Tuesday, February 05, 2008

Poetry in your genome?

Now that we are able to synthesize complete genomes for organisms, we can also write what we want in its individual genes. Andrew Pollack describes several such literary efforts:
You were expecting poetry, perhaps? The secret messages hidden in J. Craig Venter’s synthetic bacterial genome have now been revealed. They are Dr. Venter’s name, and that of his research institute and co-workers....Dr. Venter announced last week in the journal Science that his team had become the first to synthesize the complete DNA of a bacterium. He revealed that the genome had five “watermarks,” sequences of genetic code that would spell words using the letters for the amino acids that would be produced by the DNA...Wired Science reported Monday that it had ferreted out the messages, with help from government scientists. One watermark said “VenterInstitvte,” using the unusual spelling because there is no amino acid represented by the letter “u.”...The other messages were CraigVenter, HamSmith, GlassandClyde and CindiandClyde for his co-authors Hamilton O. Smith, Clyde A. Hutchison III, John I. Glass and Cynthia Andrews-Pfannkoch. A Venter spokeswoman confirmed them...In 2003, scientists from Icon Genetics, a German biotechnology company, engineered the plant Arabidopsis thaliana to contain a line from Virgil’s “Georgics,” with the meaning “Neither can every soil bear every fruit.”

Monday, February 04, 2008

Stronger or weaker brain synapses after sleep?

Why do we spend a third of our lives asleep? The answers suggested so far are varied and controversial. It is well documented that improvement in learning and memory accompanies a night of sleep. One idea is that most new information is discarded during sleep, as diurnal animals are bombarded by stimuli during the day, most of which we want to (or need to) forget. Synapses need to recover. If this is the dominant reason why we sleep, then decreased numbers of synapses or synapse weakening should be a prominent neuronal feature of sleep. Fountain points to an article by Tonini and colleagues (Nature Neuroscience 11, pp. 200 - 208, 2008) that provides evidence for this option. Tononi suggests that after sleep "“we get a leaner brain — there’s a gain in terms of energy, space and supplies, and you are ready to learn anew.” Here is their abstract:
Plastic changes occurring during wakefulness aid in the acquisition and consolidation of memories. For some memories, further consolidation requires sleep, but whether plastic processes during wakefulness and sleep differ is unclear. We show that, in rat cortex and hippocampus, GluR1-containing AMPA receptor (AMPAR) levels are high during wakefulness and low during sleep, and changes in the phosphorylation states of AMPARs, CamKII and GSK3beta are consistent with synaptic potentiation during wakefulness and depression during sleep. Furthermore, slope and amplitude of cortical evoked responses increase after wakefulness, decrease after sleep and correlate with changes in slow-wave activity, a marker of sleep pressure. Changes in molecular and electrophysiological indicators of synaptic strength are largely independent of the time of day. Finally, cortical long-term potentiation can be easily induced after sleep, but not after wakefulness. Thus, wakefulness appears to be associated with net synaptic potentiation, whereas sleep may favor global synaptic depression, thereby preserving an overall balance of synaptic strength.

The algorithms of love...

John Tierney writes an interesting article on internet match finding services in the Jan 29 New York Times.
Online matchmaking has become a boom industry as rival scientists test their algorithms for finding love...The leading yenta is eHarmony, which pioneered the don’t-try-this-yourself approach eight years ago by refusing to let its online customers browse for their own dates. It requires them to answer a 258-question personality test and then picks potential partners...Another company, Perfectmatch.com, is using an algorithm designed by Pepper Schwartz, a sociologist at the University of Washington at Seattle. Match.com, which became the largest online dating service by letting people find their own partners, set up a new matchmaking service, Chemistry.com, using an algorithm created by Helen E. Fisher, an anthropologist at Rutgers who has studied the neural chemistry of people in love.

