How To win at Rock Paper Scissors??

In 2007, one Jamie Langridge became $50,000 richer after winning intense national tournament in Las Vegas. Langridge beat his opponent decisively, with a classic open-hand technique. The sport? Rock-paper-scissors.

Rock-paper-scissors seems deceptively simple. Pairs of opponents display one of three hand gestures. Paper covers rock, rock blunts scissors, and scissors cut paper. It’s so straightforward that children the world over learn to play it. But this is not just a game of chance. Played at the highest level, it becomes a game of psychological strategy, one that justifies five-figure trophies in large competitions and even the publication of strategy guides.

Such advanced games are possible because people don’t choose their hand shapes randomly. They are affected by moves that have gone before, and what other people are doing. Consider a new experiment by Richard Cook at University College London. Cook asked 45 people to face off against each other in several rounds of rock-paper-scissors, in exchange for real money. In every game, either one or both players were blindfolded.

Cook found that the players drew with each other more often when one of them could see (36.3% of the matches) than when both were blindfolded (33.3% of them). The latter figure was exactly the proportion of draws you’d expect if the players were choosing randomly; the former was significantly higher than chance.

Cook devised this study because he was interested in the idea that we all automatically and unconsciously imitate one another. There’s plenty of evidence that we do indeed copy one another, from obvious gestures like touching our face to subtle movements like tensing our muscles. But it’s not clear whether these actions are truly involuntary in the way that the knee-jerk reflex is. To find out, Cook wanted to see if people can stop themselves from performing these acts of mimicry.

That’s why he turned to rock-paper-scissors. Here is a game where you have to avoid imitating your opponent in order to win – the rules implicitly encourage people to avoid copying what their adversaries do. The results of Cook’s face-offs suggest that the sighted player has a slight tendency to imitate the blindfolded one – that’s why a blindfolded player will draw more often against a sighted one than another blindfolded opponent. And indeed, players were particularly likely to imitate rocks and scissors.

The sighted players weren’t using any obvious strategies. Their gestures weren’t related to the ones their opponents made in the previous round, or the one before that. Instead, Cook thinks that they were acting involuntarily.

The timing of their moves supports his conclusion. There simply isn’t enough time to see what the other player does and make a conscious decision to ape it. If the players were doing that, there would have been a noticeable delay, and an overseeing referee would have notified the researchers. There was, however, enough time for the brain to process signals from the eyes, and send instructions to the arm without any conscious thought. It takes at least 200 milliseconds to do this, and in his experiments, Cook saw that the sighted players made their move more than 200 milliseconds after their opponent on around half of the games.

Cook invokes the idea of mirror neurons, which fire both when animals act and when they see others performing the same actions. According to this interpretation, the sight of someone else’s falling hand would trigger neurons that encode the same movement in our brains, nudging us towards doing the same thing. The existence of mirror neurons in the human brain is controversial(they’re only formally been identified in monkeys), but Cook notes that playing rock-paper-scissors lights up parts of the brain where human mirror neurons are supposed to lie.

Of course, Cook says, “The tendency to imitate need not be overwhelming.” People can overcome it if they have enough concentration, motivation or experience, which is presumably why folks like Jamie Langridge can walk away with big tournament prizes.

Now, what happens when people play rock-paper-scissors-lizard-Spock?

Some novice-level tips for rock-paper-scissors:

1. Paper first, or perhaps scissors. Rookies tend to lead with rock, so paper could score an easy opening victory. However, if you’re playing an experienced player, they will know this. If they think you’re a rookie, they’ll play paper; if they think you know what you’re doing, they’ll play scissors. In this case, scissors if your best bet – it will either draw or win.
2. When in doubt, paper. Rock is the most popular move and scissors is the least popular.
3. Lose to their last move. When players have no plan, they often play the move that will beat their last one. If they threw paper, they’ll do scissors next, so you should play rock.
4. Spot double runs. People are unlikely to play three of the same move in a row. If they throw two rocks, their next move will probably be scissors or paper, so you should play scissors for, at worst, a draw.
5. And if you want to take this far too seriously…

Reference: Cook, Bird, Lunser, Huck & Heyes. 2011. Automatic imitation in a strategic context: players of rock–paper–scissors imitate opponents’ gestures. Proc Roy Soc B.http://dx.doi.org/10.1098/rspb.2011.1024

Why Does Time Fly?

