
all the odd kinds of injuries. How many of you buy this argument? Another
question which bothers me and is related to the evolution theory is that
why the shape of an egg is so perfect even from the time of dynosorous?
This may sound a rather vague question but one would expect that to reduce
pain in laying eggs nature has discovered the shape, so to speak, by the trial
and error. May be someone a litle less dumb than me out there will be able
to shed some light on these questions.
Sandip Chakra
cjh@petsd.UUCP (Chris Henrich) (06/13/85)
[] For years, I have wondered (intermittently and tepidly) about a commonly expressed opinion. It just came around again: in article <783@oddjob.UUCP> sandip@oddjob.UUCP (Sandip Chakra) writes: >For some days the following question is bothering me. If the evolution >theory is right, then why the human brain evolved to about six times >as that of an orung-otung and yet human uses only about 5 percent of the >brain cells? Is there any current data or informed opinion to support the statement that we use only X% of our brains? In recent books, for the general reader, on brain function, I have never seen it asserted or supported. I conjecture that it is a new kind of folklore: scientific folklore. (Actually, mathematicians think that physicists believe in a lot of "folk theorems" but these are probably an artifact of different emphases in the two subjects.) Perhaps, decades ago, when investigators were beginning to discover the detailed functions of different parts of the brain, they were able to assign roles to only X% of it, and said so, and the popular mind got the message wrong. Can this conjecture be supported? Are there other folk theorems that you have noticed? Regards, Chris -- Full-Name: Christopher J. Henrich UUCP: ..!(cornell | ariel | ukc | houxz)!vax135!petsd!cjh US Mail: MS 313; Perkin-Elmer; 106 Apple St; Tinton Falls, NJ 07724 Phone: (201) 758-7288
sandip@oddjob.UUCP (Sandip Chakra) (06/14/85)
> > ......why human evolved about six times > >as that of an orung-otung and yet human uses only about 5 percent of the > >brain cells? > > Is there any current data or informed opinion to > support the statement that we use only X% of our brains? In > recent books, for the general reader, on brain function, I > have never seen it asserted or supported. > I conjecture that it is a new kind of folklore: This conjecture shows that Chris is really out of touch with the modern techniques. I ain't a medical student and can not cite ready references but I recently watched a PBS broadcasting on brains (a series in fact), which showed with the example of four people that even though their brains are virtually entirely damaged and only an extremely thin layer of brain cells touching the skull is functioning they are perfectly normal person. In fact, the subjects did not know that their brains are damaged at all. These people are adults and are doing their jobs in a rather respectable fashion. Their intelligence also were found to be above normal (if I recall correctly). The method used to check such "hollowness" of their brain was Tomography (called CAT scanning, I suppose). The test was clearly convincing, and I do not doubt that my assertions based upon what I have observed are correct. > beginning to discover the detailed functions of different > parts of the brain, they were able to assign roles to only X% > of it, and said so, and the popular mind got the message > wrong. Can this conjecture be supported? Are there other > folk theorems that you have noticed? > > I suppose this clarifies my issue. Doubly regards. Sandip P.S: By the way, Einstein was supposed to have used only 15% of his brain. Since I did not read this first hand, I did not cite this example. In fact, I would have called this a folklore myself until I read about it but I am perfectly willing to believe it now based upon what I watched. > Full-Name: Christopher J. Henrich > UUCP: ..!(cornell | ariel | ukc | houxz)!vax135!petsd!cjh > US Mail: MS 313; Perkin-Elmer; 106 Apple St; Tinton Falls, NJ 07724 > Phone: (201) 758-7288 *** REPLACE THIS LINE WITH YOUR MESSAGE ***
rbg@cbosgd.UUCP (Richard Goldschmidt) (06/14/85)
Let me start by saying that after ten years of doing brain research, and a Ph.D. in neuroanatomy, there is NO evidence that people only use some small fraction of thier brain cells. In article <784@oddjob.UUCP>, sandip@oddjob.UUCP (Sandip Chakra) writes: > > > ......why human evolved about six times > > >as that of an orung-otung and yet human uses only about 5 percent of the > > >brain cells? > ... I recently watched a PBS broadcasting on brains (a > series in fact), which showed with the example of four people that > even though their brains are virtually entirely damaged and only an > extremely thin layer of brain cells touching the skull is functioning > they are perfectly normal person. In fact, > the subjects did not know that their brains are > damaged at all. These people are adults and