Cloud computing in the brain

I meant to post on this earlier this summer but got distracted... work & life have a way of doing that.

This past July saw one of my most grueling projects finally come to a close. Published in the Journal of Neuroscience and titled “How each movement changes the next: an experimental and theoretical study of fast adaptive priors in reaching" this paper goes well beyond the topic of simple motor control and into fundamental issues about how our brains learn from experience (this is the reason why it took over 2.5 years to get through the review process!).  In particular we show how neurons in the brain might do something akin to cloud computing.

Confused? Let me explain.

First I'll have to talk about a little hard science for some background.  What my co-author and I found was that whenever we move, our brain keeps track of where we go.  Over time, the motor control regions of the brain begin to generate an internal model of the recent movements we've made.  It then uses this memory when we make future actions.  For example, if I keep reaching for this soda can on my desk (and return it to the same position), then over time my brain retains the history of all the reaches I've made to that same spot on my desk.  Over time my reaches to the soda get a little more accurate.  So in a sense, practice makes perfect.

Now, here's the kicker... if I suddenly want to reach for something else ("Hey, that cookie over there looks mighty tasty!") then my brain biases this new movement in the direction of the soda can. We don't really notice it that much, but it's detectible with the fancy machines that we use to monitor your movements.  The more often I reach for that soda can, the more biased my reach for the cookie gets.

It turns out that this type of learning is really sophisticated and follows what appears to be rigid statistical principles.  What I mean is that our brain somehow encodes our recent actions as a prior probability distribution (think of the "bell curve" you've heard about).  It then integrates this prior with all the incoming sensory information you're getting from your eyes, your hand, etc.  This integrated information is then used when you make your next reach.  The stronger the prior, the more biased your future actions will be.  The stronger the sensory input is, the less biased you'll be.

For the math-nerds out there, this is a form of adaptive Bayesian inference.  I wont go in to the awesome details of Bayesian statistics because I don't want to lose 90% of whoever it is actually reads these posts ("Hi Mom!"). This is a branch of mathematics that's used to filter Spam from your inbox, improve images of the stars from telescopes, optimize airline travel, make video games more difficult, and almost everything else that's cool these days.  Needless to say, these are some pretty freaking sophisticated computations that our brains are doing almost effortlessly.  And not just for any high level cognitive process (I mean this process worked in both Shakespeare's brain and in Pauly D's brain)... but for something as simple as reaching for a can of soda.

Okay... hopefully I haven't lost anybody.  Because here's the truly insane part.

Through simulations of neural tissue, my co-author and I found that this really cool mathematical computation likely happens through a form of "cloud computing" in the brain.  For those of you who don't know, cloud computing is the process by which a computation is broken down into a set of little chunks and then distributed to a whole bunch of computers that live in the vast ether of the internet (Note: So technically what I'm talking about is more similar to a computer clusters, but "cloud computing" is the hip new thing these days).  You know those nasty things called "botnets" that take down servers in foreign countries or send you all that spam in your inbox... they're cloud computing gone bad.

We found that a similar principle might work in the brain.  There might not be a single neuron or group of neurons that store this statistical prior.  Instead, we were able to show how this memory can naturally emerge in the dynamics of the information passing between neurons.  Thanks to Hebbian learning ("neurons that fire together wire together") our brain is able to store little bits of information distributed across a mass of connected cells.  Basically populations of neurons remember their collective pattern of activity from the recent past.  Over time, this distributed collective memory shapes the way the network responds to new inputs.  Eventually, this learning exhibits very sophisticated properties that look almost exactly like human behavior, as well as the expectations of statistical theory.  So the whole is, in fact, greater than the sum of its parts.

Let's put this all together shall we?  We've got a group of neurons in your brain that are building a complex statistical model of everything you just recently did. But this model isn't encoded by the activity of any one cell or even in the response properties of a group of cells.  Instead this model simply exists in the abstract dynamics of how these neurons talk to one another.  Mind blown yet?

