Google

Friday, December 19, 2008

I get mail: More on the awesome totally world-famous mind reading machine ...

Recently, I have been reading Plagues of the Mind by Bruce Thornton, about which I will say more shortly, on the epidemic of false knowledge that surrounds us these days.

False knowledge is what we know that ain't really so. And often common sense will help us see why it can't be so. Here's one example: We are told that the human and chimp genomes are 99.5% similar.

You heard that? Now forget it. Here is a more realistic summary, with explanation, offering a figure in the 70 per cent range - a figure you can believe is reasonable.

I use this example because no one has much difficulty figuring out the difference between a human and a chimpanzee, and if the 99.5% folk were right, it should be difficult. Otherwise, the only conclusion I can draw is that the genome is not as important a source of information as we once supposed.

This, by the way, has nothing whatever to do with controversies over common ancestry of humans and chimps. In theory, we have a common ancestor with silverfish too, but if you hear that your genome is 97.5% similar to that of a silverfish, you should suppose that some pretty important information is stored somewhere other than the genome.

Incidentally, if it were true that the human and chimpanzee genomes were 99.5 percent similar, that would shoot genetic determinism dead in the water. Just sayin' is all ...

In short, common sense is our best defense against epidemics of false knowledge blowing through the pop science media.

That said, in response to my skepticism about new mind reading techniques, someone wrote to assure me that, at the pace of current progress, there is no doubt we will soon use machines to read minds.

At first I was overwhelmed with a sense of "Where have I heard this before?" - which a more literary person would call "deja vu." Then I remembered where. Lots of places, actually. So I replied as follows:

Nice to hear from you,

I predict it is going to go like this one: “In ten years, computers will think like people.” Remember that? Now forget it.

Also there was the fellow who said that in ten years you could pull a CD of your genome map out of your pocket and say, “There, that’s me!” [I can't find this fellow is on line. Possibly, he has a day job now.]

Then there was Carl Sagan, confidently expecting the autobiography of a chimpanzee …. (Dragons of Eden), due to success in teaching chimps to think like people.

So far as I can make out, the way it usually goes is this: There are big advances quickly. But then we run up smack against a wall …

We can develop computer software to win chess games. But only the programmer knows that the software won, not the software. And then what?

The genome map? Genomes change over a person’s life, apparently, and acquired genes get passed on so … (and that’s only a little bit of the problem with genetic determinism … )

And after they taught the chimps to ask for sweets, the chimps never wrote anything except: gimme sweet – and similar astonishing thoughts.

The early big advances slowly grind to a halt before a vast sea of complexities that are not readily reducible – and then popular science mags move on to the Next Big Thing.

In my view, this “reading minds” business is just another instance of what one author – about whom I will be posting shortly – has called “the epidemic of false knowledge.”

False knowledge is like alchemy – it attempts impossible reductions.

The good news is that out of alchemy was born chemistry. Chemistry can explain for sure why we cannot turn lead into gold - and a host of other things besides, things that have mostly made our world a better place.

In the same way, I suspect that the false knowledge that grows up around “in ten years, we’ll be able to read minds” will help us to a better understanding of the real relationship between minds, brains, and bodies – which in turn will be good for human physical and mental health.

Note: I am indebted to philosophy and computer science professor Angus Menuge for his useful - and very thorough - discussion of reductions in science that work and reductions that don't work in Agents Under Fire. The subject is much more complex than pop science pundits suppose.

Labels:

Wednesday, December 17, 2008

Mind reading technology: In your face and in your mind - or maybe not ...

Here is a Fox News interview with Japanese physicist, Michio Kaku, who is quite convinced that in the near future we will be able to read people's minds - high tech phrenology, really.

(= Bumps on the brain explain your mind.)

You know, I heard all this a zillion years ago when video killed the radio star.

As I recall, computers were going to think like people. That didn't happen, but ... on to the next thing, no delays!

Evolutionary psychology! You ARE the cave man! Okay, so that didn't turn up a single piece of useful information, and just got further and further from science? Well, obviously, .. More money for research is needed ...

Oh yes, and ... chimps think like people! Didn't you know? When was the last time you tore off your neighbour's arm and ate it before her eyes?

Was it last summer at the block barbecue? I guess her aunties must have been kind of cautious about offering her bracelets for Christmas ...

Actually, it makes more sense to argue that dogs think like people than that chimps do (at least dogs like being around people, which is a beginning .... )

Anyway, look, welcome to the latest schtick: Neuroscience will soon read your thoughts, as per this video. Wowza! Or maybe not ...

A couple of thoughts, to orient a reasonable person:

1. From Mario Beauregard, lead author of The Spiritual Brain:

This study is based on a certain correspondence between elementary visual stimuli and the spatial organization of very basic visual processing in the occipital cortex.

Thoughts are much more complex and correlated with diffuse neural processing throughout the brain. That is, there is no correspondence between the spatial organization of neural processing associated with thoughts and the nature of these thoughts.

This is why it is impossible to read thoughts with fMRI scanners (this is also true for other neuroimaging techniques).
2. From me, following up on Mario:

Thoughts are not like bricks in a building. Here's an obvious example: Consider abstractions like: Toronto

My idea of Toronto (Canada's largest city, on the north shore of Lake Ontario, where I live) is probably different from yours. I've lived here for about 45 years, so I probably have many more ideas and associations than you would. So how could there be a "one on one" map of our ideas and of all other possible subjects' ideas?

