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- Newsgroups: talk.abortion
- Path: sparky!uunet!mnemosyne.cs.du.edu!nyx!mcochran
- From: mcochran@nyx.cs.du.edu (Mark A. Cochran)
- Subject: Re: Spoken Like a True ProLifer
- Message-ID: <1993Jan13.025950.8555@mnemosyne.cs.du.edu>
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- References: <1993Jan11.065635.16749@organpipe.uug.arizona.edu> <1993Jan12.040001.6011@mnemosyne.cs.du.edu> <JBATES.93Jan12132814@pinocchio.encore.com>
- Date: Wed, 13 Jan 93 02:59:50 GMT
- Lines: 230
-
- In article <JBATES.93Jan12132814@pinocchio.encore.com> jbates@encore.com (John W. Bates) writes:
- >
- >In article <1993Jan12.040001.6011@mnemosyne.cs.du.edu> mcochran@nyx.cs.du.edu (Mark A. Cochran) writes:
- >>In article <1993Jan11.065635.16749@organpipe.uug.arizona.edu> sfm@manduca.neurobio.arizona.edu (Stephen Matheson) writes:
- >
- >>>>>> Given that myelination is necessary for proper
- >>>>>> conduction of impulses in the brain
- >>>
- >>>>>Just how "given" is this? Before myelination, aren't most fibers
- >>>>>nevertheless conducting impulses, albeit much more slowly than after
- >>>>>myelination? I'm going to go check this, but I'm rather sure at this
- >>>>>point that myelination speeds conduction rather than making it possible
- >>>>>(that's the job of ion channels). Pre-myelinated fibers, in at least
- >>>>>some cases, are just as competent to have excitable membranes.
- >
- >This is true. The question is, just how "tuned" are our thought processes?
- >How much do they depend upon internal synchronization? I don't believe
- >that the answer to that is known. Certainly processes exist in less
- >complex systems which do require a great degree of synchronization:
- >take, for example, the escape reflex of a squid. How comparable that
- >is to human thought, I couldn't tell you.
- >
- I tend to discount anything labeled as reflex as being part of a
- thought process. The reflex pathway in humans is a "short cut" which
- bypasses the need for the signal to reach the brain before a response
- can be made.
-
- >>>> Premylinated fibers do conduct some impulses, certainly. They are, as
- >>>> you pointed out, conducted at a much slower rate. They are also (if I
- >>>> remember my neuro) subject to transmission failure at a fairly high
- >>>> rate.
- >>>> As an analogy, consider the conversation we are having. If every third
- >>>> line were dropped, or if random words were deleted, it would no longer
- >>>> bear any resemblance to rationality.
- >>>> How could we have rational thought with the same random loss of
- >>>> impulses?
- >>>
- >>>I suppose if we built in enough redundancy, we might be able to pull
- >>>it off.
- >>>
- >>Redundancy does not help if the signal is *lost*, although it would
- >>help if *multiple* signals were being sent, and only *some* were being
- >>lost. Does your study or neurology indicate tha tthe brain sends out
- >>multiple copies of each signal? I admit I don't know one way or the
- >>other.
- >
- >Pardon me for butting in here, but I have a small amount of relevant
- >experience, and this is a fascinating conversation.
- >
- Feel free to butt in, I'm not an exclusivist, and I doubt if Steve is
- either. :)
-
- >Redundancy in the brain is not the same as redundancy in a computer,
- >or even in most human engineered systems. Whereas humans tend to build
- >redundancy in by having multiple copies or backups, the brain's
- >reduncancy comes about as a result of its distributed nature. A great
- >deal of signal error or loss can be endured before the output, such as
- >it is, is significantly affected. Losing signal might be equivalent to
- >say, losing a pixel from each letter in this post.
- >
- It's far from a perfect analogy, certainly. But how many of those
- pixels can be lost before the meaning of your words is lost?
