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Saturday, June 4, 2011

Death is not my brain's friend

One of the deleterious effects of believing in a religion is in particular the idea that through this belief one would be assured some form of after life. This is a very damaging idea because it is based on an illusion, a fantasy and a false hope. In the past we had not many choices, maybe religion offered some soothing feeling that the absurdity of a short existence would be in the end resolved. I think, it would have been more honest to accept the reality as it is, even then and to have tried to do the best of a short life, maybe contributing to the well being of present and future generations. But we live in special times. Through fast developing information and bio-technologies, through our amazing daily breakthroughs in understanding human physiology and nature in general, we are approaching a point where we would have the ability to defeat death once and for ever. Death is not a metaphysical problem any longer, it is a technological one. We can defeat death, once and for ever, with modern biomedicine. We can do this as we did a lot of things through science. Believing in the delusional "spiritual after life", that is the core of most religions, doesn't allow people to realize that it would be much better to fund aging research than to donate to a church. If people could realize that we are close to a solution to death based on reality, they would support this research and actually demand it. So many people are simply hoping for something that is as delusional as believing in Santa Claus or fairies. They want it so badly that they are available to make a complete nonsensical commitment to something that is clearly absurd. And this is paradoxical because if these people would support science, that often religion considers a foe, they would be given all what religion falsely promised, including eternal life.

We are the electricity and chemicals in our brains

The repertoire of experiences that a single brain can achieve is amazingly big. However, our brains are relatively similar in size, components and biochemistry. We have the same type of neurons and neurochemicals that a rat has. What differentiates us from animals and what explains the difference in behavior and personality among people are the connections in our brain.What is different between me and you  is the type of connections that you and I have, how neurons interact with each other, how they organize and get structured. In a way, we are different but in a more important way we are very similar. The human experience is differentiated more in subtle nuisances than in fundamental, deeply alien ways. This why so many people like Coca Cola, and some Pepsi. Two choices really, and at that the same time very similar. As different humans are, I'm always amazed on how similar our thoughts, fears, desires are, even across cultures, time, sex, age. But again one can explain both how similar and how different we are in the context of modern neuroscience. The picture is not complete, not perfect but we are coming closer and closer. Few days ago, I went to a lecture, here at the Department of Psychiatry, at UW, Madison where I work.  The lecturer  was showing how the injection of this particular neurotransmitter was increasing the voluntary feeding amount of a rat. And then how this other was decreasing it. He plotted a graph of the amount of the chemical substance injected in very specific part of the brain versus the amount of feeding: he obtained a perfect straight line, indicating a perfect correlation between these parameters. Then another region was inhibited and the opposite effect was obtained. It is just amazing, a complex behavior modulated by a simple substance. And that is not just true for rats but the same would happen in humans under the same conditions. In fact, the scientist explained that he would like to explore the application of this finding to help people with addictions. Maybe we are a little more complex than a rat but we respond to the same chemicals, to the same stimuli. To some, it is scary that we are these physical connections between neurons, these electrical currents, these molecules but what is scary about this? These neurons, electrical forces, molecules are fascinating, beautiful in how they work and behave, and part of the miracle of existence. On the contrary, I find that invoking spirits and elves and strange superstitions as the "soul" to explain what we are, when so much beautiful real knowledge about the nature of our beings is unfolding in front of our eyes (every day brings new and fascinating discoveries in neuroscience) is a shame. And if part of what discovered is that yes, us being our physical brain then love is a chemical, our thoughts are electrical impulses, that our personality and memories are connections among neurons, and when the brain dies we also die with it, then is not just true but alright. But that is not reason for despair but it is good news and cause for action. In fact, we can do something even about the problem of death. Science can find a way to extend life. What religion promised, eternal life (a natural and just longing by an aware mind) science can actually achieve. Maybe not today, maybe not in 100 years, but one day it can and will happen. Believing in after life when it is not true, it is like believing in Santa Claus simply because it would be nice if he did exist. I agree it would be nice if Santa existed. But it doesn't so you grow up and believe in people instead. They are real and sometime they bring you gifts if you are nice to them. 

