tag:blogger.com,1999:blog-75960966390634767712024-03-06T20:21:15.591-08:00Deconstructing ZaninessSedulous secretion of wry lapsesPavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.comBlogger45125tag:blogger.com,1999:blog-7596096639063476771.post-52601971130296086592013-02-07T17:47:00.001-08:002013-02-07T17:47:42.976-08:00In-silico hypothesis curator<div dir="ltr" style="text-align: left;" trbidi="on">
<span class="Apple-style-span" style="color: #333333; line-height: 14px;"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0]"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0].[6]"><span class="Apple-style-span" style="font-family: inherit;">In my <a href="http://deconstructingzaniness.blogspot.fi/2013/01/human-brain-project-or-euro-drain.html">earlier post</a> about the big-ticket billion euro human brain project, I drew a laborious analogy between</span></span></span></span><span class="Apple-style-span" style="color: #333333; line-height: 14px;"> the HBP and the large hadron collider (LHC). I suggested that to maximally take advantage of the proposed mega simulation of the brain, we must ask ourselves what are tens or hundreds of <a href="http://en.wikipedia.org/wiki/Standard_Model">standard models</a>, we need to look for in the properties of the simulator.</span><br />
<span class="Apple-style-span" style="color: #333333; line-height: 14px;"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0]"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0].[6]"><span class="Apple-style-span" style="font-family: inherit;"><br /></span></span></span></span>
<span class="Apple-style-span" style="color: #333333; line-height: 14px;"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0]"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[0].[6]"><span class="Apple-style-span" style="font-family: inherit;">For example, a future series of experiments that might involve a little bit of everythin</span></span></span><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[3]"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[3].0"><span class="Apple-style-span" style="font-family: inherit;"><span id=".reactRoot[63].[1][2][1]{comment596065948:10151239732400949:111_25484575}.0.[1].0.[1].0.[0].[0][2].0.[3].0.[0]">g: say pharmacological manipulation, functional imaging (fMRI), microscopic of imaging of neural circuits (EM), extracellular electrophysiology, and psychophysics, and that would be hard/impossible to run in a single lab, could be run on the simulated brain. In a potential scenario the in-silico experimentalist could download a single instance of the "live simulated brain" (or even just a single cortical region or slice, depending on the hypothesis), run programs that mimic a pharmacological intervention, and then run other programs that provide infinite-SNR electrophysiology or microscopy data.</span></span></span></span></span><br />
<span class="Apple-style-span" style="color: #333333; line-height: 14px;"><span class="Apple-style-span" style="font-family: inherit;"><br /></span></span>
<span class="Apple-style-span" style="border-collapse: collapse; color: #222222; font-size: 13px;"><span class="Apple-style-span" style="font-family: inherit;"></span></span><br />
<span class="Apple-style-span" style="font-family: inherit;">I feel that the best way to engage with the </span><span class="Apple-style-span" style="color: #333333; line-height: 14px;">HBP would be to curate a transparent, ranked, well-debated, and amendable list of top 100 hypotheses to test in-silico, given the features and limitations of the platform.</span><br />
<span class="Apple-style-span" style="font-family: inherit;"><br /></span>
<span class="Apple-style-span" style="font-family: inherit;">I propose a workshop leading to a magazine or a journal special issue, starting with an open call to neuroscientists looking to scale their hypotheses, worded as follows: </span><br />
<span class="Apple-style-span" style="font-family: inherit;"><i><br /></i></span>
<span class="Apple-style-span" style="font-family: inherit;"><i>If we could <a href="http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1002291">record from all neurons in the brain</a> and know <a href="http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001411">all about its structural connectivity</a>, OR EQUIVALENTLY if we could access molecular/ celluar-scale activity with infinite SNR (from a whole-brain simulator), what kinds of questions would we be asking? How would we scale our hypothesis to match the scaling of technology?</i></span><br />
<span class="Apple-style-span" style="font-family: inherit;"><br />The idea is to source the following classes of talks and articles:</span><br />
<br />
1. Invite supporters of the in-silico platform to submit blue-sky ideas for <b>future great experiments</b>. The set of future great experiments must span a diverse range, from the lowest to the highest levels of brain organization. Questions could include, for example:<br />
<br />
<ul style="text-align: left;"><ul>
<li>How do neurons acquire tuning properties and wiring over developmental time scales?</li>
<li>How is gene expression in a particular brain area influenced by learning, and how does that in-turn influence long-term memory storage and recall?</li>
<li>How are probabilistic computations achieved within and across circuits?</li>
<li>How does slow-wave sleep spread from single neurons across the whole brain?</li>
</ul>
</ul>
2. Invite contrarians to argue that we can learn all we need to from classic integrative experimental neuroscience.<br />
<br />
3. Invite historians of science and simulation-driven scientists from other disciplines—statistical physics comes to mind—to describe the nature of fundamental discoveries have been made from large-scale computer simulations.</div>
Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-81790533031764250362013-01-25T19:48:00.005-08:002013-01-25T20:05:31.026-08:00Human Brain Project or Euro Drain Project?<div dir="ltr" style="text-align: left;" trbidi="on">
<br />
Thursday, January 24th, 2013, saw the <a href="http://www.nature.com/news/billion-euro-brain-simulation-and-graphene-projects-win-european-funds-1.12291">announcement</a> of EUR €0.5bn funding for what has now been a <a href="http://www.scientificamerican.com/article.cfm?id=human-brain-project-digital-simulation-neuron">media darling</a> over the past five years, the <a href="http://www.humanbrainproject.eu/index.html">Human Brain Project</a> (HBP).<br />
<br />
For a sense of scale of what 500 million means, let us note that the public component of the Human Genome Project cost $3bn and the Large Hadron Collider cost $7.5bn. Have a look at some other <a href="http://en.wikipedia.org/wiki/List_of_megaprojects#Science_projects">mega projects</a> in science.<br />
<br />
Despite the sensationalist title of this post, I'll try to stay balanced. All said and done, this humble postdoc is looking forward to the trickle-down effects of mega-funding!<br />
<br />
Let's start with the criticisms. I see the common criticisms and voices of support, distributed across 4 broad camps.<br />
<br />
<b>Too many assumptions, too little detail</b><br />
The first camp is of the opinion that we simply don't have enough knowledge to simulate a brain that is faithful to nature. For example, to digital neuroanatomists such as Nobel Laureate <a href="http://en.wikipedia.org/wiki/Bert_Sakmann">Bert Sakmann</a>, the BBP assumes too much about the statistics of anatomical connections within a <a href="http://en.wikipedia.org/wiki/Cortical_column">cortical column</a>. Without detailed microscopy-driven reconstruction of columnar connectivity (a goal of <a href="http://en.wikipedia.org/wiki/Connectomics">connectomics</a>), Sakmann believes that the eventual computer simulation of columnar function is merely an unverifiable candidate for how a true column behaves. To generalize a little, I would say that his is attitude is similar to that of Tony Movshon (see <a href="http://www.youtube.com/watch?v=fRHzkRqGf-g">Movshon vs. Seung</a>), who believes that neuroscience is <a href="http://www.quickmeme.com/meme/3s0u59/">not ready yet for unified theories</a>, and must try to become comfortable about its identity as a collection of cottage industries for another half a century or more.<br />
<br />
<b>Too much detail, not enough abstraction</b><br />
The second camp consists of astute modelers such as Gustavo Deco, who seem to believe that running experiments on a simulated brain will only tell us what we already know. They question the epistemic value of the <i>simulate everything</i> approach. Modelers in general, tend to believe that artful abstractions <i>alone —</i> abstractions which leave noisy details out — will eventually lead to testable predictions and new knowledge. Personally, I believe that this criticism comes from a failure to grasp the difference between modeling and simulation-with-the-purpose-of providing an in-silico experimental platform.<br />
<br />
<b>Markram is difficult and unconventional</b><br />
The third camp consists of the majority of scientists who feel that Henry Markram is hard to work with and doesn't subject enough of his findings to peer-review. One recent example of his fiery temper is the debate between him and IBM's Dharmendra Modha about simulating the cat brain, <a href="http://spectrum.ieee.org/tech-talk/semiconductors/devices/blue-brain-project-leader-angry-about-cat-brain">which ran afoul</a>.<br />
<br />
<b>Technological consequences</b><br />
Finally, we have a camp of pragmatic technocentrists, who suggest that as usually is the case with ambitious projects, there are necessary technological by-products such as the <a href="http://www.nature.com/nmeth/journal/v9/n6/abs/nmeth.1993.html">patch-clamp robot</a> (perfect postdoc), and the <a href="http://en.wikipedia.org/wiki/Blue_Gene">IBM Blue Gene</a>. Thus, they believe that although the HBP might not achieve its stated goals, the technology left in its wake might ultimately help neuroscientists. Indeed, this could be an amazing learning experience for neuroscientists to make the transition from cottage-industry-scale to industrial-revolution-scale knowledge creation, as certain other fields have done.<br />
<div>
<br /></div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
All of the above views are important, but there is yet another aspect that I would like to bring up. In one sentence, <b>I believe that the HBP is operating in an epistemological gap</b>. Let me explain by analogy.</div>
</div>
<div>
<br /></div>
<b>LHC. Yes. Standard model. No</b><br />
I personally think of the HBP as the Large Hadron Collider (LHC) of neuroscience. The LHC creates states of extremely high energy which are rare on earth, but are nevertheless known to be abundant in the known universe. Now, there are two crucial points about studying these high-energy states for the purposes of our analogy:<br />
<br />
1. The properties of matter and interaction in these states are not completely known, but we have strong hypotheses about them based on theoretical work.<br />
<br />
2. These states are impossible to naturally access and therefore directly characterize with known technology.<br />
