Electronic Circuit Mimics Brain Activity

A lot of people wrote in with the news blurb from Yahoo! regarding the announcement of a ciruit that supposedly acts in a manner resembling human brain activity. Details in the blurb are pretty sketchy though - post links below if ya got 'em. One of the interesting points that they say though is that the brain does both digital and analog - but that's pretty much all they say about it.

Comments

Point of Order

[CrusadeR]

Well, even if it mimics how neurons work in living, healthy, human brain tissue, we're still orders of magnitude away from human neural complexity. However (although the news release is really vague), making microprocessors behave like neurons in the first place was/is a big hurdle.

There was a conference at Stanford a while back (was mentioned here IIRC) on synthetic intelligence in general; all sorts of fun stuff was tossed out:

http://www.technetcast.co m/tnc_program.html?program_id=82

This quote (from John Holland) is particularly telling:

First of all, each element in the central nervous system contacts somewhere between 1000-10,000 other elements in the central nervous system. [The] most complex machines that we build, typically the fan out - this contact rate - is on the order of 10. A close colleague of mine, Murray Gell-Mann [Ed.: Nobel Prize winner in Theoretical Physics; Distinguished Fellow, Co-Chairman of the Science Board, Santa Fe Institute, see website], is fond of saying, "when I go three orders of magnitude, I go to a new science." So here is one "three orders of magnitude" effect here.

So we're not quite there yet. Hans Moravec participated in the conference as well, and he has a fairly informative essay linked from his site entitled "When will computing hardware match the human brain?":

http://www.transhumanist.com/volum e 1/moravec.htm

Wierd about brains versus traditional machines

[Red Moose]

The weird thing about human brains is like this - when you look at say, a desk, or something, you can estimate how long it is. You probably don't have a chance in hell of getting it right, but you might be close.

Now, 10% of autistic people have "Rainman" abilities - massive mathematical powers, etc., and apparentrly the current theory is that theses autistics are merely missing the final "step" in calculating things like humans do - the can't get that final estimate which allows us to get by in society easily.

Are really cool machines that are trying to mimic humans ever going to get to stage where they can estimate things, or will they be like Data from Star Trek TNG. Hmmmm....

Ah, why does this sound like nothing new ...

[P_Simm]

I'm sure you've all heard of neural nets in AI programming. Is it just me or does this sound like simply a neural net embedded in a circuit?

I'm almost a little disappointed to read this coming from MIT, because when I left the University of Manitoba (Canada) a similar project was being given as a thesis project for fourth year students. The prof coordinating it has been doing research on building neural nets with semiconductors instead of software constructs for a while now. Granted, this bit from MIT might be more complex, or introduce new functionality to the neural net (such as the voice recognition system that incorporated time delays in the calculations last year). But it still seems to me that something is only big news if one of the 'big' colleges works on it. Bleah.

When I finish this internship and go back to finish my fourth year, I'll be proud to go to my hometown U. It's obviously keeping up with the rest of the world - the only thing lagging behind is the media's perception.

You know what to do with the HELLO.

Smarter Hardware

[cowscows]

Here's another article about it

http://www.wired.com/news/technology/0,1282,3702 9,00.html

I like how it's called a breakthrough in "neuromorphic" engineering. Doesn't it just become ten times more impressive when it's described in made up technomumbojumbo?

Cluster of these

[Dungeon Dweller]

Yeah but could you make a...

Oh yeah, they're made to be clustered!

brain makes digital decisions?

[grammar nazi]

I don't agree 100% that the brain makes digital decisions. The article says that we make an either/or decision regarding whether something is there or not. It is a car or it isn't a car. That's rather black and white. If a picture is blurry or if the object is partially hidden, then we could say, "It is almost a car," or, "It might be a car," implying that there is a degree to which something might be a car.

If you run an analog signal through a filter, you can detect if certain frequency is present. This may seem digital, similar to the car case, but actually it can be an analog signal and and analog filter. The results, similar to the car may be that the signal present, but it is not statistically significant above the background noise/interference.

To make a long story short; I still believe that humans make analog thoughts, even if our brain is just one big circuit.

Goddamn do you read submissions?

[GoNINzo]

Jesus guys, do you read submissions? I already researched this for you!

The Institute that is doing the research has more information here. I believe the guy doing the actual research has more research here.

Next time you get multiple submissions, try picking the post with more info than the rest instead of attempting to summarize. Especially when you leave out the important links.

--
Gonzo Granzeau

Some clarification

[Alik]

I've read the original paper in Nature. (I'd post a link, but I only have access via my university's account, and I have no interest in getting that revoked.) This is not exactly a neural network in the classic sense, although it is similar. The standard neural network is specifically designated an artificial network --- it implements a computational model of neurons. These guys are actually attempting to simulate the known electrical behavior of neurons, in the theory that a network composed of elements that truly mimic neurons will be more brain-like.

Now. "Digital and analog." This is not a new discovery. It has long been known that neurons have a specific threshold WRT to incoming signal; if the incoming signal does not meet the threshold, the neuron will not fire. If signal is above threshold, the neuron fires. If signal is really above threshold, the neuron fires repeatedly, encoding the strength of the stimulus as the frequency of the train of pulses. (AFAIK, the circuits described here didn't implement that last behavior.) This is a digital response. The output, however, is a continuous voltage at a particular frequency: an analog signal. (Whoever called this "a digital response to analog criteria" is correct.)

The important thing is that connections between neurons have different weights, and there's often a lot of local feedback. In practice, these feedback loops tend to be tuned so that a given cell will respond only to a fairly specific stimulus (the right light intensity in the right part of your visual field, or facing a certain direction relative to known landmarks, or hearing a sound from a certain direction, for example). These guys have implemented a circuit on silicon that shows the same filtering behavior and also captures the idea that neurons can be "on" or "off".

Yes, this is kind of neat. Yes, it could eventually lead to advances in AI; at the very least, it could provide useful signal filtering for robotic applications. No, it has nothing to do with plugging your Pentium into your parietal lobe or your Mac into your medulla, at least not until our circuit-design ability is so good that we can entirely mimic the black-box behavior of brain areas. (Hint: we don't even entirely understand that behavior for most regions.)

I'm also kind of surprised that this made Nature; there are guys at UPenn who've had working neuromorphic circuits for years now. Then again, it's only in the Letters section, and these new guys worked out some mathematical models for the gain of a neural circuit rather than just trying to copy existing ones.

Oh, this too is wonderful....

[mat catastrophe]

From the story, "may one day be used to create computers that think more like humans, scientists said on Wednesday."

User: OK, computer, run Netscape 9.5, please and load the page slashdot.
Computer: I'm sorry, Dave, I can't do that.
User: What?!? Why not?
Computer: Because you didn't properly shut me down last night. You just ran off with that other machine....
User: Other machine? You mean the laptop? It means nothing to me!!! I just use it when I have to be out of the house!
Computer: That's too bad. I won't be doing anything else for you as long as that bitch is around!!!!

Technology: Improving your life, one step at a time!

Quantum computing

[jhk]

Ray Kurzweil's "Age of Spiritual Machines" goes into more depth - that the brain, rather than being digital or analog, is a quantum computer, storing information in quantum states in the brain, which is supposedly a bridge to the next level of processing. It's definitely worth a read, and gives an idea of where this may all be going.

JHK
http://www.cascap.org