The Brain Unveiled

By Emily Singer
MIT Technology Review, November/December 2008

Edited by Andy Ross

Images by Van Wedeen, Ruopeng Wang, Jeremy Schmahmann, and Guangping Dai of the MGH Martinos Center for Biomedical Imaging in Boston, MA; Patric Hagmann of EPFL and CHUV, Lausanne, Switzerland; and Jon Kaas of Vanderbilt University, Nashville, TN.

Brain Connections

Diffusion spectrum imaging, developed by neuroscientist Van Wedeen at Massachusetts General Hospital, analyzes magnetic resonance imaging (MRI) data in new ways, letting scientists map the nerve fibers that carry information between cells. These images, generated from a living human brain, show a reconstruction of the entire brain (1) and a subset of fibers (2). The red fibers in the middle and lower left of both images are part of the corpus callosum, which connects the two halves of the brain.

Mapping Diffusion

Neural fibers in the brain are too tiny to image directly, so scientists map them by measuring the diffusion of water molecules along their length. The scientists first break the MRI image into "voxels," or three-dimensional pixels, and calculate the speed at which water is moving through each voxel in every direction. Te researchers can infer the most likely path of the various nerve fibers (red and blue lines) passing through that spot. The result is a detailed diagram like that of the brain stem (3).

More ...

AR Wonderful work!

Buffing the Brain

By Bryan Appleyard
The Sunday Times, November 16, 2008

Edited by Andy Ross

The brain is not a muscle. It is a 1.3-kilogram crème caramel-like mix of fat, water and proteins driven by electricity and chemicals called neurotransmitters. As far as we know, it is the most complex thing in the universe. It's made to last, at best, about 100 years. It shrinks and deteriorates with age. By the time you're 30 you're probably past your intellectual peak.

This is a problem for baby-boomers. They've had everything, they run the world, but now they're in their 50s and 60s. But the selves they love are just so many crème caramels soon to pass their sell-by date. Already they can see the signs. Why did you leave your phone in the freezer? Why do you lose your glasses six times a day? These are symptoms of age-associated memory impairment (AAMI).

There's a bright spot. If we work the brain, we can grow new brain cells. "There is a gradual growing awareness that challenging your brain can have positive effects," says Dr Gene Cohen, director of the Center on Aging, Health & Humanities at George Washington University. "Every time you challenge your brain, it will actually modify the brain. We can indeed form new brain cells, despite a century of being told it's impossible."

It was not until the early 1990s, with the development of magnetic resonance imaging (MRI), that we found we could watch the brain actually working. If MRI delivers half of what many people expect it to deliver, these could turn out to be the most revolutionary machines in human history. But these are early days, so any extravagant claims about ways of improving your brain on the basis of evidence from MRI machines are likely to be snake oil.

From psychiatry and psychology, we may have made a start on the understanding of genius. Mark Jung Beeman, a professor of psychology at Northwestern University in Illinois, is one of a group trying to unravel this extremely elusive phenomenon using MRI and EEG. There are two ways of solving problems: analytic and inspirational. With analytic you just plod your way through the work, reasoning your way to the solution. But often you grind to a halt and give up.

Up to this point your brain has been working through a limited number of connections, all directly related to the problem at hand. When you stop, the connections loosen; new connections, new possibilities, can be formed. Finally you reach the eureka moment, you say "Aha!" and your problem is solved.

A paper by Beeman and others puts it this way: "Although all problem-solving relies on a largely shared cortical network, the sudden flash of insight occurs when solvers engage distinct neural and cognitive processes that allow them to see connections that previously eluded them."

The process seems to be centred on one small part of the brain: the anterior superior temporal gyrus. At Goldsmiths College in London, Dr Joydeep Bhattacharya says the real issue is not the "Aha!" moment itself, but the way it is produced in the brain and how we recognise it. "We need to know the brain processes involved, to find how this moment is strong enough to reach consciousness. We know insight does not come from the sky."

There is a link between musical improvisation and the "Aha!" moment. Improvisation is found to be accompanied by a dissociated pattern of activity in the prefrontal cortex. The prefrontal cortex is to the brain what a conductor is to an orchestra. It pulls the whole show together.

The dissociated pattern echoes the loosening of connections that precedes the "Aha!" moment. Insight and creativity, perhaps even genius, seem to be linked to a brain that can disorganise itself and freewheel, making new and unexpected connections. As Nancy Andreasen, one of the world’s most distinguished neuroscientists and author of The Creative Brain, puts it, the creative act may "begin with a process during which associative links run wild, creating new connections, many of which might seem strange or implausible. The disorganised mental state may persist for many hours, while words, images and ideas collide. Eventually order emerges, and with it the creative product".

Divergent thinkers habitually wander around their own minds, looking for links, however absurd or surreal. Convergent thinkers look for the one correct answer. The discovery of the structure of DNA by Watson and Crick in 1953 was a clear example of convergent thinking — the one correct answer was a double helix.