Everybody knows that the passage of time is not constant. Moments of terror or elation can stretch a clock tick to what seems like a life time. Yet, we do not know how the brain “constructs” the experience of subjective time. Would it not be important to know so we can find ways to make moments last, or pass by, more quickly?

A recent study by van Wassenhove and colleagues is beginning to shed some light on this problem. This group used a simple experimental set up to measure the “subjective” experience of time. They found that people accurately judge whether a dot appears on the screen for shorter, longer or the same amount of time as another dot. However, when the dot increases in size so as to appear to be moving toward the individual -- i.e. the dot is “looming” -- something strange happens. People overestimate the time that the dot lasted on the screen.  This overestimation does not happen when the dot seems to move away.  Thus, the overestimation is not simply a function of motion. Van Wassenhove and colleagues conducted this experiment during functional magnetic resonance imaging, which enabled them to examine how the brain reacted differently to looming and receding.  

The brain imaging data revealed two main findings. First, structures in the middle of the brain were more active during the looming condition. These brain areas are also known to activate in experiments that involve the comparison of self-judgments to the judgments of others, or when an experimenter does not tell the subject what to do. In both cases, the prevailing idea is that the brain is busy wondering about itself, its ongoing plans and activities, and relating oneself to the rest of the world.

Second, brain areas including the left anterior insula were more active during the receding condition relative to the looming condition. The insula as a whole has been the focus of many recent studies and is thought to be involved in complex emotional processing.  In particular, Craig has suggested that there is an emotional asymmetry, in which the left forebrain is associated with approach, safety, positive affect and theright forebrain is associated with arousal, danger, and negative affect. An object moving away might be seen as non-threatening, signaling the self to relax. 

In fact, some investigators have suggested that the amount of energy spent during thinking and experiencing defines the subjective experience of duration.  In other words, the more energy it takes to process a stimulus the longer it appears as a subjective experience of time.  Something moving toward you has more relevance than the same stimulus moving away from you:  You may need to prepare somehow; time seems to move more slowly.

The experience of time is not linear. Fear and joy stretches time as do stimuli that move towards us.  What can we learn from these studies for our day-to-day experiences?  When we experience something as “taking a long time” it is really the result of three inter-twined processes: the actual duration of the event, how we feel about the event, and whether we think the event is approaching us.  There is little we can do about the first factor but there are obvious ways of modulating how we feel about an event and how we think about an event approaching us.  Future studies will need to address the question of whether modifying these factors can alter our subjective time experience so that that we can shorten life’s painfully extended moments of boredom and extend those wonderful moments of bliss. 

The Neurobiology of Bliss--Sacred and Profane

In studies that observe the brain in action, the right hemisphere seems to be the sexy hemisphere. It lights up during orgasm—so much so that, in one study, much of the cortex went dark, leaving the right prefrontal cortex as a bright island. New research suggests the right hemisphere is also hyperactive amongst the “hypersexual,” a symptom of brain injury loosely defined as groping, propositioning or masturbating in public without shame.

What is surprising about this is that pleasure is classically thought of as the province of the left hemisphere, not the right. The left is most active when recalling happy memories, meditating on love for another, and during the expansiveness of grandiosity or mania.

The left hemisphere is even preferentially more active among people free of depression and less active among the unhappy. If the brain were a simpler and more cooperative organ, the left hemisphere would be lit up like the Fourth of July during an orgasm. Instead, it is surprisingly silent. Why might this be so?

Until eight years ago, neuroscience had little scientific basis from which to comment on bliss, sexual or otherwise. Despite our public fascination with things sexual, as researcher, Gemma O’Brien put it, “orgasm is not impersonal and third person enough for the sciences.” Neuroscience was hobbled by the avoidance of such squashy topics, even if it meant setting aside important parts of human experience. However, a clearer portrait of pleasure is now emerging. Bliss, both sacred and profane, shares the diminution of self-awareness, alterations in bodily perception and decreased sense of pain. And while the left frontal lobe may be linked to pleasure, the other three characteristics are bilateral.

