The brain

Consciousness lives in here. Which is really weird.

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Ed Boyden, Neuroscientist at MIT, A new way to study the brain's invisible secrets

The density of the brain is incredible. In a cubic millimeter of your brain, there are about 100,000 of these neurons and maybe a billion connections.

A huge hierarchy of pattern recognisers

Ray Kurzweil, How To Create A Mind: Ray Kurzweil at TEDxSiliconAlley

A lot of the methods used in Watson in fact are very similar to the mathematics of what the human brain does, which is to build up ideas and concepts - patterns, if you will in a hierarchical fashion.

So let me quickly describe how this works - we have 300 million little pattern recognizers. So I have a number that recognizes the crossbar in a capital A and that's really all it cares about. A pretty girl can walk by, a beautiful song can play; it doesn't care. But when it sees the crossbar a capital A gets very excited and fires 'Wow! Crossbar' and that goes up to a higher level.

Another pattern recognizer that's getting that input as well as other primitive feature detectors and goes "Ah, capital A." And it fires with a high probability. That goes to a higher level. That might go up to the printed word "Apple" in another part of the visual cortex that might be recognized and it goes "An actual apple!". That because an actual apple in the auditory cortex that might be one that fires it says "Oh, somebody just said Apple."

Go up another 20 levels and its now sitting at a very high point of a hierarchy and that below it is getting input - from the visual system, the auditory systems, the olfactory system, and it smells certain perfume and sees a certain fabric it has a certain voice and goes "uh-huh my friend just entered the room." Go up another 20 levels and you've got pattern recognizers that might say "oh she's pretty," "that was ironic," "that's funny"…

So you probably think that those high level pattern recognizers - beauty, humor; are much more complicated than the ones just recognize the edge of an object or a crossbar in a capital A but they're actually the same, except that the high level ones are used to sitting in a different position in that grand hierarchy.

I talk about in the book, this girl had to have brain surgery and she was conscious - you can be conscious during brain surgery because there's no pain receptors in the brain - and whenever the surgeons triggered a particular spot in our neocortex she would laugh, and they thought 'maybe they're triggering some laugh reflex', but they quickly discovered no, they're actually triggering the perception of humor. She just found everything hilarious whenever they triggered the spot; "you guys are so funny just standing there" was a typical remark. And these guys were not funny. So she obviously has more than one spot that recognizes humor; we have tremendous redundancy in general.

I've got lots of pattern recognizers that recognize the crossbar and a capital A but they're all organized in this grand hierarchy - so where does this hierarchy come from? We’re not born with it. The subtitle of the book is: "a secret of human thought revealed" and that is the secret - the neocortex recognizes these patterns and actually sees, and its own experience and then wires itself up in this hierarchy. I have a one year old grandson now and he's already laid down several layers of this hierarchy - we can actually learn one conceptual level at a time, that's why it takes a long time to get up to high-level concepts like irony. And many civilizations actually never got to understanding irony which is unfortunate. But, so we create this, our brain creates our thoughts, our thoughts create our brain, we can actually see this on brain scans and all of these recognizes all the same.

Some of the best evidence for that came out just as I was sending the book out, for example what happens to the visual cortex, which is this region that processes visual information - actually the one particular region that's the first region that handles the lowest level patterns in visual images, like the crossbar in a capital A or the edge of an object - what happens to that in the congenitally blind person, who's not getting any visual information? It actually gets taken over by the frontal cortex which deals with high-level language concepts like beauty and irony to help it with those high-level concepts, showing that the these low-level pattern recognizers are actually the same thing.

They are capable of handling high or low level features as the case may be it just depends on where they actually wire themselves to be in the in this hierarchy; that's why you can learn a new skill that may be wiped out in a stroke or our brain accident - you actually learn it with another region of the neocortex.

What's inside the neuron?

Ed Boyden, Neuroscientist at MIT, A new way to study the brain's invisible secrets

If you could zoom in to a neuron, and, of course, this is just our artist's rendition of it. What you would see are thousands and thousands of kinds of biomolecules, little nanoscale machines organized in complex, 3D patterns, and together they mediate those electrical pulses, those chemical exchanges that allow neurons to work together

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