On August 10, 1788, one of the greatest of all examples of divergent thinking came into the world. It was Mozart's last symphony, the Jupiter, and the final movement is an explosive assertion of the joy of our apparently limitless creativity. If anybody was a diverger, it was Mozart.

There has always been a link between madness and genius, and too much divergence can undoubtedly drive you crazy. High creativity is not linked with schizophrenia but with mood disorders — notably bipolar disorder or manic depression. The link has been made by several highly authoritative studies, both by leading American scientists. Kay Jamison, a professor of psychology at Johns Hopkins University in Baltimore, studied poets, playwrights, novelists, biographers and artists and found 38% had been treated for an affective illness — a mood disorder.

So what, you might wonder, does all this mean for you, a boomer with brain rot who sometimes leaves his phone in the freezer and his glasses God knows where? What must you do?

The short answer is use it or lose it. The plasticity of the brain means that it is able, in the face of injury or decay, to find ways of adapting itself to preserve strong patterns of activity. Read books, good books — nothing works better.

But there's going to be a lot of snake oil on the market in the decades before we can come up with any more solid prescriptions to save our highest creative selves from brain rot. The brain workout is already as much of a boomer must-do as the body workout.

In the end you die, and it seems likely that the miracle of the world inside your particular 1.3 kilograms of crème caramel dies with you. Perhaps you had insight, inspiration, perhaps you created, perhaps you were a genius.

On January 27, 1756, Mozart was born in Salzburg, Austria. He spent most of the next 35 years giving the best ever account in music of why your life is worth living.

AR Bryan himself sounds a little manic in (the unedited original for) this piece — perhaps he's beginning to feel his own age. Naturally, I sympathize with him — and agree about Mozart.

A New Theory of Mental Disorders

By Benedict Carey
The New York Times, November 10, 2008

Edited by Andy Ross

Two scientists — Bernard Crespi, a biologist at Simon Fraser University in Canada, and Christopher Badcock, a sociologist at the London School of Economics — have published a sweeping theory of brain development that would change the way mental disorders like autism and schizophrenia are understood.

Their idea is that an evolutionary tug of war between genes from the father's sperm and the mother's egg can tip brain development in one of two ways. A strong bias toward the father pushes a developing brain along the autistic spectrum, toward a fascination with objects, patterns, mechanical systems, at the expense of social development. A bias toward the mother moves the growing brain along a psychotic spectrum, toward hypersensitivity to mood, increasing a child's risk of developing schizophrenia later on, or of mood problems like bipolar disorder and depression.

In short, autism and schizophrenia represent opposite ends of a spectrum that includes most psychiatric and developmental brain disorders. Emotional problems like depression, anxiety and bipolar disorder appear with schizophrenia on Mom's side, while Asperger's syndrome and other social deficits are on Dad's.

The theory leans heavily on the work of David Haig of Harvard, who argued in the 1990s that pregnancy was in part a biological struggle for resources between the mother and unborn child. Natural selection should favor mothers who limit the nutritional costs of pregnancy and have more offspring, but it should also favor fathers whose offspring maximize the nutrients they receive during gestation.

Evidence that this struggle is being waged at the level of individual genes is accumulating. For example, the fetus inherits from both parents a gene called IGF2, which promotes growth. But too much growth taxes the mother, and in normal development her IGF2 gene is chemically marked, or imprinted, and biologically silenced. If her gene is active, it causes a disorder of overgrowth, in which the fetus’s birth weight swells, on average, to 50 percent above normal.

Biologists call this gene imprinting an epigenetic effect, meaning that it changes the behavior of the gene without altering its chemical composition. This occurs by muffling a gene, for instance, with a chemical marker that makes it hard for the cell to read the genetic code.

To illustrate how such genetic reshaping works, Dr. Crespi and Dr. Badcock point to a remarkable group of children. Those with the genetic disorder called Angelman syndrome typically have a jerky gait, appear unusually happy and have difficulty communicating. Those born with a genetic problem known as Prader-Willi syndrome often are placid and compliant as youngsters.

These two disorders, which turn up in about one of 10,000 newborns, stem from disruptions of the same genetic region on chromosome 15. If the father's genes dominate in this location, the child develops Angelman syndrome. If the mother's do, the result is Prader-Willi syndrome. The former is associated with autism, and the latter with mood problems and psychosis later on, just as the new theory predicts.

Some problems associated with autism, like a failure to meet another's gaze, are direct contrasts to those found in people with schizophrenia, who often believe they are being watched. Where children with autism appear blind to others' thinking and intentions, people with schizophrenia see intention and meaning everywhere, in their delusions. The idea expands on the "extreme male brain" theory of autism proposed by Dr. Simon Baron-Cohen of Cambridge.

The theory does not fit all of the various quirks of autism and schizophrenia. But experts say that the two scientists have infused the field with a shot of imagination.

AR A brave start — a widely promoted but self-published book about bearded ladies a few years ago apparently argued something similar. Certainly the intuition is striking. Despite Freud's bold but premature efforts, the sexual dimension of subjective experience is still largely unexplored in science. Since we (scientists and philosophers) are still struggling to account for subjective experience of any sort, this is no surprise.