Again, there are some relatively simple things that certainly
can be detected by measuring brain activity. But you want
to read someone's thoughts -- their private "mental" events.
First, we really have no clue as to how the very high level
constructs we call "mind" and "mental processes" are
implemented by the physical machinery called the brain.
Second, from what we know of neural circuits, there is no
guarantee that two peoples brains are wired in the same
way to produce the same results. Yes, there are particular
sensory and motor circuits that are known. But not for
any relatively sophisticated kind of complex sensory or
motor pattern detection or production
The standard metaphor is hooking an oscilloscope to every
point on a computer. (This was at least conceptually possible
in the days when electronics was made of discrete components,
but imagine putting a probe on every connection point inside the
CPU chip of a computer.) Even if you could somehow tell
whether the computer was processing a spreadsheet vs. a
graphic image, could you distinguish whether the spreadsheet
was my grade sheet or my income tax? whether the image was
a technical diagram or pornography?
But brains are even worse. Suppose the circuitry of the brain
forms in one way that artificial neural networks get programmed
-- keep tinkering with the connections with training until you get
good results. Now try to assign a particular "function" or "meaning"
to the elements. You can't -- the "function" is distributed over the
entire ensemble and no particular element has "meaning".
Identical twins have different fingerprints because the details
depend on accidents of development rather than genetic
programming. And the tiny details of fingerprints are about
a millimeter in size, the overall pattern spans centimeters.
Individual synaptic connections are much smaller than this --
the dendritic trees of cortical neurons might typically be on
the order of a millimeter or so. And in one cubic millimeter
of human brain, there may be thousands of neurons, each
synapsing with thousands of others in the vicinity and
receiving synapses from thousands. It is not possible that
all these connections be determined from the 30,000 or so
genes we possess. Certainly many of the details depend on
accidents of development (just like fingerprints) and then are
shaped by learning and experience -- the cumulative history
of activity in the system. So on the fine details, everyone's
brain is certainly unique. And quite likely, the details of
how I "compute" particular details with my nerve cells are
also unique. So that reading someone's "thought" by means
of recording nerve cells is, in my opinion, impossible.
Maybe it would be like recording activity from the CPU when
you don't have any clue as to what type of processor it
is in which chip revision level. Except there are some
ten billion computing elements in the brain (not counting
glia which might end up being important, too!).
"John Leonard" <remove_for_spam_johnrleonard at excite.com> wrote in message
news:7PmJ6.129$ow2.71818 at news.intnet.net...
> But the brain is just a collection of neurons that transmit signals
> electrically. With sufficient observation, shouldn't it be possible to
> understand what is being transmitted? For instance, if one were to compare
> the incoming aural signal from the eardrum to the brain with the efferent
> signal(s) emerging from the body of neurons that process and deliver this
> signal wouldn't it be possible to understand the encoding method used by
the
> brain? In other words, why would it be so difficult to intercept the
signal
> emerging from this aural complex, decode it and reconstruct the aural
signal
> that originally entered the ear?
>> John Leonard
>>> "Richard Norman" <rsnorman at mediaone.net> wrote in message
> news:UIcJ6.40146$qD1.735995 at typhoon.mw.mediaone.net...> > If "reading someone's mind" means I am in the process of
> > (or planning on) making this muscle move by this much,
> > then yes. Essentially you read the motor signals and
> > create artificial "muscles" execute the command. So I can
> > shrug my shoulder or wink my eye to control external
> > equipment (it actually is more subtle than that.)
> >
> > But if you want to know just why I feel like winking my eye
> > or whether I am happy or angry about the fact that I have
> > to shrug my shoulder -- that is rather a different story. And
> > all the while, I am daydreaming about what is going to happen
> > to me and whether I really remembered to turn off the coffee
> > maker and it suddenly occurred to me that I forgot to pay the
> > electric bill and I really am worried about how my career is
> > going, not to mention how my teenage kids are developing
> > --- no, probably never.
> >
> > ""Ron Blue"" <rcb5 at msn.com> wrote in message
> > news:002601c0d5e4$ea10c040$2e1d183f at pavilion...> > > The Air Force has a procedure that allows pilots to control their
> aircraft
> > > by thoughts and it is 98% accurate. This is close to what you are
> asking.
> > >
> > > Ron
> > > http://turn.to/ai> > >
> > > ----- Original Message -----
> > > From: "John Leonard" <remove_for_spam_johnrleonard at excite.com>
> > > To: <neur-sci at hgmp.mrc.ac.uk>
> > > Sent: Saturday, May 05, 2001 7:51 PM
> > > Subject: Is it possible to read someone's mind?
> > >
> > >
> > > > Given the current state of the science, is it possible to attach
> > > electrodes
> > > > to someones brain and read their thoughts? If it is not, then, what
is
> > > your
> > > > projection for the time at which it will be possible?
> > > >