are doing their jobs in a rather > respectable fashion. Their intelligence also were found to be above normal > (if I recall correctly). The method used to check such "hollowness" of their > brain was Tomography (called CAT scanning, I suppose). The test was clearly > convincing, and I do not doubt that my assertions based upon what I have > observed are correct. > > I suppose this clarifies my issue. Doubly regards. > Sandip No clarification at all, just misunderstanding. It is true that people can function effectively with some degree of brain damage, but it depends greatly on the task and on their degree of experience with the task prior to brain damage. The classic series of experiments in this area were done by Lashley in the 20's and 30's. He found that if he trained rats in a visual discrimination task for thousands of trials beyond the criteria usually used to demonstrate learning, that he could still get criterion level performance after removing 95% of their cerebral cortex. However, without OVERtraining, this result can not be obtained. It is true that there is a certain level of redundancy in the brain so that it can still function at some level after injury, and there are also repair mechanisms which can sometimes contribute to recovery from injury, but you can also be certain that any injury to the brain reduces the level of functional ability in specific ways, depending on the location of the injury. All of the living neurons in your brain work, and contribute to the distributed processing and storage which make behavior, learning and thought possible. It is in the nature of the distributed architecture that some function is preserved even when some of the processors are removed, but that does not mean they don't normally contribute to the overall function. But to get back to the more interesting issue of brain evolution, the large growth of the brain is not spread out equally over all areas, but is concentrated primarily in cortex, and especially in a few areas called "association" cortex. So there has been a functional reorganization in the brain during evolution with an emphasis on particular areas, not simply an increase in size. This story is repeated over and over again in brain evolution, with new layers being added on top of older ones, such that the human brain is a hodge-podge of layers, with many sensations or functions being represented at many different levels. It is very complicated, and it amazing that it works at all, but if it didn't we wouldn't be here! Rich Goldschmidt {ucbvax,ihnp4,decvax,allegra,seismo} !cbosgd!rbg ARPA: cbosgd!rbg@seismo or cbosgd!rbg@ucbvax
wfi@rti-sel.UUCP (William Ingogly) (06/14/85)
In article <783@oddjob.UUCP> sandip@oddjob.UUCP (Sandip Chakra) writes: >For some days the following question is bothering me. If the evolution >theory is right, then why the human brain evolved to about six times >as that of an orung-otung and yet human uses only about 5 percent of the >brain cells? If the other cells were not needed then why produce them? Does >any of you have an answer? ... The hypothesis that we only use a small fraction of our brain cells is an old one that's been since abandoned by most neurobiologists. At least, that's what the books I've read in the last year or two on the brain and nervous system say. You might check out a couple of recent books from your local library and read up on this. There are some very accessible books written by neurobiologists on the subject of the brain's functions, but I can't point you to one. We DO use our entire brain; it's just that many of the brain's functions were not identified until fairly recently ... -- Cheers, Bill Ingogly
neveu@lll-crg.ARPA (Charles Neveu) (06/17/85)
> >For some days the following question is bothering me. If the evolution > >theory is right, then why the human brain evolved to about six times > >as that of an orung-otung and yet human uses only about 5 percent of the > >brain cells? > Is there any current data or informed opinion to > support the statement that we use only X% of our brains? In > recent books, for the general reader, on brain function, I > have never seen it asserted or supported. > I conjecture that it is a new kind of folklore: > scientific folklore. [...] > Perhaps, decades ago, when investigators were > beginning to discover the detailed functions of different > parts of the brain, they were able to assign roles to only X% > of it, and said so, and the popular mind got the message > wrong. Can this conjecture be supported? Are there other > folk theorems that you have noticed? > > Regards, > Chris I agree with you. Somebody probably made an offhand statement to journalist and it was published in Reader's Digest and now it is part of Common Knowledge. Here is another folk theorem : It is Common Knowledge that Albert Einstein was a terrible student as a child and flunked math. As far as I know, the young Einstein was an excellent student. Charles Neveu