Now to be completely honest this is hardly the first time that someone has come up with the idea that information is broken down and stored across a network of neurons (in fact there's a formal name for this called "sparse coding").  But what's interesting from our study is that complicated, mathematically principled information can just emerge naturally in the brain thanks to the fact that neurons are recurrently connected (i.e., send information back and forth) and they have associative learning.  This dramatically increases the complexity of information that our brain can store.  Information isn't just encoded in how the cells fire, but also in how they talk to each other as a group. It's a sort of meta-level type of information storage.

Let's end with this... our simulation used about 180 simulated neurons (with 32,400 connections) and we were able to do some pretty fancy mathematical processing.  The human brain has more neurons than there are stars in the Milky Way.  Each of these neurons has, on average, 10,000 connections or so.  A conservative estimate puts it as about 100 billion neurons with about 100 trillion axons.   Think about just how complex of a biological computer that this system could hold!

Yup.... crazy stuff like this is why I do science!

If you don't like the message, kill the messenger

As some of you may know, one of my goals in life is to facilitate the role of science in society.   Last week I came across a little gem that reminds me of what we, as scientists, are up against as far as how science is discussed outside the lab.

Now before I start, let me be honest.  There have always been, and always will be, those who will instinctively disavow science.  For some it's a matter of fear ("That appears to threaten my world view and scares me").  For others it's simple ignorance ("That doesn't easily make sense to me, so I don't believe it").  But for a few it is really more a matter of power ("By minimizing science and its scope, I can act how I want regardless of what evidence there is that I shouldn't.")

The first two groups I can understand and even empathize with.  It's our nature to be cautious and skeptical.  Hell, as a scientist I'm trained to be skeptical and to wait for mounting evidence to make the case that I should reject my current beliefs.   However, usually those who dislike science out of fear or ignorance can be reasoned with if approached in the right way.  Remember that even Pope John Paul II, a man who lead an institution that was terrified of the concept of evolution, eventually conceded that it exists.

It is that third group of science denier terrifies me. And that brings me to what started this whole post.  Check out this clip of Presidential candidate Rick Santorum speaking to a law school audience last week.

Let's listen very carefully to what Mr. Santorum says.  First he appeals to authority" "Because I believe what the Catholic church teaches with respect to homosexuality" he therefore should be allowed to hold his beliefs that same-sex couples should not have equal rights in terms of marriage and adoption.  Now if it were just a personal belief that would be fine.  We all have to appeal to authority at some point in order to have baseline assumptions with which to act in the world.  But when faced with new evidence that those assumptions are incorrect, a logical person would change the assumption.  Mr. Santorum inherently acknowledges this fact when he goes on to say that there is no evidence to refute his "bigoted" beliefs.

But now listen to what Mr. Santorum says when confronted with two critical pieces of information that there is, in fact, evidence to refute his assumptions.  First the fact that the American Psychiatric Association (not the American Psychological Association as stated in the video, although they take the same stance) delisted homosexuality as a mental illness in the DSM-III in1974.  This, by the way, was after numerous empirical studies showing that, in all other aspects, homosexuals had no other presenting symptoms or negative life outcomes than heterosexual individuals.  Second, the fact that there is overwhelming peer-reviewed research by behavioral scientists that children growing up in same-sex households are no different, in terms of mental health and emotional well-being, than those who grow up with heterosexual parents.

Mr. Santorum replies "The American Psychological Association is made up of people who agree with the American Psychological Association." He then follows up with this gem, "A lot of psychologists don't belong to the American Psychological Association. A lot of doctors don't belong to the American Medical Association."

Now keep in mind this is a serious (albeit unlikely) candidate for the GOP nomination.  He's a trained lawyer and served in Congress both as a Representative and a Senator.  So he should, by all accounts, be a very bright and logical man.  Yet his response to just the existence of scientific evidence refuting his beliefs is the same as that taken by the lunatic anti-science fringe: if you don't like the message, attack the messenger.

As a scientist, I'd be fine if Mr. Santorum argued with the science itself.  Every study and every field has its weaknesses. Had he argued that showing a lack of a difference is not the same thing as there not being a difference, he'd actually be correct.  In science, we call it "arguing the null."  Had he said that the research was still preliminary because the children adopted by homosexual couples are just now reaching adulthood, that would also be a valid and reasoned response.

