The brain does not stop developing until we are in our 30s or 40s – meaning that many people will still have something of the teenager about them long after they have taken on the responsibilities of adulthood.

The finding, from University College London, could perhaps help explain why seemingly respectable adults sometimes just can’t resist throwing a tantrum or sulking until they get their own way.

The discovery that the part of the brain key to getting on with others takes decades to fully form could perhaps also explain why some people are socially awkward well past their teenage years.

Neuroscientist Professor Sarah-Jayne Blakemore said: ‘Until about 10 years ago, it was pretty much assumed that the human brain stops developing in early childhood.

‘But we now know that is far from the truth, in fact most regions of the human brain continue to develop for many decades.

{ Daily Mail | Continue reading }

photo { Fette Sans }

Humans experience pleasure from a variety of stimuli, including food, money, and psychoactive drugs. Such pleasures are largely made possible by a brain chemical called dopamine, which activates what is known as the mesolimbic system — a network of interconnected brain regions that mediate reward. Most often, rewarding stimuli are biologically necessary for survival (such as food), can directly stimulate activity of the mesolimbic system (such as some psychoactive drugs), or are tangible items (such as money).

However, humans can experience pleasure from more abstract stimuli, such as art or music, which do not fit into any of these categories. Such stimuli have persisted across countless generations and remain important in daily life today. Interestingly, the experience of pleasure from these abstract stimuli is highly specific to cultural and personal preferences.

{ BrainBlogger | Continue reading }

collage { Eric Foss }

What happens in our bodies when we kiss?

In a good kiss, our pupils dilate, which is one of the reasons we close our eyes, our pulse quickens, and our breathing can deepen and become irregular. But we’re also hard at work on a subconscious level. Scent plays a really powerful role in whether it’s a good kiss or not. Women are actually most attracted to the natural scents of men who have a different set of genes called the major histocompatability complex that codes for immunity. We’re most attracted to people whose MHC genes have a lot of diversity from ours—the advantage of that would be if you reproduce, that child’s probably going to have a stronger immune system, and so be more likely to survive to pass on their genes. This isn’t something that we’re consciously aware of, but we do seem to know if something feels off. And actually, more than half of men and women—fifty-eight per cent of women, fifty-nine per cent of men—report ending a budding relationship because of a bad kiss.

How important is a couple’s first kiss?

A first kiss has the power to shape the future of a relationship for a particular couple. Of course, there are other factors that play a role, but kissing is really nature’s ultimate litmus test. It puts us right up close so that we can sense whether this is someone we want to continue a relationship with.

{ New Yorker | Continue reading }

A recent meta-analysis has indicated that falling in love can take a little as a fifth of a second and can produce similar euphoric effects to cocaine.

“These results confirm love has a scientific basis,” says Stephanie Ortigue who conducted the study at Syracuse University. (…)

Ortigue claims that while this is interesting in terms of being a neuroscience curiosity it could have potential therapeutic possibilities for those suffering depression after heartbreak.

{ B Good Science | Continue reading }

related { Researchers have identified five distinct styles of communicating romantic interest. }

painting { Gustav Klimt, Water Serpents I, 1904–1907 }

Feelings, especially the kind that I call primordial feelings, portray the state of the body in our own brain. They serve notice that there is life inside the organism and they inform the brain (and its mind, of course), of whether such life is in balance or not. That feeling is the foundation of the edifice we call conscious mind. When the machinery that builds that foundation is disrupted by disease, the whole edifice collapses. Imagine pulling out the ground floor of a high-rise building and you get the picture. That is, by the way, precisely what happens in certain cases of coma or vegetative state.

Now, where in the brain is that “feel-making” machinery? It is located in the brain stem and it enjoys a privileged situation. It is part of the brain, of course, but it is so closely interconnected with the body that it is best seen as fused with the body. I suspect that one reason why our thoughts are felt comes from that obligatory fusion of body and brain at brain stem level.

{ Antonio Damasio/Wired | Continue reading }

Antonio Damasio is David Dornsife Professor of Neuroscience at the University of Southern California, where he heads USC’s Brain and Creativity Institute.

