Over at the Times site, Errol Morris has just posted the last installment of a five-part series about the role his late brother Noel played in the invention of e-mail. In addition to being a fascinating and valuable oral history of the time-sharing era of computing, it’s a moving memoir and a meditation on life’s refusal to be calculable:

Part 1

Part 2

Part 3

Part 4

Part 5

A new study provides evidence that heavy internet use by the young results in “brain structural alterations” of a kind associated with “impairment of cognitive control.” The study, published this month in PLoS ONE, was conducted in China, where approximately 14 percent of urban youths – some 24 million kids – are believed to suffer from so-called “internet addiction disorder.” Using brain scans, the researchers compared the brains of 18 adolescents who spend around eight to twelve hours a day online (playing games, mainly) with the brains of 18 adolescents who spend less than 2 hours a day online. The heavy Net users exhibited gray-matter “atrophy” as well as other “abnormalities,” and the changes appeared to grow more severe the longer the kids engaged in intensive Net use.

The whole subject of Internet addiction remains controversial among experts, but, according to a Scientific American article on the new research, the study “cuts through much of the debate and hints that excessive time online can physically rewire a brain.” The Scientific American piece translates the key findings into layman’s terms:

One set of [MRI] images focused on gray matter at the brain’s wrinkled surface, or cortex, where processing of speech, memory, motor control, emotion, sensory and other information occurs … The researchers discovered several small regions in online addicts’ brains shrunk, in some cases as much as 10 to 20 percent. The affected regions included the dorsolateral prefrontal cortex, rostral anterior cingulate cortex, supplementary motor area and parts of the cerebellum.

What’s more, the longer the addiction’s duration, the more pronounced the tissue reduction. The study’s authors suggest this shrinkage could lead to negative effects, such as reduced inhibition of inappropriate behavior and diminished goal orientation …

As another crucial part of the new study on Internet addiction, the research team zeroed in on tissue deep in the brain called white matter, which links together its various regions. The scans showed increased white matter density in the right parahippocampal gyrus, a spot also tied to memory formation and retrieval. In another spot called the left posterior limb of the internal capsule, which is linked to cognitive and executive functions, white matter density dropped relative to the rest of the brain. [The researchers suggest that the white matter changes] may make it harder for Internet addicts to temporarily store and retrieve information … [and] could impair decision-making abilities—including those to trump the desire to stay online and return to the real world.

University College London neuroscientist Karl Friston tells Scientific American that while the shrinkage in gray matter is “quite extreme,” it’s “not surprising” when you take into account the plasticity of the adolescent brain: “Our brains grow wildly until our early teens, then we start pruning and toning areas to work more efficiently. So these areas may just be relevant to being a good online gamer, and were optimized for that.” But the study was a rigorous one, and the fact “that the results show anything significant at all is very telling,” Friston says. Further research will be required to confirm the study’s findings and to shed further light on behavioral and cognitive consequences of the changes.

It was shaping up to be a dreary Thursday until I stumbled upon this headline over at The Official Google Blog: “There’s a perfect ad for everyone.” I felt as if some benevolent god had hurled a spear of sunlight through the clouds and hit the bullseye of my heart dead-on. For close to a half century now, I have been searching for my perfect ad, and I have to confess that I had begun to despair that the object of my desire, the ad that would be the apple of my eye, simply didn’t exist in this world. A couple of nights ago, after perhaps one too many glasses of wine, I found myself tearfully saying to myself: I will never find my perfect ad.

I should not have underestimated Google and its kindhearted ad-serving algorithms. Now I know that somewhere deep in the Googleplex a flock of code-writing cupids is hard at work fashioning a promotional message that will dovetail perfectly with each and every one of my rational and emotional purchasing triggers. I need only be patient. My ad will come.