As the matchmakers compete for customers — and denigrate each other’s methodology — the battle has intrigued academic researchers who study the mating game. On the one hand, they are skeptical, because the algorithms and the results have not been published for peer review. But they also realize that these online companies give scientists a remarkable opportunity to gather enormous amounts of data and test their theories in the field. EHarmony says more than 19 million people have filled out its questionnaire...In the battle of the matchmakers, Chemistry.com has been running commercials faulting eHarmony for refusing to match gay couples (eHarmony says it can’t because its algorithm is based on data from heterosexuals), and eHarmony asked the Better Business Bureau to stop Chemistry.com from claiming its algorithm had been scientifically validated. The bureau concurred that there was not enough evidence, and Chemistry.com agreed to stop advertising that Dr. Fisher’s method was based on “the latest science of attraction.”

Dr. Fisher now says the ruling against her last year made sense because her algorithm at that time was still a work in progress as she correlated sociological and psychological measures, as well as indicators linked to chemical systems in the brain. But now, she said, she has the evidence from Chemistry.com users to validate the method, and she plans to publish it along with the details of the algorithm...“I believe in transparency,” she said, taking a dig at eHarmony. “I want to share my data so that I will get peer review.”
On reading that Chemistry.com didn't discriminate against gay match making, I naturally decided to give it a spin and went through their series of questions (including one on the relative lengths of one's index and ringer finger). It included psychological profile questions and some interesting tests of susceptibility to visual illusions. Alas, the list of prospective mates for a 65 yr. old retired professor was rather lean, and I ended my experiment by withdrawing my chemistry.com profile after one day.

Sunday, February 03, 2008

Super Bowl preliminaries....the anthropoligist from Mars

The description in the header of this blog includes the phrase "and random curious stuff." Well....this post qualifies. I show you one of the videos used Sunday to warm patrons up for the super bowl orgy at my happy hour bar. "Macho Man", the Village People. Watching this did make me feel like Oliver Sacks' anthropologist from Mars.

Friday, February 01, 2008

Will cognition-enhancing drugs become as acceptable as coffee?

In my backlog of blog-postings-to-do is one on an article in the Dec. 27 issue of Nature on the use of cognition-enhancing drugs not only to treat cognitive disabilities, but also to enhance performance in those without medical issues (Nature 450, 1157–1159; 2007). Two drugs commonly used to reduced extraneous activity and focus attention are methylphenidate (Ritalin) and atomoxetine; both increase brain levels of the neurotransmitter noradrenaline. Sahakia and Morein-Zamir pose a series of questions whose answers become increasingly less obvious, and invite responses in an online forum:
-Should adults with severe memory and concentration problems from neuropsychiatric disorders be given cognitive-enhancing drugs?
-If drugs can be shown to have mild side effects, should they be prescribed more widely for other psychiatric disorders?
-Do the same arguments apply for young children and adolescents with neuropsychiatric disorders, such as those with ADHD?
-Would you boost your own brain power?
-How would you react if you knew your colleagues — or your students — were taking cognitive enhancers?
-How should society react?
I have now received a message from the Nature people, sent to a number of bloggers in the brain and behavior area, suggesting that readers check out some responses to this article and also participate in a survey.

Faith and Healing

Jerome Groopman reviews Anne Harrington's new book "The Cure Within - A History of Mind-Body Medicine" in the NY Times Book review of Jan. 27. Harrington is professor and chair of the History of Science department at Harvard. Here is the final section of that review:
Harrington offers close observations of the interactions between the Harvard cardiologist Herbert Benson (and later the neuroscientist Richard Davidson of the University of Wisconsin) and the Dalai Lama and his Tibetan monks. She admits longing for scientific support for what is, in essence, an “Orientalist” conception, that the “Other” holds wisdom and therapeutic treasures beyond those imaginable to us in the West. Some of Harrington’s wish is fulfilled in the biology of the placebo response. Recent studies show that belief, even in inert treatments, can have profound benefits in relieving pain, likely via release of endorphins and other mediators in the brain. But despite several decades of concerted research in the field of psychoneuroimmunology, to my scrutiny no robust effects of meditation or other relaxation techniques that could combat illnesses like cancer or AIDS have been identified.

