Let's play a game. Quickly name three philosophers of any historical era and write them down. If you are really ambitious, name five.

Take your time and think about it. It's OK. I'll wait.

Now look at your names. Were any of the men or women you wrote down born east of Afghanistan? Where any of the names of Indian, Chinese or Japanese origin? If you are like most Westerners (myself included), your list only included Westerners. Odds are your list had guys like Plato, Aristotle and Kant on it (note the rarity of women on the lists too, something Tania got into yesterday). Such geographic provincialism in the tools of our thinking raises some profound issues.

Is it really possible that the civilizations of the "other" hemisphere have nothing useful to say about value, the categories of experience or the nature of mind? If not, what does it mean that the only non-Western philosopher most people can name is the Confucius?

An excellent piece by Justin Smith in The Stone, laid out the roots of maintaining such a divide between "philosophy" and "non-Western philosophy":

Non-Western philosophy is typically represented in philosophy curricula in a merely token way. Western philosophy is always the unmarked category, the standard in relation to which non-Western philosophy provides a useful contrast.

But this is surely a mistake because thinking about the nature of the real and the human relationship to such reality cannot be solely a province of the West. Smith explains:

Europe is, literally, a peninsula of Eurasia, comparable roughly in size, cultural diversity and civilizational antiquity to the Indian subcontinent. Certain significant things happened first in Europe rather than elsewhere, such as industrialization; other important things first appeared outside of Europe, such as movable type. Now it is of course very difficult to define "philosophy," but if we think of it broadly as systematic reflection on the nature of reality and on humanity's place in that reality, then it is clear that Europe can make no special claim to be the home of philosophy.

He argues that a broader understanding of both the history of philosophy and of philosophy itself would necessarily "treat both Western and non-Western philosophy as the regional inflections of a global phenomenon."

In his wonderful book Why the West Rules – For Now, historian Ian Morris speaks of the post-glacial age development of Western and Eastern "cores" of civilization. As Morris writes:

These core regions had all been fairly typical of the relatively warm habitable regions during the Ice Age, but now they grew increasingly distinct, both from the rest of the world and from each other.

Thus, we have had a number of trajectories for the development of what we call "civilization." The fact that Western Europe developed the set of practices called science does not mean it cornered the market on "systematic reflection on the nature of reality and on humanity's place in that reality." Such reflection has occurred in all the civilizations. And, as Smith emphasizes, philosophy is not science:

[Philosophy] is much more intricately wrapped up in cultural legacies ... Much of the difficulty of taking a rigorous and serious approach to the teaching and study of non-Western philosophy in Western philosophy departments is that many philosophers remain attached to the article of faith that philosophy is something independent of culture.

There is no doubt that the results of science are independent of culture (the value of Newton's constant doesn't care where you were born or what you call it). The practice of science, however, is subtly informed by philosophical traditions, especially at the hairy edges.

Which questions are deemed important? Which categories are used to slice and dice reality into questions? The answers to these questions are often reflections of philosophical history and its impact on culture.

Knowing nothing at all about the Buddhist atomism of Dharmakirti in the 7th century CE or the classical period of Indian logical reasoning as systematized by Dignaga in the 6th century means we've cut a lot of smart people out of our thinking about smart people. (I had to look these guys up myself, by the way.)

Is there a way around this? Yes and it may very well happen on its own.

Smith points to the idea that the commerce of illumination tends to piggy-back on the commerce of goods. With so much wealth being generated in the civilizations of the Eastern core these days, it may only be matter of time before the term "non-Western philosophy" seems quaint. Hopefully we will soon see some balance, with the commerce of illumination flowing in all directions.

Roll over Aristotle, won't you tell Mr. Plato the news!

You can keep up with more of what Adam Frank is thinking on Facebook and on Twitter: @AdamFrank4

Last Friday I found myself in a lovely lecture hall at Brown University with some 50 philosophers and psychologists attending the annual meeting of the Society for Philosophy and Psychology, affectionately known as "SPP." Daniel Dennett was in the seat just ahead of me; additional luminaries were scattered about the room. A quick count revealed about equal numbers of men and women in the audience — an unusual figure for an event in philosophy, where women make up less than 20 percent of full-time faculty.

That was precisely the topic we'd gathered to discuss: the underrepresentation of women in philosophy, where numbers mirror those for math, engineering, and the physical sciences, making philosophy an outlier within the humanities.

There's been no shortage of speculation about why. Perhaps, to quote Hegel, women's "minds are not adapted to the higher sciences, philosophy, or certain of the arts." Perhaps women are turned off by philosophy's confrontational style. Perhaps women are more inclined toward careers with practical applications.

But the most plausible hypothesis is that various forms of explicit and implicit bias operate in philosophy, as they do within and beyond other academic disciplines. Unfortunately, though, this explanation refines our question rather than answering it.

Why should bias be any greater in philosophy than in other humanistic disciplines? Is sexual harassment unusually common within philosophy, as might be suggested by the recent scandal involving Colin McGinn, not to mention some chilling experiences reported in the blog What is it like to be a woman in philosophy? Might our implicit assumptions about what a philosopher should look like and sound like be especially hard to reconcile with our implicit assumptions about women?

Until recently, most of these hypotheses lacked empirical grounding. Collecting relevant data is no easy task, and social scientists weren't exactly lining up for the task. So part of the excitement last Friday — as we waited for a presentation titled "Women and Philosophy: Why is it 'Goodbye' at 'Hello'?" — was the promise of data. The speakers were Toni Adleberg and Morgan Thompson, two master's degree students at Georgia State University, presenting preliminary findings from work with Professor Eddy Nahmias.

Adleberg and Thompson noted that we don't know exactly why women leave philosophy, but thanks to SPP-supported research by Molly Paxton, Carrie Figdor and Valerie Tiberius, we have some idea of when: the biggest drop in the proportion of women in the philosophy pipeline seems to be from enrollment in an introductory philosophy class to becoming a philosophy major. At Georgia State, for example, women make up about 55 percent of Introduction to Philosophy students but only around 33 percent of philosophy majors.

To better understand why, Adleberg, Thompson, and Nahmias collected data from over 700 male and female students on their experiences in the Introduction to Philosophy course at their university. The findings were revealing, as Adleberg explained:

We expected, of course, to find some gender differences in the survey responses. But the extent of those differences was surprising to me. Male and female students seem to have quite different experiences in introductory philosophy courses.

Overall, female students found the course less enjoyable and the material less interesting and relevant to their lives than male students. Compared to male students, they also felt that they had less in common with typical philosophy majors or with their instructors, reported feeling less able and likely to succeed in philosophy, were less comfortable participating in class discussions and were less inclined to take a second philosophy course or to major in philosophy. (Interestingly, however, they didn't anticipate receiving lower grades.)