<br />
Thus, we have three recourses to the two problems:<br />
(A) Develop theories that make testable predictions as we wait for technology to improve so that we may test them.<br />
<br />
(B) Improve the technology needed to access these hard-to-access states*, or<br />
<br />
(C) Simulate with high fidelity, everything we know about these states, and then do controlled experiments on the simulated system.<br />
<br />
Having said this much, the similarities between the LHC and the HBP become immediately obvious. We don't know everything about neural circuits but have a few testable predictions. We cannot simultaneously access and measure the whole brain at all levels. Further, both the HBP and the LHC adopt strategy (C) to problems 1 and 2, except that the HBP is a computer simulation.<br />
<br />
*Incidentally, <a href="http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1002291">a lesser known project</a> that aims to record from all neurons in the mouse brain, provides an exciting and ambitious solution adopting strategy (B).<br />
<br />
However, and finally coming to my point, it is also possible to note that unlike in the case of the LHC, whose flagship project tested the <a href="http://en.wikipedia.org/wiki/Standard_Model">standard model of particle physics</a>, neuroscientists have <b>(I) no agreed-upon hypothesis which is difficult to test in vivo or in vitro, but easy to test in silico</b>. Further, since the HBP is a computer simulation, we have <b>(II)</b> <b>no agreed-upon way to declare the simulation as faithful to nature</b>. This is what I refer to as operating in an epistemological gap.<br />
<br />
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
So now that the HBP has been funded, what can cottage-industry-scale neuroscientists do, other than wringing hands, pointing fingers, twiddling thumbs, and umm, writing blogs?</div>
<br />
<b>Downscaling the HBP on your ordinary cluster</b><br />
First, the computational neuroscientists, and high performance computing fields could independently simulate much smaller-scale brains or brain phenomena, so as to work out the details that would feed into the HBP.<br />
<br />
There are two ways to downscale the HBP: downscale the level of complexity of a single neuron while maintaining the order of magnitude of the brain size: e.g. simulate 1 million integrate-and-fire neurons, as a <a href="http://www.nature.com/news/simulated-brain-scores-top-test-marks-1.11914">Canadian group has recently done</a>, or downscale the number of neurons while preserving the complexity, as the Blue Brain Project, the precursor to the HBP, has done.<br />
<br />
<b>Agree on killer apps</b><br />
Second, the HBP could organize regular panels or boards, where leading neuroscientists could come up with ways to bridge the epistemological gap, that are not just hand-waving: "we will test the effect of drugs on diseased brains". Specifically,<br />
<br />
(I) Propose and vote on a battery of tests that can benchmark the fidelity of the simulation.<br />
(II) Propose and vote on a transparent list of the top 10 hypotheses that cannot be tested in vivo but can be tested on the HBP infrastructure.<br />
<br />
So to summarize, neuroscience now has an LHC in the making but doesn't have a Higgs. In the 10 years that it might take to get the LHC built, those of us who wish to use it, could work on formulating as exactly as possible, our favorite top 10 hypotheses to test in-silico.<br />
<br /></div>
Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com3tag:blogger.com,1999:blog-7596096639063476771.post-87647118190323505562012-12-02T19:43:00.005-08:002012-12-02T19:47:40.253-08:00Science: a family business?<div dir="ltr" style="text-align: left;" trbidi="on">
1. As I was reading <a href="http://en.wikipedia.org/wiki/Subrahmanyan_Chandrasekhar">S Chandrasekhar</a>'s collection of <a href="http://www.amazon.com/S-Chandrasekhar-Man-Of-Science/dp/9350290294">essays and family reminiscences</a>*, I couldn't help but notice the intellectual heavyweights in his family. Many of us know that his uncle, Sir <a href="http://en.wikipedia.org/wiki/C._V._Raman">C V Raman</a>, was another eminent physicist and Nobel laureate. But how many of us know that his mother translated <a href="http://en.wikipedia.org/wiki/Henrik_Ibsen">Henrik Ibsen</a>'s plays to Tamil, his sister <a href="http://www.thehindu.com/arts/article493460.ece">Vidya Shankar</a> was a notable veena artist, and his brother Purasu Balakrishnan, a notable physician, writer and Sanskrit scholar?<br />
<br />
2. Likewise, on a previous trip to Madras, I met someone who was related to the <a href="http://en.wikipedia.org/wiki/Alladi_Ramakrishnan">Alladi Ramakrishnan</a> family, and he informed me later on that <a href="http://en.wikipedia.org/wiki/Vilayanur_S._Ramachandran">V S Ramachandran</a>, the eminent neurologist, is from the same lineage.<br />
<br />
3. Yet again, as I was reading about microsaccades, a type eye movement that remains poorly understood even today, I was amused to learn that <a href="http://en.wikipedia.org/wiki/Robert_Darwin#Scientific_contributions">Robert Darwin</a>, the father of Charles Darwin, was the first to describe them. Likewise, the wealthy <a href="http://en.wikipedia.org/wiki/Francis_Galton">Francis Galton</a>, a cousin of Charles Darwin, although remembered more for promoting eugenics, described synesthesia, and promoted and financed the Biometrika journal, a watershed in 20th century statistical thinking.<br />
<br />
These examples led me to ponder <a href="http://en.wikipedia.org/wiki/Outliers_%28book%29">the idea</a> popularized by Malcolm Gladwell, that one's environment is a much stronger determinant of success (however you choose to define it) than any individual traits. Incidentally, as I was researching the Alladi family, I encountered a note about a neighborhood called <a href="http://my-mylapore.blogspot.fi/2007/04/palathope-lawyers-enclave-part-ii.html">Palathope</a> in Mylapore, Chennai, which produced an extraordinary number of lawyers during pre-independence India. This neighborhood reminded me of the Italian village <a href="http://www.nytimes.com/2008/11/30/books/chapters/chapter-outliers.html?pagewanted=all&_r=0">Roseto Valfortore</a>, which produced extraordinarily healthy immigrants.<br />
<br />
While the idea of environment breeding success is by no means new, the above examples provoked a journalistic curiosity in me, to learn more about the inner workings of elite intellectual families throughout history.<br />
<br />
Among other notable examples of intellectual families, I can recall Mary and Pierre Curie, Niels and Aage Bohr, and although not a family, Ernst Rutherford and his academic descendants. Anybody has any lesser known examples?<br />
<br />
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<br /></div>
*As I might never get around to writing a gushing review, I would like to note that <a href="http://www.amazon.com/S-Chandrasekhar-Man-Of-Science/dp/9350290294">Man of Science</a> was a moving book, which gracefully captures the exalted thoughts of the great, and somewhat under-celebrated man that was Prof. Chandrasekhar. I would go so far as to confess that, reading the lectures of Chandra, his thoughts on great scientists and artists in history, his ideas about classical literature, private letters to his siblings, and the reminiscences of his family members, I felt the same emotions that <a href="http://bigthink.com/ideas/17863">Stephen Fry might have felt</a> when he discovered Oscar Wilde, a private, incommunicable joy of having encountered a rare and kindred spirit from a bygone era.<br />
<br />
Let me give you just one of at least a dozen examples from the book that helped me make the connection to Fry and Wilde. S Balakrishnan writes in a reminiscence after Chanrasekhar's death, about an incident shortly after Chandrasekhar returned from Cambridge with his PhD, and shortly prior to his departure for Chicago:<br />
<br />
<blockquote class="tr_bq">
I recall on two evenings, we walked on the Marina of Madras. He was a recognized scientist. He had shot into the Indian sky like a meteor, or shall I say like Professor Heisenberg in the German sky. But I saw walking beside me an earnest, eager student, thinking only in terms of the pursuit of knowledge, warmed immediately by the mention of high endeavour in any sphere, persuading me, without being patronizing, to think highly of myself. Truly, here is the seed of greatness, I thought.</blockquote>
<br />
I was compelled to buy all of <i>merely three</i> copies from bookshelves in all of Chennai's bookstores, and distribute it to friends. One day in the near future, I hope to make the trip down to University of Chicago, where he did his life's work, and get access to his other books, <a href="http://www.press.uchicago.edu/ucp/books/book/chicago/T/bo4432943.html">Truth and Beauty</a>, and <a href="http://www.amazon.com/Newtons-Principia-Common-Reader-Physics/dp/0198517440">Newton's Principia for the common reader</a>.</div>
Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com2tag:blogger.com,1999:blog-7596096639063476771.post-8255965614831593202012-12-02T17:50:00.002-08:002012-12-02T17:50:37.038-08:00[Link] A brief history of neuroscience<div dir="ltr" style="text-align: left;" trbidi="on">
Resonance is a monthly magazine published by the Indian Academy of Sciences, targeted at high-school or undergraduate readers. I used to read it during my JEE days. I came across a very readable piece on the <a href="http://www.ias.ac.in/resonance/November2012/p1054-1064.pdf">history of neuroscience</a>.</div>
Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-68452316557440420312012-03-04T09:48:00.015-08:002012-04-02T09:05:26.184-07:00Newell's twenty questionsIn an <a href="http://deconstructingzaniness.blogspot.com/2011/09/how-can-history-of-gravitational-theory.html">earlier post</a>, I had brought up the contrasting attitudes towards what constitutes physics, attributed to Rutherford and Feynman, respectively.<br /><blockquote>That which is not physics is stamp collecting. ~Ernest Rutherford.</blockquote>In the haughty perspective of Rutherford, the primary concern of science was to construct explanations (theories) for observed phenomena (stamps), and it was only the physicist who would fit this role. Indeed, under this view, it would seem that all other sciences were sources of observations for physics to explain.<blockquote>Physicists often have the habit of taking the simplest explanation of any phenomenon and calling it physics, leaving the more complicated examples to other fields. ~Richard Feynman.</blockquote>In the more humble of perspective of Feynman, it seems that the fields outside of physics patiently investigate and characterize anomalies lying outside the realm of the most common instance of a given phenomenon. Their role could thus be viewed as fulfilling the business of collecting and describing rare stamps. Rare stamps when fed back into the activity of theory building (Rutherford's physics), would enable the development of simpler theories with greater predictive power.<br /><p class="MsoNormal"><span style="font-weight: bold;">The blind men and the elephant</span><a href="http://www.noogenesis.com/pineapple/elephant/elephant.JPG"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 500px; height: 325px;" src="http://www.noogenesis.com/pineapple/elephant/elephant.JPG" alt="" border="0" /></a></p><p style="text-align: center;" class="MsoNormal"><span style="font-size:85%;"><a href="http://www.noogenesis.com/pineapple/blind_men_elephant.html">Image courtesy</a></span><br /></p><p class="MsoNormal">To understand the state of a field in progress, it is worth considering the Indian parable of <a href="http://www.noogenesis.com/pineapple/blind_men_elephant.html">the blind men and the elephant</a>. The story goes that six blind men decide to understand how an elephant looks by touching it. Each manages to touch only a small part of the elephant. As a result each develops strong beliefs about the nature of the elephant. They liken the tusk to a spear, the trunk to a snake, the tail to a rope, the feet to a tree, the ears to a fan, and the torso to a wall. Since they are unable to perform further experiments, they end up debating the nature of the elephant ad nauseum.<br /></p><p class="MsoNormal">The gist of the parable is that (1) partial and noisy observations of a system result in erroneous conflicting hypotheses, and (2) the hypotheses are at a stalemate because of the lack of right tools to perform further experiments.<br /></p><p class="MsoNormal"><span style="font-weight: bold;">Enter Newell<br /></span></p><p class="MsoNormal">With this background, it is perhaps useful to pause and consider what <a href="http://en.wikipedia.org/wiki/Allen_Newell">Alan Newell</a> had to say back in 1973. Newell is known, among many things, for advocating the mind as an information processing system, along with his advisor and Nobel laureate Herbert Simon. In a valedicatory talk titled, <a href="http://www-psychology.concordia.ca/fac/deAlmeida/COGSCI/Newell-1973-TwentyQuestions.pdf">You cannot play 20 questions with nature and win</a>, he attempted to characterize the field of experimental psychology, and as we shall see, his ideas are broadly applicable to the state of cognitive neuroscience today. It is interesting to note that at the time of this lecture, Ed Posner, the founder of the <a href="http://nips.cc/">Neural Information Processing Systems </a>(NIPS) conference was in the audience.</p><p class="MsoNormal">To understand the essence of his ideas, let us consider the metaphor of nature as a jigsaw puzzle.<br /></p><p class="MsoNormal">Imagine that you have the pieces of a jigsaw puzzle face down. You don't know what the puzzle looks like, and you don't know how many pieces there are. To flip each piece, you need to do very rigorous experiments and verify the results carefully, multiple times. Each piece may be likened to a phenomenon of the mind, such as auditory short term memory, or one of its properties, such as how long a certain type of information resides in auditory short term memory. The act of spotting each new piece may be likened to an observation of the phenomenon, and the act of flipping it may be likened to the careful elucidation of its properties. Each of these acts is performed by a number of scientists working together or independently, over a number of years. Sometimes new phenomena are discovered; at other times, new properties are elucidated. At still other times, a deeper understanding of the phenomenon is gained, as Feynman explains <a href="http://www.youtube.com/watch?v=o1dgrvlWML4&feature=g-vrec&context=G269a7e6RVAAAAAAAAAw">here</a> with a chess analogy.<br /></p> <p class="MsoNormal">Newell articulated beautifully that the journey from empirical exploration to unified theory is a complex one. Consider the following paragraph:</p><p class="MsoNormal"></p><blockquote>I stand by my assertion that the two constructs that drive our current experimental style are (1) at a low level, the discovery and empirical exploration of phenomena [...] and (2) at the middle level, the formulation of questions to be put to nature that center on the resolution of binary oppositions. At a high level of grand theory, we may be driven by quite general concerns: to explore development; to discover how language is used; to show that man (sic!) is a processor of information; to show that he (sic!) is solely analysable in terms of contingencies of reinforcement responded to. But it is through the mediation of these lower two levels that we generate our actual experiments and give our actual explanations. Indeed, psychology with its penchant for being explicit about its methodology has created special terms, such as "orienting attitudes" and "pretheoretical dispositions," to convey the large distance that separates the highest levels of theory from the immediate decisions of day to day science.<br /></blockquote><p></p><p class="MsoNormal">Newell's attitude was as follows. One half of him was very excited about the fact that multiple new pieces are being discovered all the time. But another half of him was concerned that if the trend of upturning new jigsaw pieces was to be extrapolated into the future, the field would be nowhere closer to seeing how the pieces fit.<br /></p><p class="MsoNormal">Consider this statement:</p><p class="MsoNormal"></p><blockquote>Science advances by playing twenty questions with nature. The <a href="http://www.cdl.cbcb.umd.edu/files/PDF/strong-infrerence.pdf"><span style="font-style: italic;">proper </span>tactic</a> [hyperlink, mine*] is to frame a general question, hopefully binary, that can be attacked experimentally. Having settled that bits-worth, one can proceed to the next. The policy appears optimal--one never risks much, there is feedback from nature at every step, and progress is inevitable. Unfortunately, the questions never seem to be answered, the strategy does not seem to work.<br /></blockquote>*This is a reference to another outstanding opinion piece from the 1960s called <span style="font-weight: bold;">Strong Inference</span> by John Platt. He stresses the importance of alternate hypotheses and systematically ruling out one of the two, with examples from theoretical physics and molecular biology.<br /><br />After commending a selection of outstanding individual studies for example, he states:<p></p><p class="MsoNormal"></p><blockquote>What I wanted was for these excellent pieces of the experimental mosaic to add up to the psychology that we all wished to foresee. They didn't, not because of a lack of excellence locally, but because most of them seemed part of a mosaic of psychological activity that didn't seem able to cumulate.<br /></blockquote><p></p><p class="MsoNormal">If you replace experimental psychology with cognitive neuroscience, and 1973 with 2012, Newell's assessment would still ring true.<br /></p><p class="MsoNormal">In a subsequent post, I will get around to analyzing Newell's recommendations to get unstuck, and how they could apply to the state of modern cognitive neuroscience.<br /></p>Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-16510687890666914022011-12-26T08:26:00.000-08:002011-12-26T15:25:39.365-08:00Science of the human condition<div>As 2011 draws to a close, here are two extremely broad BBC documentaries (and companion books) about what makes us fundamentally human.</div><div><br /></div><a href="http://sunwalked.files.wordpress.com/2011/08/dr_alice_roberts.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 640px; height: 360px;" src="http://sunwalked.files.wordpress.com/2011/08/dr_alice_roberts.jpg" border="0" alt="" /></a><div style="text-align: left;">The stunning Dr. Alice Robert's <a href="http://en.wikipedia.org/wiki/The_Incredible_Human_Journey">The Incredible Human Journey</a> takes us through the migration of Homo Sapiens Sapiens from West Africa to every continent in the world between 70,000-10,000 years ago. It is a 5 part series (5 hours of screen time), with each episode focusing on one continent. A very broad and fascinating discussion including speciation, <a href="http://en.wikipedia.org/wiki/Hominini">the hominini</a>, various archeological sites, genetic evidence, climate models for sea levels, competing theories of our lineage, creation myths of indigenous peoples, and much more. Some thoroughly fascinating questions include: How many waves of migration from Africa eventually survived? One or several? Did we interbreed with the Neanderthals? Did East Asians evolve from the Homo Erectus? Guaranteed to stimulate. I'm currently reading Bryan Sykes's <a href="http://en.wikipedia.org/wiki/The_Seven_Daughters_of_Eve">The Seven Daughters of Eve</a> to get a richer understanding of the archeological and genetic methods involved in this richly interdisciplinary, politically charged, and data-starved field that attempts to provide a scientific alternative to epics and creation myths. Eager watchers, catch it on youtube before it gets taken down.</div><div><br /></div><a href="http://mcbillhow.files.wordpress.com/2011/10/planet-word_stephen-fry.jpg?w=480&h=508" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 480px; height: 508px;" src="http://mcbillhow.files.wordpress.com/2011/10/planet-word_stephen-fry.jpg?w=480&h=508" border="0" alt="" /></a><div><br /></div><div>Stephen Fry's <a href="http://www.amazon.co.uk/Planet-Word-Stephen-Fry/dp/0718157745">Planet Word</a> takes us through the evolution, modern day use, and dysfunction of language and symbolic communication. The breadth of this 5 part series (yet again) is impeccable with a coverage of everything from Chimpanzee communication, the FOXP2 gene, Tourette's and swearing, an introduction to Ulysses, the creation of modern Chinese and much else. Unfortunately taken down from youtube.</div><div><br /></div><div>"Exact science is not an exact science" ~Nicola Tesla according to Christopher Nolan, in The Prestige.</div><div><br /></div><div>Here's to another year of awe and wonder!</div>Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com2tag:blogger.com,1999:blog-7596096639063476771.post-17896825198913904172011-10-29T11:14:00.000-07:002011-10-29T14:00:21.258-07:00Change of seasons<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyeBGpBu19tZShRFLWYiBWgrzGpMhtcptpzVM58Yfi_LiX_lIJR-4n9WFgZOiK28Bdv3HA62YTONRWS3bcZRh5-nZGhvNhwFQEq8gOqj_AgUT6Vl3k7DYnlhMIr_AAzkcuseZUrlGpVRWE/s1600/FxCam_1319893832159.jpg"><img style="float: right; margin: 0pt 0pt 10px 10px; cursor: pointer; width: 200px; height: 134px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyeBGpBu19tZShRFLWYiBWgrzGpMhtcptpzVM58Yfi_LiX_lIJR-4n9WFgZOiK28Bdv3HA62YTONRWS3bcZRh5-nZGhvNhwFQEq8gOqj_AgUT6Vl3k7DYnlhMIr_AAzkcuseZUrlGpVRWE/s200/FxCam_1319893832159.jpg" alt="" id="BLOGGER_PHOTO_ID_5669021663937848450" border="0" /></a>The late October Sun smiled weakly today, like a devout caregiver who has been strong for too long, and is unable to hide his waning strength any longer. "Stay strong without me", he said, in an unsuccessful attempt to inspire fortitude during his absence. A yellow, perforated, autumn leaf fell to the matted brown floor lined with its recently deceased kin --- apologetic, for having overstayed its welcome, and in quiet acceptance of its fate. A solitary gull, now devoid of its cacophonous bravado that the summer warmth had inspired merely months ago, circled the <a href="http://maps.google.com/maps?q=Lehtisaari,+Helsinki,+Finland&hl=en&sll=37.0625,-95.677068&sspn=57.249013,134.560547&vpsrc=0&hnear=Lehtisaari&t=m&z=15">Lehtisaari</a> bridge in silent anticipation of the inevitable.