What happens when we meditate

We picture meditation as a switching off, a making of emptiness. The brain says the opposite: when a seasoned practitioner meditates, it does not switch off, it lights up in an ordered way. Measurement shows it.

In Richard Davidson's laboratory in Madison, Tibetan monks with tens of thousands of hours of practice meditated with EEG on their heads. During compassion meditation, the electrical activity showed gamma waves - around 40 Hz - of very high amplitude and, above all, highly synchronous: distant areas of the brain oscillating together, at the same rhythm. Among the highest amplitudes ever recorded in healthy people, and larger the longer the practice (Lutz and colleagues, 2004). Synchrony is the signature of a brain more united and at the same time more differentiated: the very thing we elsewhere call intense consciousness.

And it is not just a state that comes and goes: it is training that changes the organ. People who meditate for years have a thicker cortex in the regions of attention and of listening to the body (Lazar and colleagues, 2005), and their attention networks work differently, more efficient at holding focus steady for long (Brefczynski-Lewis and colleagues, 2007). Attention is a muscle, and it can be trained.

It is again the thesis of this pillar. Consciousness is not a lamp of fixed intensity: on the threshold it can rise. The monks show that the ceiling is higher than what we call ordinary waking, and that one reaches it not by chance but by training.

And the road? Here the link is simple and honest. Meditation, stripped of everything else, is attention turned on attention: noticing what your own state is, now. The drowsy driver fails at exactly this: they cross the threshold without noticing. You need not be a monk. But the first messages of sleepiness - the heavy eyelid, the sliding thought, the kilometre you cannot remember - can be caught, if attention is listening. What monks train for years, the road asks in a few honest seconds: notice, and stop.

To meditate is not to flee the threshold: it is to learn to stay awake on it. At the wheel too, for the time it takes to notice.