"John H." <John at faraway.com.au> skrev i melding
news:aCgz7.568$Qj7.37509 at ozemail.com.au...
> "Liar42" <liar42 at aol.com> wrote in message
> news:20011013220650.15187.00001852 at mb-fa.aol.com...> >
> > >And long term memory is NOT directly by itself connected to short term
> > memory,<
>> This line has to be a bait. If not connected, then how is long term memory
> ever initiated?
Yep, sure is - I wrote this just after I read about their tests on the
Aplysia.
I know now that Short Term Memory imprints on the Cortex, but if it is
disrupted early, it might not be imprinted.
And please remember I'm getting details daily, and that my understanding is
increasing by the pages.
> > Apart from that you do not discern which of the long term memory
systems,
> with
> > two of them my own I is getting data from there, so we are connected.
> >
> > > no - it (LTM) is established in another domain directly and
> > indirectly (through the Corpus Callosum, aka the Faux Fax of Calvin)<
> >
> > Why does that sound like b.s. to me?
>> It is my understanding that Kandel and Co established LTM processes
through
> studying the humble Aplysia(snail), which to the best of my knowledge is
not
> in possession of a corpus callosum. Not to mention any other number of
> species lacking the same but seem capable of establishing LTM. I haven't
> read Calvin's work, and his Darwin Machine idea sounds like Edelman 20
years
> ago which sounded like some Italian neuro in late 60's I think re
reentrant
> and probabilities and the reality that the immune and cns are the only 2
> memory systems capable of LTM and arise from a common embryological
origin.
> William Calvin is good stuff, I've saw him on TV interview science special
> many years ago where he described Gerald Edelman as making the rest of us
> look rather dim(and if I look at Edelman's record I have to agree). I'll
> need to read this text one day to see what he's on about.
Then I can recommend "The Celebral Code" and "Conversations with Neils Brain
"
(which was the first book of the CNS I have ever read if we exclude Purves
et al's
book "Life: The Science of Biology".
> What of split brain patients? I can't recall any loss of LTM in the same.
> Other cognitive changes for sure, and probably some memory dysfunction,
but
> not global LTM loss. Caveat: usually the anterior commissure remains
intact
> and there remains thalamic connections. Not sufficient though, should
remain
> big deficits.
I think that STM imprints on both hemispheres simultainously, the left
parahippocampal cortex, entorhinal cortex and perirhinal cortex (which is
part
of the STM) imprints on the cortex on the occipital lobe (visually) and
partially on the
parietal lobe if it doesn't include items that demands special attention
(like the
picture of a tool, a picture of an animal doesn't give the same response).
Then it would include parts of the frontal lobe.
Got it from "Memory - from Minds to Molecules" by Kandel.
It is a nice read, and yes - it includes the Aplysia when it handles the
habituational
(and classical conditioning + sensitization).
Forgive me my bad English :-)
> What of those who have undergone hemispheroctomy(spelling!) - removal of
> large portion of one cortex to control intractable epilepsy? These people
> will experience deficits to varying degrees, but the inherent loss of so
> many collosal connections should leave them without any real capacity for
> intelligence if you believe in the gross neuroanatomical substrate idea
for
> human intelligence try having a look at the work of John Skoyles, a
British
> dude. You can find it at the socog archives in the UK. Not well accepted,
> but he does collect some very interesting cases of gross brain injury and
> dysfunction.
Epilespy is handled quite well in "Conversations" as I understand it.
It isn't about removal of an entire lobe or hemisphere (!!), but of a small
area
in the medial temporal lobe, on the inside near (but not upon) the
hippocampus.
> There are some born without a callosum, usually low iq, circa 90 in one
> study I read (I should call that low, I barely make 100), but these people
> are quite capable of forming LTMs. As for my corpus callosum, I still have
> trouble discerning left from right, so I must be rather thick.
I sincerely doesn't know the mechanism for the genetic programming that
would
result in such a condition.
There are 50.000 genes for the brain alone.
As for CC, it is purely for communication between the hemispheres (as the
Faux Fax
by Clavin; very good idea about the hexagons!!!) etcetera.
I have never heard that CC is an operational area like the Cortex.........
> > Have you ever bothered to consider the Corpus Callosum as
transconnections
> > between brain halves?
I have always thought that way, yes.........
> > > (...) When ideas compete (in our brains) for attention,<
>> How does an idea compete?
It is a fight for attention, and it is as I see it a battle between several
ideas
primarely instigated by visual or any other senses.
The cues will 'lite up' one or possibly two of Hebb's cell-assembly.
They will in turn create a hexagon, and it will conquer territory adjacent
to it.
Usually neighbours, and as long as the territory isn't lit up by another
idea, they
will expand until they meet another idea (thought).
Then the one with most hexagons will win, but not always.
It depends upon if the hexagons have been a part of;IE Apple; when the
territory
is tested by the hexagon for Orange.
> > Hae?! If I have ideas, they do not compete for attention, but I have
them
> and
> > think about them.
> >
> > Say I were to consider if it is better to call you an idiot or some
nutter
> who
> > mistakes his belief for fact and therefore writes b.s. like facts,
> > then there is no competition for attention, they are just parallel
> options,
> > where I might consider their values, like that one is shorter and the
> other
> > more explicit, etc.