<br /><br />In Helsinki, the change of seasons is an everyday affair. Starting <a href="http://www.timeanddate.com/worldclock/clockchange.html?n=101">tomorrow</a>, it's time to switch back the clocks and prepare for yet another winter.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-66702885750378543532011-09-06T13:19:00.000-07:002011-09-06T18:32:55.602-07:00How can the history of gravitational theory inform modern day neuroscience?<span style="font-style: italic;">We've all heard it said before. Neuroscience is the physics of the 21st century. The vast ocean of unknowns lies before us, we've just learned to build a vessel, we've just learned to navigate. Let's unfurl the sails, go forth and discover new lands!</span><span style="font-style: italic;"><br />In this essay, I'll attempt to simplify such portentous omens by first prying open physics and then neuroscience.</span><div><br /><p><br />The 20th century atomic physicist, Ernest Rutherford is famous for having said, "That which is not physics is stamp collecting". Let's indulge Rutherford for now, as we try to understand what he meant by physics. But first, let's start with a brief history of studying planetary motion.<br /><br /><span style="font-weight: bold;">Stamp collecting</span><br /><br />Tycho Brahe, the Danish astronomer is most famous in the popular imagination for having observed the first modern supernova. However, a lesser appreciated fact about Brahe is that he extensively and systematically documented the trajectories of planets (#1).<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://sp.life123.com/bm.pix/stamp-collecting.s600x600.jpg"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 417px; height: 288px;" src="http://sp.life123.com/bm.pix/stamp-collecting.s600x600.jpg" alt="" border="0" /></a><br />In just a generation, along came Brahe's assistant, Johannes Kepler. Kepler deduced from all of Brahe's accurate observations that the trajectory of planets could be explained by three simple laws or regularities. First, by carefully making calculations of the Martian orbit, he noticed that all (known) planetary orbits were in fact elliptical, as opposed to the conventional Copernican belief before him that they were circular. He further noticed that the Sun was centered at one of the foci of the ellipses. Second, he noticed that the line joining the planet and the sun swept out sectors of equal areas along the orbit. Since orbits were elliptical, this implied that planets moved with variable speed---again a radical departure from Copernicus! He published both these observations in 1609 [I'm suprised he didn't write two papers on these potent mythbusters]. Third, he noticed that the square of the orbital period was proportional to the cube of the major axis of the elliptical orbit. He only published these 10 years later in 1619 [I wonder how he got tenure]. These are now known as Kepler's laws of planetary motion (#2).<br /><br /><span style="font-weight: bold;">Would Rutherford call Kepler a physicist? Would you call Kepler a physicist?</span><br /><br />If we define a physicist narrowly as someone who engages in deductive reasoning based on observations of the natural world, then Kepler was not a physicist. However, if we recognize that a physicist must wear multiple hats along the journey from making observations (stamp collecting) to reasoning about them (physics a la Rutherford), then I would call him an exemplary physicist. Let's get more granluar about Kepler. What was he? Using modern terms, I would call him an applied statistician or more specifically, a curve fitter.<br /><br />Kepler basically looked at the orbital trajectories and said, "wait a minute! this doesn't look circular to me. Hmmm...". He then selected a functional form to represent the trajectories (the equation of an ellipse) and simply fit the parameters to the data, the parameters being the foci and the major/minor axis of the ellipse to the orbit. Next, he looked carefully at the non-uniform speeds of the planet during the course of its revolution around the sun and said to himself, "Hmmm, what needs to be equal in order that the speeds can be unequal?". Finally he graphed the orbital period against the major axis length and mumbled, "There's a pattern here but I don't quite get it. Could it be a power law!". And it was.<br /><br />In doing thus, Kelper had reduced the painstakingly detailed data recorded by Brahe into three simple regularities or laws. He made an epistemological innovation, i.e. he told us how to organize our observations neatly, in much the same way that Darwin organized species into the tree of life or Mendeleev organized the elements into a periodic table. Kepler's laws could now make accurate predictions about planetary motion.<br /><br />In the parlance of modern statistics, we could interpret Kepler's laws as a descriptive statistical generative model. It described the statistics of planetary motion by generating them from underlying regularities. However, for all its genius, Kepler's work was merely descriptive, i.e. it succinctly answered the <span style="font-style: italic;">what</span> questions but not the <span style="font-style: italic;">why</span> questions. Why were planetary orbits elliptical? Why did they move faster when they came closer to the sun? For these answers, we had to wait another 100 years.<br /><br /><span style="font-weight: bold;">Newton and the <span style="font-style: italic;">why</span> questions</span><br /><br />Newton first formalized the concept of a force acting between two bodies. He postulated and verified the laws of motion. In posulating the gravitational force, and observing that the force was inversely proportional to squared distance, the universal theory of gravitation took shape.<br /><br />Newton's theory was a causal explanation of the data observed by Brahe and the regularities captured by Kepler's laws: i.e. it could now answer the why questions. Just to take one example: as the planet comes closer to the sun, more force acts upon it, causing a greater acceleration increasing its speed!<br /><br />I hazard a guess that Rutherford would have included Newton into his elite definition of a physicist!<br /><br /><span style="font-weight: bold;">Marr's three levels modified</span><br /><br />From that prelude into the history of gravity, it is interesting to note that the answers to <span style="font-style: italic;">why</span> questions also lead to <span style="font-style: italic;">how</span> questions. How is gravitational force transmitted between two bodies without a medium? For nearly three centuries after Newton, a number of proposals were made for the mechanical explanation of gravity, all of which are known to be wrong today. The current explanation is attempted by quantum gravity, a theoretical framework that attempts to unify gravity with the other three fundamental forces, but as of today, we don't have a mechanistic explanation of gravity!<br /><br />The sequence of what-why-how questions brings us to David Marr, a 20th century vision scientist and AI researcher, who postulated three necessary conditions for a computational theory of sensation or perception. Marr and his contemporaries conceived of vision as an information processing system. He said, to have a computational theory of a system, we need to understand:</p><ol><li>The computational level: what computation/ task does the system intend to perform?</li><li>The algorithmic level: how does it represent this computation/ task and what strategies does it adopt to achieve its goal?</li><li>The implementational level: what is the precise sequence of steps in the physical wet brain during the execution of the above algorithm?<br /></li></ol><p>Now, the universe is not an intentional system with a well defined goal, so Marr's postulates are more suited to building nature-inspired computational systems for solving specific tasks, rather than describing nature. Let's slightly modify (#3) Marr's levels to fit our what-why-how framework:<br /></p><ol><li>What happens in the visual areas of the brain? [This is the stamp collecting task of Brahe] </li><li>Can we build a simple statistical model that captures its regularities and predicts some of its dynamics? [This is the applied statistics / descriptive modeling task of Kepler]<br /></li><li>Why is it happening i.e. what is the brain trying to achieve through the observed dynamics? [This is the causal modeling task of Newton]<br /></li><li>How does it go about achieving its goal? [This is the mechanistic modeling task of quantum gravity]<br /></li></ol><span style="font-weight: bold;">Whither neuroscience?</span><br /><p>With parables from Brahe down to Quantum Gravity, along with perspective from Marr, is it possible to meaningfully contextualize the need for theory in neuroscience as a discipline?</p><p>Let's take the primary visual cortex and see whether we can analyze developments about its understanding using the above framework.<br /></p><p>The work of Brahe and (to a large extent) Kepler was done by the early greats (1960s onwards): David Hubel and Torston Wiesel. These guys measured from single neurons in the cat V1, recognized that there were cells selective to things like orientation, spatial frequency, ocular dominance, etc. [a Brahe task]. Next, along with Horace Barlow and other contemporaries, they explained natural images as constituted by oriented edges and gratings [a Kepler task]. Barlow and his contemporaries also attempted to give causal or normative explanations of what the visual cortex was doing. They proposed that the visual cortex was efficiently coding (in the Shannon information sense) the retinal image [a Newton task]. A little later, descriptive statistical generative models of natural images were proposed using Fourier and Gabor basis functions. The models were successful in describing the retinal image in terms of a few regularities [a Kepler task]. With the advent of artificial neural network models, it became possible to take the efficient coding hypothesis one step further and build mechanistic models of neural activity which efficiently represented the retinal image. It was possible to show mechanistically that efficient coding was realized by performing decorrelation in a distributed neural network to achieve this efficiency [a quantum gravity task]. With the advent of overcomplete basis functions: robustness, not just efficiency of visual information representation could also be normatively explained [a Newton task]. With further advances in natural image statistics by Olshausen and Field, it became clearer that besides efficient, decorrelated and robust coding of the retinal image, a key function of the visual cortex was to learn and update hypotheses (Bayesian posteriors) about the statistics of natural images [yet another Newton task]. How is Bayesian inference mechanically realized in a neural network? Again, artificial neural network models have been postulated for the same [yet another quantum gravity task].