[MURG] Cortex activity

[Thomas Weber]

Hi MURG, hi digfarenough,

> digfarenough: 
> first, the brain as hardware, mind as software
> thing.. there's a finer distinction between hardware
> and software, even in a computer, than you might
> think.. for instance, the software exists as
> physical data: magnetic spots on harddisks and
> transistor states in ram.. even varied colors and
> brightness of phosphors on the monitor.. I suppose
> it seems as if software magically exists apart from
> the hardware but simply runs on it, instead of
> software just being a state of the hardware.. in
> this way the mind does seem like software running on
> the brain, but only on this more sophisticated level
> I think
>  Thomas: The analogy here can be drawn that the
brains software is the state of neurons and the
synaptic activity.

digfarenough:
> but as joseph said, you can't take the analogy too
> far because while computers have a simple way to
> read out data, the brain doesn't--the computer has
> direct access to every bit of memory, something our
> brains don't have..
Thomas: Our brains are an old neantherthal design.
This example proves superiority of computers over
brains. Now imagine the brain paired with the
computer. All important as well as new memories are
stored in the computer part and easily accessible.

digfarenough:
 we would have to use an external
> probe to access each neuron, but unlike a computer
> in which execution can be paused so the data doesn't
> change while it's being read, the brain goes on in
> time, so the entire state would have to be read
> nearly simultaneously to get all the data

Thomas: In a paired system it would be possible to
stop the computer part while allowing the brain to
think what to do next.

digfarenough:
>  
> as for your idea of a cortical interface between the
> brain and computer (which someone else had mentioned
> last week as well), the problem is that at *best*,
> the brain would use the computer as an addition to
> its neural network and would become inexorably tied
> to your identity...

Thomas: That would bring us very close to my vision of
mind uploading.

digfarenough:
 I suppose if the number of
> neurons in the computer were much much larger than
> those in the brain (like orders of magnitude
> larger), and if you set up one of these huge
> networks for each function area of the cortex,
> eventually, if the brain was plastic enough, you'd
> be able to get enough function into the network that
> removing the brain wouldn't much effect the new
> cortex
> Thomas: In my view when that happens the mind is....
UPLOADED. Do we have a computer system big enough for
this? Yes we do! Imagine that the computer brain
extention is connected to the internet. Interactive
web sites would take care of various functions. And of
course you would have a direct intimate brain
connection to all the internet information.

digfarenough: 
> but that's based on some not necessarily true
> assumptions.. and my problem with that would be that
> I don't feel I'm completely defined by my cortex,
> sure that's where executive function and sensory
> memories and such are stored, but, for instance, I'm
> a musician and I have all those nice motor programs
> stored in my basal ganglia that I'd lose..

Thomas: No you would not. I can very well relate to
your concern as I do creative work myself. Each time
you practice or even perhaps think about your music it
would be gradually bit by bit uploaded to the
computer. Some time ago I proposed what I called'
"selective mind uploading". That means if asked which
aspect of my mind I would want to upload if I had to
pick only one - my answer would be my talents in
mechanical design.

digfarenough:
 and what
> about my problem telling left from right and west
> from east? that might be my hippocampus and that
> wouldn't get transferred either (but that might be
> good).. not to mention emotional problems.. wait..
> it seems like all my bad stuff is stored away from
> the cortex.. :)
> 
Thomas: Don't worry about your mind's imperfections -
we all have them. Your left - right problem is a very
good example how computer augmented mind can be
improved. It would take a very simple function to
communicate the left and right to your brain. One step
further the computer can be equipped with a magnetic
compass solving your east - west problem.

digfarenough:
> I'm not saying you shouldn't do this, but I'm saying
> you should consider the full consequences before you
> do... if you wanted to be a voluntary autist (a la
> greg egan's distress), I'd say go for it, as long as
> you know what autism is like.. note that I'm not
> saying cortical transfer is related to autism,
> that's just an example
> 
Thomas: I am not exactly sure why extending the brain
should result in autism, but I do realise it can be a
risky business. The computer - brain communication may
be difficult to learn. Especially in the beginning
there could be serious coherence problems causing
confussion and in the worst case the experiment may
result in insanity. Autism could be one of the
problems.

digfarenough: 
> you also talked some about visual cortex and visual
> mental imagery.. I'm definitely not a vision person,
> so I can't say much.. but there's an abstract on
> pubmed from kosslyn and thompson that says that
> there's sometimes activation in early visual cortex
> (areas 17 and 18) during imagery, but that seems to
> be about it.. personally I'm not sure I'd expect
> primary visual cortex to activate during visual
> imagery, because it seems to be that such imagery
> isn't a picture so much as a conglomeration of
> visual characteristics (which makes it easy to
> picture green grass, then just switch the color to
> red), so I would expect more associative cortical
> activity.. but that's just a guess
>  
> however, when you hear that there's an image formed
> on the primary visual cortex (area v1 I'm guessing),
> it isn't like a digital photograph..

Thomas: It doesn't have to be like digital photograph
as long as the cortex activity is consistent with the
objects seen. We can talk some symbolics here. After
some long enough observation we can create a cortex
dictionary - a particular activity will represent a
particular picture.

digfarenough
 I've only
> seeing imaging data of it once, on a poster showing
> evidence for multiple spotlights of attention in the
> visual field, but it was more like very rough shapes
> from the visual field.. by the time the visual
> information reaches the visual cortex, it has
> already been processed by retinal ganglia as it
> leaves the eye, things like edge enhancement and
> even crude motion detection and is broken into
> multiple spatio-temporal channels
Thomas:
I have seen that or similiar photo in one of the books
on the brain I have read. It was a monkey's brain. The
monkey was made stare at a light pattern and then it
was sacrificed. Corresponding dots were located on the
occicipal lobe. I don't remember what technique was
used to make these dots vissible.

Kind Regards,
Thomas Weber





> 
> Thomas Weber <aad1trailmaker at yahoo.ca> wrote:
> Hi MURG, Hi digfarenough,
> Good to know we have a neuroscientist around. As you
> have been watching our conversation you have
> observed
> that Joe and I spoke of mind uploading from two
> different angles. Which parts of our conversation
> you
> agreed with and which you did not?
> 
> Kind Regards,
> Thomas Weber
> 
> 
> 
> 
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