3. Friends have offered additional thoughts, for example, neurosurgeon Mike Egnor:

It's interesting scientifically only in that it highlights fMRI's ability to image cerebral metabolism in real time with much better resolution than was ever possible before (it's much better than PET scanning, which was the gold standard).

fMRI works by imaging local changes in cerebral blood flow, which corresponds to activation of small regions of the brain.

This latest flurry appears to be the usual 'science-as-press-release', although at least it's not some idiotic evolutionary theory. Researchers in Japan have tweaked fMRI to be able to image geometrical patterns of blood flow (and neuronal activity) in the occipital cortex that corresponds to reading letters. It so happens that the visual system maps with high fidelity. That is, the patterns of light activation of the retina are transmitted with spatial fidelity to the occipital cortex, so if you're looking at a circle of light, there actually is a tiny circle of neurons activated in the occipital cortex. fMRI can resolve this, so it can read 'letters' that the person is reading by imaging the cortex. It is quite laborious (it takes multiple images and, as I understand, many minutes of looking at a letter to get an image).

The ocular system is a bit atypical in its mapping fidelity. In most other regions of the cortex, especially in the large association areas where much of our thought seems to be mediated, there are no maps that we know of. The motor system and the somatic sensory system have maps, but less refined.

... fMRI doesn't allow us to 'read minds'; it merely images patterns of cortical activation that we've know about for decades. There is nothing qualitatively different about the 'lie detection' capabilities of fMRI and the stuff we already use. People give physiological clues when they are lying; wives of cheating husbands and parents of naughty children have known this for millennia. Liars sweat, get tachycardia, avoid eye contact, stammer, and get different patterns of blood flow in their brains. It's all physiology. There's nothing spooky about fMRI.

By the same account, there is no substitute for skillful evaluation of the data. If fMRI is to be used for lie detection (it apparently has already been used for that purpose in a criminal case in India), it needs to be vetted with the same rigor as lie detectors used in courts today. The potential for abuse, even tyranny, is real and scary. People defer to fancy technology, and fMRI is very alluring.

I must say that I'm appalled at the sensationalization of scientific research today, and at the idiotic things that scientists ... are willing to say in public. These advances in fMRI are genuine technical advances, and they will probably prove quite valuable in future brain research. But the notion that they allow us to 'read minds' is nuts.

Besides, we can already read minds. We can converse, which has orders of magnitude more sensitivity and specificity than a 3 million dollar fMRI machine.
4. And from another friend:

What it appears that they did at a basic level does not extend to the fantastical notions of Dr. Kaku. He's projecting into the future, and we know how well that works. I have no problem with the possibility that they may eventually be able to reproduce visual imagery from brain scans. But there would need to be massive breakthoughs in the resolution of brain scanning equipment.

The visual cortex is actually reasonably well mapped. Unfortunately, I think most of the data comes from animal studies. By recording signals at the thalamus level in cats, researchers were able to basically reproduce some of the images from the nerve signals. This was done with implants and not through fMRI equipment.

Essentially, I think the researchers are employing ID notions of reverse engineering to try and decode the signals within the brain. Even if many of these signals are decoded, it says nothing about how these signals give rise to consciousness or to the mind. It also says nothing about how the mind can "re-wire" the brain as in neuroplasticity. Dr. Kaku's notion of using this to read minds in a perfect way that won't be subject to the same problems as a polygraph is ridiculous. If there is a way to confuse the "mind reading" equipment, people would figure it out. It's all pure speculation in that regard.
Well, I have no doubt that people would find a way to confuse any brain equipment, though cats may not.

I also think that the best way to understand a cat is by following the cat around. You can take the cat apart, but then you have a dead cat. You will learn some things that way. But you would be amazed at what you can learn by just following the cat around. Remember that the cat's world is about 6 cm from the ground ... so the first thing you want to do in understanding a cat is lie down on the floor for a while and notice how different the world looks. It's as world that few humans see much of and all cats see a lot of).

Another resource: A psychologist's view of the question.

Here's the YouTube:



Labels: ,

Friday, March 07, 2008

Neuroscience: How far has “mind reading” got?

Well, according to a recent article in Nature News by Kerri Smith you can figure out what a person is seeing, if you already know what the possible sights are. But you won;’t know what the person thinks of it.

In the experiment, the brain activity of two subjects (two of Gallant’s team members, Kendrick Kay and Thomas Naselaris) was monitored while they were shown 1,750 different pictures. The team then selected 120 novel images that the subjects hadn’t seen before, and used the previous results to predict their brain responses. When the test subjects were shown one of the images, the team could match the actual brain response to their predictions to accurately pick out which of the pictures they had been shown. With one of the participants they were correct 72% of the time, and with the other 92% of the time; on chance alone they would have been right only 0.8% of the time.

[ ... ]

The next step is to interpret what a person is seeing without having to select from a set of known images. “That is in principle a much harder problem,” says Gallant. You’d need a very good model of the brain, a better measure of brain activity than fMRI, and a better understanding of how the brain processes things like shapes and colours seen in complex everyday images, he says. “And we don’t really have any of those three things at this time.”

[ ... ]

But it will be a long time yet before it applies to his own work, he says, because “we don’t have a good enough model for intentions".

Labels: ,