Friday, June 3, 2011

Everything from Nothing

The Universe came from nothing. It is absolutely clear. All the symmetries present in the universe are what you will expect from vacuum and nothingness. This is difficult to understand for somebody that doesn't understand anything about the basics of physics. All the laws of physics came from symmetry and the breaking of symmetry that ensued in the early universe. Conservation of momentum, angular momentum, energy are a consequence of the symmetry of emptiness. The initial symmetry breaking that allowed for different particles to be created and the differentiation of the natural law are also a consequence of the initial condition of emptiness and the fragility of maintaining that state. Like a pencil balancing on its tip, this state can be achieved even if for a short time. In fact, it is easier for a pencil balanced on its tip to flip on one side than to stay in that state for a long time. This why there something rather than nothing. Because it is easier for a pencil to fall than to stay in this perfectly balanced state. The perfectly balanced state is nothing (unlikely to exist) and the unbalanced state is everything (much more likely). There is nothing extraordinary in that act of symmetry breaking and we consider it pretty natural. It would be supernatural for the pencil to magically be balanced on its tip. This is a perfectly matching analogy with what happened when the Universe arose from the Big Bang from nothing. It was as easy as a pencil falling from being perfectly balanced on its head. How the pencil got balanced? Throw many pencils and one would be bound to be balanced on its tip, even if for a short time. It is that simple. Yes, the universe was created from nothing. Sum all the energy of the Universe, positive kinetic and negative gravitational, you get zero. The laws of nature are the same left, right, up and down. That is the symmetry of empty space. Rotate around yourself and the universe is the same in every direction.Throw a ball on the left or on the right and it will move in the same way. Go few feet away from where you stand and throw the ball again and it behaves as before. Wait for few seconds and throw the ball again. Its behavior is the same as in the past. Symmetry of empty space. Matter can be created from energy but only in pairs of matter and anti-matter that destroy each other and go back go nothingness. The list goes on and on. The slight asymmetrical events that we observe are the equivalent of the balanced pencil that falls from this unlikely state. It is easier to make a universe from nothing than from anything else. It is that simple. And from this simplicity, that highest simplicity of them all, nothingness, through a fantastic sequences of unavoidable steps, the simplicity transformed itself in something more and more complicated to create finally the amazingly complex self-aware structure that is the brain. 

Monday, May 30, 2011

Wisdom of Crowds

My friend Andrea Kuszewsky posted in her Facebook page an interesting blog article on the "wisdom of crowds", the idea that a group of people is smarter in general and more often than single individuals. The article is interesting among the other things because it contains a criticism by a working neuroscientist of a well known amateur or using a popular term, citizen scientist, Johan Lehrer, author of "Proust was a Neuroscientist" and "How we decide". The title of the critical blog article is "Johan Lehrer is not a Neuroscientist". Peter Freed, Md, the author of the blog, did a good job in pointing out a clear misleading and let's say amateurish misunderstanding of a paper, with important social consequences, that Lehrer mentions (without a proper citation) in the Wall Street Journal. It is great that more journalists and bloggers, without a formal background in professional research, are discussing about science and helping in spreading the enthusiasm of discovering to the public. But when this is done at the price of over simplifications, blatant errors and basic misunderstandings the professional scientists have the right to point out these errors. It seems though that the professional  neuroscientist didn't completely grasp (by his own admission) some basic statistical properties of different types of means and he arrives to the conclusion that not just Lehrer interpretation of the paper is wrong but even the scientists that wrote the paper are spinning the significance of their results. I don't quite agree. Here is my rebuttal to his blog article:

"While I applaud you for the investigative work you did in finding the silly and misleading mistake of Mr.Lehrer, not understanding what is the significance of a median, I don't agree with your generalconclusion. Let me start with saying that the questions asked to the students mentioned in the paper are a kind of problem (making an educated guess) called Fermi's problem. From Wikipedia :"In science, particularly in physics or engineering education, a Fermi problem, Fermi question, or Fermi estimate is an estimation problem designed to teach dimensional analysis, approximation, and the importance of clearly identifying one's assumptions." While the Swiss students didn't go consciously through the steps of a typical Fermi's problem (I imagine they had to give quick intuitive answers) unconsciously they maybe have done exactly that. But even if they had the time and inclination to go through the steps, a typical Fermi's problem allows for an error in the estimate that is up to an order of magnitude. In other words, if the exact number is 10.000, guessing 30,40, or even 90 thousands would have been good in the context of a Fermi problem. So getting an error in the hundred is actually pretty good (it means a factor of fews that is basically nothing). Fermi problems are considered a golden standard in the context of a guessestimate and in fact it takes a good deal of convincing to explain students that guessing wrong by a factor of 10 as a first rough estimate of the numerical answer of a problem, where little or no information is given is actually pretty good and a useful thing to do.
So actually the single individuals have done pretty good in most of the cases in the experiment (with some exceptions as in the assault estimate).

Second, there is a reason the geometric means is actually doing so much better.
Again from the definition of Geometric Mean in Wikipedia:
"Although the geometric mean has been relatively rare in computing social statistics, in 2010 the United Nations Human Development Index switched to this mode of calculation, on the grounds that it better reflected the non-substitutable nature of the statistics being compiled and compared:
The geometric mean reduces the level of substitutability between dimensions [being compared] and at the same time ensures that a 1 percent decline in say life expectancy at birth has the same impact on the HDI as a 1 percent decline in education or income. Thus, as a basis for comparisons of achievements, this method is also more respectful of the intrinsic differences across the dimensions than a simple average."
The idea here is that if you have statistically independent samples, representing different processes and parameters of a problem, taking an arithmetic mean is not that significant. A geometrical mean characterizes in a more meaningful way the different weights of the individual estimates. An intuitive understanding of how this could be useful in the context of crowd wisdom is to think about where the source of crowd wisdom may actually be (if it exists at all). 

Imagine that in a small group of students that don't have any clue about how many immigrants there are in Zurich there is one or even few that are immigrants, or have studied the topic at school, or have read for themselves some material about the subject. Their answer will be much closer to the correct one. An arithmetic average would wipe this "higher wisdom" if the number of expert is small (as indeed is the case for random crowds). Statistically the answer of the non experts would be quite all over the place while the response of the experts would be in a narrow range. You can consider these two types of answers as different "dimension" and they should be emphasized in a different way that is what the geometric mean does. It is actually a significant result that the Swiss scientists were able to show that the geometric mean works much better in this case. Now a more relevant and interesting question is how then there is anecdotal evidence that we recognize this "geometrical mean wisdom" in crowds? Do we do a geometrical mean calculation in our heads when we ask the crowd for a word of wisdom on a particular question? 

Well, I think it has to do on how the data is displayed. Let's take an example, that is the popular game "Who wants to be a millionaire?". One of the life savers is to ask the public to help, in other words to use the wisdom of a crowd. I noticed, that rarely the crowds are wrong. How the data is displayed in this particular example? In a histogram, showing the different counts for the possible answers. If most people don't have a clue the distribution would be flat. And in fact, probably, for the difficult questions the distribution would look pretty flat. But if in the crowd there are few experts the right answer would stick out of the flat distribution as sore thumb. Geometrical means, and our eyes looking at a distribution are good in picking up this spiky features. An arithmetical mean would be pretty useless in this context. If I'm right in this analysis, then this should also explain why communicating crowds would destroy the wisdom effect. Most people would listen to what the majority has to say and the experts would not be listened and in fact they too, being humans, may feel compelled to change their initial guess (in particular if they were not truly experts and they were simply just better than the other ones in making educated guesses).

 I think this idea of the wisdom of crowds deserves more investigation and in particular the usefulness of the geometric mean or other statistical ways of the extracting the wisdom from the crowd should be explored. Indeed, what distinguishes a scientist, professional or citizen, is patience, tenacity and taking the time to understand both the general picture than the details of a problem. "

Brain cells and galaxies.