-
- >[deletions]
- >
- >>Further, we know that in early pregnancy, these same
- >>roots must be myelinated before movement (other then twitches, which
- >>occur as much from random excitability of the muscle tissue as
- >>anything) takes place i nthe fetus. Considering this, and considering
- >>how much more complex the electrical activity of thought must be, do
- >>you not think it is resonable to say that thought is unlikely to be
- >>present?
- >
- >I consider that a reasonable assumption.
- >
- >[deletions]
- >
- >>>Can you prove that consciousness exists?
- >>>
- >>To my own satisfaction, yes. But if "personhood" is based almost
- >>wholey on subjective data and personal philosophy, isn't
- >>"conciousness" as well?
- >>If we define conciousness as the ability to respond intentionally to
- >>oputside stimulation, then I think we can show it's existance. The
- >>"intentionally" qualifier rules out the reflex motions o a fetus is
- >>capable of, but also puts neonates on shakey ground.
- >
- >So? I don't see why any definition of personhood based on consciousness
- >necessarily includes neonates. If evidence points away from it, why bend
- >over backwards to fit them in? Science is really no basis for morals, and
- >often makes a poor basis for laws. (Except when "ye canna change the laws
- >of physics, Captain.")
- >
- I throw that in or DODie will start chanting that I'm condoning
- infanticide.
-
- >>>On a different tack, if I show that the developing brain of a
- >>>6-week-old fetus is busily firing impulses (long before "brainwaves"
- >>>can be detected by an EEG), then I can make a case for the
- >>>POSSIBILITY of mental function. Of course, I can't prove it
- >>>exists, but this makes the situation quite different than, say,
- >>>the contention that Elvis is alive on Mars.
- >>>
- >>Of course he's not, or I couldn't speak for his ghost. ;-)
- >>The mass of tissue in a 6 week embryo (not fetus, not until week 9, as
- >>you pointed out to another poster... ) which may eventually become a
- >>brain may well be firing impulses. But does it qualify as "mental
- >>function" (which I take to mean some relation (cousin, perhaps) to
- >>intelligence)? Motor neurons fire at random, even in adults (you've
- >>seen peopel twitch), so it can be assumed (or proven, possibly) that
- >>others do as well. But for it to qualify as some omen of developing
- >>intelligence, it would need to be (to me anyway) organized.
- >>I don't put much faith in the EEG, honestly. I've a friend in the
- >>neurophysiology area who has been known to say "I can get an EEG of 3
- >>cells in a petri dish." It's a far cry from the brainwaves seen in
- >>adults, or even neonates, but it is an EEG...
- >
- >Here's where it gets interesting. I recently saw a paper which was an
- >analysis of the activity in a fetal cat's geniculo-striate pathway and
- >the lateral geniculate nucleus. What was assumed to be random activity
- >now seems not to be, but rather a hard-coded sort of "training exercise."
- >Even when the cat's eyes are closed (and in fact, have not ever been
- >opened) this training is preparing the visual system for eventual use.
- >
- >Which raises the question: is the activity in a fetus' brain, which
- >might be mistaken for random thought processes, actually a training
- >exercise for eventual thought and consciousness? If so, when does it
- >cease to be training? I would tend to lean towards the point at which
- >external stimuli begin affecting the patterns.
- >
- The training exercise makes sense. Do we know (resonably accurately)
- the point at which external stimuli begins to affect the patterns? If
- we do, can we differentiate between those patterns and thought, in at
- leat a theoretical way? I'm assuming that a cat will have alterations
- to it's EEG when external stimuli are applied, but I don't think a cat
- can have what we refer to as thought in the human sense.
-
- >Unfortunately, I don't have the references for the paper here, and
- >I did not read it thoroughly when I had it. I'll dig it out tonight
- >and see what it says. It's entirely possible that I read too much
- >into their conclusions.
- >
- I dunno about Steve, but I know I'd love to see the article.
-
- >[deletions]
- >
- >>>> I don't think there is going to be a good answer, not for everybody.