Absence of pain is predictably akin to pleasure, but the other two—losing a sense of identity and of bodily limits—are less obvious. Self-awareness, apparently, is no picnic. William James described the self as that kernel of consciousness that persists throughout various experiences and sensations. The self is divided between the stream of consciousness and an internal observer—except in those rare moments when we dissolve into mysticism.

Self-awareness exists as a running critique organizing conscious experience. Telling stories to ourselves (often about ourselves) is the cognitive default.

Escaping continual self-observation seems an underappreciated pleasure. Roy Baumeister wrote an entire book devoted to the premise that self-awareness is frequently a burden. Across cultures, we blunt awareness with alcohol, drugs, auto-hypnotic rituals and when times are dire, suicide. Meditation offers relief from this self-preoccupation and one of the few tools for creating a durable boost in happiness—perhaps by dampening activity in regions implicated in judgment, comparison, planning and self-scrutiny. Left prefrontal cortex activation correlates with happiness and Tibetan Buddhist monks have created the greatest measured spike in activity in this region produced by simple thought when meditating on compassion. The reported depth of meditation also corresponds to activity in the brain’s pleasure centers, such as left forebrain bundle, anterior insula and precentral gyrus. This overt pleasure is accompanied by a shift in emotional self-regulation; meditators are more aware of thoughts and feelings conceptually, but less emotionally disrupted by them, according to one study. Both hemispheres are involved in self-observation.

Pleasure is also linked to a loss of awareness of the boundaries of our body, and this, too, involves both sides of the brain. Orgasm and meditation dissolve the sense of physical boundary, but the activation patterns are distinct. Meditation does so in a somewhat cerebral way, altering bodily self-awareness by enhancing activity in specific brain regions, such as right angular gyrus—regions that become most lively during attempts to imagine ourselves from a stranger’s perspective, during out of body experiences or déjà vu, and in a neurologically obscure disorder in which patients lack awareness of their own paralysis or bodily infirmity.

But during orgasm, the cerebellar deep nuclei and vermis, also in the cerebellum, glow. The cerebellum used to be thought of as the “motor bit” tacked onto the back of the brain. The deep nuclei are mysterious, but they seem involved in planning and initiating movement, motor learning, rhythm, synchronizing and smoothing of movement. The vermis tracks the movement of the body through space outside of conscious awareness. Unlike meditation, orgasm seems a heightened sense of being within one’s body rather than the sense of being outside of it. The disconnected awareness meditation (“I am not my thoughts, I am not this experience”) is antithetical to the self-forgetting of sex in which wallowing in the experience, and the relationship, is precisely the point.

Being mister fantastic

Look at yourself in your bathroom mirror. Why, you look younger than you age!

And the farther you are from the mirror, the younger you look. If the mirror were really really far … remember the scene in “2001: A Space Odyssey” in which David Bowman sees himself as a fetus in the womb? Yup.

As you stand in your bathroom and you look down, the skin of your feet looks noticeably younger than that of your hands. Wait–bend forward and touch your feet. Do they still look younger?

Now walk to the kitchen and open the refrigerator. See that head of lettuce? The leaves are long—they reach halfway to the back of the shelf. The edges at the front look brown and wrinkly, but farther back the lettuce still look fresh green. If you stare at the lettuce long enough, you’ll see the wrinkles slowly move toward the back until they cover the entire thing.

It gets weirder. When you wave your arm straight out in front of you, it seems to drag in space, like sea grass bending in the waves. The hand eventually catches up, but with a delay.

Next, you walk across the living room. When you get to the other side, you turn around and you look back. You notice that your feet didn’t move at all. It’s like they were stuck to the floor where you were standing before. Your entire body is stretched diagonally from here to other side of the room, as if you were pulling a trick worth of the Fantastic Four. Soon, your feet start moving, too, and eventually they catch up with you.

None of this is science fiction, Mister Fantastic. We see things because light travels from those things to our eyes. But light moves at a finite speed. The farther the object is, the longer it takes for light to reach you. So everything we see, we see with a delay. It is a very small delay—10 nanoseconds for something that’s ten feet away. For practical purposes, that’s too tiny for us to observe with the naked eye. But it’s just a matter of degrees.

