Stephen Dougherty, MS – Brain Blogger http://brainblogger.com Health and Science Blog Covering Brain Topics Wed, 30 May 2018 15:00:03 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.6 Inside Your Brain on Holiday http://brainblogger.com/2011/11/23/inside-your-brain-on-holiday/ http://brainblogger.com/2011/11/23/inside-your-brain-on-holiday/#comments Wed, 23 Nov 2011 12:00:55 +0000 http://brainblogger.com/?p=7798 Sit back, close your eyes, relax for a minute and allow your mind to wander wherever it wants to go. Don’t try to think of anything… Have you ever wondered what is going on inside your brain when your mind isn’t doing anything in particular, just like a moment ago? It turns out quite a lot. One of the most astonishing qualities of the brain is its voracious appetite for energy. It accounts for only 2% of body weight, yet it burns an amazing 20% of the total calories consumed by the body. So you might think that the brain at rest would be conserving energy until the next task, but this is hardly the case. The energy consumption of the brain at rest decreases by only 5% compared to a brain at full capacity. Scientists have named the energy consumed during rest the brain’s “dark energy,” since the massive energy consumption during this so-called rest period is one of the biggest mysteries in neuroscience today.

Scientists call the state of the brain at rest the default mode network (DMN), which can be described as a discrete collection of brain regions that exhibit greater activity during rest periods than during performance in effortful cognitive tasks. This pattern of activity is associated with daydreaming as well as light sleep. While researchers have not determined the full range of processes that the brain undergoes at rest, recent evidence has revealed that resting brain abnormalities are associated with schizophrenia, depression, autism and Alzheimer’s disease.

In a recent study published in PLoS One, researchers in Japan at Tohoku University found a link between the DMN and general intelligence and creativity.

Researchers scanned the brains of 63 healthy volunteers during rest using functional MRI to measure the cerebral blood flow (CBF) in different regions of the brain. CBF is a way to measure brain activity since regions with greater activation demand more oxygen delivery via blood. To measure general intelligence, researchers administered a standard psychometric test to volunteers. Creativity was assessed using a divergent thinking test, which assesses the ability to think in unique ways and generate novel ideas rapidly.

Brain imaging revealed that individuals who scored higher on measures of intelligence also showed higher blood flow in the gray and white matter of the brain at rest. Similarly, individuals who demonstrated greater creativity exhibited higher blood flow in regions of white matter at rest, but not gray matter.

So what does this mean, exactly?

Well, gray matter is the portion of brain tissue consisting mainly of nerve cell bodies, which may be thought of as the processing center of the nerve cell. White matter consists of nerve fibers covered by myelin, a protein coating responsible for the white appearance, which transmit electrical signals from one nerve cell to another. To use a computer network as an analogy, the gray matter would be the actual computers and the white matter is the network cables connecting the computers together.

The authors of this study speculate that more blood flow to gray and white matter in individuals with higher intelligence may be an indication that they have intrinsically more active brains. It’s possible that brains that are more active at rest are undergoing specific biochemical processes to increase the integrity and efficiency of the system.

Creative individuals also showed more white matter blood flow, but no difference in gray matter. This makes sense because white matter is involved in the overall connectivity of the brain and a key aspect of divergent and novel types of thinking is greater communication among distinct regions of the brain.

These results offer exciting clues to the function of the brain’s mysterious dark energy. The brain is not a machine that has an ON and OFF state. Instead, the brain is a dynamic system engaging in integral processes continuously, especially when we’re unaware of it, as with daydreaming and sleep.

Insights from research on the brain’s DMN suggest an alternative to the old adage “an idle mind is the devil’s workshop.” As the great mathematician Henri Poincaré observed regarding his own creative process, “Often nothing good is accomplished at the first attack. One takes a rest; and then all of a sudden the decisive idea presents itself to the mind.” Indeed, an idle mind may be an extremely useful tool for solving a problem, coming up with an innovation, or simply maintaining a healthy brain.

References

Buckner RL, Andrews-Hanna JR, & Schacter DL (2008). The brain’s default network: anatomy, function, and relevance to disease. Annals of the New York Academy of Sciences, 1124, 1-38 PMID: 18400922

Raichle ME (2009). A paradigm shift in functional brain imaging. The Journal of neuroscience : the official journal of the Society for Neuroscience, 29 (41), 12729-34 PMID: 19828783

Takeuchi H, Taki Y, Hashizume H, Sassa Y, Nagase T, Nouchi R, & Kawashima R (2011). Cerebral blood flow during rest associates with general intelligence and creativity. PloS one, 6 (9) PMID: 21980485

Image via bendao / Shutterstock.