<br /></p><p>One positive example does not make a theory, you quite rightly say (#4)? Ok. As we look around in other areas of neuroscience, what do we see?<br /></p><p>I see that on a day to day basis we are all organized as cottage-industries and guilds, learning through apprenticeships, how to solve Brahe tasks, Kepler tasks, (and less frequently) Newton tasks, and quantum gravity tasks. Wider-scale databasing efforts [Brahe tasks] are also beginning to take place. Examples include Bert Sakmann's digital neuroanatomy project, the human connectome project (HCP), etc. Parallely, wider-scale big-data mining [Kepler tasks] is gaining ground. Examples include various connectomics projects, and contests to leverage big-data (such as the ADHD fMRI/ VBM/ DTI data analysis contest). Brahe and Kepler tasks certainly seem to be the mainstream activities of the day.<br /></p><p>What do you see around you?<br /><span style="font-weight: bold;"><span style="font-weight: bold;"></span></span></p><p><span style="font-weight: bold;">What would Feynman say to Rutherford? </span><br /></p><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://imgs.xkcd.com/comics/physicists.png"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 358px; height: 540px;" src="http://imgs.xkcd.com/comics/physicists.png" alt="" border="0" /></a><br />The above comic strip generated some <span style="text-decoration: underline;"></span><a href="http://forums.xkcd.com/viewtopic.php?f=7&t=64234&hilit=physicists">brilliant discussion</a> in the forum. A commentor succinctly summarized this to be the everlasting tension between Rutherford's famous quote and a pithy equivalent by Feynman, attributing the following quote to the latter:<br /><br /><blockquote>Physicists often have the habit of taking the simplest explanation of any phenomenon and calling it physics, leaving the more complicated examples to other fields.<br /></blockquote><br />Is neuroscience ready for Newtons, or do we still need more Brahes and Keplers for now?<br /><br />Here's another gem from the forum:<br /><br /><blockquote><span class="posthilit">Physicists</span> who do bad biology say, "It's so simple! Look, model it <span style="font-style: italic;">so.</span>" These do not understand the concept of 'unknown unknowns.' What if, for example, your insects normally behave predictably, but release an alarm pheromone when handled clumsily - for example, by a theoretical physicist?<br /><br /><span class="posthilit">Physicists</span> who do good biology say, "It's so messy! Is there any way we can control for as much of that messiness as possible? How do we pry apart this noise to get at the underlying rules?" They bring their disdain for vague claims to the field, and back up their claims with data. They aren't airy anti-biologists, but intense, experiment-driven pragmatists.</blockquote><br /><p><span style="font-weight: bold;">Notes</span><br /><br />(#1) Incidentally, Brahe was not the first to catalogue planetary motion. The Babylonians, the Greeks and the Chinese each built their own MySQL servers to document the movement of heavenly bodies across the sky, with the Chinese effort taking up the most servers by far.<br /><br />(#2) Interestingly, laws do not come to be known as laws as soon as they are proposed. Voltaire was the first to refer to Kepler's observations as laws in 1738, more than 100 years after they were first published!<br /></p><p>(#3) <a href="http://www.albany.edu/%7Eron/papers/marrlevl.html">Here</a>'s a very interesting modification of Marr's levels discussing the difficulty of studying of hierarchical with emergent properties.</p><p>(#4) In a Feynman sense, you just got physicisted!</p></div>Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com2tag:blogger.com,1999:blog-7596096639063476771.post-34089433349015056892011-07-31T03:47:00.000-07:002011-07-31T04:22:26.901-07:00Microeconomic complexity and developmentAt <a href="http://www.tedxchennai.com">TEDx Chennai 2010</a> I had the good fortune to meet Dr. Tara Thiagarajan, who heads <a href="http://www.maduramicrofinance.com">Madura Microfinance</a>. Tara blogs occasionally on issues peripheral to the business of microfinance. At <a href="http://www.physicsofpoverty.com">Physics of Poverty</a>, with her analytical background in neuroscience and complexity theory, she dissects questions about the meaning of socioeconomic development, and strives to bring those questions to the core rather than the periphery of the microfinance industry.<br /><br />Her latest post, titled <a href="http://physicsofpoverty.blogspot.com/2011/07/productivity-line.html#comments">Productivity Line</a>, attempts to reconceptualize the poverty line. She suggests that instead of dividing the world into segments based on their incomes, and then agreeing upon a reasonable income as the threshold, i.e. the poverty line, why not segment the world based on economic productivity?<br /><br />Her post provoked a few questions about the relationship between production and consumption both at the social and the individual level. I note these below.<br /><br />Firstly, I understand and acknowledge that taking a developmental design approach is more useful and socially sustainable than an approach that hand-holds the poorest of the poor just up to the threshold of the cycle of consumption.<br /><br />1. What is an ideal ratio of producers to consumers in a society so that the society is economically sustainable (let's define economic sustainability as the capacity to diversify, grow and self-renew).<br /><br />2. What is an ideal ratio of consumption to production in an individual's life? One could think of this ratio as an index of <a href="http://en.wikipedia.org/wiki/Marx%27s_theory_of_alienation#In_the_labour_process">Marxist alienation</a> and therefore a proxy to measure work-satisfaction or happiness.<br /><br />3. In general, how do these ratios vary as a function of population size and other demographics as well as economic complexity (let's define economic complexity as the complexity of division of labor and the diversity of goods and services produced and consumed)? For instance, in a subsistence farming society where the economic complexity is relatively low, one could imagine that the ratio of producers to consumers is one, but that is scarcely an indicator of progress. Similarly in an extremely large and diversified society the ratio of consumption to production at an individual level is extremely high, but that is not an indicator of well being necessarily.<br /><br />4. If one could measure these ratios from the demographic data of target communities receiving MFI, then one could go about defining bounds on these ratios and subsequently designing developmental interventions to optimize them.<br /><br />Further Reading:<br /><a href="http://blogs.cgdev.org/open_book/">David Roodman's Open Book Microfinance Blog</a><br /><a href="http://ineteconomics.org/grants">The Institute for New Economic Thinking</a><br /><a href="http://ideas.repec.org/p/ise/isegwp/wp492008.html">A recent article comparing metrics of economic complexity using input-output measures</a><br /><a href="http://www.hks.harvard.edu/var/ezp_site/storage/fckeditor/file/pdfs/centers-programs/centers/cid/publications/faculty/wp/186.pdf">The building blocks of economic complexity</a>: A white paper that applies <a href="http://en.wikipedia.org/wiki/Complex_network">complex network</a> metrics to quantify macroeconomic complexity.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-14185312306637762132011-05-26T03:51:00.000-07:002011-05-26T04:02:19.756-07:00Naturalistic is a fate worse than a fate worse than deathTwo years ago, I had written about <a href="http://deconstructingzaniness.blogspot.com/2009/07/on-neologisms.html">neologisms in science</a>. I am finally able to give a bad example of a neologism: "naturalistic". The term I am referring to has very little to do with the ideas of <a href="http://en.wikipedia.org/wiki/Naturalism_%28philosophy%29">naturalism</a> in philosophy of science, or the arts, but a lot more to do with stimuli used in studies of neuroimaging. "Naturalistic" is vaguely defined as: a laboratory stimulus that is an approximation of the stimuli encountered in the natural world. So a movie would be a naturalistic stimulus. It really is a niggling issue, but I have seen a certain hesitation in the scientific community to call these stimuli "natural stimuli", and a preference towards using "naturalistic stimuli".<br /><br />"Natural" itself can be defined as similar to or pertaining to nature. So, are we to understand that "naturalistic" is then "similar to or pertaining to something that is similar to or pertaining to nature"?<br /><br /><a href="http://www.youtube.com/watch?v=XLlpFyk46es">A fate verse zan deth</a>, I say.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-73328160033911593862011-04-12T15:11:00.000-07:002011-04-12T15:14:26.118-07:00Computational neuroscience vs NeuroinformaticsBelow are some hastily sketched thoughts, by no means complete, on the distinction between computational neuroscience and neuroinformatics.<br /><br /><span style="font-weight:bold;">Computational Neuroscience</span>: The field posits computational candidates for mechanisms by which the brain carries out a certain function. When we say computational candidates, we loosely talk about algorithms. I think algorithms have two or more theoretical aspects. I'll try to articulate those below.<br /><br />First, the goal of the function performed by the brain must be articulated by a cost function. For example, if the goal is reaching out for an object and grasping it, then the cost function could minimize muscular effort, minimize the #neurons needed to encode the task, or minimize the error rate of the task assuming that it is performed several times. Sometimes, the cost function need not describe a very specific task such as grasping, but could describe a general organizing principle of the brain - such as minimize energy consumption, minimize the use of connective tissue, etc.<br /><br />Second, the process by which the cost function is optimized must be articulated, keeping in mind that such a process must be feasible in the wet brain. The wet brain provides structural and functional bounds on what a candidate algorithm can and cannot do.<br /><br />With these basic ingredients, the flavours then vary because the choice of level of description can be vastly different. Someone can talk about how ion channel ratios on the cell membrane are optimal for grasping, whereas someone else can talk about why the number of cortical areas devoted to grasping the brain is optimal. Both these optimalities could be treated computationally by using selective pressures during evolution, or selective pressures during brain<br />development as explanatory variables. To complicate matters further, optimality in the brain can be posited at the level of evolution, brain development, learning (plasticity), and adaptation.