Harrington concludes with the questions that her students at Harvard regularly ask: Which mind-body narratives are “true”? Are all the stories we tell ourselves about illness equally valuable? Harrington has already answered these queries in part in the voice of the woman with breast cancer in the Stanford study. Yet, she has still been “haunted” over the years by unusual events, like the case of a man whose tumors seemed to melt “like snowballs on a hot stove” in response to a “worthlesss” cancer treatment that he nonetheless believed in. The physicist Freeman Dyson once noted that, to a scientist, an event like the spontaneous remission of a tumor is viewed as occurring at the asymptote of probability, one in several million, but through the eyes of a believer it becomes not mathematics but a miracle. Harrington shows us that, whatever science reveals about the cause and course of disease, we will continue to tell ourselves stories, and try to use our own metaphors to find meaning in randomness.

The fruits of promiscuity...more dancing and food

From the research highlights section of the Jan. 24 issue of Nature, summarizing work by Matilla et al:
A honeybee colony led by a promiscuous queen does better than one led by a faithful queen: the colony forages more, stores more food and grows faster. Heather Mattila and her colleagues at Cornell University in Ithaca, New York, think this happens because genetically diverse colonies dance more....Honeybees 'waggle dance' to tell each other where to fly to find food. Mattila's team compared colonies in which the queen always bred with the same male to colonies ruled by a queen that had been inseminated by 15 drones. On average, worker bees from the latter category performed 36% more dances daily, kept waggling for 62% longer and communicated about food discoveries farther from the nest than did workers from single-father colonies.

Thursday, January 31, 2008

Why men are at the top.

Helena Cronin presents an interesting idea about why men walk off with most of the top positions and prizes that sidesteps the usual assumption of average differences between men and women in innate talents, tastes and temperaments. She notes that there not only more Nobels, but also more dumbbells among men, and suggests that it is a fourth "T" that most decisively shapes the distinctive structure of male — female differences. Some clips from her essay:
That T is Tails — the tails of these statistical distributions. Females are much of a muchness, clustering round the mean. But, among males, the variance — the difference between the most and the least, the best and the worst — can be vast. So males are almost bound to be over-represented both at the bottom and at the top...Consider the mathematics sections in the USA's National Academy of Sciences: 95% male. Which contributes most to this predominance — higher means or larger variance? One calculation yields the following answer. If the sex difference between the means was obliterated but the variance was left intact, male membership would drop modestly to 91%. But if the means were left intact but the difference in the variance was obliterated, male membership would plummet to 64%. The overwhelming male predominance stems largely from greater variance...Similarly, consider the most intellectually gifted of the USA population, an elite 1%. The difference between their bottom and top quartiles is so wide that it encompasses one-third of the entire ability range in the American population, from IQs above 137 to IQs beyond 200. And who's overwhelmingly in the top quartile? Males. Look, for instance, at the boy:girl ratios among adolescents for scores in mathematical-reasoning tests: scores of at least 500, 2:1; scores of at least 600, 4:1; scores of at least 700, 13.1.

The legacy of natural selection is twofold: mean differences in the 3 Ts and males generally being more variable; these two features hold for most sex differences in our species and, as Darwin noted, greater male variance is ubiquitous across the entire animal kingdom...The upshot? When we're dealing with evolved sex differences, we should expect that the further out we go along the right curve, the more we will find men predominating. So there we are: whether or not there are more male dumbbells, there will certainly be — both figuratively and actually — more male Nobels.

Unfortunately, however, this is not the prevailing perspective in current debates, particularly where policy is concerned. On the contrary, discussions standardly zoom in on the means and blithely ignore the tails. So sex differences are judged to be small. And thus it seems that there's a gaping discrepancy: if women are as good on average as men, why are men overwhelmingly at the top? The answer must be systematic unfairness — bias and barriers. Therefore, so the argument runs, it is to bias and barriers that policy should be directed. And so the results of straightforward facts of statistical distribution get treated as political problems

Creationists launch 'science' journal

Oh my gawd........ a new Creationist 'scientific' journal. This from the Jan. 23 online Nature News:
Papers will be peer reviewed by those who “support the positions taken by the journal”, according to editor-in-chief Andrew Snelling, a geologist based in Brisbane, Australia.
The Answers Research Journal makes life simple. You start with the result you want, and work from there. Much more efficient than conventional science.