But that wasn't Mr. Santorum's reaction.  This initial reaction reveals something far deeper than a simple lack of understanding of the issue.  It shows a complete and utter lack of respect for the science being discussed.  In fact, he turned the appeal to authority on it's head.  It's okay for Mr. Santorum to hate homosexuality because the Catholic church says so, but it's not okay for scientists in the APA to feel that there's nothing wrong with homosexuality because they're just preaching to the choir.  Do you see that Catch-22?

If Mr. Santorum were the only major politician to act this way toward science, I could let it slide.  He'd be annoying but not threatening.  Unfortunately this is the rule these days and not the exception.  For many politicians, as well as media personalities and a growing minority of the U.S. population, refuting a scientific fact outright because scientists say it is a badge of honor.  It's something to brag about.  In fact, we live in a world where most of the contenders for a major political party's presidential nomination don't believe in evolution or global climate change.  Both of which have thousands (that's right.. thousands!) of empirical publications supporting them.

And that brings us back to the motive. As I mentioned before, Mr. Santorum has to be a smart and logical man in order to get as far as he did.  The same is true for the other leaders who instinctively attack science as a whole (with the exception of Mrs. Bachmann who's a whole other kind of crazy).  I'm afraid, their attack comes from a need for power.  "I can ignore the research on homosexuality and evolution because I want to court the religious vote."  "I can ignore the evidence of climate change because I want to court the industries who it will affect."

Unfortunately, this is an endgame move in the debate.  There's nothing you as a scientist can say or do that will change their beliefs because their ignorance is a source of power.  Arguing with those who take this stance is like arguing with the three year old holding his fingers in his ears... you just have to wait until they grow up so you can talk to them like an adult.

Update: As if on cue, last night's GOP primary debate featured Rick Perry demonstrating my point perfectly.  "Just because you have a group of scientists standing up and saying 'Here are the facts'... Galileo got outvoted for a spell."  The important point being distorted by Mr. Perry is that Galileo was not outvoted by his scientific peers... he was outvoted by the Catholic Church.  His "natural philosophy" peers respected and built off of his work.  In fact, by taking such a stance against the empirical findings, Mr. Perry is putting himself in the same boat as those who "outvoted" Galileo.

Virus-guided laser neurons and the need for creative exploration

Like all meetings, this year's Human Brain Mapping conference was packed with the ubiquitous blend of brilliance and social awkwardness that permeates nearly every neuroscience meeting. That's why I like science.

Real geeks, unlike chic geeks, embrace the fact that they live 90% of the time in their heads, trying to frame the world that they see into the science that they know. Either trying to understand how something works or what would happen if two disparate things were suddenly fused together to make something new.

Most of us are constantly living in our own heads. That's why the "absent minded professor" isn't really much of a stereotype as it is a valid descriptor of our behavior.

But it is this mental wandering that makes good scientists great. Daydreaming has it's creative advantages. Those "what if?" or "how did that work?" scenarios that constantly bounce around within our cranium are the key to pushing science forward.

Case in point, the story behind "virus-guided laser neurons" (also known as "optogenetics"). For those of you who have never heard of optogenetics, it's the mind blowing technology by which viruses are used to insert genetic material from algae or bacteria into the neurons of living mammals. This genetic clipping changes the properties of neurons so that they will either fire or not fire in response to light pulses of particular wavelengths.

You heard that right. Viruses change neurons so that they can be controlled by lasers... in living animals. I'll let you think about that one for a minute.



This technology was developed by Karl Deseroth and his lab at Stanford around 2004. In just a short time, this tech has revolutionized neuroscience and lead many to speculate (privately and openly) that the Nobel is waiting in the future.

Dr. Deseroth was featured as a keynote speaker last week and while the whole lecture was absolutely fascinating, something he said at the beginning caught my attention. Deseroth mentioned that when his lab started working on the idea of optogenetics, they were using funds from a grant from the National Institute of Mental Health that had proposed to do something VERY different. But his lab wanted to try this new venture and they took the risk and it paid in dividends.