Contrary to some speculation in the field, female students did not perceive classroom discussions as overly aggressive, and they were no more likely to say that students in the class failed to treat each other with respect. In an email, Thompson told me:

I was really surprised that both women and men do not perceive the philosophical discussions in their introductory course to be excessively combative. Given my experience attending both philosophy talks and neuroscience talks, I've noticed a distinct difference in the types of questions asked and the way that criticisms are raised.

Notably, the differences in men's and women's responses were equivalent when the course was taught by male and female instructors, but in both cases female students were more likely to disagree with the claim that the syllabus included a "fair proportion" of readings authored by women. In fact, the readings on the syllabus were overwhelmingly by men (over 89 percent). And, furthermore, Thompson explained:

This problem is compounded by the fact that introductory philosophy textbooks have an even worse gender balance; women account for only 6 percent of authors in a number of introductory philosophy textbooks.

Do some of these features of women's experiences make them less likely to pursue philosophy? Some additional analyses suggested that they do: the researchers found that the perception of the gender ratio on the syllabus and the perception of philosophy's usefulness for getting a job were both partial mediators of the relationship between gender and an intent to persist in philosophy.

The researchers also considered how students' experiences differed as a function of race. In an email, Nahmias told me:

I was a little surprised to see that there were so many parallels in the different patterns of responses to our survey between men and women and between white and black students.

Adleberg said the data may point to a need for new approaches in the classroom:

If we want to attract and retain a more diverse group of students to philosophy (which I hope we all do), we may need to change something about how we introduce students to philosophy.

Reflecting on their findings so far, Nahmias suggested that philosophy can do a better job introducing itself to incoming students:

We need to figure out why so many women and minorities say "goodbye" to philosophy right when we say "hello" to them. College students typically have little idea what philosophy is all about when they step into the intro class (almost none had philosophy in high school). First impressions are therefore that much more important. We need more data, but so far, I suspect it makes a difference when these students get the impression that men do philosophy and women don't, because, for instance, they only read one woman author and 20 men over the semester. I also think women, minorities, and first-generation college students may be more concerned about whether their major will help them get a job. Even if these students leave the intro course thinking philosophy is fun (and to be clear, it looks like white males find it more fun and interesting), they may not take more unless they can see that philosophy majors are valued on the job market. Since philosophy is a good major for a wide variety of careers (and philosophy majors do better than almost all other majors on tests like the LSAT and do well getting into various graduate degree programs), we might need to do a better job of "marketing" our field.

Of course, students' experiences in introductory philosophy courses are but one part of a larger story — assorted social and cultural forces influence women's decisions and careers at all life stages, with some special challenges for mothers. As in math, engineering, and the physical sciences, some gender-based differentiation is likely occurring even before college. Louise Antony, for instance, a prominent philosopher who heard the presentation, was glad that research of this sort was being conducted, but worried that the gender parity observed in introductory course enrollment numbers could be an artifact of university breadth requirements and therefore obscure differences between male and female students that develop well before their first day of Philosophy 101.

To borrow a metaphor from a paper by Antony herself, philosophy could involve a "perfect storm" of social and psychological factors that conspire to make it difficult for women to persist in the field. No single intervention is likely to change the climate.

Nonetheless, the findings from Adleberg, Thompson and Nahmias suggest some simple recommendations that could have important effects. With the support of the Georgia State Department of Philosophy, for example, the researchers will test out one strategy for attracting more women to the major: this fall, graduate student instructors will use course syllabi with 20 percent or more female authors, at least doubling the current proportions.

It's not enough, but it's a great place to start.

You can keep up with more of what Tania Lombrozo is thinking on Twitter: @TaniaLombrozo

This text is adapted from Alva's book Out of Our Heads.

Who, or what, is conscious? How can we decide? Where in nature do we find consciousness? This can seem like the hardest problem in this whole field: the question of the consciousness of others. I am aware. So are you. We think, we feel, the world shows up for us. But what about an ant, or a snail, or a paramecium? What about a well-engineered robot? Could it be conscious? Is there a way of telling, for sure?

The start of almost all reflection on this problem is the idea that our knowledge of how others think and feel, indeed, our knowledge that they think and feel and are not mere automata, is based on what we can see and hear and measure. We observe behavior, or, as in the case of patients with persistent vegetative state or locked-in syndrome, we measure neural activity. It can seem, then, that the closest we can come to knowing other minds, in a theoretically respectable way, is having some account according to which behavior and neural activity provide reliable criteria of a person's psychological state.

But this is really to concede that we don't have knowledge of other minds, at least not in a respectable way. For observations of behavior (what people say and do) and measurements of neural activity, don't yield knowledge of other minds. Surely this is an important lesson from persistent vegetative states and locked-in syndrome. Mere behavior is at best an unreliable guide to how things are for a person. And moreover, we really don't understand the connection between neural activity and experience any way.

Would the results of a brain scan ever convince us that our daughter was no longer a living person, especially when she continues to appear to respond to us, to our words, sounds, touch? If what people say and do, and measurements of what their brain is doing, are the best we have to go on, then it would seem that our commitment to the minds of others is epistemically ungrounded, a mere act of faith.

There is another piece of the puzzle about our knowledge of other minds. It is this: No sane person can take seriously the suggestion that our knowledge of other minds is merely hypothetical. However weak our evidence that others have minds may be, it is plainly outrageous to suggest that we might, for this reason, give up our commitment to the minds of others. That my friends and children and parents are thinking, feeling beings, that a world shows up for them, that they are not mere automata, is something that only insanity could ever allow one to question.

So we face a paradox: Although we lack sufficient reason to believe in the minds of others, it would be plainly unreasonable for us to give up this commitment.

Paradox is a dead giveaway that we've made a mistake in our thinking somewhere along the line. There must be something amiss in the way we have framed the question at the outset.

Our challenge: Where did we go wrong?

You can keep up with more of what Alva Noë is thinking on Facebook and on Twitter: @alvanoe

In the wake of the 439 comments on my last post about obesity and weight-bias in our society, I've been thinking about issues of comparative health around the world and, as I have before, about the Paleo diet.

A vigorous thread on last week's post (see the top of the comments section) assailed the multi-million-dollar food industry and its manipulation of consumers in this country. That theme is echoed in a book I've just read, Michael Moss's Salt Sugar Fat. Moss's central point is that the giant food companies pursue a "deliberate and calculating" approach to ensure that the "allure" — indeed, the "bliss point" — of our favorite foods comes about through salt, sugar and fat in ways that keep us coming back for more, more, and more.

The result is, as we all know by now, zooming rates of obesity in this country and around the world.

