Category: Science
A revisionist perspective on ADHD
This article is not perfect, but it is much better than most MSM coverage of its topic. Here is one good paragraph:
That said, some adults with ADHD are highly intelligent, energetic, charismatic and creative, and are able to focus intently on a narrow range of topics that interest them. David Neeleman, the founder of JetBlue Airways, and Paul Orfalea, founder of Kinko's, have spoken out about how the disorder helped them come up with innovative ideas for their corporations, despite their having done poorly in school.
I have tried to track this point through the research literature, but it still seems to me that the way in which ADHD brings a high variance of attention — rather than just jumpy, scatterbrained behavior — is poorly understood. There is, by the way, some preliminary evidence that ADHD is overrepresented in entrepreneurs.
The iPad
Could this be the medium through which the fabled convergence finally occurs?
Most of all, think of it as a substitute for your TV.
It has the all-important quality of allowing you to bend your head and body as you wish (more or less), as you use it. By bringing it closer or further, you control the "real size" of the iPad, so don't fixate on whether it appears "too big" or "too small."
The pages turn faster than those of Kindle. The other functions are also extremely quick and the battery feels eternal.
So far my main complaint is how it uses "auto-correct" to turn "gmu" into "gum."
While I will bring it on some trips, most of all it feels too valuable to take very far from the house.
On YouTube I watched Chet Atkins, Sonny Rollins, and Angela Hewitt.
Note all the categories on this short post!
Attracted to Evil?
In transcranial magnetic stimulation (“TMS”), a coil of wire is placed near the head. Alternating current flowing through the coil induces a magnetic field with a strength of up to 2.5 teslas (one tesla is 20,000 times the strength of the earth’s magnetic field). The field passes harmlessly through the skull and influences the electrical
signals passing among neurons in the brain.
(Image and quote from Progress Daily.)
TMS has been used to stimulate or suppress different centers of the brain including those involved with attention, language and memory. A new paper in PNAS used TMS to disrupt part of the brain involved in judging intention and morality. Here is a summary:
Magnets can alter a person's sense of morality, according to a new report in the Proceedings of the National Academy of Sciences.
Using a powerful magnetic field, scientists from MIT, Harvard University and Beth Israel Deaconess Medical Center are able to scramble the moral center of the brain, making it more difficult for people to separate innocent intentions from harmful outcomes….
Magnetic fields made people judge outcomes more than intentions.
The effect was small and temporary but no less disturbing especially if the effect could be made to operate at a distance. Perhaps the tin-foil-hat-people have had it right all along.
Headlines to ponder
NASA to investigate cause of Toyota problems
The story is here. For the pointer I thank Steve Silberman.
The Slartibartfast Principle
From Wired:
Canadian poet Christian Bök wants his work to live on after he’s gone. Like, billions of years after. He’s going to encode it directly into the DNA of the hardy bacteria Deinococcus radiodurans. If it works, his poem could outlast the human race.
If it is conceivable, just 57 years after the identification of DNA's structure, for a Canadian poet to imprint his poetry into the DNA of a living organism then isn't it probable that an intelligent designer in the past would have had similar desires and perforce much greater abilities to accomplish the task?
Thus the evidence for intelligent design ought to be readily available in the graffiti of DNA. "Slartibartfast was here," or perhaps "3.14159265," or given what we know of economics, "All rights reserved, MegaCorp. Call for a free estimate."
The fact that we have not found such evidence reduces my belief in intelligent design, although I am not against more investigation. Indeed, one of the few arguments for god that I have ever given much credence to was the putative discovery of codes predicting future events in the Bible. A serious paper on this topic was published in Statistical Science in 1994. The paper was later convincingly rebutted but I still think it was the best evidence ever presented for an intelligent designer.
Addendum One: Interestingly one of the few people who thought as I did, although coming from a quite different direction, was Nobel prize winner Robert Aumann who early on supported the Bible codes research. However, after further research, supervised by Aumann, concluded that the paper could not be replicated Aumann returned to his prior view that the codes were improbable. It's unclear what, if anything, would further shift his prior.
Addendum Two: Steven Landsburg was here yesterday and at lunch suggested that perhaps the great designer's name was in fact 3.14159265…
Gender risk-aversion, using data from chess
Dan Houser sends me a link to this paper, by Christer Gerdes and Patrik Gränsmark:
This paper aims to measure differences in risk behavior among expert chess players. The study employs a panel data set on international chess with 1.4 million games recorded over a period of 11 years. The structure of the data set allows us to use individual fixed-effect estimations to control for aspects such as innate ability as well as other characteristics of the players. Most notably, the data contains an objective measure of individual playing strength, the so-called Elo rating. In line with previous research, we find that women are more risk-averse than men. A novel finding is that males choose more aggressive strategies when playing against female opponents even though such strategies reduce their winning probability.
I am pleased to see that studying chess data is suddenly a "trendy" way to do behavioral economics. Admittedly one is dealing with an unusual group of subjects. Yet the quality of the data is high and the stakes are usually high too. Computers can be used to judge the quality of moves.