friesen@psivax.UUCP (Stanley Friesen) (06/17/85)
In article <783@oddjob.UUCP> sandip@oddjob.UUCP (Sandip Chakra) writes: >For some days the following question is bothering me. If the evolution >theory is right, then why the human brain evolved to about six times >as that of an orung-otung and yet human uses only about 5 percent of the >brain cells? If the other cells were not needed then why produce them? Does >any of you have an answer? I thought that may be since brain cells >do not multiply nature has provided us enough at a time to protect against >all the odd kinds of injuries. How many of you buy this argument? This is based on a miscomception. We *do* use *all*(or nearly all) of our brain cells. The old statement you are thinking of is the (possibly incorrect) statement that we only use 5% of our brain for *conscious* thought, the rest is used for "subconscious" thought. Sort of like a bunch of pre-processors or filters in fromt of a complex DB system. Please move further responses to this to net.origins where it belongs. -- Sarima (Stanley Friesen) {trwrb|allegra|cbosgd|hplabs|ihnp4|aero!uscvax!akgua}!sdcrdcf!psivax!friesen or {ttdica|quad1|bellcore|scgvaxd}!psivax!friesen
werner@aecom.UUCP (Craig Werner) (06/20/85)
>and it was published in Reader's Digest and now it is part of Common Knowledge. >Here is another folk theorem : It is Common Knowledge that Albert Einstein was > a terrible student as a child and flunked math. As far as I know, the young > Einstein was an excellent student. > > Charles Neveu This appeared as an article in one of last year's New York Times Science Times (every Tuesday) articles. The misconception arose because of the following. Early in his schooling Einstein got 1s (on a scale of 1 to 6) in his mathematics courses. Later, he got 6s. For years people assumed that he failed the early years and then bloomed. What actually happened was that the grading system was changed so that 6 became the highest grade, whereas prior to that 1 had been the highest. That cleared up, it became clear that 1 or 6, he acheived the best possible grades. (I learned this prior to my entering Albert Einstein Coll. of Med., BTW) -- Craig Werner !philabs!aecom!werner "The world is just a straight man for you sometimes"
doug@escher.UUCP (Douglas J Freyburger) (06/24/85)
> For some days the following question is bothering me. If the evolution > theory is right, then why the human brain evolved to about six times > as that of an orung-otung and yet human uses only about 5 percent of the > brain cells? If the other cells were not needed then why produce them? Does I have followed parts of the discussion about percentage of brains cells used, but I have three other suggestions as to why humans have such large brains. 1) Humans have very long lifespans compared to other creatures (mammals) of similar mass. This is also in terms of "heartbeats per life" since the heart rate typical of a species is related to its typical mass. Most mammals live to a maximun of about 10^9 beats, but that's between 25 and 30 years for a human. Anyways, since humans live very long, and since brain cells stop replicating very early on in most (all?) mammal species, we need the extras so our elders don't get feeble quickly. Then, having experienced elders as knowledge stores, tribes with the trait tended to survive better. I remember reading something like this in a physical anthropology text, but it was written in terms of language and intelligence. It sounds reasonable phrased either way. 2) There could be some sort of "critical mass" required for a typically human task, like complete language, or tool making, or something. I know there are arguments of what a "typically human task" is, but you still get the idea. I've used Z80 and Vaxen before, and there are programs that simply can't be run on the smaller machine's address space. It could be a similar situation with humans versus orangutangs. I don't think the number of neurons is linear with brain mass or volume, or that its linear with processing power either. Still there might be some sort of threshhold involved. 3) The specialization of the human brain involves most of its mass being in the cerebrum (the part on the top if I got the name wrong). That part is a new invention in evolution. Since it is so new, it is probably done brute-force. Other creatures have had plenty of time for their systems to be incrementally optimized by evolution, but humans have had less than a million years (or less than five million, depending on where you start using the word "human"). Ants and bees have been around for N times that long, and they get along with VERY few neurons. If this is the case, I hope our incremental optimization involves more functionality instead of less mass for the same functionality. I don't really want to end up in the sort of efficiency trap that the ants did. Doug Freyburger JPL 171-235, Pasadena< CA 91106 DOUG@JPL-VLSI, doug@aerospace, ...trwrba!escher!doug, etc.
