Brain Pickings

Posts Tagged ‘neuroscience’

10 AUGUST, 2012

The Science of How Music Enchants the Brain, Animated

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How harmony, melody, and rhythm trigger the same reward systems that drive our desires for food and sex.

The profound connection between music and the brain has long fascinated scientists and philosophers alike, and has even shaped the course of our evolution. The wonderful duo Mitchell Moffit and Gregory Brown, better known as AsapSCIENCE, breaks down music’s ability to create a state of arousal by inducing the release of the neurotransmitter dopamine, which also regulates the neurochemistry of love, and offsetting a reward circuit similar to the one drugs exploit — something I can certainly attest to as a hopeless music addict.

In the same way that a drug-induced dopamine surge leaves you craving more, music becomes addictive — the dopamine tells your body it was rewarded and creates a desire to seek out more.

For more, see these 7 essential books on music, emotion, and the brain.

It’s Okay To Be Smart

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09 AUGUST, 2012

Why Success Breeds Success: The Science of “The Winner Effect”

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Biochemistry and the self-reinforcing upward spiral of winning.

The past century of science has demonstrated the pivotal role of biochemistry in such human phenomena as love, attraction, and lust. But to consider that individual neurobiology might impact things as rational and complex as, say, stock markets seems rather radical. Yet that’s precisely what trader-turned-neuroscientist John Coates explores in The Hour Between Dog and Wolf: Risk Taking, Gut Feelings and the Biology of Boom and Bust (public library) — an ambitious look at how body chemistry affects high-stakes financial trading, in which Coates sets out to construct — and deconstruct — a “universal biology of risk-taking.”

One particularly fascinating aspect of risk-taking has to do with what is known as “the winner effect,” a self-reinforcing osmosis of the two key hormones driving the biochemistry of success and failure — testosterone, which Coates calls “the hormone of economic bubbles,” and cortisol, “the hormone of economic busts.” In traders — as in athletes, and in the rest of us mere mortals when faced with analogous circumstances — testosterone rises sharply and durably during financial booms, inducing a state of risk-seeking euphoria and providing a positive feedback loop in which success itself provides a competitive advantage. By contrast, the stress hormone cortisol spikes during financial downturns; traders with sustained high levels of cortisol become more risk-averse and timid, ultimately being less competitive.

Coates explains:

The euphoria, overconfidence and heightened appetite for risk that grip traders during a bull market may result from a phenomenon known in biology as the ‘winner effect.’

[…]

Biologists studying animals in the field had noticed that an animal winning a fight or a competition for turf was more likely to win its next fight. This phenomenon had been observed in a large number of species. Such a finding raised the possibility that the mere act of winning contributes to further wins. But before biologists could draw such a conclusion they had to consider a number of alternative explanations. For example, maybe an animal keeps winning simply because it is physically larger than its rivals. To rule out possibilities such as this, biologists constructed controlled experiments in which they pitted animals that were equally matched in size, or rather that were equally matched in what is called ‘resource holding potential,’ in other words the total physical resources — muscular, metabolic, cardiovascular — an animal can draw on in an all-out fight. They also controlled for motivations, because a small, hungry animal eating a carcass can successfully chase off a larger, well-fed animal. Yet even when animals were evenly matched for size (or resources) and motivation, a pure winner effect nonetheless emerged.

An intriguing correlation, certainly, but what is the causal mechanism at work? Scientists have suggested that there are several elements at play: First, testosterone levels rise when animals face off, producing anabolic effects on muscle mass and hemoglobin, quickening reactions, improving visual acuity, and increasing the animal’s persistence and fearlessness. Then, once the fight is over, the winning animal emerges with even higher levels of testosterone, and the loser with lower ones. Coates sums it up thusly:

Life for the winner is more glorious. It enters the next round of competition with already elevated testosterone levels, and this androgenic priming gives it an edge that increases its chances of winning yet again. Through this process an animal can be drawn into a positive-feedback lop, in which victory leads to raised testosterone levels which in turn leads to further victory.

So does this winner effect also occur in humans? Coates thinks so. He cites a study, in which researchers rigorously examined a database of 630,000 professional tennis matches and found that the winner of the first set had a 60% chance of winning the second one and, since the win in these matches comes down to the best of three sets, winning the match itself. (Anecdotally, a quick glance at Michael Phelps’s Olympic scorecard would suggest a similar conclusion.)

The precompetitive surge in testosterone has been documented in a number of sports, such as tennis, wrestling and hockey, as well as in less physical competitions, such as chess, even medical exams. Winning athletes in sports experience a postgame spike in testosterone, suggesting that a positive-feedback loop is indeed the physiological substrate to winning and losing streaks. Incidentally, these testosterone-driven sporting victories appear to be more common when an athlete is on home turf, the so-called home-field advantage. Athletes on a winning streak may thus have a very different body chemistry than those on a losing streak. IN all these experiments, with both animals and humans, the winners experienced a self-reinforcing upward spiral of testosterone.

