Meditation and Gamma Waves

This is a study from Scientific American that came out of the Center for Compassion and Altruism at Stanford. It gives preliminary results on some EEG studies that are being performed using the Dalai Lama's monks showing the difference between newbie and seasoned meditators' brain waves.

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http://compassion.stanford.edu/

May 26, 2009 | 34 comments
Meditation on Demand
New research reveals how meditation changes the brain

By Peter B. Reiner

meditation


Brenda McEwan
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In the fall of 2005, the Dalai Lama gave the inaugural Dialogues between Neuroscience and Society lecture at the Annual Meeting of the Society for Neuroscience in Washington, DC. There were over 30,000 neuroscientists registered for the meeting, and it seemed as if most of them attended the talk. The Dalai Lama’s address was designed to highlight the areas of convergence between neuroscience and Buddhist thought about the mind, and to many in the audience he clearly achieved his objective. There was some controversy over his being invited to deliver this lecture insofar as he is both a head of state and a religious leader, and for that reason he largely stuck to his prepared text. But he strayed from the text at least once, reminding the audience that not only was he a Buddhist monk but also an enthusiastic proponent of modern technology.

Elaborating, he shared a confidence with the audience, telling the audience of scientists that meditating was hard work for him (even though he meditates for 4 hours every morning), and that if neuroscientists were able to find a way to put electrodes in his brain and provide him with the same outcome as he gets from meditating, he would be an enthusiastic volunteer. It turns out that a recent set of experiments, from researchers at MIT and Stanford, moves us a step closer to making his wish a reality.

The Dalai Lama’s interest in neuroscience has been reciprocated by at least some members of the neuroscience community. Reasoning that studying the brains of people who meditate might lead to novel insights about the human brain, investigations of long-term meditators has been fertile ground for scientific investigation, with some of the more rigorous work emerging from Richard Davidson’s laboratory at the University of Wisconsin. From the perspective of neuroscience, meditation can be characterized as a series of mental exercises by which one strengthens one’s control over the workings of their own brain. The simplest of these meditation practices is ‘focused attention’ where one concentrates on a single object, for example one’s breath. When expert meditators practiced focused attention meditation, demonstrable changes were seen using fMRI in the networks of the brain that are known to modulate attention. A second set of experiments studied long-term meditators practicing ‘open monitoring meditation’, a more advanced meditation practice which in many ways is a form of metacognition: the objective is not to focus one’s attention but rather to use one’s brain to monitor the universe of mental experience without directing attention to any one task. The unexpected result of this experiment was that the EEG of long-term meditators exhibited much more gamma-synchrony than that of naive meditators. Moreover, normally human brains produce only short bursts of gamma-synchrony. What was most remarkable about this study was that long-term meditators were able to produce sustained gamma-activity in a manner that had never previously been observed in any other human. As such, sustained gamma activity has emerged as a proxy for at least some aspects of the meditative state.

Gamma Waves

But what causes gamma rhythm? And are there any potential benefits of sustained gamma-activity? The strongest hypothesis for the cellular mechanisms underlying generation of the gamma rhythm is that it is due to the activation of fast-spiking interneurons in the cerebral cortex. In two new papers to be published in Nature, the laboratories of Christopher Moore and Li-Huei Tsai at MIT and Karl Deisseroth at Stanford tested this hypothesis directly. The experimenters utilized optogenetics, developing custom-designed viruses to infect only the fast-spiking interneurons of either the prefrontal or barrel cortex in mice with genetically engineered, light-sensitive cation channels. Then, they inserted fine optical fibers into the relevant region of the cortex, allowing light to be delivered to the infected neurons and thereby activating only the fast-spiking interneurons. (In essence, this allowed them to switch particular brain cells on and off.) In both experiments, selectively stimulating the fast-spiking interneurons evoked gamma oscillations, thereby confirming the hypothesis that these neurons drive the gamma rhythm.

http://www.scientificamerican.com/article.cfm?id=meditation-on-demand

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Graded Symptom Checklist

Hello, Yes-brainers,

The symptom checklist for head injuries presented here may fit like old hat on the brains of Cindy and Kerry, our neuro-practitioners at Sierra Nevada Memorial Hospital, but I thought I'd post the list anyway, introduced by Jane Brody's commentary on it. It's good to know that such a list exists and that it caught the spotlight of the New York Times. To jump to the online article, click here. —John

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Symptom List Helps Gauge Head Injures

By JANE E. BRODY

Published: August 24, 2009

Dr. Robert C. Cantu, a neurosurgeon who is an expert on sports-related concussions, says every parent with a child who plays a contact or collision sport should have what is called the Graded Symptom Checklist.

Issued by the National Athletic Trainers’ Association, the checklist should be used at the time of a head injury and at least four times afterward: at 2 to 3 hours, 24 hours, 48 hours and 72 hours after the injury, or until all symptoms have cleared.

The checklist can help determine whether a concussion has occurred, its severity and whether a player is fit to return to the game.

But the checklist is also important to use later, on the recommended schedule, because symptoms of a concussion are sometimes delayed. A player who sustained a direct or indirect blow to the brain may feel all right initially, then develop symptoms hours or days later.

Athletic trainers, doctors or other medical personnel who suspect that an athlete has suffered a concussion can use the checklist to evaluate a player both at rest and during physical exertion. Coaches and parents can be trained to use it as well.

Professional evaluators, parents and players must understand that a return of symptoms when a brain-injured athlete is physically or cognitively stressed is a clear sign that the brain has not healed.

“Any one of these symptoms occurring in the aftermath of a head trauma would disqualify an athlete from participating in the sport,” emphasized Dr. Cantu, co-director of the Center for the Study of Traumatic Encephalopathy at Boston University School of Medicine. “No athlete should be engaged in physical exertion if any symptom is present.” — JANE E. BRODY

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Attention Yes-brainers:

Because of our blog's format constraints, we are unable to see the far right edge of the checklist graphic. What gets cut off is the number 72 and the column of spaces below it. To get a copy of the original as it appears in the Times, go to this page, and click on the hot text for graphic on the left.

Copyright New York Times 2009

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