bob@islenet.UUCP (Bob Cunningham) (06/25/85)
> ... Another > question which bothers me and is related to the evolution theory is that > why the shape of an egg is so perfect even from the time of dynosorous? Eggs come in shapes other than the grocery store variety. Take a look at a shark egg sometime. -- Bob Cunningham {dual|vortex|ihnp4}!islenet!bob Honolulu, Hawaii
wfi@rti-sel.UUCP (William Ingogly) (06/26/85)
In article <34@escher.UUCP> doug@escher.UUCP (Douglas J Freyburger) writes: >1) Humans have very long lifespans compared to other >creatures (mammals) of similar mass. ... > Anyways, since >humans live very long, and since brain cells stop >replicating very early on in most (all?) mammal species, we >need the extras so our elders don't get feeble quickly. >Then, having experienced elders as knowledge stores, tribes >with the trait tended to survive better. ... This argument is based on the assumption that natural selection operates on the group level. Several people in the evolutionary science community were pushing group selection a few years back. As near as I can remember, group selection fell out of favor because there are some serious, fundamental problems with it except in certain very restricted cases. It seems that selection at the group level is simply a bad argument in many cases. Perhaps someone else who's been a little more active in the biological field can expand on this ... >2) There could be some sort of "critical mass" >required for a typically human task, like complete >language, or tool making, or something. I know there are >arguments of what a "typically human task" is, but you >still get the idea. I've used Z80 and Vaxen before, and >there are programs that simply can't be run on the smaller >machine's address space. It could be a similar situation >with humans versus orangutangs. I don't think the number >of neurons is linear with brain mass or volume, or that its >linear with processing power either. Still there might be >some sort of threshhold involved. And that we evolved big brains because we needed to pass this threshold for survival? The problem here (if I'm understanding your argument correctly) is that natural selection has no idea where it's going. You seem to be saying that human brains are big because we need them big to be human. This would seem to be a circular argument, or one that fails to understand how natural selection works. >3) The specialization of the human brain involves most >of its mass being in the cerebrum (the part on the top if I >got the name wrong). That part is a new invention in >evolution. Since it is so new, it is probably done >brute-force. Other creatures have had plenty of time for >their systems to be incrementally optimized by evolution, You're viewing Mother Nature as a rational designer, and she's not. Take The Easy Way Out and If It Ain't Broke Don't Fix It are her mottos. A complex system arises incrementally, through a lot of microchanges according to one view. The punctuationalists, on the other hand, believe that large changes can happen all at once via certain "controller" genes (that may be the wrong term). For example, some evolutionists have suggested that we humans look the way we do because we're neotenous primates. That is, we've lost the genetic equipment to make us 'grow up.' Take a look at a picture of an infant chimpanzee and compare it to an adult chimp. The infant chimp has a LOT of human-like characteristics that are lost in the adult. Consider, also, that young humans and young chimps learn at approximately the same rate until a certain point (I think around the age of two), then the chimp falls behind. The implication is that a controller gene has kicked on in the chimp, now on his way to becoming a dull adult. This hypothesis claims that we're human because we never grow up! -- Cheers, Bill Ingogly
rrizzo@bbncca.ARPA (Ron Rizzo) (06/28/85)
