This image dates to 1619. Here’s the reference:

Utriusque cosmi maioris scilicet et minoris […] historia, tomus II (1619), tractatus I, sectio I, liber X, De triplici animae in corpore visione

I believe “Mundus Intellectualis” translates to “Intellectual Globe,” e.g., a map of the intellect, or consciousness.

We represented a rat-scale cortical model (55 million neurons, 442 billion synapses) in 8TB memory of a 32,768-processor BlueGene/L

Dharmendra Modha of IBM’s Blue Brain project presented these results yesterday at the Supercomputing 2007 Conference in a paper titled “Anatomy of a Cortical Simulator.” (pdf) This is by far the largest simulation in the history of computational neuroscience, trumping their previous mouse-scale model by a factor of 3.5. While it accounts for interactions at the resolution of molecules, giving them the title of “biologically-inspired,” it does not account for the large-scale anatomical connectivity and neural differentiation of the rat brain. This model is, quite literally, neuron soup. Cortical neuron soup, that is. Here we can see the size of the model as a function of the number of CPUs and neurons per group:

I plan to write more about their simulator, C2, and other interesting details of the paper soon.

Another interesting question is whether simulated artificial intelligence could be very different from our own. By simulated I am specifically referring to a computational agent, and not the sort of artificial life (Venter Institute) that Craig Venter is after, although that is interesting as well. David Deutsch makes the argument that, based on insights from formulating quantum computation, from which quantum mechanics follow, mathematics also follow physics more generally. Does this rule out creating a simulated environment with constraints that are hospitable for the emergence of intelligence and yet, so different from our own that we wouldn’t recognize it? Computer science, physics and mathematics are so intertwined that is difficult to impossible to draw a distinct line between them. Thus, it would seem that any simulated intelligent agent would have to have properties of intelligence similar, in principle, to our own. The contents of consciousness may be different, and it may be impossible to know “what it is like” to be them, but the computations they perform would be, in a literal sense, fundamentally the same. And does this similarity go back up the simulation chain (Cortical Column)? If we are simulated, does it imply that the intelligent agents running the simulation are performing computations that are fundamentally similar to our own, since ours derive from theirs?

That’s an awful lot of hand-waving and shots in the dark, but some of these questions have legitimate answers. Further, they may be answered within my generation’s lifetime, a generation who may undergo engineered negligible senescence (Wikipedia), so it’s interesting to speculate on what we’ll see. And I am always on the lookout for information that sheds light on what we know about the nature of intelligence. Enter my next question:

What is it like to be a Tardigrade?

Tardigrades, or water bears, are not intelligent by most yardsticks. But they are alive, they are considered animals in the tree of life, and they are the most extreme form of life that I have ever heard of (so called “extremophiles”). They evolved under incredibly inhospitable circumstances that, at the least, make me question whether all intelligence throughout the universe must be intelligence as we know it. It seems that, if you can show an incredibly counterintuitive form of life, it should also be evidence for the possibility of counterintuitive forms of intelligence.

Now, if you want to know what it’s like to be a Tardigrade, you’re going to have to be willing to get very, very cold, because the Tardigrade can handle temperatures just above absolute zero (–459.67 °F). But you’re also going to have to get very hot, because they can further survive temperatures as high as 303°F. If getting that hot doesn’t completely dry you out, that’s good, because next up is vacuum desiccation (Nature). This is a process whereby all of the water will be removed from your body and you will enter a state of anhydrobiosis, which the Tardigrade, but not the Ferengi (Memory Alpha wiki), can survive. The MythBusters are presently doing an experiment to determine if cockroaches could really survive nuclear fallout (Tri-City Herald). They must not have heard about Tardigrades, which can withstand 570,000 rads (Journal of Radiation Biology) of radiation. Humans? 2000 rads. Perhaps the most interesting part is the findings of the linked study:

Conclusion: Our study suggests that radiation tolerance in tardigrades is not due to biochemical protectants connected with the desiccated state. Rather, cryptobiotic tardigrades may rely on efficient mechanisms of DNA repair, the nature of which is currently unknown.

Is it possible for an extremophile such as the Tardigrade, on some other planet in some other galaxy far far away, to evolve into an intelligent agent with properties completely dissimilar from our own? Maybe, but perhaps the computations they evolve to perform, assuming Darwinian evolution is at work, must conform to the known laws of physics, which dictate computability, meaning they won’t be so dissimilar. Humans are, after all, Turing complete (Nature article, pdf). If they can compute it, given enough time, we can too.