In risk factors for obesity and poor health, though, poor diet isn't alone — lack of exercise is considered a major culprit as well. After all, we in the West have diverged from that original hunter-gatherer lifestyle that Paleo advocates love to evoke, and we know that hunter-gatherers not only eat minimal levels of salt, sugar, and fat but also expend far more energy than we ourselves do when they forage actively across large swaths of the landscape.

Don't they?

Thanks to a pointer by Adam van Arsdale in a great review article in the new issue of American Anthropologist, I made time this week to read a paper from 2012 that offers a surprising answer to this question.

In "Hunter-Gatherer Energetics and Human Obesity," anthropologist Herman Pontzer and his co-authors take direct aim at one aspect of the popular association between obesity and modern lifestyle. Pontzer et al., compared energy expenditure levels of Hadza hunter-gatherers living in Tanzania with people in the United States and Europe living more sedentary lifestyles.

Because the Hadza are vigorously active as they forage — the men hunt with bows and also gather honey, the women gather plants — researchers expected to find that the Hadza expended way more energy than we do.

Except, that's not at all what they found.

As expected, the Hadza have lower body fat levels than Westerners and they did have greater levels of physical activity. Their average daily energy expenditure, though, didn't differ from Westerners', even when body size was controlled.

In other words, the Hadza are more active than most of us but don't burn more calories. That "counter-intuitive" result, Pontzer et al., write, challenges "current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure." The researchers hypothesize that there's a sort of ingrained human set-point for energy expenditure, impervious to cultural variation.

In a piece for The New York Times, Pontzer speculates that the Hadza's bodies compensate for high energy output in foraging by conserving energy on other physiological tasks.

Of course, this study focuses on a single group of hunter-gatherers: 13 Hadza men and 17 women whose energy levels were measured over 30 days. The tired phrase "more research is needed" fits well here.

Pretty obviously, the take-home message of the Hadza study is not that physical activity isn't beneficial. Massive amounts of data show the positive effects of exercise on cognitive and physical well-being.

So what are the take-home messages? I'll mention two.

In the Times, Pontzer flatly concludes that the obesity epidemic is not about being sedentary but about diet. In my words, it's about those alluring, blissful foods the food industry encourages us to eat. I know that's a sweeping generalization, one that deserves testing by way of more research into diet, exercise, and health.

The Hadza data also points, yet again, to the poor reasoning that underlies attempts by some "paleo" advocates to emulate a hunter-gatherer lifestyle. The surprising study results remind us that, when tested, our expectations about hunter-gatherer physiology and health may yield data quite divergent from our assumptions.

Data from anthropology do indicate that there has always been enormous variety in hunter-gatherer diet, foraging and health; any notion of the hunter-gatherer model is an illusion. I took flak from some quarters for saying so here at 13.7 in 2011. But a great post this month by Ferris Jabr at Scientific American brings the case home in an informed and engaging way.

"The Paleo diet," Jabr writes, "is founded more on privilege than on logic."

Barbara's new book is How Animals Grieve. You can up with what she is thinking on Twitter.

We think we know the real world; it's the one we perceive around us. All we have to do is open our eyes, sharpen our ears and we have a portrait of reality based on our senses. Most of us are perfectly happy with this construction, not knowing or caring that there is a whole lot of reality lurking beyond our senses, invisible and essential.

One of the most extraordinary aspects of science is how it amplifies our perception of reality, opening unexpected windows to the world. The canonical examples are the microscope and the telescope, both from the 17th century and both deeply transformative. Fast genetic sequencing, computer visualizations and fMRIs are some of the tools transforming our current worldview.

On the other hand, science creates its own paradox. The more we learn about the world, the more elusive reality seems to be. Our notion of progress as a linear goal needs to be reevaluated.

Plato, in ancient Greece, anticipated this issue. In his "Allegory of the Cave," part of the Republic, he imagines a group of slaves chained inside a cave since their birth. All they can do is look forward to a wall where images appear. To them, these images are reality, all of it.

What they don't know is that behind them a group of philosophers hold objects against a huge fire, projecting shadows on the wall. What the slaves see, and think of as real, are distortions, two-dimensional projections: a ball is seen as a circle, a pyramid as a triangle, and so forth. Plato's point is that our sensorial perception of the world creates a false notion of reality. We are tricked into constructing a worldview and believing it to be the real thing. When it comes to understanding the nature of reality we are all shortsighted.

History teaches us the same. Before Copernicus, the Earth was the center of the world and everything turned around it. The universe was closed, layered like an onion, and God and his court were on the outside. There was a vertical dimension to existence, and man's mission was to ascend from Earth to eternal bliss in the heavens.

When Newton proposed his theory of gravitation, he realized that the cosmos had to be infinite in extent; otherwise, instabilities would slowly creep in, forcing all the stars to collapse to the center.

Suddenly, reality changed and the world became open and infinite. Man lost his compass, as vertical ascension was no longer the way to go. Darkness was all around us, and no direction was more special than any other. What place for man in this new cosmos? To make things worse, Newton's ideas led to a radical determinism where the future was predictable from the present, at least in principle. In this clockwork universe, what place for free will? Such a bleak, rational outlook led German sociologist Max Weber declare that man had lost his sense of enchantment.

Fortunately, this strict determinism was not to be long-lived. In the beginning of the 20th century, quantum physics put an end to the notion that we can use physics as an oracle. Heisenberg's Uncertainty Principle showed that we can't know a particle's position and velocity (momentum, really) with arbitrary precision. In this case, predicting the future from the present becomes impossible.

Furthermore, quantum physics shows that the nature of reality is truly elusive: we don't see an electron or a photon; we infer their existence indirectly, through detectors. Somehow, in ways which remain unclear, the detector establishes a bridge between the world of the very small and our world of human senses.

In a radical interpretation of quantum physics — the one that we teach in schools and that the overwhelming majority of physicists endorse — we can't even say that the particle exists before we measure it. Reality is defined by how we interact with it.

We have a new way of seeing the world, accepting that there are aspects of reality which are unknown to us. Even more surprising, there are others which are inaccessible. In unexpected ways, modern physics has restored a sense of enchantment which, although not magical, brings back a much-needed sense of wonder.

You can keep up with more of what Marcelo is thinking on Facebook and Twitter: @mgleiser

New technologies are not all equal. Some do nothing more than add a thin extra layer to the top-soil of human behavior (i.e., Teflon and the invention of non-stick frying pans). Some technologies, however, dig deeper, uprooting the norms of human behavior and replacing them with wholly new possibilities. For the last few months I have been arguing that Big Data — the machine-based collection and analysis of astronomical quantities of information — represents such a turn. And, for the most part, I have painted this transformation in a positive light. But last week's revelations about the NSA's PRISM program have put the potential dangers of Big Data front and center. So, let's take a peek at Big Data's dark side.

The central premise of Big Data is that all the digital breadcrumbs we leave behind as we go about our everyday lives create a trail of behavior that can be followed, captured, stored and "mined" en-mass, providing the miners with fundamental insights into both our personal and collective behavior.