Damasio’s books deal with the relationship between emotions and feelings, and what their bases may be within the brain. His 1994 book, Descartes’ Error: Emotion, Reason and the Human Brain, is regarded as one of the most influential books of the past two decades.

In his third book, Looking for Spinoza: Joy, Sorrow, and the Feeling Brain, published in 2003, Damasio suggested that Spinoza’s thinking foreshadowed discoveries in biology and neuroscience views on the mind-body problem.

{ Wikipedia | Continue reading | USC }

photo { Nathaniel Ward }

Have you ever watched a loved one stub their toe and wince yourself in sympathy? If so, you’ve perhaps unknowingly experienced a psychological phenomenon known as ‘embodied simulation’.

When you see someone making a gesture, be it emotional or physical, the regions activated in their brain are also activated in yours, creating a common network. Scientists think that this network is needed for effective communication of information.

What had not been shown before, however, was direct evidence of embodied simulation in between two people. A group of scientists, including Dr Nikolaus Weiskopf from the Wellcome Trust Centre for Neuroimaging at UCL, have been working on this using functional magnetic resonance imaging (fMRI) to directly investigate the workings of couple’s brains. […]

Analysis of the data showed that sending emotional information via facial expressions resulted in similar activity in both the sender’s and perceiver’s brains. Several brain areas showed common activity, suggesting that emotion-specific information is encoded by similar signals in both sender and perceiver. The results also showed that the part of the brain known to be activated when people fake an emotion in their facial expression, known as the ventral premotor cortex, was not activated during this experiment.

{ WellcomeTrust | Continue reading }

“Most thought is unconscious. It doesn’t work by mathematical logic. You can’t reason directly about the world—because you can only conceptual what your brain and body allow, and because ideas are structured using frames.” Lakoff says. “As Charles Fillmore has shown, all words are defined in terms of conceptual frames, not in terms of some putative objective, mind-free world.”

“People really reason using the logic of frames, metaphors, and narratives, and real decision making requires emotion, as Antonio Damasio showed in Descartes’ Error.” (…)

People Don’t Decide Using ‘Just the Facts’ (…)

Don’t Repeat the Language Politicians Use: Decode It

{ Explainer | Continue reading }

photo { Jessica Craig-Martin }

Imagine being attacked by one of your own hands, which repeatedly tries to slap and punch you. Or you go into a shop and when you try to turn right, one of your legs decides it wants to go left, leaving you walking round in circles.

Last summer I met 55-year-old Karen Byrne in New Jersey, who suffers from Alien Hand Syndrome.

Her left hand, and occasionally her left leg, behaves as if it were under the control of an alien intelligence.

Karen’s condition is fascinating, not just because it is so strange but because it tells us something surprising about how our own brains work.

Karen’s problem was caused by a power struggle going on inside her head. A normal brain consists of two hemispheres which communicate with each other via the corpus callosum.

The left hemisphere, which controls the right arm and leg, tends to be where language skills reside. The right hemisphere, which controls the left arm and leg, is largely responsible for spatial awareness and recognising patterns.

Usually the more analytical left hemisphere dominates, having the final say in the actions we perform.

The discovery of hemispherical dominance has its roots in the 1940s, when surgeons first decided to treat epilepsy by cutting the corpus callosum. After they had recovered, the patients appeared normal. But in psychology circles they became legends.

That is because these patients would, in time, reveal something that to me is truly astonishing - the two halves of our brains each contain a kind of separate consciousness. Each hemisphere is capable of its own independent will.

{ BBC | Continue reading }

photo { Chris McPherson }

A new paper in Nature Neuroscience by a team of Montreal researchers marks an important step in revealing the precise underpinnings of “the potent pleasurable stimulus” that is music. (…)

Because the scientists were combining methodologies (PET and fMRI) they were able to obtain an impressively precise portrait of music in the brain. The first thing they discovered (using ligand-based PET) is that music triggers the release of dopamine in both the dorsal and ventral striatum. This isn’t particularly surprising: these regions have long been associated with the response to pleasurable stimuli. It doesn’t matter if we’re having sex or snorting cocaine or listening to Kanye: These things fill us with bliss because they tickle these cells. Happiness begins here.