You can describe people in words, or you can describe them in numbers. Either system can be abused, but in general words tend to create bonds while numbers tend to create distance. (There’s a reason why parents give their babies names rather than numbers.) History, though, seems to tilt toward numbers, and the tilt is getting steeper as the potential profits get larger. Even the data miners are starting to get creeped out. In a thoughtful article over at O’Reilly Radar, Jim Stogdill, an IT consultant with expertise in large-scale data-management systems, poses a question to his colleagues:

Let me just ask this: If you are involved in data capture, analytics, or customer marketing in your company, would you be embarrassed to admit to your neighbor what about them you capture, store and analyze? Would you be willing to send them a zip file with all of it to let them see it? If the answer is “no,” why not? If I might hazard a guess at the answer, it would be because real relationships aren’t built on asymmetry, and you know that. But rather than eliminate that awkward source of asymmetry, you hide it …

I think what’s interesting is that you can’t help but get caught up in the moment. “If we could just join this stuff with that stuff, and then get this additional attribute, we could build a really sweet model. I’m sure that would get you some prospecting lift.” And then we all look at each other for a moment and go “wow, and that would be kinda creepy, too.” …

Ft. Meade in Maryland is that state’s single biggest consumer of electricity, and no small amount of it is being consumed by Hadoop (or similar) [data-mining computer] clusters that, as it turns out, are probably surveilling you. That is a troublesome thought, but only about half as troublesome to me as the even more thorough, broad, and pervasive corporate surveillance we are unleashing on ourselves. The only thing that keeps me sleeping is that the competitive dimension will slow the rate that these pools of data coalesce.

The time has come, says Stogdill, to think seriously about the ethics of what the geeks and the suits have come to call Big Data.

A day made of glass:

I’m reminded of an interesting passage in the book Glass: A World History:

As we have seen, one of the rapid developments in glass technology was the making of panes of window glass, plain and coloured, which was particularly noticeable in the northern half of Europe [after the twelfth century]. One very practical effect of this was on working conditions. In the cold and dark northern half of Europe people could now work for longer hours and with more precision because they were shielded from the elements. The light poured in, yet the cold was kept out. Prior to glass only thin slivers of horn or parchment were used and the window spaces were of necessity much smaller and the light admitted, dimmer.

It could also be argued that windows altered thought at a deeper level. The question here is the way in which glass, whether in a mirror, window, or through a lens, tends to concentrate and frame thought by bounding vision, and at the same time leads to abstraction and attention to the details of nature. It seems likely that the glass window altered the relations between humans and their world in ways which it is now difficult to recover.

This echoes an earlier observation by Lewis Mumford, in his book Technics and Civilization: “In losing color and ceasing to serve as a picture – the function it had occupied in medieval church decoration – and in letting in, instead, the forms and colors of the outside world, glass served also as a symbol of the double process of naturalization and abstraction which had begun to characterize the thought of Europe. More that that: it furthered this process. Glass helped put the world in a frame: it made it possible to see certain elements of reality more clearly; and it focussed attention on a sharply defined field – namely, that which was bounded by the frame.”

The windows that surround us, once clear, are increasingly filled with summoned images and symbols. We don’t look through them but into them. Naturalism fades; abstraction loses its backdrop of “the outside world.” The window turns back into a picture – a series of pictures, rapidly moving. The field blurs. The frame changes.

The paperback edition of The Shallows has just been published and should be in stores now. It includes a new afterword, which takes a look at the mounting backlash against the Net’s cultural hegemony. Here’s an excerpt:

I’ve always been suspicious of those who seek to describe the effects of digital media in generational terms, drawing sharp contrasts between young “Internet natives” and old “Internet immigrants.” Such distinctions strike me as misleading, if not specious. If you look at statistics on Web use over the past two decades, you see that the average adult has spent more time online than the average kid. Parents are as besotted with their BlackBerrys as their children are with their Xboxes. And the idea that those who grow up peering at screens will somehow manage to avoid the cognitive toll exacted by multitasking and persistent interruptions is a fantasy contradicted by neuroscientific research. All of us, young and old alike, have similar neurons and synapses, and our brains are affected in similar ways by the media we use.