"It's a great example of the need for creative exploration," Deseroth said.

And therein lies one of the many problems facing today's researchers. Funding agencies like the National Institutes of Health (NIH) are taking fewer and fewer risks in science. They're hedging their bets on what seems to be the safest horse and in the process stifling most of the creative processes that lead to developments like optogenetics. As the government cuts more funding to science and education, what's left in the pot gets distributed mainly to the established laboratories who are building on established ideas.

Ask anyone who's written an NIH grant recently about the process. Go ahead, buy them a beer. They'll go on at length about how you need to have already finished half the experiments that you "propose" to do in the grant application. This is before it's even considered "fundable." Indeed, the average age at which researchers get their first full NIH grant is now 43 years old! Consider that most professors start their first position in their mid-to-late 30's.

As a result, most scientists in my field spend a vast majority of their time designing and performing research projects that they don't really want to do. They write grants to tell the NIH what it wants to hear. They'll write grants creatively dancing around the projects that are of interest to them, so that they can get the funds to do the real science.

I've even had one established scientist (with decades of experience in neuroscience) tell me that he always writes grants knowing that he'll only do 50% of what he proposes. He'll then spend the other 50% of funds on projects he really wants to do.

This problem is compounded when you consider that, in neuroscience, the current funding rates for grants at the NIH range from ~2.5-16.0%, depending on the agency (down from a stable ~20-25% in the 1990s). That's a lot of highly intelligent brain power being wasted on useless dead ends that could be spent creatively exploring something really interesting.

Unfortunately, that's the dirty secret of the world in which we do science in this country. Unless it changes, the US may stop becoming the place where people can turn crazy ideas like making virus-guided laser-neurons into a reality.

In the meantime, I'm going to keep on daydreaming my weird science ideas.

(Image taken from Technology Review)

Moving over and starting anew

Well it's been a little while, but I've decided to start putting my thoughts to digital paper again. So I've shifted all the old posts from my old blog (Scientia Publica) to the new domain that better encapsulates my interests. Stay tuned for more to come soon.

A request to save the NAE and NSF

So it turns out that a couple of Senators have proposed gutting stimulus funds for the National Endowment for the Arts and the National Science Foundation, as well as other programs.

From the New York Times:

The effort is being led by two centrist senators — Ben Nelson, Democrat of Nebraska, and Susan Collins, Republican of Maine.

Among the initiatives that could be cut are $50 million for the National Endowment for the Arts, $14 million for cyber security research by the Homeland Security Department, $1 billion for the National Science Foundation, $400 million for research and prevention of sexually transmitted diseases, $850 million for Amtrak and $400 million for climate change research. But so far, none of the suggestions come close to being enough to shrink the package on the scale proposed.

I think this is an enormous mistake. I detailed why in a letter sent to the Times. Who knows if it'll be published, so here it is for the record:

Dear Editor,

On Thursday the Times reported that Senators Bob Nelson and Susan Collins are proposing to cut $200 billion from the stimulus bill by gutting support for the National Endowment for the Arts, the National Science Foundation, and other similar programs (http://www.nytimes.com/2009/02/06/us/politics/06stimulus.html?hp).

As a full-time, professional scientist, I would be remiss without defending these institutions. Both science and the arts are two of the major industries in which the US is still dominant around the world. Every year, flocks of people come to the US to attend graduate school, get into Hollywood movies or Broadway plays, work for technology startup, etc. In a way, arts and science are our remaining flagship industries. Despite this, however, we are drastically losing ground each year to countries such as China, India, and Russia. The relatively meager investment for these fields in the stimulus bill would foster the momentum we currently have in these areas.

