Mindfulness in the Brain, An Excerpt


"A 2007 study called "Mindfulness meditation reveals distinct neural modes of self-reference" by Norman Farb at the University of Toronto, along with six other scientists, broke new ground in our understanding of mindfulness from a neuroscience perspective.

Farb and his colleagues worked out a way to study how human beings experience their own moment-to-moment experience. They discovered that people have two distinct ways of interacting with the world, using two different sets of networks. One network for experiencing your experience involves what is called the "default network", which includes regions of the medial prefrontal cortex, along with memory regions such as the hippocampus. This network is called default because it becomes active when not much else is happening, and you think about yourself. If you are sitting on the edge of a jetty in summer, a nice breeze blowing in your hair and a cold beer in your hand, instead of taking in the beautiful day you might find yourself thinking about what to cook for dinner tonight, and whether you will make a mess of the meal to the amusement of your partner. This is your default network in action. It's the network involved in planning, daydreaming and ruminating.

This default network also become active when you think about yourself or other people, it holds together a "narrative". A narrative is a story line with characters interacting with each other over time. The brain holds vast stores of information about your own and other people's history. When the default network is active, you are thinking about your history and future and all the people you know, including yourself, and how this giant tapestry of information weaves together. In this way, in the Farb study they like to call the default network the 'narrative' circuitry. (I like the 'narrative circuit' term for every-day usage as it's easier to remember and a bit more elegant than 'default' when talking about mindfulness.)

When you experience the world using this narrative network, you take in information from the outside world, process it through a filter of what everything means, and add your interpretations. Sitting on the dock with your narrative circuit active, a cool breeze isn't a cool breeze, it's a sign than summer will be over soon, which starts you thinking about where to go skiing, and whether your ski suit needs a dry clean.

The default network is active for most of your waking moments and doesn't take much effort to operate. There's nothing wrong with this network, the point here is you don't want to limit yourself to only experiencing the world through this network.

The Farb study shows there is a whole other way of experiencing experience. Scientists call this type of experience one of direct experience. When the direct experience network is active, several different brain regions become more active. This includes the insula, a region that relates to perceiving bodily sensations. The anterior cingulate cortex is also activated, which is a region central to switching your attention. When this direct experience network is activated, you are not thinking intently about the past or future, other people, or yourself, or considering much at all. Rather, you are experiencing information coming into your senses in real time. Sitting on the jetty, your attention is on the warmth of the sun on your skin, the cool breeze in your hair, and the cold beer in your hand.

A series of other studies has found that these two circuits, narrative and direct experience, are inversely correlated. In other words, if you think about an upcoming meeting while you wash dishes, you are more likely to overlook a broken glass and cut your hand, because the brain map involved in visual perception is less active when the narrative map is activated. You don't see as much (or hear as much, or feel as much, or sense anything as much) when you are lost in thought."