……………………..Limits are for governments.

Excerpt from “The Science of Concentration”

Neurons firing in synchrony "a bit like getting strangers in one section of a stadium to start clapping in unison, thereby sending a signal that induces people on the other side of the stadium to clap along." Image credit TurboPhoto.

‘Robert Desimone, [is] a neuroscientist at M.I.T. who has been doing experiments somewhat similar to my [distracting] taxicab TV experience. He has been tracking the brain waves of macaque monkeys and humans as they stare at video screens looking for certain flashing patterns.

When something bright or novel flashes, it tends to automatically win the competition for the brain’s attention, but that involuntary bottom-up impulse can be voluntarily overridden through a top-down process that Dr. Desimone calls “biased competition.” He and colleagues have found that neurons in the prefrontal cortex — the brain’s planning center — start oscillating in unison and send signals directing the visual cortex to heed something else.

These oscillations, called gamma waves, are created by neurons’ firing on and off at the same time — a feat of neural coordination a bit like getting strangers in one section of a stadium to start clapping in unison, thereby sending a signal that induces people on the other side of the stadium to clap along. But these signals can have trouble getting through in a noisy environment.

“It takes a lot of your prefrontal brain power to force yourself not to process a strong input like a television commercial,” said Dr. Desimone, the director of the McGovern Institute for Brain Research at M.I.T. “If you’re trying to read a book at the same time, you may not have the resources left to focus on the words.”

Now that neuroscientists have identified the brain’s synchronizing mechanism, they’ve started work on therapies to strengthen attention. In the current issue of Nature, researchers from M.I.T., Penn and Stanford report that they directly induced gamma waves in mice by shining pulses of laser light through tiny optical fibers onto genetically engineered neurons. In the current issue of Neuron, Dr. Desimone and colleagues report progress in using this “optogenetic” technique in monkeys.’

~John Tierney, NY Times

2 responses

  1. From the Ptak Science Book Blog:

    “Can We See More or Less than We Used To Be Able To See?

    Jevons An early study of attention and perception (or “How Many Items Can it Embrace at Once?”) popped out at me while muscling my way through another year of Nature magazine for 1871. The article was by the polymatic W. Stanley Jevons (“The Power of Numerical Discrimination,” in Nature volume III, 18711) who contributes an interesting and very early experimental bit on the success of the brain to correctly formulate an accurate memory when in a flash shown a number of items. (That is to say, when shown a certain group of X-number of items instantaneously and then removed, how often will the mind be able to remember the correct number upon recall–and without committing them to memory per se or counting them?) In this fascinating study Jevons records not only right/wrong answers but how “close” the remembered fit is to the original number, and in effect is a pioneering scientific effort towards understanding our abilities and limits in information processing. And as it turns out the ability to precisely recognize and remember groups of objects with success and without counting stops at about four items for the vast number of people tested.”


    Comment: It never ceases to amaze me how much attention and experimentation is done using “flashing images” in neuroscience. Apparently this type of experimentation goes back to the late 1800’s. It might be interesting to see the limits of the brain’s ability to interpret and remember information, and quantify this ability down to seconds or milliseconds. However, the sheer number of studies I have seen which involve flashing information to subjects in popular books about the human brain is remarkable. Experimenters seem to be obsessed with creating highly arbitrary circumstances in their studies and making great generalizations about the human brain’s function based on their findings.

    When I have time I will give more specific examples from a popular brain science book. Almost every experiment cited involved flashing images, despite the fact that the book is about the intriguing subject of rapt attention, and the benefits of deep periods of focus.

    December 21, 2012 at 1:20 pm

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