<br /><br /><span style="font-weight:bold;">Neuroinformatics</span>: The field is concerned with issues of data analysis and visualization of neuroimaging data for human interpretation purposes. The algorithms applied here (such as ICA/CCA/ridge regression etc.) need not conform to any constraints posited by the wet brain. The field does not aspire to explain how the brain performs a certain function - it just aids the process of evidence accumulation, which is of course important for theoretical and CNS because otherwise we wouldn't have phenomena to explain and our theories cannot be validated. In this sense neuroinformatics is a tool for experimental neuroscience.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com1tag:blogger.com,1999:blog-7596096639063476771.post-36974585045139831562011-03-15T01:58:00.000-07:002011-03-15T02:53:39.518-07:00Deb Roy on wordling junior's lifeStumbled upon a fascinating longitudinal data-intensive, visualization-intensive series of ongoing work at <a href="http://web.media.mit.edu/%7Edkroy/">Deb Roy's group</a> at the MIT Media Lab which prompted me to share some quick thoughts. Watch it here:<br /><br /><iframe title="YouTube video player" width="400" height="280" src="http://www.youtube.com/embed/VwgkT34g61w" frameborder="0" allowfullscreen></iframe><br /><br /><span style="font-weight: bold;"></span>The talk is brilliantly structured: starting with an emotional moment, walking through some stunning data visualizations, transitioning into a pitch for bluefinlabs (his startup) with more chutzpah, and ending with the personal yet transcendental.<br /><span style="font-weight: bold;"><span style="font-weight: bold;"></span><br /></span>Scientifically, the work itself, IMHO is meant to be treated as a glimpse into the kinds of hypothesis that can be tested, rather than a definitive statement on language acquisition patterns in children.<span style="font-weight: bold;"> </span>Further, I've only watched the TED talk and 18 minutes is not enough time to point out caveats, that too obvious ones. I imagine that among the various controls, they would have in fact segmented and separately treated utterances of 'water' by adult to adult vs. by adult to child, since implicit and explicit learning presumably have different mechanisms. But I'll refrain from speculating further without digging deeper <a href="http://web.media.mit.edu/%7Edkroy/publications/index.html">here</a>.<br /><br />Technically, managing parallel feeds of audiovisual data does not seem straightforward in the least. Further, segmenting humans from cluttered fisheye scenes or target words from natural speech, and 100 TB of it, despite 50 years of AI research, is still a pretty big deal. Besides, it's the first graph on a TED talk with error bars! Respect!<br /><br />Commercially, social media is one big ticket application, but couldn't the same infrastructure be applied to support decisions in interviews or boardrooms, or evaluations in high end schools or creches? What else?<br /><br />But what captured my fascination the most was the power of big data to accelerate discovery at an unprecedented rate.<br /><br /><span style="font-weight: bold;">On large datasets and fishing expeditions</span><br /><br />Scientists are just beginning to appreciate the power of trawling the world for extremely large datasets and subsequently testing various hypotheses on small subsets of the data. This approach (sometimes derogatorily called a fishing expedition) is in stark contrast to classical scientific method where an apriori hypothesis dictates an experiment design and an analysis procedure. The LHC experiment is one such expedition to fish for postulated elementary particles.<br /><br />To illustrate the power of the fishing expedition approach, imagine if Deb had decided apriori that he wanted to study word utterance length over time. In a conventional longitudinal experiment he might have chosen a subset of words used in natural conversation, asked several child and caregiver pairs to come into a studio for 1h/day and recorded their speech. He might then have analyzed the data, observed this U shaped phenomenon, and reported it in a journal about language acquisition, where it would have promptly gathered dust. Even potentially interested colleagues might think several times before replicating the study with a different set of words, or correlating the word utterance length with spatial context, since acquiring funding and approvals for a longitudinal study would be prohibitive. Instead, with Deb's fishing expedition dataset which might become publicly available someday, any armchair scientist with computational resources can ask their own creative follow up questions of the data with minimal entry barrier!<br /><br />However, fishing expeditions have their downsides. First and most obvious perhaps is the risk involved: what if there are no fish to be found? In other words, what if a generic experiment design is not powerful enough to eliminate alternative hypotheses until the ones being tested are left standing? Second, what if something is found but it is hard to tell with any confidence whether that something is in fact, a fish? Put differently, does the subset of data relevant to a particular hypothesis being tested (such as a correlation between two variables) have enough statistical power to falsify its corresponding null hypothesis? Last (and perhaps the hardest to spot), fishing expeditions may encourage scientists to operate in a complete vacuum of hypotheses (as opposed to designing for a multiplicity of hypotheses).<br /><br />What are some other fishing expeditions and their successes and failures? How is the Human Genome Project different from the LHC experiment?Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-50751837332048371932010-10-27T06:02:00.000-07:002010-10-27T06:12:53.736-07:00Quality poverty in Indian higher educationCame across an interesting essay by Ashok Jhunjhunwala, championing quality in Indian higher education.<br /><br />Here is his paper:<br /><a href="http://rtbi-iitm.in/Ashok/education_link.html" target="_blank">http://rtbi-iitm.in/Ashok/<wbr>education_link.html</a><br /><br />He argues that quality is lacking in higher education primarily because of underpaid teaching staff, thus making the vocation unattractive for the best and brightest. He claims that teachers can only be better paid (salaries tripled) through increasing fees since government budget for higher education cannot be doubled overnight. Then, he does a lot of analysis for building the case of increasing fees while keeping access open, through financial instruments and strong regulation to prevent profiteering institutions.<br /><br />An interesting aspect, that he touches upon but does not elaborate, is the fundamental conflict of interest between primary/secondary education and higher education! Improving the quality of primary eduation will increase the demand for higher education, because lower drop-out rate and better exposure will mean that more teenagers are college ready. This would triple the current levels of 3 million new college entrants and put a strain on supply or quality of higher education.<br /><br />I agree with him about how underpaid university lecturers are, and how difficult it is for academics in the west to even consider a return to Indian institutions. But it seems to me that he misses out on three potential pieces to the puzzle, that can shift the burden from the end user (i.e. fee paying students) to some other intermediary parties.<br /><br />First, enabling third parties to enter the training and educational content domain can decrease the teacher:student ratio (e.g. 1:20 --> 1:40), enabling more students to pay for fewer teachers' wages.<br /><br />Second, allowing lecturers to supplement their income through consulting gigs made easier through stronger industry-university relations can decrease the strain on the institutional wage bill. It will also offer short-term rather than long-term return for indian industries, making more companies willing to participate. Lecturers can also be given sufficient freedoms to be intrapreneurs in this regard, by identifying and creating partnerships in their field of expertise.<br /><br />Third, western universities that depend to a large extent on their supply of graduate students from India, might be incentivized to fund entry-level university education in India. In this context too, university lecturers can be paid to create formal programs of student/researcher exchange, creating an alternate income stream.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-66770015131030691252010-05-24T10:04:00.000-07:002010-05-24T10:07:15.161-07:00Reading wishlist<!-- BookBox widget BEGIN--><br /><script type="text/javascript" src="http://www.sharebookbox.com/widget2.php?id=1110"></script><a href="http://www.sharebookbox.com/index.php?id=1110"><img src="http://www.sharebookbox.com/images/bookbox2.png" style="border:0" width="139" height="18" alt="BookBox: embed book widget, share book list" /></a><br /><!-- BookBox widget END-->Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-67764045969955387382010-05-24T03:16:00.000-07:002010-05-31T14:12:55.458-07:00Chaturashrama as a metaphor for personal and professional management<a href="http://www.hindupedia.com/en/Varna_Ashrama_Dharma#Ashramas">Chaturashrama</a>, an ancient Hindu subtext (part of the <a href="http://en.wikipedia.org/wiki/Manusmriti">Manusmriti</a>) describes the four ideal stages of a human's (man's) life. Indeed, Chaturashrama has received a lot of <a href="http://en.wikipedia.org/wiki/Manusmriti#Views_and_criticism">flak</a> for being patriarchal, for being the source of much determinism in modern Indian society, and for being But this post is not about such existing debates.<br /><br />The four stages (or ashramas) are Brahmacharya (the stage of learning and preparation for life), Grihastha (the stage of taking responsibility and acquiring material, and emotional wealth, thus performing one's core evolutionary duty), Vanaprastha (the state of learning to let go of wordly comforts and spreading wisdom) and Sanyasa (the stage of isolated contemplation). Implicit in the Chaturashrama is that the path to each stage is through the previous. For instance, one cannot learn to let go in the right way unless one has been in complete control. Thus, these four stages represent four key functions of a person's journey through life: learning, taking control, letting go, and reflection.<br /><br />While the four stages are prescribed for different periods in life, the modern world is seldom so linear. I'll proceed to claim that each stage is constantly present in our lives, and further, that each stage individually can provide both positive and negative feedback on the other. I'll argue that mastering the balance between these constraints or tensions can result in unprecedented success (spiritual, emotional, and or financial).