The initial "ick" factor from Big Data is the loss of privacy, as pretty much every aspect of your life (location records via mobile phones, purchases via credit cards, interests via web-surfing behavior) has been recorded — and, possibly, shared — by some entity somewhere. Big Data moves from "ick" to potentially harmful when all of those breadcrumbs are thrown in a machine for processing.

This is the "data-mining" part of Big Data and it happens when algorithms are used to search for statistical correlations between one kind of behavior and another. This is where things can get really tricky and really scary.

Consider, for example, the age-old activity of securing a loan. Back in the day you went to a bank and they looked at your application, the market and your credit history. Then they said "yes" or "no." End of story. In the world of Big Data, banks now have more ways to assess your credit worthiness.

"We feel like all data is credit data," former Google CIO Douglas Merrill said last year in The New York Times. "We just don't know how to use it yet." Merrill is CEO of ZestCash, one of a host of start-up companies using information from sources such as social networks to determine the probability that an applicant will repay their loan.

Your contacts on LinkedIn can be used to assess your "character and capacity" when it comes to loans. Facebook friends can also be useful. Have rich friends? That's good. Know some deadbeats, not so much. Companies will argue they are only trying to sort out the good applicants from the bad. But there is also a real risk that you will be unfairly swept into an algorithm's dead zone and disqualified from a loan, with devastating consequences for your life.

Jay Stanley of the ACLU says being judged based on the actions of others is not limited to your social networks:

Credit card companies sometimes lower a customer's credit limit based on the repayment history of the other customers of stores where a person shops. Such "behavioral scoring" is a form of economic guilt-by-association based on making statistical inferences about a person that go far beyond anything that person can control or be aware of.

The link between behavior, health and health insurance is another gray (or dark) area for Big Data. Consider the case of Walter and Paula Shelton of Gilbert, Louisiana. Back in 2008, Business Week reported how the Sheltons were denied health insurance when records of their prescription drug purchases were pulled. Even though their blood pressure and anti-depression medications were for relatively minor conditions, the Sheltons had fallen into another algorithmic dead zone in which certain kinds of purchases trigger red flags that lead to denial of coverage.

Since 2008 the use of Big Data by the insurance industry has only become more entrenched. As The Wall Street Journal reports:

Companies also have started scrutinizing employees' other behavior more discreetly. Blue Cross and Blue Shield of North Carolina recently began buying spending data on more than 3 million people in its employer group plans. If someone, say, purchases plus-size clothing, the health plan could flag him for potential obesity—and then call or send mailings offering weight-loss solutions.

Of course no one will argue with helping folks get healthier. But with insurance costs dominating company spreadsheets, it's not hard to imagine how that data about plus-size purchases might someday factor into employment decisions.

And then there's the government's use, or misuse, of Big Data. For years critics have pointed to no-fly lists as an example of where Big Data can go wrong.

No-fly lists are meant to keep people who might be terrorists off of planes. It has long been assumed that data harvesting and mining are part of the process for determining who is on a no-fly list. So far, so good.

But the stories of folks unfairly listed are manifold: everything from disabled Marine Corps veterans to (at one point) the late Sen. Ted Kennedy. Because the methods used in placing people on the list are secret, getting off the list can, according to Connor Freidersdorf of The Atlantic, be a Kafka-esque exercise in frustration.

A 2008 National Academy of Sciences report exploring the use of Big Data techniques for national security made the dangers explicit:

The rich digital record that is made of people's lives today provides many benefits to most people in the course of everyday life. Such data may also have utility for counterterrorist and law enforcement efforts. However, the use of such data for these purposes also raises concerns about the protection of privacy and civil liberties. Improperly used, programs that do not explicitly protect the rights of innocent individuals are likely to create second-class citizens whose freedoms to travel, engage in commercial transactions, communicate, and practice certain trades will be curtailed—and under some circumstances, they could even be improperly jailed.

So where do we go from here?

From credit to health insurance to national security, the technologies of Big Data raise real concerns about far more than just privacy (though those privacy concerns are real, legitimate and pretty scary). The debate opening up before us is an essential one for a culture dominated by science and technology.

Who decides how we go forward? Who determines if a technology is adopted? Who determines when and how it will be deployed? Who has the rights to your data? Who speaks for us? How do we speak for ourselves?

These are the Big Questions that Big Data is forcing us to confront.

You can keep up with more of what Adam Frank is thinking on Facebook and on Twitter: @AdamFrank4

Modern medicine and technology can change the way we define our physical and psychological selves. Is a prosthetic arm "your own arm" in the same sense that its biological predecessor seemed to be? Might taking antipsychotic medication fundamentally change your personality? Could an organ transplant from a pig, or from a violent murderer, somehow change who you are?

Understanding how people think about significant medical interventions not only has practical implications, it can also shed light on how people conceptualize themselves and their bodies. That's one reason psychologists have investigated how people think about organ transplants and their sources, with some intriguing results.

A 2011 paper by Bruce Hood and colleagues, for example, found that people were much less happy about the idea of receiving a heart transplant from a violent murderer than from a volunteer worker. The researchers speculated that this could reflect a fear of "moral contagion," the idea that morally bad characteristics or their consequences can somehow be transmitted through physical contact. (In one famous illustration of the phenomenon, Carol Nemeroff and Paul Rozin found that most people strongly disliked the idea of wearing a sweater worn by someone they considered evil – think Adolf Hitler – even after it had been carefully laundered.)

But are people merely creeped out by the thought of having a murderer's heart (or wearing a morally-tainted sweater), or do they think that contact with these items will actually change who they are, their very essence? A new paper by Meredith Meyer, Sarah-Jane Leslie, Susan Gelman, and Sarah Stilwell, just published in the journal Cognitive Science, suggests some answers.

The researchers had people indicate how they would feel about a heart transplant, a DNA transplant, or a blood transfusion from a donor who was like them (e.g., same age and gender, same sexual orientation, same background) or not like them (e.g., different gender or different sexual orientation), and also varied whether the hypothetical donor had positive characteristics (e.g., high IQ, well-known for philanthropy and charity work) or negative characteristics (e.g., convicted of violent murder, homeless).

The data revealed that people preferred a donor similar to themselves, and that similarity to self mattered more than positive or negative characteristics. People also reported feeling less creeped out by the thought of receiving donations from those similar to themselves, without a significant effect for positive versus negative characteristics. But most interesting of all, some people believed that they would take on the characteristics of the donors, including their personality and behavior. For example, one participant justified resistance to the donor who was convicted of violent murder by explaining that "the cruel murderer's qualities will come to me."

