William Reville: Let’s be mindful about the benefits of meditation

Meditation has never been more popular than it is now. Transcendental meditation (TM), a mind-emptying type of meditation, used to be the most popular form, but it has now ceded pole position to mindfulness meditation.

Meditation can undoubtedly confer benefits, and extensive scientific investigations are afoot to tease out its effects on the human brain. This work is summarised by Matthieu Ricard and colleagues in the November 2014 edition of Scientific American. The authors define meditation as the cultivation of a more stable and secure mind, emotional balance, a sense of caring, mindfulness, even love and compassion, and a more serene way of life.

Meditation has its roots in the contemplative practices of the major religions (for example, the rosary is a Catholic meditation and Buddhists use the prayer wheel). Apart from TM, which comes from the Vedic tradition, the best-known forms of meditation were developed by Buddhism and are now practised in a secular context.

Of these, focused-attention meditation centres the mind in the present moment, while remaining vigilant to distractions. Mindfulness meditation cultivates a less emotionally reactive response to emotions, thoughts and sensations, preventing their distressing escalation out of control. And loving-kindness meditation fosters an altruistic outlook towards others.

Neuroscience has shown that the adult brain remains transformable through experience, a process known as neuroplasticity. For example, if I take up playing the guitar, the brain region that controls movement of my string-plucking fingers will get progressively larger as I master the instrument. Something similar happens in meditation. Several studies have shown that meditation affects brain structure and function, “rewiring” brain circuits to produce discernible effects.

Brain scans of focused-attention meditators have shown that their practice enhances their ability to remain vigilant.

Mindfulness meditation, which develops awareness of all that is happening, without particular preoccupations, helps meditators to handle daily irritants more easily and to develop a psychological sense of wellbeing. This non-reactive awareness has been demonstrated by measuring the capacity to detect images rapidly presented to the eye. Subjects are asked to detect two numbers rapidly flashed on a screen amid a succession of letters. If the second number is flashed 300 milliseconds after the first, people often miss it (an “attentional blink”), but if the delay is 600 milliseconds, the second number is easily detected. Experiments have shown that mindfulness meditators can perceive numbers flashed at 300 milliseconds intervals more reliably than non-meditators.

Pain control

Recent research suggests that, although pain intensity is not reduced by it, mindfulness meditation can make pain less bothersome to those who practise it. Several other studies have demonstrated the benefits of mindfulness in relation to anxiety, depression symptoms and sleep patterns. Mindfulness, in conjunction with cognitive therapy, is also thought to be effective in reducing relapses into major depression. (Information on therapeutic uses of mindfulness is available on Oxford University's Mindfulness Centre website, oxfordmindfulness.org.)

Evidence is also quoted by Ricard and his colleagues that meditation can diminish biological stresses at the molecular level. The longevity of cells is regulated by an enzyme called telomerase, which prevents the shortening of DNA segments, called telomeres, at the ends of chromosomes. When a cell divides, chromosomes also divide and telomeres shorten. When telomeres shorten below a critical length, the cell stops dividing and enters senescence. Meditators have higher telomerase activity than control groups, suggesting that meditation may slow cellular ageing.

Meditation is a tool whose efficacy depends on the ends for which it is used. I practice TM intermittently and find it helps me to handle the ups and downs of everyday living more easily. I learned TM many years ago at an American university and recall that many American colleagues took the course primarily because they hoped it would allow them to get by with less sleep so that they could work longer hours. To take an extreme example of negative usage, the Norwegian mass murderer Anders Breivik used meditation to numb himself in order to kill.

Yes, meditation is undoubtedly helpful, but its benefits are frequently oversold and you need a system of values as well to get the most out of it.

[ understandingscience.ucc.ie ]