Net culture isn’t youth culture; it’s mainstream culture. And my guess is that if the incipient Net backlash expands into a broad movement, the people leading it will be not the nostalgic old but the idealistic young. It’s worth remembering that one of the original targets of the sixties counterculture was the then-new mainframe computer, which seemed to be reducing human beings to strings of numbers. Campus protesters didn’t just burn draft cards; they folded, spindled, and mutilated IBM punch cards. “Punch cards, used for class registration, were first and foremost a symbol of uniformity,” historian Steven Lubar has written, and “they became the symbolic point of attack.”

Those times, and those attitudes, feel like ancient history now. As computers shrank, they became a lot less threatening. Eager for their assistance, we welcomed them into our homes and then into our pockets. But the young are still the enemies of uniformity, and the Internet, as it extends its reach into all the nooks and crannies of our days, is looking more and more like an enormous conduit of conventionality. What are Facebook and Google but giant institutions, arms of the new establishment? What are smartphones if not high-tech leashes? Today, online databases hold more information about us than could fit on a mile-high stack of punch cards. Some kind of rebellion seems in order.

The wisdom of a crowd is often in the eye of the beholder, but most of us understand that, at its most basic level, “crowd wisdom” refers to a fairly simple phenomenon: when you ask a whole bunch of random people a question that can be answered with a number (eg, what’s the population of Swaziland?) and then you add up all the answers and divide the sum by the number of people providing those answers – ie, calculate the average – you’ll frequently get a close approximation of the actual answer. Indeed, it’s often suggested, the crowd’s average answer tends to me more accurate than an estimate from an actual expert. As the science writer Jonah Lehrer put it in a column in the Wall Street Journal on Saturday:

The good news is that the wisdom of crowds exists. When groups of people are asked a difficult question – say, to estimate the number of marbles in a jar, or the murder rate of New York City – their mistakes tend to cancel each other out. As a result, the average answer is often surprisingly accurate.

To back this up, Lehrer points to a new study by a group of Swiss researchers:

The researchers gathered 144 Swiss college students, sat them in isolated cubicles, and then asked them to answer [six] questions, such as the number of new immigrants living in Zurich. In many instances, the crowd proved correct. When asked about those immigrants, for instance, the median guess of the students was 10,000. The answer was 10,067.

Neat, huh?

Except, well, it’s not quite that clear-cut. In fact, it’s not clear-cut at all. If you read the paper, you’ll find that the crowd did not “prove correct” in many instances. The only time the crowd proved even close to correct was in the particular instance cited by Lehrer – and that was only because Lehrer used the median answer rather than the mean. In most cases, the average answer provided by the crowd was wildly wrong.

Peter Freed, a neuroscience researcher at Columbia, let loose on Lehrer in a long, amusing blog post, arguing that he (Lehrer) had misread the evidence in the study. Freed pointed out that if you look at the crowd’s average answers – “average” as in “mean” – to the six questions the researchers posed, you’ll find that they are, as Freed says, “horrrrrrrrrrrrrendous”:

… the crowd was hundreds of percents – yes, hundreds of percents – off the mark. They were less than 100% off in response to only one out of the six questions! At their worst – to take a single value, as Lehrer wrongly did with the 0.7% [median] – the 144 Swiss students, as a true crowd (unlike the 0.7%), guessed that there had been 135,051 assaults in 2006 in Switzerland – in fact there had been 9,272 – an error of 1,356%.

Or, as the researchers themselves report:

In our case, the arithmetic mean performs poorly, as we have validated by comparing its distance to the truth with the individual distances to the truth. In only 21.3% of the cases is the arithmetic mean closer to the truth than the individual first estimates.

So, far from providing evidence that supports the existence of the wisdom-of-crowds effect, the study actually suggests that the effect may not be real at all, or at least may be a much rarer phenomenon than we assume.