Now, science and the arts are often seen as dead weight because they are heavily subsidized by the government. However, there is popular support to fund the military first-responders, and infrastructure programs which receive just as much support (if not more). In addition, the fields of arts and science have the added bonus that they also create new jobs. This investment would not only provide primary jobs for researchers, aspiring film makers, engineers, etc., but the resulting discoveries and creations that they build will foster an exponential growth in secondary jobs as new industries (or whole new fields) are born. Think about how many bio-technology, pharmaceutical, and high-tech companies are started each year from of novel scientific discoveries from federally supported research. Consider how the symphony orchestra you just attended or the movie you just download from iTunes was put together by people who were supported by arts grants in college.

Speaking from what I know best, the past eight years have been depressingly hard on my occupation as a scientist. Budget cuts have resulted in fewer and fewer research grants being awarded each year. As a result I have witnessed new and innovative research and development in my field be stifled due to lack of funding. There is no telling how many innovative discoveries have already been lost because of the current funding environment. The money allocated to the NEA and NSF in the stimulus package are badly needed booster shots to these ailing parts of what's left of the US economy. It is simply shorted sighted to think that they do not also need a bailout.

Sincerely,
Timothy Verstynen, Ph.D.

Global Warming might now be "irreversible"

I remember reading the 1998 State of the World report for a class in college. One of the articles was on the risk of global climate change reaching a saturation point, where no matter how we changed our habits, a tragic sequence of events would proceed to change our planet for hundreds or even thousands of years. That was considered dire threat 10 years ago.

After 8 years of suffering the will of self-centered oilmen, a new study out in PNAS shows that the latest climate models suggest we have just passed this point of no return.

Climate change is essentially irreversible, according to a sobering new scientific study.

As carbon dioxide emissions continue to rise, the world will experience more and more long-term environmental disruption. The damage will persist even when, and if, emissions are brought under control, says study author Susan Solomon, who is among the world's top climate scientists.

Now I am not an expert on these types of dynamical climate models, but I have worked on similar attractor systems for my own research and I can say that once these competitive forces cascade, there often is nothing to do but to let the system stabilize. Whether we really have reached this point is still up for debate. However, the fact that we're even worried about it is disturbing enough. I hope that Al Gore's Nobel Prize didn't come 10 years to late.

Chess or Checkers in Diplomacy?

Scientific American has a beautiful post on the policy genius of J. Robert Oppenheimer. We normally associate Oppenheimer with mathematical brilliance and nuclear physics. However, Oppenheimer was also a man of Chess in an international game of Checkers. A tactical wizard who understood the complexity and depth of international politics.

From the article:

During the run-up to the 2004 presidential election between John Kerry and George W. Bush, I appeared as a guest on comedian and social commentator Dennis Miller's television talk show on CNBC, during which he made the following comparison: John Kerry is like a wickedly smart chess player, capable of looking ahead many moves, anticipating what his opponent might do and carefully weighing all his options before arriving at a rational decision. By contrast, George W. Bush is more like a checkers player, moving by instinct and glancing around the board for an easy way to king his men. In this world of good and evil, Miller explained, simple black-and-white thinking based on unwavering principles of absolute right and wrong trumps the drawn-out consideration of the nuanced thinker. In other words, with evil empires and malevolent terrorists on the loose, Miller would prefer a checkers player over a chess master.

...

Oppenheimer was a chess grand master in a game of checkers. He was looking to checkmate the other guy's king by trapping his queen, maneuvering around his bishops and sidestepping his knights, whereas his opponent was merely planning to jump his pieces and have himself kinged. For most of his political and military (and to a lesser extent scientific) colleagues, building the atomic bomb and dropping it on the enemy was a moral no-brainer. Oppenheimer was tormented by the bomb's moral complexities, particularly its postwar expansion into an arms race. It's not that the other leaders of the Manhattan Project had not carefully thought through their decisions; it is that once they made their decisions they moved forward without compunction. What ultimately brought down Oppenheimer was that the government prosecutors in the 1954 hearings trapped him in what they considered to be blatant lies that were, for Oppenheimer, difficult moral choices that caused him to change his positions on people (whom he associated with before or during the Manhattan Project—namely, an ex-lover and a communist sympathizer) and decisions (to share or not to share atomic secrets after the war).

Read the whole article for more, but if ever there was a Prometheus of the atomic-age, it was J. Robert Oppenheimer.