The more interesting finding emerged from a close study of the timing of this response, as the scientists looked to see what was happening in the seconds before the subjects got the chills. I won’t go into the precise neural correlates – let’s just say that you should thank your right NAcc the next time you listen to your favorite song – but want to instead focus on an interesting distinction observed in the experiment.

In essence, the scientists found that our favorite moments in the music were preceeded by a prolonged increase of activity in the caudate. They call this the “anticipatory phase” and argue that the purpose of this activity is to help us predict the arrival of our favorite part.

{ Wired | Continue reading }

We are living in the middle of a revolution in consciousness. Over the past few decades, geneticists, neuroscientists, psychologists, sociologists, economists, and others have made great strides in understanding the inner working of the human mind. Far from being dryly materialistic, their work illuminates the rich underwater world where character is formed and wisdom grows. They are giving us a better grasp of emotions, intuitions, biases, longings, predispositions, character traits, and social bonding, precisely those things about which our culture has least to say. Brain science helps fill the hole left by the atrophy of theology and philosophy.

A core finding of this work is that we are not primarily the products of our conscious thinking. The conscious mind gives us one way of making sense of our environment. But the unconscious mind gives us other, more supple ways. The cognitive revolution of the past thirty years provides a different perspective on our lives, one that emphasizes the relative importance of emotion over pure reason, social connections over individual choice, moral intuition over abstract logic, perceptiveness over I.Q. It allows us to tell a different sort of success story, an inner story to go along with the conventional surface one.

{ The New Yorker | Continue reading | Thanks Tim }

screenshot { Kissinger and Nixon | excerpted from The Kid Stays in the Picture, 2002 }

Oxytocin has been described as the hormone of love. This tiny chemical, released from the hypothalamus region of the brain, gives rat mothers the urge to nurse their pups, keeps male prairie voles monogamous and, even more remarkable, makes people trust each other more.

Yes, you knew there had to be a catch. As oxytocin comes into sharper focus, its social radius of action turns out to have definite limits. The love and trust it promotes are not toward the world in general, just toward a person’s in-group. Oxytocin turns out to be the hormone of the clan, not of universal brotherhood. Psychologists trying to specify its role have now concluded it is the agent of ethnocentrism.

{ NY Times | Continue reading }

photo { Glynnis McDaris | Interview }

One of psychology’s most respected journals has agreed to publish a paper presenting what its author describes as strong evidence for extrasensory perception, the ability to sense future events.

The decision may delight believers in so-called paranormal events, but it is already mortifying scientists. Advance copies of the paper, to be published this year in The Journal of Personality and Social Psychology, have circulated widely among psychological researchers in recent weeks and have generated a mixture of amusement and scorn.

The paper describes nine unusual lab experiments performed over the past decade by its author, Daryl J. Bem, an emeritus professor at Cornell, testing the ability of college students to accurately sense random events, like whether a computer program will flash a photograph on the left or right side of its screen. The studies include more than 1,000 subjects.

Some scientists say the report deserves to be published, in the name of open inquiry; others insist that its acceptance only accentuates fundamental flaws in the evaluation and peer review of research in the social sciences.

The editor of the journal, Charles Judd, a psychologist at the University of Colorado, said the paper went through the journal’s regular review process. “Four reviewers made comments on the manuscript,” he said, “and these are very trusted people.”

All four decided that the paper met the journal’s editorial standards, Dr. Judd added, even though “there was no mechanism by which we could understand the results.”

But many experts say that is precisely the problem. Claims that defy almost every law of science are by definition extraordinary and thus require extraordinary evidence. Neglecting to take this into account — as conventional social science analyses do — makes many findings look far more significant than they really are, these experts say. (…)

For more than a century, researchers have conducted hundreds of tests to detect ESP, telekinesis and other such things, and when such studies have surfaced, skeptics have been quick to shoot holes in them.