<br /><br />To be successful in the modern world, any entity (be it an individual direct the course of his/her personal life or a large organization) must continually cycle through these four functions every waking moment. To elaborate, one must continually<br /><ul><li>learn (update oneself about the state of the world)</li><li>take control (make decisions based on the knowledge gathered and take responsibility for the consequences)</li><li>trust and let go (be able to delegate responsibilities to those who step up and trust them to do it, as well as move on from unexpected failures)</li><li>reflect (create new knowledge through reevaluation and contextualization of own experience and state of the world).</li></ul>Seen thus, experiences from personal life have direct parallels in management. In fact, several management functions can be (and have been) organized according to these criteria. Given that one is always playing the balancing act between these functions, it is worthwhile asking when they are in conflict with each other, and when they reinforce each other.<br /><br /><span style="font-weight: bold;">The G-V Balance, or how to DO well. Lessons in executive excellence</span><br />Mastering the tension between taking control and letting go (Grihastha-Vanaprastha balance), is a trait that can be seen in the <a href="http://www.ted.com/talks/lang/eng/itay_talgam_lead_like_the_great_conductors.html">best leaders of the world</a>.<br /><br /><span style="font-weight: bold;">The B-S Balance, or how to THINK well. Lessons in strategic excellence</span><br />Likewise, closing the loop between learning and reflection (Brahmacharya-Sanyasa balance) can been seen in some of the world's best thinkers. Here learning refers to casting a wide net for ideas and knowledge and having the humility and curiosity to learn from anyone, while reflection refers to the courage to think on one's own reject good ideas at times, the vision to separate bad ideas from good ones, and the capacity to synthesize new knowledge.<br /><br />[Footnote: Couldn't resist, but excellent thinking is mostly about knowing your way around B-S!]<br /><br /><span style="font-weight: bold;">The D-T Balance, or how to THINK by DOING and DO by THINKING</span><br />While the G-V balance deals with the issue of how to be a good <span style="font-weight: bold;">doer</span> [in management world, an executive; in the scientific world, an experimentalist], the B-S balance deals with how to be a good <span style="font-weight: bold;">thinker </span>[in the management world, a strategist; in the scientific world, a theorist]. And doubtlessly, acquiring each balance is a lesson in acquiring the other. By extension, it is possible to imagine that one always pursue <span style="font-weight: bold;">excellence in thinking</span> through <span style="font-weight: bold;">excellence in doing</span> and vice versa, leading us to study a third balance: the thinking-doing balance.<br /><br />Mastering each of these balances is a book in itself and may be the subject of future posts!Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-61785625946346295092010-05-21T07:05:00.000-07:002010-05-31T14:25:53.443-07:00On crossing the chasm and reshaping the adoption curveMoore's bestseller, <a href="http://en.wikipedia.org/wiki/Crossing_the_Chasm">Crossing the chasm</a> talks about the diffusion of innovation through the <a href="http://en.wikipedia.org/wiki/File:Technology-Adoption-Lifecycle.png">technology adoption distribution</a> as though it is a static distribution of people ranging from early adopters to laggards. The book presents a framework to study the dynamics of adoption of a certain idea (or more often, commercial product) and helps us understand its spread from being niche meme to mass hysteria to slow fade out.<br /><br />Marketing-to-geek ideologies suggest that innovators, rather than making 'average products for average people' (to paraphrase the ideologies of giants such as UniLever and P&G from the mid-20th century) should target the early adopters and recruit their faith and passion to help cross the chasm.<br /><br />In reality however, the adoption distribution is not static. There is a constant traffic of people from one part of the distribution to another. Laggards sometimes open up, and tend to become mainstream adopters. In other situations, mainstream adopters can become early adopters. People evolve into some ideas, and devlove into others. This flow in turn may be steeply dependent on a few irreducible parameters. I wonder how much this kind of flow has been modeled or studied in behavioral economics, for instance.<br /><br />Given this assumption of a parametrically varying adoption distribution, it is possible to conceive of a new marketing strategy, which would come up with methods <span style="font-style: italic;">prepare</span> or <span style="font-style: italic;">pre-seed</span> the adoption distribution by tracking the right parameters which control people flow, so that we have inherently more early adopters than mainstream users or laggards. The chasm would not be one static point in the distribution somewhere between the early adopters and the early mainstream, but shuffle around depending on this people-flow across the distribution. We could call such a marketing strategy: <span style="font-style: italic;">Where is the Chasm now? </span><br /><br />It is my gut feeling that general purpose initiatives which aim to inspire people and make them take a proactive, curious, experimental stance to life such as <a href="http://www.ted.com">TED</a>, would play a very strong role in making the chasm move left, and would thus become a more and more integral aspect of marketing functions in insitutions worldwide.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com1tag:blogger.com,1999:blog-7596096639063476771.post-51831485746456955352010-04-30T08:21:00.000-07:002010-04-30T09:12:56.313-07:00The third thing about fameAmong the many assertions that have been made about fame are the following. Fame brings wealth, renown and a great social standing. Aspiring to be famous is for the selfish and power-hungry. Fame breeds arrogance, laziness and corruption. Etc. But are there only those two sides to fame?<br /><br />Perhaps a nuanced assertion that has been made less often is the following. Aspiring to fame is a deep willingness and open invitation to be judged by the world. It is a complete submission, and a handing over of the right to be criticized, praised and talked about, to everybody in the world, regardless of their qualification or emotional stake in passing judgment. Aspiring to a public life is thus an aspiration to live in complete and utter openness. I'll argue here that there is a <span style="font-style: italic;">right</span> way, a <span style="font-style: italic;">noble</span> way, to aspire to be renowned, that fame is not always <span style="font-style: italic;">base</span>. Let's call this fame 3.0 for simplicity.<br /><br />Fame 3.0 is very close conceptually to ideas from several places. For instance, it is very close to the the Bhagavad Gita's "actions > rewards" prescription, or the stress of <span style="font-style: italic;">process</span> over <span style="font-style: italic;">results</span> from the enterpreneurial school of thought.<br /><br />And it's probably fame 3.0 being confused for fame 1.0 or 2.0 that got Jesus crucified or Martin Luther King assassinated.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-29486892229310708872010-04-07T14:11:00.001-07:002010-04-07T14:28:22.969-07:00December season's reflections of a midsummer escapade<p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">What if Garcia-Marquez had been brought up a Tam Brahm? That is the subject of this experimental fiction piece.<br /></span></p><p class="MsoNormal" style="text-align: center;font-family:arial;"><span style="font-size:100%;">---------------------------x----------------------------</span></p><p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Gopal-Giridhar Madhusudhan looked out of the window, idly, about to roll over and go back to sleep, only to recall the promise he had made to himself this time: to get more out of the trip. It was his seventh visit back to Chennai in as many years. Each December, he had returned, if not from a faithfulness, then from a simple, acknowledged, fear of loneliness in the darkest weeks of the year. </span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Over Gopal’s first few visits, he had not wanted much, content to laze around in his parents’ home, get driven around, and generally fed the middle-class version of a dream vacation. In later years, he became a more conscientious vacation planner. Once, he accumulated culture-vulture oomph meticulously, attending every lec-dem session in the December sabhas, downing cups of filter coffee with <i style="">dhonnais</i> of steaming hot <i style="">kesari</i> in the mornings. Another time, he collected greenie points from wildlife trips. From a Valmik Thapar rant, through discussions with a friend about RFID collars for endangered species and the ethics of it, he had chalked out and executed a trail through Sariska. Yet another time, he sought free-spirit points by doing unplanned road trips through a randomly chosen region, performing informal case studies of microeconomic behavior. This year again, he had set himself such a goal. He would later realize that each vacation’s goal could succinctly be summarized thus: to get a sufficient dose of ‘wholesomeness’ out of the December visit to last him through the next sterile winter.</span></p> <p class="MsoNormal" style="font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: center;font-family:arial;" align="center"><span style="font-size:100%;">---------------------------x----------------------------</span></p> <p class="MsoNormal" style="font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><br /></span></p><p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Gopal sat down, pen in hand, fresh coffee by his side, lighting to his satisfaction. He wrote: </span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <span style=";font-family:arial;font-size:100%;" ><blockquote>Creativity is not a faucet.</blockquote></span> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">That same tired witticism he had picked up from a Calvin and Hobbes comic strip. Not very creative. This was not some e-mail to a junior. </span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Lately, Gopal had been exploring the effects of the environment and elaborately designed mood scenarios on writing quality, the null hypothesis being that no morbid or weak thoughts could be forthcoming from the nourished, fresh-coffee-equipped soul, on a satisfactorily-lit Chennai morning. He wrote again:</span></p><blockquote><p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">"I'll give you 30 seconds in heaven", she said. "What, literally?" he retorted, faking a nervous laugh, by now. "Yeah, my name is heaven". He was snubbed.<br /></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p></blockquote><p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">No, no that’s not right. That’s terrible. He was snubbed? Snubbed? Staccato. Faking a nervous laugh? More like trying too hard and not enough altogether at once. No flow. My name is heaven?! Stand-up comedy? He scratched it out and tried again.