George Lakoff on Obama vs. Hillary

Here are some succinct points made by George Lakoff, who has written on the power of metaphors in politics, and the importance of 'framing' political debates.

Wednesday, January 30, 2008

Newborn humans: predisposition for biological motion

This work demonstrates that when we are born, we have an innate bias towards attending to motions characteristic of other living things. Newborn chickens do this also. The abstract, a figure, and a video from Simion et al. :
An inborn predisposition to attend to biological motion has long been theorized, but had so far been demonstrated only in one animal species (the domestic chicken). In particular, no preference for biological motion was reported for human infants of less than 3 months of age. We tested 2-day-old babies' discrimination after familiarization and their spontaneous preferences for biological vs. nonbiological point-light animations. Newborns were shown to be able to discriminate between two different patterns of motion (Exp. 1) and, when first exposed to them, selectively preferred to look at the biological motion display (Exp. 2). This preference was also orientation-dependent: newborns looked longer at upright displays than upside-down displays (Exp. 3). These data support the hypothesis that detection of biological motion is an intrinsic capacity of the visual system, which is presumably part of an evolutionarily ancient and nonspecies-specific system predisposing animals to preferentially attend to other animals.

Figure: Three sample frames taken from the animation sequences used in the study: the biological motion stimulus (i.e., the walking hen) (Top), the nonbiological motion stimulus (random motion) (Middle), and the inverted biological motion display (upside-down walking hen) (Bottom). Squares indicate the point-lights.

Songbirds also have mirror neurons.

Mirror neurons in humans and other primates fire both when a given action is either performed or observed (see the 'mirror neuron' category in the left column of this blog.) Now Prather et al. have found similar neurons in the swamp sparrow, which like humans depends on auditory experience to learn its vocal repertoire. These forebrain neurons are specialized for auditory-vocal monitoring and have virtually the same response to a given note sequence, whether performed or heard. They also innervate striatal structures important for song learning, raising the possibility that singing-related activity in these cells is compared to auditory feedback to guide vocal learning. Here is a graphic from a New and Views article on this work by Tchernichovski1 & Wallman in the same issue of Nature.

(click to enlarge) Figure legend: The neurons identified by Prather and colleagues could be involved in three sensorimotor processes. a, The delayed corollary discharge of song patterns can be simultaneously compared with auditory feedback of the bird's own song, allowing tuning. b, The auditory responses (in the mirroring neurons) to songs of a neighbour might be compared with the memory of the corollary discharge produced during singing. This might allow the bird to identify an imitation by that neighbour. c, Corollary discharges while singing might be compared with a memory of the mirroring neurons' response to the parent's song. The error may then feed back to the song generator and guide vocal learning during song development, in addition to guidance from auditory input during singing (lowest arrow).

Tuesday, January 29, 2008

More on the evils of multitasking.

In a comment below, MindBlog reader Gregory points to a great article in the Atlantic on the toxic mental effects of multitasking. I wanted to bring the link into this separate post so that more of you will see it. It is by culture/technology commentator Walter Kirn:
Neuroscience is confirming what we all suspect: Multitasking is dumbing us down and driving us crazy. One man’s odyssey through the nightmare of infinite connectivity

...Multitasking messes with the brain in several ways. At the most basic level, the mental balancing acts that it requires—the constant switching and pivoting—energize regions of the brain that specialize in visual processing and physical coordination and simultaneously appear to shortchange some of the higher areas related to memory and learning. We concentrate on the act of concentration at the expense of whatever it is that we’re supposed to be concentrating on.