But in another way, Dr. Bem is far from typical. He is widely respected for his clear, original thinking in social psychology, and some people familiar with the case say his reputation may have played a role in the paper’s acceptance. (…)

In one experiment, Dr. Bem had subjects choose which of two curtains on a computer screen hid a photograph; the other curtain hid nothing but a blank screen.

A software program randomly posted a picture behind one curtain or the other — but only after the participant made a choice. Still, the participants beat chance, by 53 percent to 50 percent, at least when the photos being posted were erotic ones. They did not do better than chance on negative or neutral photos.

“What I showed was that unselected subjects could sense the erotic photos,” Dr. Bem said, “but my guess is that if you use more talented people, who are better at this, they could find any of the photos.”

{ NY Times | Continue reading }

There’s a good chance you’ve heard about a forthcoming article in the Journal of Personality and Social Psychology (JPSP) purporting to provide strong evidence for the existence of some ESP-like phenomenon. (…)

The controversy isn’t over whether or not ESP exists, mind you; scientists haven’t lost their collective senses, and most of us still take it as self-evident that college students just can’t peer into the future and determine where as-yet-unrevealed porn is going to soon be hidden (as handy as that ability might be). The real question on many people’s minds is: what went wrong? If there’s obviously no such thing as ESP, how could a leading social psychologist publish an article containing a seemingly huge amount of evidence in favor of ESP in the leading social psychology journal, after being peer reviewed by four other psychologists? (…)

Having read the paper pretty closely twice, I really don’t think there’s any single overwhelming flaw in Bem’s paper (actually, in many ways, it’s a nice paper). Instead, there are a lot of little problems that collectively add up to produce a conclusion you just can’t really trust.

Below is a decidedly non-exhaustive list of some of these problems. I’ll warn you now that, unless you care about methodological minutiae, you’ll probably find this very boring reading. But that’s kind of the point: attending to this stuff is so boring that we tend not to do it, with potentially serious consequences.

{ Tal Yarkoni | Continue reading }

The first brain scans of men and women having sex and reaching orgasm have revealed striking differences in the way each experiences sexual pleasure. While male brains focus heavily on the physical stimulation involved in sexual contact, this is just one part of a much more complex picture for women, scientists in the Netherlands have found.
The key to female arousal seems rather to be deep relaxation and a lack of anxiety, with direct sensory input from the genitals playing a less critical role.

The scans show that during sexual activity, the parts of the female brain responsible for processing fear, anxiety and emotion start to relax and reduce in activity. This reaches a peak at orgasm, when the female brain’s emotion centres are effectively closed down to produce an almost trance-like state.

The male brain was harder to study during orgasm, because of its shorter duration in men, but the scans nonetheless revealed important differences. Emotion centres were deactivated, though apparently less intensely than in women, and men also appear to concentrate more on the sensations transmitted from the genitals to the brain.

“Men find it more important to be stimulated on the penis than women find it to be stimulated on the clitoris,” Gert Holstege of the University of Groningen said.

This suggests that for men, the physical aspects of sex play a much more significant part in arousal than they do for women, for whom ambience, mood and relaxation are at least as important. (…)

The experiments also revealed a rather surprising effect: both men and women found it easier to have an orgasm when they kept their socks on. (…)

The scans also show that while women may be able to fool their partners with a fake orgasm, the difference is obvious in the brain. Parts of the brain that handle conscious movement light up during fake orgasms but not during real ones, while emotion centres close down during the real thing but never when a woman is pretending.

{ Times | Continue reading }

photo { Germaine Krull }

One of the most surprising findings is that people have a natural aversion to inequality. We tend to prefer a world in which wealth is more evenly distributed, even if it means we have to get by with less.

Consider this recent experiment by a team of scientists at Caltech, published earlier this year in the journal Nature. The study began with 40 subjects blindly picking ping-pong balls from a hat. Half of the balls were labeled “rich,” while the other half were labeled “poor.” The rich subjects were immediately given $50, while the poor got nothing. Such is life: It’s rarely fair.