</span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <blockquote style="font-family:arial;"><span style="font-size:100%;">“I’ll give you 30 seconds in heaven”, she said. “What, literally?” he retorted, trying on a macho, assured laugh. Wrong move. The ‘Wh’ came out high pitched. He kicked himself internally, but it showed and she laughed. In future recountings of the incident to himself, he would always stress that her laughter was knowing and amused, a laughter of the eye, an ‘I get you, and that’s cool’ signal rather than an exposing, sarcastic laughter. “Yeah,” she replied with a blank stare, quickly checking her impulse to flash a smile, “my name is heaven”. Her future recountings of this moment were fond, and slightly self-congratulatory on account of her spontaneous naughtiness.</span></blockquote> <p class="MsoNormal" style="margin-left: 0.5in; text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Better already. The drama was unfolding neatly. But the punchline had moved too far away for a reader to make the connection. But at this point Gopal checked himself. Too much academic writing, reader simulations, paragraph conjunctions. Humbug. More importantly, this was far from morbid. He seemed to be deviating from the task at hand. Was the null hypothesis undeniable? He tried again. Directness with two esses.<br /></span></p><p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><blockquote>He had fucked a whore, bought himself a ticket to intimacy, barely conscious of the possibility of future remorse. He would later learn to describe this moment as a signing away of his 'claim to have always strived for the greatest good'.</blockquote></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;"><o:p> </o:p></span></p> <p class="MsoNormal" style="text-align: justify;font-family:arial;"><span style="font-size:100%;">Big deal. That came out just preachy, not morbid.<br /></span></p><span style="font-size:100%;">The aesthete in him made him cringe. The coffee had lost its steamy nip and the sun had risen too high. Imperceptibly at first, but unmistakably, he felt crippled. This was his third day in a row attempting to sketch the same scene. It was going to be yet another sultry day of inaction.</span>Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com3tag:blogger.com,1999:blog-7596096639063476771.post-65536104209356966492010-03-16T15:36:00.000-07:002010-03-16T15:37:22.536-07:00More booksStuff I have been snacking on.<br /><br /><!-- BookBox widget BEGIN--><br /><script type="text/javascript" src="http://www.sharebookbox.com/widget2.php?id=986"></script><a href="http://www.sharebookbox.com/index.php?id=986"><img src="http://www.sharebookbox.com/images/bookbox2.png" style="border:0" width="139" height="18" alt="BookBox: embed book widget, share book list" /></a><br /><!-- BookBox widget END-->Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-86078580301489281322009-10-25T00:51:00.000-07:002009-11-01T04:58:15.886-08:00Sustainable swimming beaches in ChennaiChennai has a large coastline. However, there are hardly any clean and safe swimming beaches. This is largely due to fishing settlements in many inner city beaches. The fishermen do not have access to clean toilets. So, they use the sea as a toilet. This is especially common at dawn, when one would ideally like to go for a swim before it gets too hot.<br /><br />Another problem caused by the fishing settlements is the inability to build coastal roads through these settlements, leading to congestion in narrow lanes forced to become arterial roads (e.g. Anna Street connecting Kalakshetra colony and Marundeeshwarar temple).<br /><br />However, the fishing settlement can be empowered with a tremendous resource right at their doorstep. Waves. Small scale offshore wave energy turbines can be installed in each such settlement. A fraction of the energy generated can be used to power low cost housing for these settlements. The rest can be traded in the energy market. The proceeds can go towards funding low cost housing, and a sanitation system, followed by beach beautification.<br /><br />So that the fishermen can remain economically independent, we need an NGO to fund the setting up of wave turbines, which the settlement can own or part-own with an energy company.<br /><br />A derivative product can be structured around the risks (the energy company giving the knowhow and equipment for wave turbines needs high waves, the fishermen need low waves).<br /><br />If this can be piloted in a handful of beach-kuppams in Chennai, over time the beach can become clean. Beautification projects can be started, and people can feel safe to go for a swim without fear of diarrhoea.<br /><br />Obviously my suggestion is very lazy and naive. It does not take into account the cost of setting up wave turbines, their energy output efficiency, the ability to integrate the generated energy into the local grid and how the energy market works. Oracles, please help me work out the details in the comments section.<br /><br />For more info:<br />http://indiaenvironmentportal.org.in/content/ocean-wave-power-generation-concept-trial-orissa-and-other-coastal-states<br />http://www.thehindu.com/2009/06/05/stories/2009060558970400.htm<br />http://en.wikipedia.org/wiki/Chennai_Elevated_ExpresswaysPavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-22183617562562255982009-10-21T21:41:00.000-07:002009-10-21T21:45:42.001-07:00New acquisitionsSome new acquisitions from <a href="http://www.landmarkonthenet.com/index.aspx">Landmark</a> over Diwali:<br /><br /><script type='text/javascript' src='http://www.lkozma.net/bookbox/widget.php?id=549'> </script>Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-63291486826625667332009-09-29T09:56:00.000-07:002009-09-29T10:04:57.598-07:00Instantaneous and lagged seasonsHelsinki is certainly a four-season <a href="http://helsinkippusa.wordpress.com/">city</a>. I have often been asked which is the best season to visit. To this question, I often give monosyllabic answers after considering and discarding some very long and unsatisfactory answers.<br /><br />It struck me that of the four, perhaps the season that is experienced with least <span style="font-style: italic;">immediacy</span> is spring. Whereas summer, fall and winter can be experienced with great immediacy, the experience of spring critically depends on the winter that is ending (the input or the moving-average component) and its experience (the state or the auto-regressive component).<br /><br />So, I would call spring a causal, auto-regressive moving-average season, a lagged season and rank it as the least interesting when experienced instantaneously.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0tag:blogger.com,1999:blog-7596096639063476771.post-17961883930623151342009-07-16T08:21:00.000-07:002009-07-16T08:33:55.302-07:00On neologismsWhile coi<span style="font-size:100%;">ning a neologism, especially in science, but also generally, here is a checklist that one could adhere to</span>:<br /><br />1. It should sound less jargon-like than the jargons it is composed of: "Jargon added is jargon halved" effect.<br /><br />2. It should be fresh, but not just frivolous and as far as possible, intuituve.<br /><br />3. Once defined, it should have a greater sense of immediacy, and home-in on the concept faster than the definition itself. In that sense it should be focused. However, it should be more than focused in the following way. The definition should remain fresh, such that on re-reading the definition, and definitions of terms used in the definition (recursively), it should evoke a richer, diverse cloud of related ideas and thus contextually <span style="font-style: italic;">situate</span> the neologism.<br /><br />4. It should have a quality of being used by the 'in-crowd', in a manner that the anxious 'out-crowd' wants to understand what it means and start using it in sentences.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com1tag:blogger.com,1999:blog-7596096639063476771.post-90108676217312172882009-07-08T04:29:00.000-07:002009-07-08T05:00:44.095-07:00Building on the brainI came across this piece in the latest issue of Neuron.<br /><br />John P Eberhard. 2009. Applying Neuroscience to Architecture. Neuron 62:753-756.<br /><br />Basically, it is a promo piece for the author's latest book <a href="http://www.amazon.com/Brain-Landscape-Coexistence-Neuroscience-Architecture/dp/0195331729">Brain Landscape</a>, which advocates architects to apply findings of brain imaging to their design of schools, hospitals, public spaces, old age homes and memorials. Eberhard is the founding President of the non-profit Academy of Neuroscience for Architecture, established in 2003. You get the picture.<br /><br />Why have ideas such as these and other low-hanging fruit (neuroeconomics, neurocinematics) become so popular these days, <span style="font-weight: bold;">without anybody bothering to address</span> how neuroscientific knowledge (such as: the prefrontal cortex is involved in decision making) is not <span style="font-weight: bold;">completely superfluous</span> to knowledge from conventional psychology and the behavioral sciences (such as: natural light improves class grades) <span style="font-weight: bold;">as far as application domains</span> (such as architecture) are concerned? Note that I do not dispute the fact that such neuro-marriages may be intellectually stimulating.<br /><br />The saving grace is that it wasn't called neuroarchitecture (not to be confused with neuroarchitectonics: the beautiful and painstaking characterization of brain anatomy in terms of cell types, synapse densities, tissue properties, relative thickness of cortical layers, vasculature etc. etc. which early 20th century greats like Cajal and Brodmann pioneered).<br /><br />I'm not arguing for traditionalism, I'm not arguing for scientists to be conservative with their imagination. On that contrary, I am disappointed that out-of-the-box thinking falls so dreadfully short of the mark. Why can't we be more original? It is not as though fresh insight and imagination cannot be applied to traditional stuff of the brain such as anatomy, hemodynamics, connectivity, learning, memory etc.<br /><br />What next? Neuromusicology, neuromarketing, neuropublishing, neurojournalism, neurolaw, neuro-neuroscience? Up for grabs. Quick, before somebody else.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com10tag:blogger.com,1999:blog-7596096639063476771.post-5605747169998497012009-05-03T15:27:00.000-07:002009-05-03T16:20:25.293-07:00Soul aether poetryIn earnestly overdesigned, Randian, dystopic cities, ego depletes and the soul bleeds aether, one Merchant-of-Venetian fleshpound at a time. A giant gascloud of fecundity rarefies, almost imperceptibly, and the very <span style="font-style: italic;">creatability</span> of comparative-comparative-history, that great recursive weapon of ideological warfare, set to take root in c. 3500 CE, stands threatened.Pavanhttp://www.blogger.com/profile/12191539364416007901noreply@blogger.com0