What does this mean in practice? Consider a recent experiment at UCLA, where researchers asked a group of 20-somethings to sort index cards in two trials, once in silence and once while simultaneously listening for specific tones in a series of randomly presented sounds. The subjects’ brains coped with the additional task by shifting responsibility from the hippocampus—which stores and recalls information—to the striatum, which takes care of rote, repetitive activities. Thanks to this switch, the subjects managed to sort the cards just as well with the musical distraction—but they had a much harder time remembering what, exactly, they’d been sorting once the experiment was over.

Even worse, certain studies find that multitasking boosts the level of stress-related hormones such as cortisol and adrenaline and wears down our systems through biochemical friction, prematurely aging us. In the short term, the confusion, fatigue, and chaos merely hamper our ability to focus and analyze, but in the long term, they may cause it to atrophy.

The next generation, presumably, is the hardest-hit. They’re the ones way out there on the cutting edge of the multitasking revolution, texting and instant messaging each other while they download music to their iPod and update their Facebook page and complete a homework assignment and keep an eye on the episode of The Hills flickering on a nearby television.

Pinker et al. on the logic of indirect speech.

Pinker, Nowak, and Lee do an interesting perspectives article in PNAS that looks more rigorously at why we don't just blurt out what we mean, as in:
- Would you like to come up and see my etchings? [a sexual come-on]
- If you could pass the guacamole, that would be awesome. [a polite request]
- Nice store you got there. Would be a real shame if something happened to it. [a threat]
- We're counting on you to show leadership in our Campaign for the Future. [a solicitation for a donation]
- Gee, officer, is there some way we could take care of the ticket here? [a bribe]
Here is their abstract:
When people speak, they often insinuate their intent indirectly rather than stating it as a bald proposition. Examples include sexual come-ons, veiled threats, polite requests, and concealed bribes. We propose a three-part theory of indirect speech, based on the idea that human communication involves a mixture of cooperation and conflict. First, indirect requests allow for plausible deniability, in which a cooperative listener can accept the request, but an uncooperative one cannot react adversarially to it. This intuition is supported by a game-theoretic model that predicts the costs and benefits to a speaker of direct and indirect requests. Second, language has two functions: to convey information and to negotiate the type of relationship holding between speaker and hearer (in particular, dominance, communality, or reciprocity). The emotional costs of a mismatch in the assumed relationship type can create a need for plausible deniability and, thereby, select for indirectness even when there are no tangible costs. Third, people perceive language as a digital medium, which allows a sentence to generate common knowledge, to propagate a message with high fidelity, and to serve as a reference point in coordination games. This feature makes an indirect request qualitatively different from a direct one even when the speaker and listener can infer each other's intentions with high confidence.

More Retro Video

After last week's Disco flashback, I can't resist giving you a little more nostalgia (this ought to make you cringe)... The Partridge Family's "I think I love you" from their popular sitcom in the early 1970s.

Monday, January 28, 2008

Are you holding your breath?

I notice - if I am maintaining awareness of my breathing - that the breathing frequently stops as I begin a skilled activity such as piano or computer keyboarding. At the same time I can begin to sense an array of unnecessary (and debilitating) pre-tensions in the muscle involved. If I just keep breathing and noticing those tensions, they begin to release. (Continuing to let awareness return to breathing when it drifts is a core technique of mindfulness meditation). Several sources note that attending to breathing can raise one's general level of restfulness relative to excitation, enhancing parasympathetic (restorative) over sympathetic (arousing) nervous system activities. These personal points make me feel like passing on some excerpts from a recent essay which basically agrees with these points: "Breathtaking New Technologies," by Linda Stone, a former Microsoft VP and Co-Founder and Director of Microsoft's Virtual Worlds Group/Social Computing Group. It is a bit simplistic, but does point in a useful direction.
I believe that attention is the most powerful tool of the human spirit and that we can enhance or augment our attention with practices like meditation and exercise, diffuse it with technologies like email and Blackberries, or alter it with pharmaceuticals...but... the way in which many of us interact with our personal technologies makes it impossible to use this extraordinary tool of attention to our advantage...the vast majority of people hold their breath especially when they first begin responding to email. On cell phones, especially when talking and walking, people tend to hyper-ventilate or over-breathe. Either of these breathing patterns disturbs oxygen and carbon dioxide balance...breath holding can contribute significantly to stress-related diseases. The body becomes acidic, the kidneys begin to re-absorb sodium, and as the oxygen and CO2 balance is undermined, our biochemistry is thrown off.

