response 1 of 26:

Oct 18 08:30 UTC 1995

1.) I think your slight revulsion at the concept of human brain storage
    being obtainable with current computer hardware, is based more on
    human conceit and arrogance, rather than on actual scientific evidence.
2.) Humans have a problem with conceptualizing quantitys once you
    get past "1, 2, 3, many....". 10 terabytes is a tremendous amount
    of data. OTOH, the fact that our brains have that "little" storage,
    might account for why people are always misplacing their car keys. :-)
3.) I suspect that the brains methodology of storing information is so
    differnt from our current computer's paradigm, that a direct comparison
    is meaningless. Even if we can directly count the smallest quanta of
    brain storage and call that a "brain bit", I suspect that 1 megabit
    of brain bits are capable of storing a great deal more *information*
    that 1 megabit of compter storage, due to the storage methodologys
    employed in the brain.

response 3 of 26:

Oct 18 19:01 UTC 1995

Those ten (or whatever) teraneurons each have dendrites making contacts
with the dendrites of hundreds if not thousands of other neurons, each
synapse of which is capable of being in several states. It is not a
counting but a combinatorial question. If A neurons have B dendrites
synapes with C possible states, how many different states can the system
have? I'll think about that another time.... 

response 5 of 26:

Oct 19 18:35 UTC 1995

My estimate is that there are C^[A, B+1] states, where [] is the binomial
coefficient. If A=10^12, B=10, and C=3, the number of possible states is
about 10^[10^124]. A lot of these are hardwired, but there's enough to go
around. The wonder is that we are so dumb. 

response 7 of 26:

Oct 20 05:14 UTC 1995

Interesting, Greg.  I was thinking along those lines, our brains hold
programs and memory in a way RAM doesn't, but couldn't put my finger on
the diff -  it's what you said, that it's also the CPU.
 
Neurons seem perhaps more like logic gates than simple bits of memory.
They're "firing" or "not firing," but doesn't that on/off output result
from a variable numbers of inputs (dendrites)?  As you said, they're
both memory and logic circuits.
 
Rane, interesting approach.  Considering neural connections helps figure
how useful our neurons are, but maybe isn't relevant in computing just
the raw "uncompressed" storage capacity of the brain.  To elaborate:
 
 If you had a normalized relational database on an auto-compressed hard
 drive, the manufacturer's drive spec's capacity wouldn't indicate how
 much "info" it *really* stored.  The related fields and compression are
 important to the useful storage capacity, but there is still a raw,
 physical bit capacity of the hard drive.
 
 Counting what our neurons can store is similar - it may give a raw data
 capacity, but the dendrites, "data formats," etc. are what really matter.
 
Looking at *raw* capacities, I don't think bit/brain comparisons are as
far apart as apples to carburetors...more like apples to corn :-).

response 9 of 26:

Oct 21 06:27 UTC 1995

You're definitely onto something. 

Each neuron acts like a gate, but a much more complicated gate than and
and,or,nand,nor.  Some areas excite, other suppress. Over time, the degree,
and even the sign of the effect at any synapse is modified. I think the
"learning" and "memory" is somehow stored in these "coefficients" at the
synapses. That's about all the clues I have.

response 11 of 26:

Oct 22 01:27 UTC 1995

Well, no, not really - because one of the properties the brain has that
bubble memory does not is that it's highly redundant.  Bubble memory,
even more than most computer components, is highly serialized and
non-redundant.  You can, in fact, only look at one bit at a time, and if
any bit of the hardware goes, the whole chip goes.  Human memory is a
very different thing, and probably much more similar to a holograph than
anything else.  In a holograph, the whole image is stored "everywhere",
and if you break a holograph in two, each half still has the whole
picture, it's just coarser in each half.  In fact, humans can suffer
fairly massive amounts of brain damage and still have only minimal
effects on memory.  (It *is* possible to have damage to small areas that
have a massive effect on memory, but that's probably because it's
damaged the storage & retrieval parts, not the actual memory itself.)

Another interesting feature of human memory is that it's

actually a two stage process.  There's a "fast memory" and a "slow
memory" storage system.  When we first learn something, it goes into
short-term memory which is probably an electro-chemical dynamic process.
Several hours after we learn something, it goes into a purely chemical
static long-term memory process.  There are several ways to show this
must be happening - people who suffer some massive disruption of brain
processing, such as a shock, will forget everything they learned just
before the shock, but not older stuff.  There are also ways to shut down
the brain's electrical processing, and if this is done, again, the short
term memory goes, but the long term does not.

Even though we can't recall our memories in detail, that does not mean
it's not there.  mean it's not there.  In fact, the evidence that all of
that detail *is* recorded, and what's lost is not the memory, but the
ability to retrieve it.  In certain kinds of brain operations, it's
possible to stimulate certain parts of the brain, and if this is done,
the patient will recall some random long lost experience, complete in
every detail; including sound, scent, & all.  If another nearb y spot is
stimulated, a different random memory will be retrieved.

response 13 of 26:

Oct 30 00:44 UTC 1995

I quickly read throught all the previous responses and it seems no one has
yet to take into consideration one's feeling, emotions, and urges  how can
these things be quantified?   There is more to the human brain than just
different types of memory.

response 15 of 26:

Nov 1 04:40 UTC 1995

  I don't see feelings, emotions, or urges as particularly special,
but I don't count them as part of memory, either (unless remembering
feelings/emotions/urges).  They get handled in other parts of the
brain.
 
  That borders more on the "can machines think" debate, a classic
philosophical/AI question.  It's an interesting issue.  As "smarter"
machines are created and evolve to argue the question for themselves,
I'm sure it will become an important theological/political question.
Unfortunately, I don't think that will happen in our lifetimes.

response 17 of 26:

Nov 1 10:28 UTC 1995

  I do not equate a bit to a state.  A particular state, out of a
domain of N states, can be represented with a number from 1 to N.
If N=2 (maybe for a light switch, being on or off), *then* I think
a bit is comparable to a state.  But for N>2 (as in chess, where N
is a jiggagazillion), it would require a larger number of bits (in
chess, log base 2 of a jiggagazillion) to represent a given state.
 
  If it could be determined that human memory had exactly N states
(as you were estimating in #5), taking the log base 256 of N seems
a not-unmeaningful way of defining the answer to the question "how
much memory can the brain hold in computer terms [bytes]?"
 
  It's an odd question, but suppose someone asked "how much memory
does a chess board hold in computer terms?"  (Interpreted in a
canonical way - ignore "rotation" of pieces and such).  I think
the number of bytes needed to represent the layouts (or states) is
a reasonable way of answering.

response 19 of 26:

Nov 2 08:32 UTC 1995

  "Bytes" was chosen to answer the question, how much memory in
computer terms.  If you don't like the arbitrariness of bytes,
how about bits?  Makes little diff.  But if you prefer leaving
the brain number in states, it's easy enough to convert computer
memory capacity to a maximum number of states...a megabyte of RAM
could represent 256^1,024,576 states.  It just seems a lot harder
to comprehend such a big number.

response 21 of 26:

Nov 3 07:13 UTC 1995

You're right, but those differences are in how brains and computers
*use* memory, not in what the memory capacities are.  That type of
comparison would be much harder.  If you're interested in raw memory
capacity, what's the diff between specifying it in states, bits, or
bytes?  Whether you store data in an inefficient 8-bit ASCII format,
or an efficient JPEG format (which doesn't care about byte boundaries,
except in its header), the raw capacity of the memory chips is the same.

response 23 of 26:

Nov 4 02:34 UTC 1995

I believe so.  Time to go grab someone's brain and test our theories. :)