Compliments to Wikipedia for many interesting referenced facts and the photo, which is licensed under the Creative Commons ShareAlike 2.5 license.)

How might cannabis cause psychotic symptoms? Acutely psychotic patients show dopamine sensitization. For example, they release excessive striatal dopamine in response to an amphetamine challenge, and the degree of dopamine release correlates positively with the severity of the psychotic symptoms. The probable mechanism is the increased dopamine resulting in increased attention and excessive significance (salience) being attributed to everyday stimuli. In this way, an unexpected sound, the comments of a TV newsreader or eye contact with a stranger, for example, are transformed from trivial everyday occurrences into highly salient events of great personal meaning to the psychotic individual. Delusions can be understood as an attempt to explain these experiences and resolve the resultant perplexity, confusion and dysphoria.

Cannabis markedly increases dopaminergic neuronal firing, including burst-firing, and increases the release of dopamine at terminal fields in the striatum. It is tempting therefore to suggest that this is the mechanism by which it exerts its psychotogenic effects. No investigations have directly tested this in humans, although in one imaging study a subject broke the protocol by smoking cannabis during a pause between imaging sessions, and the resulting brain scans showed evidence that suggested the occurrence of a cannabis-induced increase in synaptic dopaminergic activity.

The article also presents a world map showing survey results on personal cannabis use. The survey found that greater than 8% of much of the western world has used cannabis in the last year, and that as much as 14% of cases of schizophrenia may be partly due to cannabis use. The lifetime prevalence of schizophrenia is though to be between .5% and 1%, although it varies widely.

Note: This entry was initially going to be a comment to the Cognitive Daily post, “Is there wisdom in crowds?” But as you can see, it is far too long to be a comment

The precursor to Wikipedia was Nupedia. It was run by Larry Sanger, a proper epistemologist. It had a seven point review process, as stringent as the Encyclopedia Britannica, if not moreso. Over three years, they finished around 25 articles. Relative to Wikipedia, Nupedia was a dismal failure. There are many lessons to be learned from this. Wikipedia is successful in part because it is able to tap into the wisdom of the crowds, as discussed at Cognitive Daily. It is also true that their is a sort of evolutionary process at work; memes, if you will. A researcher from UC Santa Cruz recently came up with a metric of judging text quality called Trust (http://trust.cse.ucsc.edu/). Although a complicated algorithm, what it boils down to is this: If you are a piece of text that is written by an author who tends to write text that tends to stay in the encyclopedia for a long time, and you have been in the encyclopedia for a long time, then you have a high Trust score. Luca has provided an interesting demo at the above URL, which you should try.

I have also done some work on predicting the quality of Wikipedia articles (pdf). This is a difficult machine learning task because of a particular point that I would like to add to this conversation: The encyclopedia is mostly unwritten. There is, as of yet, very little high quality text to train on. It is a work in progress! If you click on the Random Article link, you have a roughly 75% chance of landing on a “stub,” which is a very short article, that has yet to receive significant community attention. Keep in mind that the encyclopedia was started in the year 2000, and is fast approaching ten million articles in roughly 250 languages. The combined fortunes of Bill Gates and Warren Buffet could not have hired enough people to write as much as they have. And yet, the encyclopedia is mostly unwritten.

Nobody knows better the failings of Wikipedia than the Wikimedia Foundation (WMF), who run the encyclopedia, as evidenced by the Wikipedia article on “Criticism of Wikipedia.” In my view, quality control in an Internet-scale collaborative authoring system, with anonymous authors, is an unsolved problem. There is no one researcher that can solve this problem. Somewhat akin to the game Nomic, the rules of governance and quality are ever changing, albeit collaboratively determined, in much the same way that the encyclopedia is written. I see no reason to discredit such a process before it has had a reasonable amount of time to run its course. None of us knows what will emerge from it, but it is certainly exciting. New experiments in quality control methods are being conducted by the WMF, but they are just that - experiments.