If light happened to be a lot slower—for example if it took one second to cover one meter—the weirdness would become obvious. (An example, which I mentioned in my previous post about how space used to be red, is that if you were immersed in a medium that suddenly transitions from opaque to transparent–for example from ice to water–you would see a spherical wall surrounding you and expanding away from you in all directions, at the speed of light.)

To imagine a world with slow light does not require bending the laws of physics too much. Light already travels at different speeds in different media (water, air, glass), and in all those cases it goes slower in the medium than it does when it propagates through empty space. In certain very controlled situations, in fact, physicists can slow light down to the point that it becomes virtually still.

Empty space is also known as the vacuum. And Einstein’s famous rule is this: nothing can travel faster than the speed of light in the vacuum. In principle, though, nothing prevents material things from moving faster in a medium than light moves in the same medium.

In practice, it’s rare for light to slow down so much or for matter to move so fast that matter can overtake light. But in some cases it does happen: this effect it is responsible for the blue glow of the cooling pools where nuclear waste is held. Thus, you could think of a medium that slows light so much that light becomes slower than your own motion.

So here’s my tip for virtual reality geeks: develop an immersive system in which you can adjust the speed of light and see what happens to your body and the world around it. The results could be even trippier than “2001.”

Why Is Quantum Gravity So Hard? And Why Did Stalin Execute the Man Who Pioneered the Subject?

What is the hottest problem in fundamental physics today? Physics aficionados most probably would answer: quantum gravity. Of all the fundamental forces of nature, only gravity still stands outside the rubric of the quantum theory. The difficulty of quantizing gravity has led to radical theories such as string theory, with its bold predictions of higher space dimensions and parallel universes. It's unclear if these theories are "crazy enough to have a chance of being correct," as Niels Bohr used to say. And too few people know the dramatic early history of this field.

In fact, the field of quantum gravity was born in 1916, even before physicists had properly explained the other fundamental forces, electromagnetism and the nuclear forces. Twenty years later, a young Russian physicist by the name of Matvei Bronstein realized that gravity would be the hardest force of all to quantize. But before he could do something about that, he was swept up in Stalin’s Great Terror and executed at the age of 30.

Right: Matvei Bronstein shortly before his arrest, courtesy of Gennady Gorelik

Our modern understanding of gravity is based on Einstein’s general theory of relativity, but Einstein himself realized that it was incomplete. Shortly after publishing his most famous theory, he remarked that gravitational effects would cause electrons to spiral in on atomic nuclei. To stop that would take a quantum revision of general relativity. In 1916 he wrote: "Due to the intra-atomic movement of electrons, atoms would have to radiate not only electromagnetic but also gravitational energy, if only in tiny amounts. As this is hardly true in nature, it appears that quantum theory would have to modify not only Maxwellian electrodynamics, but also the new theory of gravitation.” (To be sure, the implosion of atoms would take 10^30 years to complete. At the time, Einstein assumed the universe was infinitely old. If he had known it was only just a dozen billion years young, his argument would be less compelling.)

For Einstein, the gravitational instability of atoms was one of many reasons to search for a unified field theory. Quite a few theorists felt Einstein's unification urge, although most of them gave up and turned their attention to real problems of atomic physics and to developing quantum mechanics. One was Wolfgang Pauli. Among Pauli’s many accomplishments was a theory he and Werner Heisenberg published in 1929, which applied quantum principles to electrodynamics. Their paper proclaimed that the same approach could be taken to gravity: "Quantization of the gravitational field, which appears to be necessary for physical reasons [referring to the Einstein's remark cited above], may be carried out without any new difficulties by means of a formalism fully analogous to that applied here."

Meanwhile, a young Russian physicist, Lev Landau, undertook to probe into the foundations of the quantum theory of electrodynamics. What troubled Landau was the question of how Heisenberg’s famous uncertainty principle, when combined with relativity, applied to electromagnetic fields. Landau claimed that such a relativistic uncertainty made it impossible ever to measure the field at a point. And if you cannot measure the field, even in principle, did the concept of a field really make any sense? If it didn’t, Pauli and Heisenberg’s approach fell apart.