Tying the research back to the human condition itself, Coates puts it rather poetically:

We hold the keys to victory within us, but usually cannot find them.

The Hour Between Dog and Wolf goes on to examine how this intricate exchange of information between body and brain coalesces into what we call “gut feelings,” reminding us that we are, after all, remarkable and complicated machines.

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03 JULY, 2012

Jesse Bering on the Adaptive Value and Neurochemistry of Heartbreak

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The science of why it’s possible to actually die of a broken heart.

This must be the season for fascinating books on the psychology and anthropology of sexuality, from the history of judging desire to the origins of sex. Now, in Why Is the Penis Shaped Like That?: And Other Reflections on Being Human (public library), research psychologist Jesse Bering — whom you might recall as the author of the excellent The Belief Instinct: The Psychology of Souls, Destiny, and the Meaning of Life, and who is a frequent contributor to Scientific American and Slate — examines the kaleidoscope of sexual taboos through the lens of science and psychology, from the evolution of body fluids to the politics of polyamory to the neurochemistry of heartbreak.

In one particularly fascinating chapter, highlighting studies that reveal a correlation between homophobia and repressed homosexual desire, Bering zooms in on the leaps of logic that permeate much of the rhetoric on homosexuality and the naturalistic fallacies that attempt to define notions of “normalcy”:

[I]t’s rather strange that we look for moral guidance about human sexuality from the rest of the animal kingdom, a logical fallacy in which what is ‘natural’ — such as homosexual behavior in other species — is regarded as ‘acceptable.’ It’s as if the fact that bonobos, desert toads, and emus have occasional same-sex liaisons has a moral bearing on gay rights in human beings. Even if we were the lone queer species in this godless galaxy, even if it were entirely a ‘choice’ between two consenting adults, why would that make it more reasonable to discriminate against people in homosexual relationships?

Beyond these philosophical problems with seeking out social prescriptions from a nature that is completely mute as to what we should do with our penises and vaginas, however, there’s an even bigger hurdle to taking polyamory chic beyond the tabloids, talk shows, and Internet forums and into standard bedroom practice. And that is simply the fact that we’ve evolved to empathize with other people’s suffering, including the suffering of the people we’d betray by putting our affable genitals to their evolved promiscuous use.

Heartbreak is every bit as much a psychological adaptation as is the compulsion to have sex with those other than our partners, and it throws a monster of a monkey wrench into the evolutionists’ otherwise practical polyamory.

Bering goes on to offer a kind of scientific anatomy of heartbreak, citing the familiar work of biological anthropologist Helen Fisher:

[T]here are two main stages associated with a dead and dying romantic relationship, which is so often tied to one partner’s infidelities. During the ‘protest’ stage that occurs in the immediate aftermath of rejection, ‘abandoned lovers are generally dedicated to winning their sweetheart back. They obsessively dissect the relationship, trying to establish what went wrong; and they doggedly strategize about how to rekindle the romance. Disappointed lovers often make dramatic, humiliating, or even dangerous entrances into a beloved’s home or place of work, then storm out, only to return and plead anew. They visit mutual haunts and shared friends. They phone, e-mail, and write letters, pleading, accusing, and/or trying to seduce their abandoner.’

At the neurobiological level, the protest stage is characterized by unusually heightened, even frantic activity of dopamine and norepinephrine receptors in the brain, which has the effect of pronounced alertness similar to what is found in young animals abandoned by their mothers. This impassioned protest stage — if it proves unsuccessful in reestablishing the romantic relationship — slowly disintegrates into the second stage of heartbreak, what Fisher refers to as ‘resignation/despair,’ in which the rejected party gives up all hope of ever getting back together. ‘Drugged by sorrow,’ writes Fisher, ‘most cry, lie in bed, stare into space, drink too much, or hole up and watch TV.’ At the level of the brain, overtaxed dopamine-making cells begin sputtering out, causing lethargy and depression. And in the saddest cases, this depression is linked to heart attacks or strokes, so people can, quite literally, die of a broken heart. So we may not be ‘naturally monogamous’ as a species, but neither are we naturally polygamous.

[ ... ]

[O]ne of the more fascinating things about the resignation/despair stage is the possibility that it actually serves an adaptive function that may help to salvage the doomed relationship, especially for an empathetic species such as our own…. [H]eartbreak is not easily experienced at either end, and when your actions have produced such a sad and lamentable reaction in another person, when you watch someone you care about (but no longer feel any real long-term or sexual desire to be with) suffer in such ways, it can be difficult to fully extricate yourself from a withered romance. If I had to guess — in the absence of any studies that I’m aware of to support this claim — I’d say that a considerable amount of genes have replicated in our species solely because, with our damnable social cognitive abilities, we just don’t have the heart to break other people’s hearts.

Why Is the Penis Shaped Like That?: And Other Reflections on Being Human is excellent in its entirety, woven of Bering’s rare tapestry of scientific rigor and a powerful, articulate social point of view.

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