The parasympathetic nervous system governs our sense of hunger and satiety, flow of saliva and digestive enzymes, the relaxation response, and many aspects of healthy organ function. Focusing on diaphragmatic breathing enables us to down regulate the sympathetic nervous system, which then causes the parasympathetic nervous system to become dominant. Shallow breathing, breath holding and hyper-ventilating triggers the sympathetic nervous system, in a "fight or flight" response...Some breathing patterns favor our body's move toward parasympathetic functions and other breathing patterns favor a sympathetic nervous system response. Buteyko (breathing techniques developed by a Russian M.D.), Andy Weil's breathing exercises, diaphragmatic breathing, certain yoga breathing techniques, all have the potential to soothe us, and to help our bodies differentiate when fight or flight is really necessary and when we can rest and digest.

I've changed my mind about how much attention to pay to my breathing patterns and how important it is to remember to breathe when I'm using a computer, PDA or cell phone...I've discovered that the more consistently I tune in to healthy breathing patterns, the clearer it is to me when I'm hungry or not, the more easily I fall asleep and rest peacefully at night, and the more my outlook is consistently positive...I've come to believe that, within the next 5-7 years, breathing exercises will be a significant part of any fitness regime.

Why you think that $100 bottle of wine is better...

This little bit of work notes the neural basis of some of our 'refined aesthetic preferences'...what your brain might be doing when you feel that something that costs more is better (even when you are unknowingly comparing identical items). Here is the abstract from Plassmann et al.:
Despite the importance and pervasiveness of marketing, almost nothing is known about the neural mechanisms through which it affects decisions made by individuals. We propose that marketing actions, such as changes in the price of a product, can affect neural representations of experienced pleasantness. We tested this hypothesis by scanning human subjects using functional MRI while they tasted wines that, contrary to reality, they believed to be different and sold at different prices. Our results show that increasing the price of a wine increases subjective reports of flavor pleasantness as well as blood-oxygen-level-dependent activity in medial orbitofrontal cortex, an area that is widely thought to encode for experienced pleasantness during experiential tasks. The paper provides evidence for the ability of marketing actions to modulate neural correlates of experienced pleasantness and for the mechanisms through which the effect operates.

Figure: Neural correlates of liking ratings. (A) Activity in the mOFC and the midbrain correlated with the reported pleasantness of the six liquids at degustationtime. (B) Correlationof pleasantness ratings and BOLD responses

Friday, January 25, 2008

The new commonwealth

Some interesting comments by Kevin Kelly on possible political consequences of the Wikipedia phenomenon, excerpted from his brief essay. He changed his initial assumption that an encyclopedia editable by anyone would be an impossibility. This commentary has a rather different spirit than yesterday's post on the internet phenomenon.
It has always been clear that collectives amplify power — that is what cities and civilizations are — but what's been the big surprise for me is how minimal the tools and oversight are needed. The bureaucracy of Wikipedia is relatively so small as to be invisible. It's the Wiki's embedded code-based governance, versus manager-based governance that is the real news. Yet the greatest surprise brought by the Wikipedia is that we still don't know how far this power can go. We haven't seen the limits of wiki-ized intelligence. Can it make textbooks, music and movies? What about law and political governance?

The reality of a working Wikipedia has made a type of communitarian socialism not only thinkable, but desirable. Along with other tools such as open-source software and open-source everything, this communtarian bias runs deep in the online world...In other words it runs deep in this young next generation. It may take several decades for this shifting world perspective to show its full colors. When you grow up knowing rather than admitting that such a thing as the Wikipedia works; when it is obvious to you that open source software is better; when you are certain that sharing your photos and other data yields more than safeguarding them — then these assumptions will become a platform for a yet more radical embrace of the commonwealth. I hate to say it but there is a new type of communism or socialism loose in the world, although neither of these outdated and tinged terms can accurately capture what is new about it.