I don't know about the % of gray matter "normally" used, but one installment of either the PBS series "The Mind" or another Nova program provided the following startling findings: Using recently developed (tomographic?) techniques for scanning the brain in detail along various physical variables, researchers found that a number of people who suffered massive brain damage at birth or early in life but who display not only above average abilities but high general intelligence (unlike the "calculating idiots") are using less than 10%, in some cases less than 5%, of their brain mass: the rest is clinically or effectively dead! I haven't though about how this relates to evolutionary issues, but it struck me that these simple facts must have a serious impact on various theories about how the brain works: wouldn't most of the current theories imply however vaguely a wide yet limited range of possible values for variables like % of active brain mass minimally necessary, etc., values well above those of the above findings? Ron Rizzo
bwm@ccice2.UUCP (Brad Miller) (06/29/85)
I have viewed with much scepticism claims in this newsgroup that humans only use a %age of the brain. Given some specialization of the brain, I suspect that it is nonsense to make statements like so and so only used 15% of his brain to do X, unless X includes a lot of simultaneous actions, like eating, sex, pain from every neuron in the body, drawing a perspective picture, etc........ Certain tasks will use certain parts of the brain, not all of it at the same time. You don't expect a reasonable implementation of ackermans function to use a disk driver and X.25 link do you? Brad Miller -- ..[cbrma, ccivax, ccicpg, rayssd, ritcv, rlgvax, rochester]!ccice5!ccice2!bwm
sandip@oddjob.UUCP (Sandip Chakra) (06/30/85)
> I don't know about the % of gray matter "normally" used, but one > installment of either the PBS series "The Mind" or another Nova > program provided the following startling findings: > > Using recently developed (tomographic?) techniques for scanning > the brain in detail along various physical variables, researchers > found that a number of people who suffered massive brain damage > at birth or early in life but who display not only above average > abilities but high general intelligence (unlike the "calculating > idiots") are using less than 10%, in some cases less than 5%, > of their brain mass: the rest is clinically or effectively dead! In my original article I used exactly this example. The PBS series was not on "The Mind" but on "The Brain". Sandip Chakra *** REPLACE THIS LINE WITH YOUR MESSAGE ***
friesen@psivax.UUCP (Stanley Friesen) (07/01/85)
In article <1477@bbncca.ARPA> rrizzo@bbncca.ARPA (Ron Rizzo) writes: >I don't know about the % of gray matter "normally" used, but one >installment of either the PBS series "The Mind" or another Nova >program provided the following startling findings: > >Using recently developed (tomographic?) techniques for scanning >the brain in detail along various physical variables, researchers >found that a number of people who suffered massive brain damage >at birth or early in life but who display not only above average >abilities but high general intelligence (unlike the "calculating >idiots") are using less than 10%, in some cases less than 5%, >of their brain mass: the rest is clinically or effectively dead! > >I haven't though about how this relates to evolutionary issues, >but it struck me that these simple facts must have a serious >impact on various theories about how the brain works: wouldn't >most of the current theories imply however vaguely a wide yet >limited range of possible values for variables like % of active >brain mass minimally necessary, etc., values well above those >of the above findings? > Actually, before any conclusions can be drawn more details are needed. What proportion of the dead tissue was gray matter and what white? How much was glial cells and how much neurons? What about the density of neurons in the remaining tissue - the same or perhaps higher? What sections of the brain were involved? Of course the answers to some of these questions requires a biopsy or similar invasive sampling technique, so we may have to wait until some of these patients die. Also, why were they given a tomography(a diagnostic test) if they were so normal? -- Sarima (Stanley Friesen) {trwrb|allegra|cbosgd|hplabs|ihnp4|aero!uscvax!akgua}!sdcrdcf!psivax!friesen or {ttdica|quad1|bellcore|scgvaxd}!psivax!friesen