Could there be something to the idea that a transplant leads the recipient to acquire characteristics of the donor? In one famous example, transplant-recipient Claire Sylvia developed a taste for beer and Kentucky Fried Chicken after her transplant – both characteristics of the organ donor, not her former self. And a 2004 study of male heart recipients found that a full 34% (12 of 35) entertained the idea that they'd acquired characteristics of the organ donor after the transplant.

Meyer and colleagues write that "there is no scientific model to account for why transplants might lead to transference of features," and that their findings instead reflect cognitive biases in how we conceptualize ourselves and our identities. In particular, they take their findings to support "psychological essentialism," the idea that people conceptualize some categories, such as biological species or their individual identities, as having the appearance and behaviors that they do as a consequence of some internal "essence" or force. When one individual's DNA is transferred to another, people may feel that their own essence has been compromised, and that the foreign essence will have causal consequence for appearance and behavior.

There's a lot we still don't know about the causes of people's appearance and behavior, and about how significant medical interventions might lead to changes beyond the targets of intervention. But we can learn a lot about how we conceptualize ourselves and our bodies by considering experiences at the limits of scientific understanding, and judgments about medical interventions provide a unique opportunity to do so.

You can keep up with more of what Tania Lombrozo is thinking on Twitter: @TaniaLombrozo

Two things jumped out at me when I visited the show "Encyclopedic Palace" at the Central Pavilion at this year's Venice Biennale. The first is that in a show that claims, according to the wall text, to "initiate an inquiry into the many ways in which images have been used to organize knowledge and shape our experience of the world," the work on display is openly indifferent to anything that might be called knowledge, science or learning. Instead the exhibition is a disturbing celebration of the work of mystics and self-styled visionaries.

On display are séance induced abstractions by Hilma of Klints, images from Jung's Red Book, Aleister Crowley's tarot cards, blackboard doodles from Rudolph Steiner and Guo Fengyi's Chi-Gong visions, among much else.

Is this the curator's idea of a good joke? In the age of climate-change deniers and unreasoned skepticism about human origins, I don't find it very funny.

Or could it be, is it just possible, that from the playful heights of the art world, the very difference between seeing and knowing, on the one hand, and fantasies of communication with sages on the astral plane, on the other, has become too difficult to make out?

The second thing that jumped out at me when I visited the Central Pavilion was the near absence of art.

There is a great deal that is of interest and value, to be sure. For example, the wonderful models of imagined buildings — 387 of them! — that Austrian artist Oliver Croy found in a junk shop in Vienna; or the thrilling collection of pictures made by a Russian tween, most likely for the purposes of his own onanistic pleasure. But these are stand-alones, one-offs, the private products of isolated individuals. They are not so much art as they are art's raw materials.

Art happens in community, in exchange with others, in participation with the ideas and work of others who share common questions, puzzles, fascinations.

I wonder whether the curator's indifference to knowledge and science is also what explains his apparent indifference to art.

Art and science are different, to be sure. But they have a common origin in our joint engagement with a shared reality; and each thrives only in the crucible of community. Where there is no knowledge, there can be no art. And where there is no art, there is not even the desire for knowledge.

A final note: there are a few works of bona fide art on display in the Central Pavilion. For example, there is Tino Sehgal's wonderful installation (discussed here last week), and there are also striking works by Tacita Dean, Ellen Altfest and Artur Zmijewski. For the most part, though, the show does not even try to target art.

It should also go without saying that these critical remarks about the show in the Central Pavilion of the Giardini are not intended to apply to the work in the different national pavilions. There is magnificent art at this year's Biennale. I especially recommend the work at the French, British and Romanian Pavilions.

You can keep up with more of what Alva Noë is thinking on Facebook and on Twitter: @alvanoe

On Sunday, evolutionary psychologist Geoffrey Miller, a professor currently on leave from the University of New Mexico with a visiting position at New York University, tweeted a comment that sent shock waves through academia and beyond:

Dear obese PhD applicants: if you didn't have the willpower to stop eating carbs, you won't have the willpower to do a dissertation #truth

Later that same day, Miller deleted the tweet. But screen-captures like this one were already let loose, and the tweet soared through cyberspace. Then Miller tweeted "sincere apologies," noting first that the "idiotic, impulsive, and badly judged tweet does not reflect my true views, values, or standards" and then adding "Obviously my previous tweet does not represent the selection policies of any university, or my own selection criteria."

The double "sorry" messages have not slowed the resulting firestorm, which has propelled Miller into national prominence as a fat-shaming professor. Media outlets as varied as Inside Higher Ed, The Atlantic, New York Magazine and Jezebel have covered the story.

I sent an email message to Miller on Monday, asking if he would like to make any statement for 13.7; he did not reply.

Why has the response to Miller's tweet been so powerful and so biting? I can think of at least three reasons.

Fat-shaming is all too pervasive. I asked Rebecca Puhl of Yale University's Rudd Center for Food Policy and Obesity to contextualize Miller's denigration of obese people. In an email message sent on Monday, Puhl noted that weight bias is widespread and socially acceptable in our culture:

Our research with national samples of thousands of Americans shows that reports of weight discrimination have increased by 66 percent in the past decade, and are now on par with rates of racial discrimination – especially for women.

On weight bias in higher education specifically, Puhl described two research studies published this year. The first study by Jacob M. Burmeister et al., Puhl summarized in this way:

The researchers examined 97 applicants to a graduate program in psychology at a large university. The applicants reported their height, weight, and provided information about their applications to psychology graduate programs. Researchers then analyzed and coded their letters of recommendation for positive and negative statements as well as overall quality.

It was found that applicants with a higher body weight had significantly fewer post-interview offers of admission into graduate programs, especially for female applicants, even though their body weight was not related to the overall quality of their letters of recommendation. Of notable interest is that those with a higher body weight actually had more positive adjectives in their letters of recommendation.

Once qualified overweight candidates were viewed in person, in other words, their chances of admission tanked.

Puhl described the second study by Viren Swami et al. in these terms:

198 participants (both men and women) were asked to select a female candidate that they would most and least likely choose for admission to university from an array of figures varying in body size. Results showed a clear bias against selection of overweight and obese women, who were only selected by 6 percent of participants for university admission compared to the selection of underweight figures by 60 percent of participants.

From these studies we see that Miller's tweet apparently mirrors real discriminatory practices that hurt real people, often women.

Miller continues to make assertions that strike people as bizarre. As reported Monday by UNM, Miller has informed his department chair that the tweet in question is part of a research project — as yet publicly unnamed and undescribed. UNM has pledged to look into the validity of this claim by Miller "and take appropriate measures."

Many academics have wondered aloud on social media what I wonder too: if such a research project indeed exists, has it been approved by Miller's university ethics review board? Such boards function to protect human "subjects" from physical or psychological harm when academic research is conducted. In what possible world would Miller's tweet not have the potential to cause psychological harm?