- >>>> That's my main reason for advocating leaving the choice to the
- >>>> pregnant woman. I don't think the potential of the fetus can outweigh
- >>>> the reality of the woman.
- >>>
- >>>I am resigned to the reality of choice being left to women and
- >>>abortion providers. That's why I think it's worthwhile to
- >>>discuss the moral issue of abortion (in this case by discussing
- >>>scientific aspects of the personhood question). While I agree
- >>>that the fetus mustn't outweigh the mother, I reject the notion
- >>>that the conflict is between "potential" and "reality" and assert
- >>>instead that it is between 2 different realities.
- >>>
- >>I don't think this is what you mean, but your first line above makes
- >>it sound as if the woman approaching the abortion provider has not
- >>already decided what she wants. In cases I've seen, the woman has
- >>approached her OB, or GP, who either performs the abortion or refers
- >>her to a suitable provider (especially in late term or other high risk
- >>cases). The only cases I know of in which a physician has encouraged a
- >>woman to abort has been cases of severe abnormality. And even in these
- >>cases, the choice always lies with the woman.
- >>I can agree with you on the different realities idea.
- >>We both see pre-birth "personhood" as a possiblity. I think the main
- >>point of difference we have is that you choose to make any error (wrt
- >>this possibility) in favor of the fetus (subject to the balancing you
- >>mention above), while I prefer to make that possible error on the side
- >>of the woman carrying the fetus.
- >
- >As I said above, I don't believe that science is necessarily a perfect
- >guide to morality or legislation. If it can be incontrovertibly shown
- >that "personhood" does not begin until some specific point, the conflict
- >will remain. Just look at the number of people who will argue with all
- >of their convictions that abortion is wrong, from fertilization onward.
- >Personhood is an interesting philosophical and scientific inquiry, but
- >I don't believe that it can lead to a resolution of the abortion debate.
- >
- You may have noticed that Steve and I have been making a real effort
- to keep this on a scientific level, rather then trying to drag morals
- and legislation into it. We don't (or at least I don't, and I assume
- Steve doesn't) expect to see this lead to any resolution. We're merely
- bouncing opinions off each other, and debating a few interesting
- theories. It's just our way of showing that this doesn't *all* have to
- be mindless flaming, even if certain participants in t.a (Hiya DODie,
- PHoney. Did you read this far?) seem incapable of engaging in anything
- else.
-
- >>>> BTW Steve, you forgot to include a gratuitous insult... Are you
- >>>> slipping up? ;)
- >>>
- >>>Slipping up? No. Cracking up? Why yes, you pathetic pile
- >>>of primordial soup. Was that gratuitous? I'd better look it
- >>>up...
- >>>
- >>HA! You admit you don't have the dictionary memorized? What sort of
- >>t.a poster are you? Did your last EEG get reverse polarization and fry
- >>that miserable excuse for a brain of yours??
- >
- >Can somebody please insult me? Nobody ever insults me... Do I have to
- >insult someone else first? (Actually, I think I insulted Chaney or Hall
- >sometime back, but I didn't get anything back. Oh, and I got Nyikos
- >to post his SAT scores, but he forgot who I was. He did call me a "bozo",
- >but that hardly counts. He didn't even use my name.)
- >
- It has been suggested that irritating PHoney enough to get insulted
- should be considered an honor. If thta's true, then I'm in for some
- heavy awards. ;-)
- But what the hell, I'll take a shot at insulting you, just so you feel
- welcome.
- Tell me, was that your brother I saw you with last night, or did your
- wife just forget to shave?
- How was that?
-
- >p.s. I don't have a whole lot of experience in neuroscience. My background is
- >from that hazy field of "cognitive neuroscience," which means I get to wave
- >my hands around a lot.
-
- We better check and make sure we're not violating some sort of
- net.rule by being rational in this group...
-
- --
- Mark Cochran merlin@eddie.ee.vt.edu
- These are the views of my employer, your employer, your government, the
- Church of your choice, and the Ghost of Elvis. So there.
- Member, T.S.A.K.C.
-