The subjects were then put in a brain scanner and given various monetary rewards, from $5 to $20. They were also told about a series of rewards given to a stranger. The first thing the scientists discovered is that the response of the subjects depended entirely on their starting financial position. For instance, people in the “poor” group showed much more activity in the reward areas of the brain (such as the ventral striatum) when given $20 in cash than people who started out with $50. This makes sense: If we have nothing, then every little something becomes valuable.

But then the scientists found something strange. When people in the “rich” group were told that a poor stranger was given $20, their brains showed more reward activity than when they themselves were given an equivalent amount. In other words, they got extra pleasure from the gains of someone with less.

{ Wall Street Journal | Continue reading }

photos { David Stewart | Valerie Chiang }

I wondered for probably the millionth time why I am always running late.

This time, I vowed, I was going to find out.

I turned to an obscure field of neuroscience for answers. The scientists who work on the problem of time in the brain sometimes refer to their area of expertise as “time perception” or “clock timing.” What they’ve discovered is that your brain is one of the least accurate time measurement devices you’ll ever use. And it’s also the most powerful.

When you watch the seconds tick by on a digital watch, you are in the realm of objective time, where a minute-long interval is always 60 seconds. But to your brain, a minute is relative. Sometimes it takes forever for a minute to be over. That’s because you measure time with a highly subjective biological clock.
Your internal clock is just like that digital watch in some ways. It measures time in what scientists call pulses. Those pulses are accumulated, then stored in your memory as a time interval. Now, here’s where things get weird. Your biological clock can be sped up or slowed down by anything from drugs to the way you pay attention. If it takes you 60 seconds to cross the street, your internal clock might register that as 50 pulses if you’re feeling sleepy. But it might register 100 pulses if you’ve just drunk an espresso. That’s because stimulants literally speed up the clock in your brain (more on that later). When your brain stores those two memories of the objective minute it took to cross the street, it winds up with memories of two different time intervals.

And yet, we all have an intuitive sense of how long it takes to cross a street. But how do we know, if every time we do something it feels like it a slightly different amount of time? The answer, says neuroscientist Warren Meck, is “a Gaussian distribution” - in other words, the points on a bell curve. Every time you want to figure out how long something is going to take, your brain samples from those time interval memories and picks one. (…)

Your intuitive sense of how much time something will take is taken at random from many distorted memories of objective time. Or, as Meck puts it, “You’re cursed to be walking around with a distribution of times in your head even though physically they happened on precise time.”

Your internal clock may be the reason why you can multitask. Because nobody - not even the lowly rat - has just one internal clock going at the same time.

At the very least, you’ve got two internal clocks running. One is the clock that tracks your circadian rhythms, telling you when to go to sleep, wake up, and eat. This is the most fundamental and important of all your internal clocks, and scientists have found it running even in organisms like green algae. The other clock you’ve likely got running is some version of the interval time clock I talked about earlier - the one that tells you how long a particular activity is going to take.

{ io9 | Continue reading }

photo { Logan White }

In the 1940s, the Dutch psychologist Adrian de Groot performed a landmark study of chess experts. Although de Groot was an avid chess amateur – he belonged to several clubs - he grew increasingly frustrated by his inability to compete with more talented players. De Groot wanted to understand his defeats, to identify the mental skills that he was missing. His initial hypothesis was that the chess expert were blessed with a photographic memory, allowing them to remember obscure moves and exploit the minor mistakes of their opponents.

De Groot’s first experiment seemed to confirm this theory: He placed twenty different pieces on a chess board, imitating the layout of a possible game. Then, de Groot asked a variety of chess players, from inexperienced amateurs to chess grandmasters, to quickly glance at the board and try to memorize the location of each piece. As the scientists expected, the amateurs drew mostly blanks. The grandmasters, however, easily reproduced the exact layout of the game. The equation seemed simple: memory equals talent.

But then de Groot performed a second experiment that changed everything. Instead of setting the pieces in patterns taken from an actual chess game, he randomly scattered the pawns and bishops and knights on the board. If the best chess players had enhanced memories, then the location shouldn’t matter: a pawn was still a pawn. To de Groot’s surprise, however, the grandmaster edge now disappeared. They could no longer remember where the pieces had been placed.