Few of us are certain about the right course of action in a case like this. Should Miller be sanctioned? Or should the higher-education community take his apologies at face value and move on?

That Miller should not take body weight into account when he selects, or helps to select, graduate students is self-evident; it's #truth, to use Miller's vernacular.

But another interesting point of view, coming in a Facebook comment from anthropologist Rosemary Joyce, did catch my attention:

[Anyone] who is prejudiced against people based on body size shouldn't admit larger people; the self-fulfilling prophecy potential in performance is too high.

Joyce intends, of course, to protect obese individuals from hurt or harm. We wouldn't wish to move, though, to a system in which those in power in academe are allowed never to encounter the skills, indeed the humanity, of the targets of their prejudice, would we?

What should be done? That question is still in play. In the context of fair practices in higher education, it must be answered.

Barbara's new book is How Animals Grieve. You can up with what she is thinking on Twitter.

Two weeks ago, I wrote here about my new cancer diagnosis and my upcoming robot-assisted surgery.

The surgery occurred as planned on May 24; after a single rough night in the hospital, I went home and my recovery has proceeded completely on track (with the usual ups and downs after a 6-hour operation).

Best news of all, the pathology report showed that the cancer did not spread beyond its initial location. Between July and December, I will undergo further treatment (chemo and radiation) to be absolutely certain that any lurking cells of this nasty type of cancer are zapped into oblivion.

For your many kind wishes, I want to thank sincerely the 13.7 community. I am glad to be back in action and will post shortly (today).

By the way, my surgeon tells me I met the robot da Vinci when I was first wheeled into the O.R., but I remember nothing of it!

Last week NASA scientists put the space telescope Kepler in a kind of technological coma. The craft, designed to search for Earth-like planets orbiting stars in our cosmic neighborhood (within a few thousand light-years, that is), failed and seems to be unfixable. (Hope remains, though.)

Launched in 2009, Kepler has found a total of 132 potentially habitable planets and scientists have a long list of another 2,740 candidates awaiting more detailed analysis. Terrestrial telescopes will undertake the confirmation, since they now know where to look.

At a cost of $550 million, Kepler changed our view of the Universe and of how we fit in, very much like the homonymous brilliant German astronomer from the seventeenth century, an arduous defendant of a sun-centered cosmos and the first to provide mathematical laws describing planetary orbits.

The idea that stars have planets orbiting around them is very old, dating back at least to fourth-century BCE Greece, where philosophers like Epicurus suggested the existence of other worlds:

Moreover, there is an infinite number of worlds, some like this world, others unlike it. For the atoms being infinite in number, as has just been proved, are borne ever further in their course. For the atoms out of which a world might arise, or by which a world might be formed, have not all been expended on one world or a finite number of worlds, whether like or unlike this one. Hence there will be nothing to hinder an infinity of worlds.

In the sixteenth century, Giordano Bruno elaborated on this notion in his On the Infinite Universe and Worlds. To Bruno, such worlds would be like Earth, inhabited and full of good and evil.

Of course, if other Earths existed, the centrality of ours would be threatened. This was, and remains, an essential question in the debate on the plurality of worlds: are we unique and hence important in some sense, or are we the norm and typical of what's out there across the vastness of space?

It took some 413 years after Bruno's (most unfortunate) death for us to have an answer, even if partial, to this question. In four centuries, we moved from mere speculation about the existence of other Earths to the observation of other planets that, if not like ours, are — or could be — very similar. Today, astronomy has a new branch known as "comparative planetology," where properties of diverse planets are contrasted and studied in detail.

Even if still in its infancy as a discipline, we have learned much: that the majority of stars have planets circling around them; that life is only possible in those that obey a series of regularities in their astronomical properties and that have a relatively narrow chemical composition; that simple, bacterial life may be widespread, but that complex life may be rare.

But note that when scientists talk about life they are refereeing to life as we know it, that is, carbon-based and operating in an aqueous medium. Other types (such as silicon-based and using ammonia as solvent), even if interesting, are probably more fiction than reality, although some speculations are quite unsettling: intelligent life could have evolved so beyond what we can conceive that it reached a stage where it could leave behind its carbon envelope, existing in some sort of ethereal digital web sustained by electromagnetic fields, that is, a life without a narrow spatial confine or a biochemical metabolism. Who knows?

Even if we are still like toddlers in our cosmic exploration, we can at least rejoice in what we have learned so far: that there are hundreds of billions of other planets in our galaxy alone (and their moons, making for trillions of other worlds); that the same plurality is true in hundreds of billions of other galaxies across space; that some of these planets will have properties similar to Earth; that life, if present in these worlds, will be very particular to each of them, dependent on the planet's detailed and unique history; and that, for this reason, we are unique in the Universe, a product of the Earth and its very unique history.

The history of life on a planet mirrors the planet's life history.

Other space telescopes are planned to continue Kepler's mission. But what we have learned already demonstrates our uniqueness as a life form.

You can keep up with more of what Marcelo is thinking on Facebook and Twitter: @mgleiser

America has a problem. It's an existential problem, a big one that threatens our collective future. Our problem is the failing bond between science and the American people. Luckily for us all, it's a problem that can be solved. The solution? A big party! Well, that's not the solution, but celebrating science is one way to renew our community's bond with society.

So, this week I am heading out to Seattle to participate in the Seattle Science Festival. It's a 10-day long extravaganza focusing on oceans, planets, critters, math and more. My part will be sharing the opening night stage with Brian Greene, Sean Carroll and Jennifer Ouellette in a program called "Beyond Infinity." While we will all be talking about the nature of time, Brian Greene will get backing from a full orchestra to present his just-debuted collaborative piece Icarus at the Edge of Time (the music comes from Philip Glass, Kal Penn will provide live narration).

This opening night, with its mix of big cosmic ideas and innovative artistic interpretation, is the hallmark of a new idea in science education. They are introducing science in a very personal way to folks who might otherwise not find a reason to care.

Science festivals are meant to be big collaborative events, drawing thousands in with a healthy mix of science and the arts. In the United States, science festivals have sprung up from San Diego to Boston. One of the premiere events, the World Science Festival in New York (co-founded by Brian Greene), just finished its 5th season.

These festivals represent a movement that's been gaining steam for a few years. Organizers have realized that — in a nation failing to find people to keep up with the demand for high tech jobs (and with a strong streak of denialism) — moving beyond the museum, the zoo and NOVA on TV has become essential. As John Durant, of the MIT Museum puts it:

The wind of change is blowing through the world of science outreach. Tried and tested approaches—in journalism, broadcasting, museums, science centers, and elsewhere—are being reworked in unconventional and sometimes surprising ways. At the same time, older assumptions—about the importance of emphasizing "objectivity" in science, of relying on professional mediators, or of a single-minded focus on conveying factual knowledge to under-informed audiences—are being actively questioned or simply set aside.

