Sunday, March 29, 2015
Mindfulness and the mind
I've had a lot of worries in my life, most of which never happened
Attributed to Mark Twain
How much of our lives is spent ruminating on the potential misfortunes that will befall us if our luck runs out, or daydreaming of the fights we might pick with those who slighted us in the past? Mindfulness is described as a non-judgmental awareness of the present moment. Mindfulness-based approaches are becoming increasingly popular as a means of reducing stress, as well as ameliorating psychological disorders. If mindfulness can promote ways of thinking that may differ from most of our everyday streams-of-consciousness, how might this impact upon our brain and cognition?
If mindfulness can change your way of thinking, it seems it can change your performance on cognitive tests. A mindfulness-based mind fitness training program has been found to reduce attentional lapses in a military cohort. However, mindfulness-based stress reduction (MBSR) did not have a clear effect upon sustained attention in a clinical trial, although the authors suggested that different results might be apparent for vigilance (i.e. sustained attention for a rarely occurring target). Outside the lab, an interesting field study indicated that providing mindfulness training to low-income children improved reported classroom behaviour-the one positive effect of mindfulness that extra sessions seemed to enhance was improved attention. Although the evidence is not final, it certainly seems plausible that techniques aiming to help you bring your attention back to the present moment when it wanders to the past or the future could lead to greater practice of cognitive control.
A number of recent studies have looked at changes in brain structure associated with mindfulness. A lot of studies examining the effects of meditation on brain structure have compared meditators to non-meditators. However, a recent study looked at changes in brain structure within the same people, before and after mindfulness-based stress reduction (MBSR). The findings suggest that MBSR led to higher levels of grey matter* in regions of the brain stem. These were regions associated with the production of neurochemicals that modulate mood and cognition (e.g. the locus coeruleus, which produces norepinephrine). However, the findings should be taken with a pinch of salt, as they suffer from some of the common problems with brain imaging studies (e.g. fishing for regions of activation, then labelling an observed area in the scan as corresponding to a known region in the brain, even when the use of relatively low-resolution scanners makes it difficult to know if it really is the region you specified that you were looking at). However, perhaps a more promising finding from this same group was enhanced gray matter in the hippocampus, which they had previously specified as a region of interest.
Compared to when I was a teenager, the use of the internet to flit through different sites and ideas has possibly worn down my sustained attention skills to some extent. With regard to stress, I think my levels are pretty moderate these days (perhaps I'm settling in to life as a grown-up), but there is always room for improvement**. In the interest of finding out more about mindfulness for my research (and maybe some self-improvement), I will be starting a course in mindfulness-based stress reduction shortly-should be a great chance to get a first-person view. Will let you know how I am on the far side of it!
UPDATE: It is also worth mentioning a recent review that grapples with the neuroscience of mindfulness-the senior author is Michael Posner, a major figure in the psychology of attention.
*Grey matter is made up of the cell bodies, dendrites and unmyelinated axons of neurons, the brain cells that process information. White matter, in contrast, gets its characteristic colour from the myelin that sheaths axons (allowing information to travel along the neuron more quickly).
**Note: I'm not trying to say no stress is a good thing!