Re: Specialization and Optimization Of Neural Organization By Selective Stimulation And Deprivati

Anders Sandberg ()
10 Nov 1997 19:45:25 +0100


Mike Coward <mikec@ilnk.com> writes:

> >Other areas take over the use of the cortex; this can be quite large
> >changes if they occur early or during periods of neural
> >plasticity.
> >
> ><<<
> >1:1- How do I induce plasticity?

Training seems to be the usual way. It is possible that the
cholinergic signals from the basal forebrain are important too, which
means that chemicals influencing the ACh system could be
useful. Normal synaptic plasticity is a hot research area.

> >1:2- If there was hyperplasticity what would it be like,
> >short term memory?

Do you mean a state of very high neural plasticity? In that case you
would likely learn fast but also forget fast, new memories would erase
old memories and stray thoughts would be remembered far too well. Used
in the right way it would be perfect for self programming, "mental
rejuvenation" and perhaps for intense training of new skills.

> >1:3:1- How does short term memory work?

Good question. Some of it is likely activity patterns in the cell
assemblies involved in a thought or a concept that remains over time,
and slowly fades. There are also some plastic processes in synapses
which may act here, but honestly we don't know yet.

> >> Now think about my whole body control area
> >> being taken over by my head control area.
> >> Imagine the processing power,
> >> a full brain used almost entirely for thinking!
> >
> >Unfortunately this doesn't work well for simply psychological
> >reasons. We are built to have a large sensory throughput, and by
> >removing most of the body you lose a lot of the feedback loops, some
> >of which are important for emotions and motivation. My guess is that
> >the way to go is to *extend* the mind and body, not the reverse. More
> >cortex to the people! :-)
> >
> >2:2- This basicly happens to the paralysed, what happens to them?

I have heard some reports that people with certain forms of paralysis
get a state of flat affect. But I have not looked into the area much.

> >2:3- If I wore sunglasses, earplugs, and gloves 24 hours a day
> >how would my brain change after...

Change in what way? There are change on many timescales, ranging from
seconds to years. Most likely you would quickly adapt in a few hours,
and then there would be a gradual deterioration as the lack of sensory
input made you more sensitive to "neural noise" and internally
generated sensations.

> >2:4- Why are throughput and feedback loops relevant?

Because we evolved to interact with the world, and to retain an
internal state. If this is prevented, normal activity tends to get
disrupted.

> >The only emotion I really need is courage to follow my will.

You also need the motivation you call your will. What motivates you?
What is your will? If you lack emotions you also lack will, and your
will depends on other emotions.

> >2:5-1 What parts of the brain CAN I retask?

Most of them. I think there are very few parts that cannot adapt or
modify themselves slightly. But very little is known yet (or rather,
it is all neurophysiological data with little order).

> >2:5-3- Can I overwrite some of my childhood?

The brain does not work that way. It is likely that you are
overwriting and strengthening childhood memories all the time
depending on your thoughts.

> >I need a funtional brain map
> >to see what tasks are next to eachother;
> >I've spent several hours looking but failed.

We don't know where and how "Tasks" are stored, although we have
reasonably good maps of some functions (like the visual cortex,
primary motor system, speech etc). Try a good neuroscience textbook
like Kandel, Schwartz et al. Principles of Neuroscience.

> >2:6- What is the best machine for mapping brain functions, in terms of...
> >2:6:1- locating general area?
> >2:6:2- locating specific area?
> >2:6:3- economic conservation?

Specific and general in what sense? A PET or fMRI scan shows what
areas are activated during different tasks, but gives no hint of what
they actually do. Lesion studies help to find out this by disrupring
ordinary function, and sometimes electrical stimulation and/or
recording can give more information. But it is a very complex
undertaking to understand even a small region.

I strongly suggest that you get some neuroscience textbooks, they have
much of the information you want and can provide an useful stepping
stone.

-- 
-----------------------------------------------------------------------
Anders Sandberg                                      Towards Ascension!
asa@nada.kth.se                            http://www.nada.kth.se/~asa/
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