Science festivals are a truly creative response this problem. From exhibitions on the science of beer to dance performances exploring quantum physics, festivals create a sense of excitement, engagement and just plain, damn fun that is often lacking in public discussions of science. Most of all these festivals work.

When 2011 attendees were asked if they would come back, 90 percent said "yes." When they did come back in 2012, fully 69 percent said the previous year's experience had led them to look something up they'd learned the year before. Sixty four percent said they had taken part in activities related to what they'd learned and 58 percent said they had used what they learned in their work or studies. BOOM!

Science is not just something scientists do. Like music and dance, it's a fundamental expression of what it means to be human. Given the resistance that has grown in this country to any form of science that treads too closely to someone's cherished ideology, celebrating science for the gift that it is with a big, honking festival seems like a good idea to me.

See you in Seattle.

You can keep up with more of what Adam Frank is thinking on Facebook and on Twitter: @AdamFrank4

Should the United States impose unilateral sanctions on Iran for its nuclear program? Should we raise the retirement age for Social Security? Should we institute a national flat tax? How about implementing merit-based pay for teachers? Or establishing a cap-and-trade system for carbon emissions?

Plenty of people have strong opinions about complex policy issues like these. But few people have the detailed knowledge of policy or economics that a solid understanding of the issues seems to require. Where do these opinions come from, if not from careful analysis and deep understanding?

A variety of uncharitable answers come to mind. Perhaps people just adopt the attitudes of their local community or favorite pundits. Perhaps people believe what they want to believe. Or perhaps people think they do understand the issues, at least well enough to support their own opinions.

A recent paper by psychologist Phil Fernbach of the Leeds School of Business at the University of Colorado and his collaborators, published this May in Psychological Science, provides some evidence for this final option: people overestimate how well they understand the mechanics of complex policies, and this sense of understanding helps bolster politically extreme positions.

The striking implication, for which the researchers find support, is that getting people to appreciate their own ignorance can be enough to rein in strong opinions.

Fernbach pointed me to the following video, which amusingly illustrates the "illusion of political understanding" that he documents in his paper. In this case, people have opinions about the fiscal cliff, and plenty are worried about it, despite having no idea what it is:

The video also illustrates the technique that Fernbach and colleagues used to get people to appreciate their own ignorance: asking them to explain an issue.

Here's how the study worked. People completed an online survey in which they first rated their agreement with several policies, such as sanctions on Iran and a cap-and-trade system for carbon emissions. They were then asked to estimate how well they felt they understood each policy and received an unexpected request: for two of the policies, they were told to "describe all the details" they knew about the impact of instituting that policy, "going from the first step to the last, and providing the causal connection between the steps."

In other words, people were asked to explain the nitty gritty mechanics of how the policy would play out, an exercise that led many to subsequently lower their estimates of how well they actually understood the policy.

Thus humbled, people's agreement or disagreement with the policy also became more moderate. More surprisingly, explaining also affected behavior: a follow-up study found that after explaining how various policies would work, people were less likely to donate money to an organization that supported the position they had originally endorsed.

These findings are remarkable given that people's opinions often become more extreme, not less extreme, when given an opportunity to reflect on them.

For example, a classic study in social psychology found that presenting people with evidence that challenged their views concerning capital punishment made them more likely to endorse their original position, not less. Similarly, Fernbach and colleagues found that asking people to "write down all the reasons you have for your position" was nothing like explanation when it came to moderating beliefs — only those who explained adopted less extreme positions.

Why was explanation so effective? In a New York Times piece discussing this work, co-author Steven Sloman and Phil Fernbach suggest that explanation acts as "a kind of revelatory trigger mechanism" that forces people to confront their lack of understanding. When you think you understand, probe further. Ask yourself "how?" and "why?" Ask others the same.

These findings have important implications for political discourse. In their New York Times post, Sloman and Fernbach offer the following lessons:

We voters need to be more mindful that issues are complicated and challenge ourselves to break down the policy proposals on both sides into their component parts. We have to then imagine how these ideas would work in the real world — and then make a choice: to either moderate our positions on policies we don't really understand, as research suggests we will, or try to improve our understanding. Either way, discourse would then be based on information, not illusion.

You can keep up with more of what Tania Lombrozo is thinking on Twitter: @TaniaLombrozo

Sometimes the most powerful and transformative technologies emerge by accident, an unintended consequence of other developments. When this happens, the scope and power of the new technology can't be fully appreciated until after we have embedded it in our culture.

Big Data is all that and much, much more.

By now we all recognize the many revolutions of the Internet. But who could have known back in the 1960s that getting a few hulking mainframe computers to swap digital spit could lead to the Facebooked/Googled/e-banking/YouTubed world we inhabit today? But as head spinning as it all has been, simmering within the Internet upheaval bubbles another possibility that has slowly been taking shape. For now, it's called Big Data. If it lives up to its promise (or peril), it will rework the architecture of human experience in ways we simply cannot imagine.

And because our urban centers have always been engines of information, there is likely no nexus of human culture more susceptible to Big Data's hurricane winds than Big Cities.

By now, of course, you may be wondering if there's really something going on or if Big Data is just this year's overheated hype. The answer to that question is a definitive NOT HYPE and the reason can be summed up in two words: Digital Breadcrumbs.

For years now we have all been dropping digital breadcrumbs — electronic markers in 1s and 0s — spread across the wired world. From cell-phone locations to grocery store shopping choices to Facebook posts, we are leaving a record of our life that is out there to be followed by anyone with the resources and the time.

And it's not just us.

Every function of our culture is generating reams of numbers that flow into the data sphere: from the monthly billing records of public utilities to the traffic data recorded by municipal street sensors, it's all getting recorded and most of it is getting electronically archived.

If you want a physical representation of Big Data, consider this: to store all the information humanity created in just one year you'd need 80 billion 16-GB iPhones. That's enough iPhones to create a ring circling the Earth 100 times.

The premise of Big Data is deceptively simple: hidden in all that information lies a hyper-resolution map of the world's behavior in space and time. It's a representation of human life and the natural world with a fidelity we have never had before. Think of those movies where a character can stop time and then walk around poking at people and objects frozen in action. Now give that character X-ray microscopic eyes and you begin to get a feel for what Big Data allows.

The science behind Big Data lies in learning how to dive into its digital oceans to find patterns in the real world. Those patterns are the key. From the movie-renting habits of 28-year-old factory workers to the daily flow of stock trades in companies processing salmon, those patterns represent the contours of real life captured in numbers. Once you see the patterns you can understand the world's behavior. Once you understand behavior you can predict it. Once you can predict behavior you can control it. That is the true promise — and danger — of Big Data.