wfl@maxvax.UUCP (w linke) (07/01/85)
[] > I don't know about the % of gray matter "normally" used, but one > installment of either the PBS series "The Mind" or another Nova > program provided the following startling findings: > > Using recently developed (tomographic?) techniques for scanning > the brain in detail along various physical variables, researchers > found that a number of people who suffered massive brain damage > at birth or early in life but who display not only above average > abilities but high general intelligence (unlike the "calculating > idiots") are using less than 10%, in some cases less than 5%, > of their brain mass: the rest is clinically or effectively dead! I have the same problem with my computer. When my programs are running, only a small fraction of the total mass actually does useful work (just some copper and bits of silicon). The rest of it (case, pc boards, etc.) just sits there! Perhaps a more relevant question is: how much of the brain's structure is dedicated to intelligence, as opposed to physical and chemical support? The brain is a highly structured organ, and I think it's misleading to imagine that all of it could contribute to intelligence. W. F. Linke
rrizzo@bbncca.ARPA (Ron Rizzo) (07/03/85)
Good points, Sarima. These persons were given the tomography because they were KNOWN to have suffered accidents either prenatally, at birth, or in early years, that very likely caused brain damage.
sandip@oddjob.UUCP (Sandip Chakra) (07/04/85)
> Good points, Sarima. These persons were given the tomography because > they were KNOWN to have suffered accidents either prenatally, at birth, > or in early years, that very likely caused brain damage. This does not exclude the fact that they were able to do above average level work with a few percent of their brain cells. Suppose all of us were born with 95% of our brain cells damaged, then since we would be working at an above average level anyway, how do we know that we needed the other 95% of our brain cells ?
lonetto@phri.UUCP (Michael Lonetto) (07/09/85)
> > Good points, Sarima. These persons were given the tomography because > > they were KNOWN to have suffered accidents either prenatally, at birth, > > or in early years, that very likely caused brain damage. > > This does not exclude the fact that they were able to do > above average level work with a few percent of their brain cells. > Suppose all of us were born with 95% of our brain cells damaged, then > since we would be working at an above average level anyway, how do we > know that we needed the other 95% of our brain cells ? I unfortunately missed the TV show in question, but have been exposed to a little neurobiology. I believe the key word here is YOUNG. Many functions and the connections that allow them are established AFTER birth. The connections in the visual cortex that allow visual acuity are NOT made in blindfolded or dark raised animals, or for that matter, in children with cataracts. It is quite reasonable that normal function can be established with a much smaller number of brain cells than is normal. There is undoubtedly a great deal of redundancy in the normal brain. It probably does come in handy, since brain cells don't divide, but do die off constantly throughout life. However, since most of us didn't start out with 5% of our cerebral cortex we would definately notice the loss of 95% of our brains. It will be interesting to see how these people fare as they age. No mention was made of how old they are now, does anyone out there know? -- ____________________ Michael Lonetto Public Health Research Institute, 455 1st Ave, NY, NY 10016 (allegra!phri!lonetto) Do you think it's REAL?