But since this is statistics, that’s by no means (no pun intended) the end of the story. As the researchers go on to explain, it’s quite natural for a crowd’s average answer, calculated as the mean, to be way too high – and hence ridiculously unwise. That’s because, while individuals’ underestimates for these kinds of questions are bounded at zero, there’s no upper bound to their overestimates. “In other words,” as the researchers write, “a minority of estimates are scattered in a fat right tail,” which ends up skewing the mean far beyond any semblance of “wisdom.”

Fortunately (or not), the arcane art of statistics allows you to correct for the crowd’s errors. By massaging the results – “tuning” them, as the researchers put it – you can effectively weed out the overestimates and (presto-chango) manufacture a wisdom-of-crowds effect. In this case, the researchers performed this magic by calculating the “geometric mean” of the group’s answers rather than the simple “arithmetic mean”:

As a large number of our subjects had problems choosing the right order of magnitude of their responses, they faced a problem of logarithmic nature. When using logarithms of estimates, the arithmetic mean is closer to the logarithm of the truth than the individuals’ estimates in 77.1% of the cases. This confirms that the geometric mean (i.e., exponential of the mean of the logarithmized data) is an accurate measure of the wisdom of crowds for our data.

Got that?

Well, it further turns out that the median answer – the centermost individual answer – in a big set of answers often replicates, roughly, the geometric mean. Again, that’s no big surprise. The median, like the geometric mean, serves to neutralize wildly wrong guesses. It hides the magnitude of people’s errors. The researchers point this fact out in their paper, but Freed, having criticizing Lehrer for a sloppy reading of the study, seems to have overlooked that point. Which earns Freed a righteous tongue-lashing from another blogger, the physics professor Chad Orzel:

Freed’s proud ignorance of the underlying statistics completely undermines everything else. His core argument is that the “wisdom of crowds” effect is bunk because the arithmetic mean of the guesses is a lousy estimate of the real value. Which is not surprising, given the nature of the distribution – that’s why the authors prefer the geometric mean. He blasts Lehrer for using a median value as his example, without noting that the median values are generally pretty close to the geometric means – all but one are within 20% of the geometric mean – making the median a not-too-bad (and much easier to explain) characterization of the distribution.

You get the sense that this could go on forever. And I sort of hope it does, because I enjoyed Lehrer’s original column (the main point of which, by the way, was that the more a crowd socializes the less “wise” it becomes), and I enjoyed Freed’s vigorous debunking of Lehrer’s reading of (one part of) the study, and I also enjoyed Orzel’s equally vigorous debunking of (one part of) Freed’s debunking.

But beyond the points and counterpoints, there is a big picture here, and it can be described this way: Even in its most basic expression, the wisdom-of-crowds effect seems to be exaggerated. In many cases, including the ones covered by the Swiss researchers, it’s only by using a statistical trick that you can nudge a crowd’s responses toward accuracy. By looking at the geometric mean rather than the simple arithmetic mean, the researchers performed the statistical equivalent of cosmetic surgery on the crowd: they snipped away those responses that didn’t fit the theoretical wisdom-of-crowds effect that they wanted to display. As soon as you start massaging the answers of a crowd in a way that gives more weight to some answers and less weight to other answers, you’re no longer dealing with a true crowd, a real writhing mass of humanity. You’re dealing with a statistical fiction. You’re dealing, in other words, not with the wisdom of crowds, but with the wisdom of statisticians. There’s absolutely nothing wrong with that – from a purely statistical perspective, it’s the right thing to do – but you shouldn’t then pretend that you’re documenting a real-world phenomenon.

Freed gets at this point in a comment he makes on Orzel’s post:

Statistics’ dislike of long right tails is *not a scientific position.* It is an aesthetic position that, at least personally, I find robs us of a great deal of psychological richness … [T]o understand the behavior of a crowd – a real world crowd, not a group of prisoners in segregation – or of society in general, right tails matter, and extreme opinions are over-weighted.

The next time somebody tells you about a wisdom-of-crowds effect, make sure you ask them whether they’re talking about a real crowd or a statistically enhanced crowd.