There are, broadly speaking, two different kinds of meditation: Concentrative and mindfulness. Concentrative meditations, such as mantra meditation, focus the mind exclusively on a single "object" such as a mantra or an image of a candle flame, etc. Mindfulness uses the ongoing, ever-changing, moment-to-moment experience as the focal point of concentration, such as your breath.
Lots of experiments have been
done on meditators. For example, researchers tested the startle response
of meditators. Usually if someone is sitting quietly but not meditating
and a sudden loud noise occurs, their brainwaves show a dramatic jump.
But if the sudden loud noise happens again, there is less of a dramatic
jump. And if the noise continues, it gets less and less until there is
hardly any response. The person has "habituated" to the sound.
That's the norm.
the concentrative meditators had a different kind of response to the
sudden loud noise: Their brainwaves did not register any jump.
mindfulness meditators had a different reaction. They registered the
loud noise with a dramatic jump. And each time the sound was made, the
mindfulness meditators registered the same dramatic jump. That is, they did not habituate
to the sound. Their brains responded as if each time the sound was
made, it was the first time they had heard it. That's why they say
mindfulness meditation can be dehypnotizing. It allows a fresh,
unhabituated experience of things, preventing old habits from running
the show, and allowing for new possible responses to things.
study, which measured concentrative meditators only, showed that those
who had meditated regularly were found to get less upset at
normally-upsetting stimuli, as measured by a rise in heart rate. And
their heart rate returned to normal faster than non-meditators. When
they measured their galvanic skin response (measuring sweat on the
surface of the skin — a measure of stress), meditators showed a less
stressful reaction to the stressful stimuli, and returned to normal
So for example, if they show upsetting pictures
to a subject, like a picture of a mutilated cat or grisly car accident,
and their heart rate rises to 100 beats per minute normally and takes
seven minutes to return to normal, a meditator's heart rate would only
rise to, say, 90 beats per minute and return to normal in four minutes.
Adam Khan is the author of Self-Reliance, Translated and Principles For Personal Growth. Follow his podcast, The Adam Bomb.