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Pain Is No Matter for the Meditative Mind http://brainblogger.com/2011/10/23/pain-is-no-matter-for-the-meditative-mind/ http://brainblogger.com/2011/10/23/pain-is-no-matter-for-the-meditative-mind/#comments Sun, 23 Oct 2011 12:00:04 +0000 http://brainblogger.com/?p=7512

Remove your opinion about that which appears to give you pain and you stand painless.
— Marcus Aurelius

Pain is inevitable. Suffering is optional.
— Dalai Lama

The insight of Marcus Aurelius and the Dalai Lama about the nature of pain alludes to the practical knowledge that physical pain can be managed effectively through proper training and mental discipline, neatly summarized by the popular phrase “mind over matter.”

In the West, the notion of “mind over matter” has been circulating for centuries (at least since Aurelius and previous Stoic philosophers), yet it has been relatively recently that a technique that puts this insight into practice became the subject of serious scientific examination, namely mindfulness meditation. Mindfulness meditation achieves this effect by cultivating a sense of equanimity through objective observation of the internal processes of the body. Over the past decade, the science of mindfulness meditation has revealed a wide range of cognitive and emotional benefits conferred on practitioners including enhanced attention, lower pain sensitivity, and reduced emotional reactivity. The evidence for these benefits has also been supported by brain imaging studies in long-term meditators showing that change occurs at the physiological level.

To date, the majority of mindfulness meditation studies have been conducted in individuals with long-term intensive meditation experience. In a study published earlier this year in the Journal of Neuroscience, researchers at Wake Forest University explored the impact of mindfulness meditation on pain after only a few days of meditation training.

A group of 15 healthy volunteers took part in four 20-minute sessions of mindfulness meditation instruction where they were trained to maintain awareness on their own breathing while acknowledging and letting go of distraction.

The study evaluated the effect of mindfulness meditation in two dimensions: 1) how the volunteers reported pain intensity and unpleasantness, and 2) how brain activation patterns changed as measured by functional MRI. To assess the volunteer’s pain response, a small thermal simulator heated to around 120°F was applied to the back of the leg.

Comparing responses to the heat before and after meditation training, volunteers reported a 40% reduction in pain intensity and a 57% reduction in unpleasantness associated with the heat stimulus. Brain imaging indicated increased activation in areas associated with awareness of the pain sensation and a reduced activation in areas associated with the emotional response to pain perception.

Interestingly, a decoupling of two brain areas, the dorsolateral prefrontal cortex and cingulate cortex, was observed. The prefrontal cortex is thought to control attention and other executive functions, whereas the cingulate cortex is associated with the emotional salience of a stimulus. The authors suggest that the beneficial effect of meditation may be due to a dissociation of the awareness of pain with the emotional evaluation of the pain attached to it. Accordingly, the meditators are aware of the pain sensation, but are not judging or focusing on the disturbing quality normally associated with the pain. Marcus Aurelius sums it up nicely,

If you are distressed by anything external, the pain is not due to the thing itself but to your own estimate of it; and this you have the power to revoke at any moment.

As a way to better understand the meditation experience, think about the mental focus a top endurance athlete exhibits in competition. The conviction to overcome excruciating muscle aches and pains enables world class cyclists to complete the Tour de France (a 2000 mile race over 21 days at altitude) and long distance runners to finish marathons in around 2 hours (averaging less than 5 min per mile). Of course, great endurance athletes are not necessarily meditators, but they are individuals who have cultivated mental discipline with years of training in which they have come to appreciate the essence of “mind over matter.”

This study hints at the fascinating implication that one need not pursue the path of a monk, adopt an extreme stoic philosophy or even engage in an intensive meditation retreat to experience substantial health benefits. It’s possible that intensive meditation may offer additional rewards, yet this study shows that even short-term meditation training yields a meaningful reduction in the suffering associated with common, everyday pain.

The National Institutes of Health (NIH) estimates that 70 million Americans suffer from chronic pain with an economic burden of at least $100 billion in the United States. The low cost and low risk of mindfulness meditation make it particularly attractive for chronic pain sufferers, though the value extends to anyone looking for a boost in concentration and a reduction in suffering. In a way, we all have become conditioned to react to the distractions in our environments like a dog conditioned to the sound of a bell. And so couldn’t we all use a bit of the calm, quiet mind lying dormant beneath the sound of the iPhone, the Blackberry, and Pavlov’s bell ringing in our ear?

References

May Day Fund. A Call to Revolutionize Chronic Pain Care in America: An Opportunity in Health Care Reform. 2009.

Salomons TV, & Kucyi A (2011). Does Meditation Reduce Pain through a Unique Neural Mechanism? The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (36), 12705-7 PMID: 21900549

Zeidan F, Martucci KT, Kraft RA, Gordon NS, McHaffie JG, & Coghill RC (2011). Brain mechanisms supporting the modulation of pain by mindfulness meditation. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (14), 5540-8 PMID: 21471390

Image via antoniomas / Shutterstock.

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