stpeters@steinmetz.UUCP (R L StPeters) (07/10/85)
> >I don't know about the % of gray matter "normally" used, but ... > > > >Using recently developed (tomographic?) techniques for scanning > >the brain in detail along various physical variables, researchers > >found that a number of people who suffered massive brain damage > >at birth or early in life but who display not only above average > >abilities but high general intelligence (unlike the "calculating > >idiots") are using less than 10%, in some cases less than 5%, > >of their brain mass: the rest is clinically or effectively dead! > > > >I haven't though about how this relates to evolutionary issues, > >but it struck me that these simple facts must have a serious > >impact on various theories about how the brain works: ... > > > Actually, before any conclusions can be drawn more details > are needed. What proportion of the dead tissue was gray matter and what > white? How much was glial cells and how much neurons? What about the > density of neurons in the remaining tissue - the same or perhaps > higher? What sections of the brain were involved? Of course the > answers to some of these questions requires a biopsy or similar > invasive sampling technique, so we may have to wait until some of > these patients die. Also, why were they given a tomography(a > diagnostic test) if they were so normal? The patient's death is not all that necessary. My neurosurgeon and my tomographic pictures can both attest that a sizeable region of my own brain has not held working neurons since I had a significant subarrachnoid hemorrhage and subsequent open-brain surgery not quite a decade ago. I have had the enlightening opportunity to observe up close the nearly-complete restoration of lost functionality as the initial total paralysis of my left arm and hand have gradually given way to the point where I am touch-typing this posting (sneaking in an occasional peak at the keyboard). While the damage I suffered was nothing approaching 90% overall, it was 100% throughout a region large enough to make some impressive tomographic images. Given that central nervous system neurons do not recover or regenerate, this functionality must be being supplied by other neurons, presumably in the vicinity of the destroyed region, and also presumably neurons that were not already otherwise in use. (At least I like to think so.) This leads me to the conclusion that, however evolution has managed to do so, it has put all these extra unused neurons in there in the first place as spare parts. Recoveries of major losses of functionality that take a decade to occur are unlikely to have much evolutionary benefit, so they most likely are a side benefit of a mechanism whose purpose is continual maintenance: ongoing repair of minor damage. The image I have is one of steady loss of active neurons due to disease, chemicals (e.g. alcohol), physical blows to the head, etc., accompanied by their continuous functional replacement through activation of alternate neural channels using these pre-existing replacement neurons. Thus nature, faced with only one chance ever to grow neurons, grows enough initially to provide a lifetime of spares. More precisely, an adequate *density* of spares is provided. The numbers seem to suggest that perhaps around ten possible replacements are provided for each neuron. Carrying this one step further, one can then imagine that perhaps a part of the condition we call senility is when the loss of neurons from old age requires that the brain reach ever farther to find suitable neural replacements, and the neural pathways, like old code patched many times, become ever more tangled and spaghetti-like. While I described the hypothetical repair process in one-for-one neural replacements terms, I doubt the replacement of neural pathways is that simple. I've progressed from some observations and a few known facts into some pretty tenuous conjecture, and it's time I stopped. -- R. L. St.Peters (Dick) The "R" is for "Reptile". uucp: decvax!mcnc!ncsu!uvacs!edison!steinmetz!stpeters (uucp is forever) arpa: stpeters@ge-crd (federal express) "Any opinions expressed by my employer are probably not mine."
friesen@psivax.UUCP (Stanley Friesen) (07/11/85)
In article <835@oddjob.UUCP> sandip@oddjob.UUCP (Sandip Chakra) writes: >> Good points, Sarima. These persons were given the tomography because >> they were KNOWN to have suffered accidents either prenatally, at birth, >> or in early years, that very likely caused brain damage. > > This does not exclude the fact that they were able to do >above average level work with a few percent of their brain cells. >Suppose all of us were born with 95% of our brain cells damaged, then >since we would be working at an above average level anyway, how do we >know that we needed the other 95% of our brain cells ? Actually, tomography can only demonstrate that <mimble>% of the *volume* of the brain is dead. My point was that the remaining volume could be(and probably *was*) altered from the "normal" state, having a higher capacity per volume capacity. Thus my questions about the exact pathology of the "dead" tissue and the physiology of the "living" tissue. -- Sarima (Stanley Friesen) {trwrb|allegra|cbosgd|hplabs|ihnp4|aero!uscvax!akgua}!sdcrdcf!psivax!friesen or {ttdica|quad1|bellcore|scgvaxd}!psivax!friesen