Epistemologists love to sit around and critique the encyclopedia. I’m sure it’s no coincidence that it tends to have low quality philosophy articles. But its merits seem to outweigh any significant criticisms. During midterms and finals, walk into a busy computer lab on your campus and take a brief census of the number of students scanning Wikipedia articles. We use it as a first source of information on our lab mailing list, I have caught professors giving lectures based on information in Wikipedia articles, and I use it myself and find it immensely useful. While there is certainly significant difficulty in judging the veracity of the text contained within, students should not be taught to avoid the encyclopedia and go find an ‘authoritative’ primary or secondary source. They should be taught to judge critically all of the information they digest. Educators and institutions from the previous generations who are not yet on board with the 21st century may never have this realization. But the next generation of students, who are growing up without having a good reason to reference a printed encyclopedia such as Britannica, will recognize how valuable it is. In fact, they won’t recognize Wikipedia as being any different from anything else, except perhaps, more useful.

If anything, Wikipedia is disillusioning. It is removing the bias in our educational system that, when you want “facts,” you should go to the library. Because everything you find written there is true. This isn’t the exact message being taught in grade school, but it’s certainly the impression I had growing up, before I knew any better. I suspect I’m not alone… As long as we continue using it, the evidence seems to be that it will only get better. Britannica, on the other hand, is for the most part stagnant. Once a factual error has been printed, it can never be corrected. So why not continue by supporting the encyclopedia that was started with the goal of making all human knowledge free, for all humans? That’s what I plan to do…

• Max Tegmark tells us why there are three dimensions of space and one of time, with an enlightening diagram.
• Michael Shermer shows us how to use the Drake Equation to estimate the number of civilizations in our galaxy.
• David Deutsch explains why it is that, if we had a time machine and tried to enact paradoxes, we would simply go back to a universe in which those events really happened. (!)
• Donald Hoffman proves that the proposition that “the mind is what the brain does” is false.
• Alun Anderson shows us the significance of many-to-many systems such as the social web: 2^N-N-1
• Paul Davis shows us the equation needed to model the universe, starting before the existence of particles.
• Nicholas Humphrey elucidates the nature of the mystery of private conscious qualia.

But is DBS the only way to stimulate the thalamus? In a recent New Yorker article by Jerome Groopman titled “Silent Minds,” we learn of a technique called Deep Pressure Stimulation (DPS), which is almost completely undocumented in the literature, except by autistic professor Temple Grandin in her “Hug machine.” DPS was applied to a patient in a vegetative state due to a brain hemorrhage by Dr. Joseph Giacino at the J.F.K. Johnson Rehabilitation Institute:

The neurologists examined the woman, who lay with her eyes half closed and did not respond to the doctors’ commands. The neurologists concluded that she was in a vegetative state. “So I sort of sheepishly said, ‘Let me show you what happens when we stimulate her,’ ” Giacino recalled. He had been using a technique called “deep-pressure stimulation,” which involves squeezing a patient’s muscles with force and precision. Giacino started with the woman’s face and worked his way down to her toes, pinching her muscles between his fingers. As he explained, the nerve endings of the muscles send impulses to the brain stem, which relays them to other brain structures and rouses the patient to consciousness. “I did a cycle of deep-pressure stimulation, and within a minute or so she was talking to us,” Giacino said. “The neurologists were flabbergasted.” The woman was able to say her name and her husband’s name, and answer simple questions, such as “Is there a cup at your bedside?” After a few minutes, however, she became unresponsive again.

Now consider this diagram of the thalamus. This is mere speculation, but the brain stem projects to the midline nuclei, which is an anatomical neighbor of the intralaminar nuclei:

Could these two nuclei be functionally related? Consider further the conclusions of Werf et al. (2002) in “The intralaminar and midline nuclei of the thalamus. Anatomical and functional evidence for participation in processes of arousal and awareness“:

These anatomical relationships, in combination with functional studies in animals and in humans, lead us to propose that the midline and intralaminar nuclei as a whole play a role in awareness, with each of the groups subserving a role in a different aspect of awareness.

DBS and DPS are both fascinating, but I have to wonder, did this patient go through this highly invasive surgery when all she needed was a good massage? I hope they get the memo!

This video is interesting because of the scientific context it gives to creationist theories. Before Moore’s Law, the simulation argument was unreasonable. But now, with the advent of increasingly specialized physics processing hardware (this may also be of interest), it is becoming increasingly reasonable to consider ourselves in the position of such a hyper-intelligent creator.

The video includes interviews with Professor Max Tegmark of MIT and FXQi, Foundational Questions in Physics & Cosmology, Professor John Conway of Conway’s Game of Life fame, neuroscientist Dr. Michael Hofman of the Netherlands Institute for Brain Research, and philosopher Dr. Nick Bostrom from Oxford University.