Terri Schiavo Question
Glen M. Sizemore
gmsizemore2 at yahoo.com
Sun Mar 27 13:50:45 EST 2005
You're not the R Norman who, with Buchwald and Villablanca, looked at
classical conditioning in decerebrate cats, are you?
"r norman" <rsn_ at _comcast.net> wrote in message
news:iihd41pcc64ulh81hv056k9drai1t73bu7 at 4ax.com...
> On Sat, 26 Mar 2005 23:41:45 -0500, Carey Gregory
> <tiredofspam123 at comcast.net> wrote:
> >Steven O. <null at null.com> wrote:
> >>First of all, according to the best available public evidence, is
> >>Terri Schiavo's cerebral cortex completely, totally liquified, or has
> >>there instead been a major loss of cortical tissue but with some
> >>tissue remaining.
> >Not totally, but a significant portion is gone now and replaced with CSF.
> >>Second -- would it be possible for oxygen deprivation to cause loss of
> >>the cerebral cortext, but for the lower brain centers to remain more
> >>or less intact? That is, can the cerebellum, limbic system, and
> >>mid-brain remain pretty much functional and alive?
> >>And, if yes, is there any evidence as to how much of Terri Schiavo's
> >>lower brain centers remain active?
> >She breathes and regulates blood pressure and pulse, so her lower brain
> >clearly functioning.
> >>Finally -- and here is the real kicker -- if the cerebral cortex is
> >>gone, but the other brain centers remain alive, is there any
> >>possibility that some kind of primitive experience continues, even
> >>with all cortical-based thinking gone?
> >Well, no way to know with certainty, of course, but ask someone who's
> >under anesthesia if they had a primitive experience. Even before amnesia
> >agents, the answer would have been no. So even if they did experience
> >something primitive, it appears to be irrelevant to life as we know it.
> >>My understanding is that some lower animals have no cortical brain at
> >>all, yet one would assume they still have some kind of experience or
> >>awareness. So, I am wondering if that could be the case for TS.
> >She is responsive to physical stimuli, but so is an earthworm. Does an
> >earthworm know it is an earthworm? Does it have thoughts and cares and
> >desires? Well, I don't think so, but that's un-provable. What I do know
> >we would question the value of heroic surgical methods for keeping one
> Perhaps a better analogy would be a brain-pithed frog (or other
> decerebrate animal preparation). You can completely destroy the brain
> of a vertebrate, leaving the spinal cord intact, and produce clear,
> seemingly "purposeful" reflex responses. That is, tickle the
> brain-pithed frog's belly and it scratches its belly. Tickle its back
> and it scratches its back. It "knows" where the stimulus is located
> and directs it response appropriately. Of course, there is no such
> "knowledge", only automatic activity. People with spinal injury have
> no knowledge or feeling or consciousness of what happens below the
> injury point even though their bodies down there can respond.
> Terri Schiavo has a lot more lower CNS function remaining than just
> the spinal level, but the fact that there does exist a very low level
> of CNS function does not automatically mean that the "person" is still
> conscious or aware or perceptive or, if you will, "alive".
More information about the Neur-sci