The Meaning of Statistical Significance
Science News has a good piece by Tom Siegfried on statistical significance and what it means. Siegfried covers a lot of ground including Ioannidis' argument, Why Most Published Research Findings are False, Oomph versus statistical significance, and the meaning of the p-value. On the latter point, Siegfried writes:
Correctly phrased, experimental data yielding a P value of .05 means that there is only a 5 percent chance of obtaining the observed (or more extreme) result if no real effect exists (that is, if the no-difference hypothesis is correct).
He then explains why a 5% level of significance doesn't mean that there is a 95% chance that the result could not have happened by chance.
All of this is correct but there is another more common error that Siegfried does not address. Suppose that a researcher runs a regression and gets a coefficient on some variable of interest of 5.2 and a p value of .001. In explaining his or her results the researcher says "a effect of this size would happen by chance alone only 0.1% of the time." Now that sounds very impressive but it is also misleading.
In economics and most of the social sciences what a p-value of .001 really means is that assuming everything else in the model is correctly specified the probability that such a result could have happened by chance is only 0.1%. It is easy to find a result that is statistically significant at the .001 level in one regression but not at all statistical significant in another regression with small changes such as the inclusion of an additional variable. Indeed, not only can statistical significance disappear, the variable can change size and even sign!
A highly statistically significant result does not tell you that a result is robust. It is not even the case that more statistically significant results are more likely to be robust.
Now go back to Siegfried's explanation for the p-value. Notice that he writes "Correctly phrased, experimental data yielding a P value of .05…" Almost everything of importance is buried in those words "experimental data." In the social sciences we rarely have experimental data. Indeed, even "experimental data" is not quite right – truly randomized data might be a better term because even so-called experimental data can involve attrition bias or other problems that make it less than truly random.
Thus, the problems with the p-value is not so much that people misinterpret it but rather that the conditions for the p-value to mean what people think it means are really quite restrictive and difficult to achieve.
Addendum: Andew Gelman has a roundup of other comments on Siegfried's piece.
I worry about this
The Russians are not alone in pushing the idea that the next generation of nuclear reactors should have more in common with the small power plants on submarines than the sprawling installations of today.
And this in particular:
The promise of miniature reactors powering homes, offices and schools is still years from being realized. The first Russian design, a pontoon-mounted reactor intended to be floated into harbors in energy-hungry developing countries, is already being built. But most promoters expect small reactors to come online at the end of this decade.
And this:
Some models are tiny. One, for example, would be small enough to fit into a shipping container and would be trucked from site to site, like a diesel generator, except that it would need to be refueled only once every seven years or so.
The opening cost for these "mini-reactors" is expected to run about $100 million. The full story is here.
Solar Furnace
Hat tip: Boing Boing. And here is an interesting interview with Bill Gross of eSolar who argues that information technology and modularity can be used to scale solar furnaces (by using cheaper mirrors combined with IT to focus the mirrors) in a way that panels cannot.
Good sentences
"We originally wrote this article in Word, but then we converted it to Latex to make it look more like science."
The link is here. It is the best analysis of zombification I have seen to date. For the pointer I thank John Chilton.
The strangest sentence John de Palma read yesterday
"(…)Tourists at the Koorana Saltwater Crocodile Farm in Coowonga, Queensland, Australia, including 62 males and 41 females, aged 18–66 (M = 34.2, SD = 13.3), were randomly assigned to play a laptop-simulated Electronic Gaming Machine (EGM) either: (1) prior to entry, or (2) after having held a 1-m saltwater-crocodile(…)"
The link and explanation, if you could call it that, is here.
The role of the blogosphere
New research supports the notion that we fixate on enemies, and inflate their power, as a defense mechanism against generalized anxiety.
The longer article is here. This is another way of putting the point:
According to one school of thought, this tendency to exaggerate the strength of our adversaries serves a specific psychological function. It is less scary to place all our fears on a single, strong enemy than to accept the fact our well-being is largely based on factors beyond our control. An enemy, after all, can be defined, analyzed and perhaps even defeated.
What the brain values vs. what you wish to buy
I have not read this paper (gated full copy here), and I usually get nervous when it comes to brain scan interpretations, not to mention press release interpretations, but even if this has been botched it is still worth thinking about. A new paper suggests the following:
Researchers at Duke University Medical Center found that as participants were watching a sequence of faces, their brains were simultaneously evaluating those faces in two distinct ways: for the quality of the viewing experience and for what they would trade to see the face again.
As the authors put it, experienced value and decision value are not the same. The main test involves heterosexual men looking at the faces of women and thus one concrete implication, or so it seems to me, is that the pornography men enjoy the most is not necessarily what they are willing to pay the most for. The authors also note:
…that decision value signals are evident even in the absence of an overt choice task. We conclude that decisions are made by comparing neural representations of the value of different goods encoded in posterior VMPFC in a common, relative currency.
Hat tip goes to MoneyScience on Twitter.
Questions that are rarely asked
On my electric stove, there are two big coils and two little coils. The big coils, not surprisingly, heat up food much better. Why can't I have four big coils? There seems to be room for them. Is that asking too much? Do the little coils have some special use I am not aware of?