It was Bohr who came to rescue Pauli and quantum electrodynamics in an article he wrote with Leon Rosenfeld in 1933. Notoriously obscure’, the 60-page article identified the weak point of Landau's thought experiment - namely, its assumption of point-like particles. Bohr and Rosenfeld explained why one should measure an average field in an extended region of space, not at a single point. However, Landau, with his famous passion for clarity, was not persuaded.

It was at this point that a close friend of Landau, Matvei Bronstein, entered the scene and - - comprehended Bohr's idea better than Bohr did.

In 1934 he published a short 3-page paper elucidating why the act of measurement did not call the concept of a electromagnetic field into question. You can always suppose the measurement apparatus to be arbitrarily massive, allowing the field to be measured to arbitrary precision. Bronstein was equally at home with both gravity and atoms, and here came the moment when he grasped why Pauli was too optimistic about quantum gravity. The reason is that, when it comes to gravity, mass is the gravitational analog of electric charge. You do not have freedom to choose mass and (gravitational) charge separately, as you do in electromagnetism. The more massive the apparatus is, the more it affects the force of gravity you are trying to measure.

In Bronstein's full-dress research on quantum gravity, published in 1936, the most fascinating part was the essential difference between quantum electrodynamics and the quantum theory of gravity. Bronstein showed that the quantum limit of measurability would become apparent for particles with a certain characteristic mass, which is now known as the Planck mass (which Max Planck had introduced in 1900 with no reference to quantum gravity). Since gravity in general relativity is described by geometry, Bronstein concluded that the difficulty of quantizing gravity brought the entire nature of space and time into question: "The elimination of the logical inconsistencies ... requires a radical reconstruction of the theory, and in particular, the rejection of a Riemannian geometry dealing, as we have seen here, with quantities which are unobservable in principle, and perhaps also the rejection of our ordinary concepts of space and time, replacing them by some much deeper and nonevident concepts. Wer's nicht glaubt, bezahlt einen Thaler."

The last phrase in German came from a Grimm's fairy tale: "If you don't believe, pay a Thaler." It connoted that Bronstein’s conclusion, however implausible it might seem, was unavoidable.

Bronstein might have gone on to look for those "nonevident concepts" instead of space and time, but first he had to deal with an existential problem in cosmology. Some physicists felt that the redshift in the light of distant galaxies, which Edwin Hubble took evidence for the expansion of the universe, might be due to the phenomenon of “œtired light.” The idea was that as photons interacted with the quantum vacuum on their long journey across the cosmos, they might "œage" and redden. Bronstein disproved this hypothesis. If the photons were aging, the amount of redshift would differ in different regions of the spectrum, whereas Hubble had showed that the redshift was the same for photons of every color.

Bronstein also had a keen interest in education and published three books for teenagers on the discoveries of helium, x-rays, and on invention of radio. He was proving to be one of the most promising physicists of his generation.

Left: Lev Landau, Niels Bohr, Leon Rosenfeld, and Matvei Bronstein at the Kharkov conference of 1934, courtesy of Gennady Gorelik

But on the night of August 6, 1937, he was arrested. The police demanded that he turn over his weapons and his poisons - he gave a laugh as his response. He was executed in a Leningrad prison in February 1938, one of the hundreds of thousands of innocent victims of Stalin's terror.

Today, 75 years after Bronstein's forecast, thousands of articles and dozens of books on quantum gravity later, the problem is still a great challenge. Although a thousand theoretical flowers have bloomed, they still lack a firm basis in physical principles. Never before in physics have so many people worked for so long with so little tangible success. Should not they pay their thalers to the memory of Matvei Bronstein?

Twenty years ago I met a man who had shared a prison cell with Bronstein and more than a hundred other inmates. This man miraculously survived labor camps on the Kolyma, in Magadan and Norilsk. But he remembered his first weeks in prison. Few of the inmates, he said, felt like talking about crazy accusations and torturous interrogations. They tried to escape through lectures and quizzes. Bronstein earned applause with his lecture on the relativity theory. And he knew more poetry by heart than anybody else in the cell.