For de Groot, this failure was a revelation, since it suggested that talent wasn’t about memory – it was about perception. The grandmasters didn’t remember the board better than amateurs. Rather, they saw the board better, instantly translating the thirty-two chess pieces into a set of meaningful patterns. They didn’t focus on the white bishop or the black pawn, but instead grouped the board into larger strategies and structures, such as the French Defense or the Reti Opening.

This mental process is known as “chunking” and it’s a crucial element of human cognition. As de Groot demonstrated, chess grandmasters automatically chunk the board into a set of known patterns, which allow them to instantly sort through the messy details of the game. And chunking isn’t just for chess experts: While reading this sentence, your brain is effortlessly chunking the letters, grouping the symbols into lumps of meaning. As a result, you don’t have to sound out each syllable, or analyze the phonetics; your literate brain is able to skip that stage of perception. This is what expertise is: the ability to rely on learned patterns to compensate for the inherent limitations of information processing in the brain. As George Miller famously observed, we can only consciously make sense of about seven bits of information (plus or minus two) at any given moment. Chunking allows us to escape this cognitive trap.

{ Wired | Continue reading }

New York City in the 1920s and ’30s was a hotbed of criminal activity. Prohibition laws banning the production, sale and distribution of alcohol had been introduced, but instead of reducing crime, they had the opposite effect. Gangsters organized themselves and seized control of the alcohol distribution racket, smuggling first cheap rum from the Caribbean, then French champagne and English gin, into the country. Speakeasies sprang up in every neighbourhood, and numbered more than 100,000 by 1925. When prohibition was abolished in 1933, the gangsters took to other activities, such as drug distribution, and crime rates continued to increase.

At the forefront of the city’s efforts to keep crime under control was a man named Carleton Simon. Simon trained as a psychiatrist, but his reach extended far beyond the therapist’s couch. He became a ‘drug czar’ six decades before the term was first used, spearheading New York’s war against drug sellers and addicts. He was a socialite and a celebrity, who made a minor contribution to early forensic science by devising new methods to identify criminals. He also tried to apply his knowledge to gain insights into the workings of the criminal brain, becoming, effectively, the first neurocriminologist.

Simon was born in New York City on February 28th, 1871, and studied in Vienna and Paris, graduating with an M.D. in 1890. Afterwards, he conducted sleep research. (…) Eventually, Simon became interested in criminology and psychopathology, and by the turn of the century had abandoned his psychiatric research to focus on these disciplines. (…)

Towards the end of the 1930s crime was estimated to cost the U.S. approximately $15 billion annually. Knowledge of brain function and dysfunction was very rudimentary by today’s standards, and criminals and psychopaths were often lobotomized or subjected to electroconvulsive therapy in order to keep them under control. Another treatment available was insulin shock therapy, which had been introduced by Manfred Sakel in 1933, and involved giving patients large repeated doses of the hormone to induce coma. It was around this time that Simon proposed a new theory, which he believed would help science to understand and control the criminal mind.

The theory drew on the concept of cerebral dominance, which had emerged some 70 years earlier, largely from Paul Broca’s investigations of stroke patients. (…) According to Simon’s theory, criminality occurs as a result of a shift in cerebral dominance, whereby the normally submissive right hemisphere gains mastery of the brain, leading to irrational behaviour.

{ Neurophilosophy | Continue reading }

photo { Alessandro Zuek Simonetti }

Social cognition is the scientific study of the cognitive events underlying social thought and attitudes. Currently, the field’s prevailing theoretical perspectives are the traditional schema view and embodied cognition theories. Despite important differences, these perspectives share the seemingly uncontroversial notion that people interpret and evaluate a given social stimulus using knowledge about similar stimuli. However, research in cognitive linguistics (e.g., Lakoff & Johnson, 1980) suggests that people construe the world in large part through conceptual metaphors, which enable them to understand abstract concepts using knowledge of superficially dissimilar, typically more concrete concepts.