ray@rochester.UUCP (Ray Frank) (07/18/85)
> > I unfortunately missed the TV show in question, but have been exposed to > a little neurobiology. I believe the key word here is YOUNG. Many > functions and the connections that allow them are established AFTER > birth. The connections in the visual cortex that allow visual acuity > are NOT made in blindfolded or dark raised animals, or for that matter, > in children with cataracts. It is quite reasonable that normal function > can be established with a much smaller number of brain cells than is > normal. There is undoubtedly a great deal of redundancy in the normal > brain. It probably does come in handy, since brain cells don't divide, > but do die off constantly throughout life. However, since most of us > didn't start out with 5% of our cerebral cortex we would definately notice > the loss of 95% of our brains. It will be interesting to see how these > people fare as they age. No mention was made of how old they are now, > does anyone out there know? I saw this TV show. It was to me quite amazing. If memory serves me correctly the people studied (those with 5 or 10% of their brain left intact) were in their thirties and were functioning perfectly. The reason they were asked to participate in this study was because they were know to have had the disease as young children and survived it because of the advent of a shunting technique that alowed the liquid to drain from the brain. Again if memory serves me correctly, these people were born with normal brains with no symptoms of the disease till their early years, ie several months to several years. Till a remedial cure was found (shunting) most if not all victims died by 4 or 5 years of age. I suppose by this time so much of the brain was destroyed that death was inevitable.
throopw@rtp47.UUCP (Wayne Throop) (07/20/85)
> If memory serves me correctly the people studied (those with 5 or 10% of > their brain left intact) were in their thirties and were functioning > perfectly. The reason they were asked to participate in this study was > because they were know to have had the disease as young children and > survived it because of the advent of a shunting technique that alowed > the liquid to drain from the brain. This is also largely how I recall the episode. However, the interviews I saw were all with people in their late teens or early twenties (the shunt was not developed early enough to have any 30-year-old survivors). Also, I beleive it was more like 15-25 % brain volume remaining. The CAT and PED scans showed were quite striking. > Again if memory serves me correctly, these people were born with normal > brains with no symptoms of the disease till their early years, ie > several months to several years. Till a remedial cure was found > (shunting) most if not all victims died by 4 or 5 years of age. I > suppose by this time so much of the brain was destroyed that death was > inevitable. One more nit to pick. I beleive that symptoms were present from birth, but were not detected for some months (since this is a fairly rare condition, and is not routinely looked for). What was finally noticed was the enlargement of the cranium due to increased pressure within. Other than these nits, this is the way I remember the episode also. The interviews were quite interesting, and to some degree a tribute to human perserverance. A young woman interviewed, when asked how she could possibly acheive so much with so little brain left, said that "whenever anybody said I couldn't possibly do something, I just had to prove them wrong". -- Wayne Throop at Data General, RTP, NC <the-known-world>!mcnc!rti-sel!rtp47!throopw
ray@rochester.UUCP (Ray Frank) (07/22/85)
> This is also largely how I recall the episode. However, the interviews > I saw were all with people in their late teens or early twenties (the > shunt was not developed early enough to have any 30-year-old survivors). > Also, I beleive it was more like 15-25 % brain volume remaining. The > CAT and PED scans showed were quite striking. > Bravo to you're better recall. Do you remember if anyone survived this disease without treatment? Or perhaps a less refined technique was used way back when. But in any case they interviewed a teacher and an accountant or bookkeeper. It seems truly amazing that with extensive research and study that some anomaly would not be discovered in these people.
afs@bunkerb.UUCP (Andrew F. Seirup) (07/25/85)
> > ... the loss of 95% of our brains. > ... those with 5 or 10% of their brain left intact ... I saw this show, and my impression was that the symptom was fluid collecting in the in the head, compressing the brain and stunting it. This is subtlely different than having a large portion of the brain destroyed or removed. I would expect brains suffering from the former to be able to adapt better and appear more normal than in the latter case. Andrew Seirup - Bunker Ramo, Trumbull CT - (203)386-2086 uucp address: {decvax|ittatc}!bunker!afs