A recently reported brain-scanning study has found evidence that sustained meditation alters the physical structure of the brain by increasing the thickness of the grey matter.
The researchers, led by neuroscientist Sarah Lazar, scanned the brains of 20 people with long-term experience of meditation, and compared them with 20 other, non-meditating people.
Brain regions associated with attention, sensation, perception and monitoring the body’s internal state were thicker in meditation participants than in the comparison group.
There is now increasing evidence – in line with a 2000 study, that reported that London Taxi drivers may have a larger hippocampus (an area of the brain known to be crucial for navigation), that mental practice may alter the brain’s structure on a relatively large scale.
Update: Grabbed from the comments page… Some cautionary words on interpreting ’cause’ from this sort of study (Thanks ‘Coffee Mug’!):
The only way to say that meditation can alter the structure of the brain would be to do a longitudinal study following people who hadn’t chosen to meditate prior to the study. Otherwise you run into the same problem as you did with the London cabbie study. Correlation is not causation. People born with bigger hippocampi might self-select as cab-drivers. People with bigger ‘attention centers’ might be more predisposed to get into meditation.
Link to write-up from LiveScience.
Link to scientific paper abstract.
Mind Hacks 
The only way to say that meditation can alter the structure of the brain would be to do a longitudinal study following people who hadn’t chosen to meditation prior to the study. Otherwise you run into the same problem as you did with the London cabbie study. Correlation is not causation. People born with bigger hippocampi might self-select as cab-drivers. People with bigger ‘attention centers’ might be more predisposed to get into meditation.
On a related note, I’m at the Society for Neuronscience conference and on Saturday i saw the Dalai Lama of Tibet give a talk about neuroscience and meditation. He suprised me by saying that if there was a surgey or drug that could give identical benefits to meditation then he’d definitely recommend it. Meditation is hard work, he said, and he wishes neuroscientists could find a short cut!
Interesting article.
Researchers at the University of Wisconson are researching “happiness” (among other things) and they’ve localized it as activity in the left prefrontal cortex.
That is, when being shown pictures of things that make you happy, you have activity in your left prefrontal cortex. People who are generally happier generally have more activity in the left prefrontal cortex.
This corroborates with evidence that depressed people have more activity in the right hemisphere than in the left, and v.v.
What’s interesting (& relevant to this study) is that they got a Tibettan Monk (A former scientist at the Pasteur school in France) to come and sit in the fMRI machine and meditate.
While in a non meditative state, his brain was relatively normal. When he meditated on “compassion” activity in his left prefrontal cortex increased to 150% that of anyone they had measured before (I think their sample was around 100 people).
Similar studies have been conducted by getting a group of non meditators & having half of them meditate & half of them not meditate. I forget the exact findings, but they were sort of along these lines as well.
Thanks for the link.
References:
http://www.washingtonpost.com/wp-dyn/articles/A43006-2005Jan2.html
http://www.cbc.ca/news/background/meditation/
Musicians who play stringed instruments have a greater area of the brain dedicated to left-hand sensation. Anyone who’s read “The Man Who Mistook His Wife for a Hat” by Oliver Sachs (excellent, entertaining book, highly recommended) knows that different regions of the brain can take over the functions of others, as is the case with Stroke victims who lose speech temorarily, but gain it back by simply having another part of their brain take over those functions.
Just this year I have began meditating, and found that I do have a more conscious present. My mind is so much clearer, it as though I have cleared the spam from my e-mail account. I can’t believe that I once went without it, and dealt so much with the anxiety ridden existence I had created for myself. I appreciate the links on this page, cause I am still learning how to be the spiritual person I have wanted to be. I recently finished reading, “Eat,Pray,Love,” and recommend it as well. Although it does not have specific tools for meditation, it is a good summarization of the path to the spiritual lifestyle.
http://www.eatprayandlove.com