> >
> > What however might distract me just slightly is the laughter in the wake
> of my
> > charming diplomacy.
Read "The Celebral Code" - it isn't expensive and it will explain it much
better than I can ever hope to do.
> > ;-)
Thanks, I hoped you weren't slamming me becasue you don't like me
personally :-)
> > > they occupy hexagonal areas (Hebb's cell-assembly),<
> >
> > Now, if you were an Amargeddon player I might wonder if you stared too
> long at
> > some hexagons there.
>> Overcast in Berlin?
>> > Some day maybe bother to notice that neither all brain cells nor magic
> systems
> > or whatever you call energy systems in the brain
> > are tending to be all in hexagonal stages in the brain.
It is NOT a hexagon as a figure with purely straight lines etc. - it is an
approximation and it is centered around Hebb's cell-assemblies.
> > > and the one with the greatest area usually wins.<
> >
> > Total b.s.
>> I dislike singular explanations for complex things like attention. There
are
> many types of attention, it is not simply a matter of area of excitation
but
> degree of excitation or type of excitation oh it could be many things and
> there are others here who can address those spike firing and memory
storage
> and signal processing questions much better than me. In terms of
attention,
> one of the best authors I have read is Patricia Goldman-Rakic, and I
believe
> she is extending the analysis to the level of now being able to measure
the
> activity of many types of synapse for a single cell. From my current
reading
> and the advice of my mentor, it is my understanding that attentional
> mechanisms are mediated through at least the pfc - bg network, to conceive
> of attention as simply some mass geometric function is to fail to
understand
> that attention is not a single thing, our attention is mediated through a
> variety of processes but in relation to most temporally frequent attention
> the pfc bg linkage seems to be critical, as does dopaminergic D1\D2
balance.
> Some antipsychotics work by blockading D2 receptors. If you want to read
> something interesting about that,
About attention.
The best part is on page 189-190:
"Why do we have a unity of conscious experience? We speak with a single
voice, even if only talking to ourselves. We have a sense of being at the
center of a convergence of various narratives that we use to explain the
past, all the while trying to choose between several speculative scenarios
about the future.
There are some trivial answers to the unity question - as when we say that
some things, such as sensing one's blood pressure, are totally inaccessible
to verbal reporting mechanisms - and so perhaps the unity is an illusion,
simply a problem with what's accessible to verbal report.
In the context of cloning competitions, a more tempting answer is to say
that we have a unity of consciousness because there can only be one winner
of a competition - and that it's simply the largest patch of the dozens
currently to be found somewhere on the dynamic reforming patchwork quilt
(or, at least it's the largest one with ready access to output pathways).
If the stalemates are prevented by perturbations from the fickle climate,
there's always a winner and it's only a question of your threshold for
converting thought into action, your quality criterion.
So the center of consciousness shifts about, from one cortical area to
others, as the train of thought progresses. This neatly explains why no
neocortical lesion seems able to abolish consciousness, only to abolish
certain types of content such as color attributes."
> Castner, S.A., G.V. Williams, & P.S. Goldman-Rakic. 2000. Reversal of
> antipsychotic-induced working memory deficits by short-term dopamine D1
> receptor stimulation. Science 287: 2020-2022.
Thanks for the reference, I appreciated that.
> I do not think we will understand this matter of attention unless our
> understanding incorporates the consideration of the dopaminergic network.
> I'm sure Willilam Calvin knows this so am interested to know how he
> addresses this aspect of the question.
>> > >William called it his Darwin Machine, <
> >
> > Sounds like an insult to Darwin, unless he came up with such mental
b.s.,
> too.
> >
> > >and all I can say is that I'm awed over his intelligence.<
> >
> > Hexagonal b.s.?
>> Never heard of it. My understanding is that the principal anatomical unit
of
> the cerebral cortex is the pyramidal column, which can vary in size etc
but
> essentially retains its integrity as a structure. If there exists these
> hexagonal structures, shouldn't this be reflected in the structural
changes
> in pyramidal columns post learning? Is this documented in Calvin's work?
> Doesn't the requirement for hexagonal structures place unnecessary
> constraints on memory formation?
These Hexagonal structures are _memories_, and LTM at that.
That is why it is much easier for a Hexagon to expand on an idea if the idea
have been imprinted from STM onto LTM before !!!
> > One might be more awed over your degree of "intelligence", but for
> differing
> > reasons.
Even if you hear I'm part of the MENSA-club now ???
Remember, I'm studying beside work - and this thing on the internet takes
quite some time as well.
So, I'm not a magician, I take the steps everybody else have taken.
> > >But alas, I still have to study more - <
> >
> > Good idea.
Of course - I got "How Brains Think" by Clavin today.
Later, when I have time, I'll get (from my wish list) "Exploring the
Thalamus"
by S. Murray Sherman, R. W. Guillery, or "The Synaptic Organization of
the Brain" by Gordon M. Shepherd (Editor).
Which of those should I get first ?
> Raining in Berlin? Good news. Rained for two days. Drought broken here.
> Wallabies will get fat again.
Sorry to hear, but it rains here in Oslo too, and it never ends.
But it was sunshine today, and it lifted the spirit if I might say so.
Brian
PS.To Liar - you're nick seems a little provocative, is that intentional ?