Cities are created human environments. They are ecosystems of energy and matter imagined into existence through human effort. Because cities are essentially ideas transformed into action, they are creatures of information and a Big Data problem. By breathing in the torrents of data cities generate every second, Big Data scientists and engineers believe they can make cities efficient, effective and responsive to human needs in ways that will reshape their very nature.

In the most ambitious vision, the Big Data of Big Cities will mean these dense hubs of human habitation, where 85 percent of all people will live by 2050, might become adaptive, almost self-aware. Given the need to create a sustainable global human culture on a finite planet with finite resources, some say the Big Data revolution can't come fast enough for Big Cities.

Examples of Big Data/Big Cities projects are everywhere as researchers, engineers and municipal planners struggle to put the rivers of data being generated to good use on issues like sustainability, security and public health.

Consider that most basic aspect of urban life for a moment: traffic. These days a trip in a car from one side of town to another would not be complete without a quick peek at Google Maps and its traffic data. Google (and a host of other platforms, like Waze) gives you a map of the city and a representation of the traffic flow (green for good, red for "you're screwed"). But how does Google get this data. To get a better real time picture of traffic flow, Google recently began using a crowd-sourcing model where people's smart phones become sensors. Smart phone locations are tracked by cell-phone companies and that gives a measure of how traffic is (or is not) flowing. So the same people who are using Google's map application may be sending Google traffic data to inform the map. Any city — or in this case Google — can buy that data and use it to monitor traffic.

But you can do more than just track traffic. You might take that traffic data and use it to find patterns that are shaping the life of your city. You could, for example, combine the traffic data with other municipal datasets to see how traffic patterns correlate with, say, the electricity use of households in neighborhoods, or the rates of heart attacks or the shopping patterns of the 18-28 year olds. All that data is out there to be mined. Within it lies the secret life of our cities.

If you're looking for the unexpected in Big Data/Big City projects you need go no further than social media. At my own school, the University of Rochester, computer scientist Henry Kuatz and his student Adam Sadilek are "mining" twitter data to track the spread of disease. Normally, the way a city gathers data about who is sick — say, how many people have the flu during flu season — is to wait for folks to come in to a hospital or to their doctor's office. So people get sick, they report it, and the numbers eventually get tallied up. But that analysis is pretty backward looking, revealing only how many people have been sick last week or last month.

Kuatz and his collaborators can search through tweets containing the words "I feel sick" in specific urban areas as they appear now. By intelligently manipulating the constraints on their data-mining, Kautz's team are trying to see the spread of the flu from one neighborhood to another by watching the degree that digital social networks map out real networks of human contact and its contagious consequences.

These kinds of Big Data uses of social media are just beginning and there will be lots of mistakes made. But, taken as a whole, they hold enormous promise. Perhaps in the future you'll get an automatic tweet telling you that yesterday you were in a room with someone who had the flu. "Drink extra fluids and get some more sleep just in case."

For all the promise of Big Data and Big Cities it's not hard to imagine the dark side. All these digital breadcrumbs we are leaving may very well leave us without a shred of privacy. And while Big Data may allow a kind hyper-subtle control over a city's functions for benign uses, like developing sustainability, that control can also be used to reign in the functions that make a vital democracy work.

Regardless, we and our big cities are entering the era of Big Data. What comes next will be what we make of it and take from it.

You can keep up with more of what Adam Frank is thinking on Facebook and on Twitter: @AdamFrank4

This is coming to you from Venice, where I am attending the opening of the Art Biennale.

I find myself interested in Tino Sehgal's live piece installed in one of the main galleries of the Giardini. If the piece has a title, it isn't posted anywhere. I say "live piece" rather than "performance" because the work itself seems crafted precisely to question the nature of performance.

It has no beginning, middle, or end; it is just there, just as pictures hanging on the wall of a gallery are just there.

In Sehgal's piece, a small number of people sit or lie on the ground; they improvise their own music with their voices. Sometimes it's vaguely electronic sounding, or even human beat-box; sometimes it's more like droning, or chanting, and always very rhythmic.

They move, evenly, slowly, to this self-generated music. Some movements are dancerly, others less so. Beyond the temporal organization of the music and smooth pacing of the movement, there is an obvious organizational structure. The performers — they are performers, after all — pay attention to each other, clearly responding to movements, gestures or sound.

I had the impression that they imitate each other, but not quite directly, always as if going to some core quality of a movement or feeling.

The piece hardly jumps out at you when you first enter the gallery. There are people on the floor moving slowly, making noise; there are dozens of visitors milling around them in the gallery. The work is invisible at first, just as it is unclear what, if any, logic or rule governs what is going on.

My first impulse was to find it uninteresting. I wanted to move on. Gradually, it came into focus. When I left, over an hour later, I felt that I had gotten to know something definite and particular.

The performers are made into objects in this piece. You feel no inclination to applaud them when they stop, no inclination to compliment them on their work. This is because their actions — though clearly their own and often quite virtuosic — seem governed by a task or instruction. Their performance is, in this sense, automatic.

Moreover, this work doesn't play the "attention" game that is so basic to the performing arts. It doesn't try to capture your attention, or direct it, or organize it. The work is just there, like a picture on the wall, and the actors might as well be battery-operated machines.

Of course, they are not automata. They are people. They are lovely, each in their own way, and they are obviously making choices about what to do and how to interpret whatever task it is that they have been given as a team and as artists.

On the surface, though, they are indifferent to you, entirely turned in on themselves and the demands of their task. Only one performer, in the course of the 90 minutes I watched, directed her gaze to me and to other people in the gallery.

Because they were on the floor of the gallery, moving and singing, and because the gallery was full of people, I actually had a vivid sense of the spatial boundaries of the piece. I also, of course, had a somewhat anxious feeling about how fragile those boundaries were. The actors colonized space on the floor, but occasionally someone — a child, for example — would walk through their grouping. Sometimes people would stand nearby talking loudly, or telephoning, as if not noticing they were intruding into the territory of the piece, disrupting it for others.

For reasons I won't discuss, Sehgal prohibits the documentation of his work. This meant that the performers in today's installation had two jobs. They were either on the floor "in" the work. Or they were out in the gallery policing the room. Every time someone with a press badge started to take pictures, the actors, like undercover cops, pounced.

Whatever the intent, this patrolling of the boundaries of the piece belongs to the work itself. What we have is a piece within a piece, and we ourselves are folded into the act.

The play within a play is an object for us to contemplate. But the play itself, the one in which we find ourselves, is anxious; its boundaries are undefined, its subject matter open ended; it is an object of contention.

Art doesn't activate us, as psychologists and neuroscientists like to think. Rather, it gives us an opportunity to activate it, to switch it on and make it happen. Sehgal's work at this year's Biennale is a fine example.

You can keep up with more of what Alva Noë is thinking on Facebook and on Twitter: @alvanoe