The Wikipedia has changed my mind, a fairly steady individualist, and lead me toward this new social sphere. I am now much more interested in both the new power of the collective, and the new obligations stemming from individuals toward the collective. In addition to expanding civil rights, I want to expand civil duties. I am convinced that the full impact of the Wikipedia is still subterranean, and that its mind-changing power is working subconsciously on the global millennial generation, providing them with an existence proof of a beneficial hive mind, and an appreciation for believing in the impossible.

Immune system subjugation of the brain

Research on links between brain, behavior, and the immune system is expanding rapidly. It has long been known that depression lowers immunity, and Dantzer et al. offer a review of causality in the opposite direction: release of cytokines by the innate immune system during infection which in the short term triggers sickness behaviors in the long term can cause depression. Here is their abstract and a PDF.
In response to a peripheral infection, innate immune cells produce pro-inflammatory cytokines that act on the brain to cause sickness behaviour. When activation of the peripheral immune system continues unabated, such as during systemic infections, cancer or autoimmune diseases, the ensuing immune signalling to the brain can lead to an exacerbation of sickness and the development of symptoms of depression in vulnerable individuals. These phenomena might account for the increased prevalence of clinical depression in physically ill people. Inflammation is therefore an important biological event that might increase the risk of major depressive episodes, much like the more traditional psychosocial factors.

Thursday, January 24, 2008

Does the internet liberate or enslave us?

A book by Lee Siegel "Against the Machine," reviewed by Janet Maslin in the NY Times, and an essay by Nicholas Carr raise a related set of arguments that challenge the assumption that the internet is a liberating force, a force for freedom, diffusing power and information among the many, rather than the few. At the same time web traffic in increasing, it is becoming more centralized. Carr notes:
-During the five years from 2002 through 2006, the number of Internet sites nearly doubled, yet the concentration of traffic at the ten most popular sites nonetheless grew substantially, from 31% to 40% of all page views
-Google continues to expand its hegemony...In March 2006, the company's search engine was used to process a whopping 58% of all searches in the United States, according to Hitwise. By November 2007, the figure had increased yet again, to 65%. The results of searches are also becoming more, not less, homogeneous. Do a search for any common subject, and you're almost guaranteed to find Wikipedia at or near the top of the list of results.
-Executives of Yahoo and Sun Microsystems have recently predicted that control over the net's computing infrastructure will ultimately lie in the hands of five or six organizations.
-To what end will the web giants deploy their power? They will, of course, seek to further their own commercial or political interests by monitoring, analyzing, and manipulating the behavior of "users." ...What's different, in comparison to the physical world, is that acts of control are more difficult to detect.

Graphical depiction of the Internet as consisting of a dense core of 80 or so critical nodes surrounded by an outer shell of 5,000 sparsely connected, isolated nodes that are very much dependent upon this core. (Shai Carmi, Bar Ilan University)

Siegel deals with socially toxic effects of the internet. From Maslin's review, describing Siegle's account of Starbucks, as one is:
...surrounded by Internet zombies, laptop-addicted creatures who have so grievously lost their capacity for human interaction “that social space has been contracted into isolated points of wanting, all locked into separate phases of inwardness.”...the semblance of a shared Starbucks experience masks endemic computer-generated isolation, a condition that has prompted psychic and ethical breakdowns that go well beyond the collapse of community....why we are living so gullibly through what would have been the plot of a science-fiction movie 15 years ago. Why does the freedom promised by the Internet feel so regimented and constricting? Why do its forms of democracy have their totalitarian side? What happens to popular culture when its sole emphasis is on popularity? How have we gone “from ‘I love that thing he does!’ to ‘Look at all those page views!’ in just a few years”?