{ Psychological Bulletin | Continue reading }

In general structure, Kant’s model of the mind was the dominant model in the empirical psychology that flowed from his work and then again, after a hiatus during which behaviourism reigned supreme (roughly 1910 to 1965), toward the end of the 20th century, especially in cognitive science.

Three ideas define the basic shape (‘cognitive architecture’) of Kant’s model and one its dominant method. They have all become part of the foundation of cognitive science.

• The mind is complex set of abilities (functions). (As Meerbote 1989 and many others have observed, Kant held a functionalist view of the mind almost 200 years before functionalism was officially articulated in the 1960s by Hilary Putnam and others.)

• The functions crucial for mental, knowledge-generating activity are spatio-temporal processing of, and application of concepts to, sensory inputs. Cognition requires concepts as well as percepts.

• These functions are forms of what Kant called synthesis. Synthesis (and the unity in consciousness required for synthesis) are central to cognition.

These three ideas are fundamental to most thinking about cognition now. Kant’s most important method, the transcendental method, is also at the heart of contemporary cognitive science.

• To study the mind, infer the conditions necessary for experience. Arguments having this structure are called transcendental arguments.

{ Stanford Encyclopedia of Philosophy | Continue reading }

photo { John Zimmerman }

The secret behind the beautiful songs that birds sing has been decoded and reproduced for the first time.

One of the great challenges in neuroscience is to explain how collections of neural circuits produce the complex sequences of signals that result in behaviours such as animal communication, birdsong and human speech.

Among the best studied models in this area are birds such as zebra finches. These enthusiastic singers produce songs that consist of long but relatively simple sequences of syllables. These sequences have been well studied and their statistical properties calculated.

It turns out that these statistical properties can be accurately reproduced using a type of simulation called a Markov model in which each syllable is thought of as a state of the system and whose appearance in a song depends only on the statistical properties of the previous syllable. (…)

But other birds produce more complex songs and these are harder to explain. One of these is the Bengalese finch whose songs vary in seemingly unpredictable ways and cannot be explained a simple Markov model. Just how the Bengalese finch generates its song is a mystery.

Until now. (…) Instead of the simple one-to-one mapping between syllable and circuit that explains zebra finch song, they say that in Bengalese finches there is a many-to-one mapping, meaning that a given syllable can be produced by several neural circuits. That’s why the statistics are so much more complex, they say.

This type of model is called a hidden Markov model because the things that drives the observable part of the system–the song–remains hidden.

{ The Physics arXiv Blog | Continue reading }

related { New research suggests that our brains have a built-in bias against people whose accents don’t sound like our own }

Despite rumors to the contrary, there’s many ways in which the human brain isn’t all that fancy. Let’s compare it to the nervous system of a fruit fly. Both are made up of cells — of course — with neurons playing particularly important roles. Now one might expect that a neuron from a human will differ dramatically from one from a fly. Maybe the human’s will have especially ornate ways of communicating with other neurons, making use of unique “neurotransmitter” messengers. Maybe compared to the lowly fly neuron, human neurons are bigger, more complex, in some way can run faster and jump higher.

But no. Look at neurons from the two species under a microscope and they look the same. They have the same electrical properties, many of the same neurotransmitters, the same protein channels that allow ions to flow in and out, as well as a remarkably high number of genes in common. Neurons are the same basic building blocks in both species.

So where’s the difference? It’s numbers — humans have roughly a million neurons for each one in a fly. And out of a human’s 100 billion neurons emerge some pretty remarkable things. With enough quantity, you generate quality.

Neuroscientists understand the structural bases of some of these qualities.

{ NY Times | Continue reading | On the Human/National Humanities Center }

The concept of trust is in many ways the connective tissue of society—governing everything from our personal relationships to our common use of currency.

Most, if not all, of the decisions we make every day rely on one form or another of trust. But what if our capacity for faith is simply the result of brain chemistry?

Economic researchers are uncovering the chemical triggers in our brains that spark feelings of trust—and using their findings to better understand how markets work.

{ Big Think | Continue reading }

installation { Francesco Fonassi }