Lee de-Wit
Institute of Continuing Education, University of Cambridge, UK
& Psychology and Language Sciences, University College London, UK

https://doi.org/10.36866/pn.106.22

Our minds are often busy planning the future or thinking about the past. Mindfulness involves becoming more aware of what is happening right now. That might involve becoming more aware of feelings in your body. It might involve becoming aware of the sensations of your breath. It might simply involve becoming more conscious of the fact one’s mind is thinking about the future or the past. This practise of mindfulness has proved effective in treating certain clinical conditions, and can influence behaviour on a range of tasks. In parallel to this, there is also a large body of evidence showing that mindfulness has a range of measurable outcomes on both neural activity and even neural structures. Research on mindfulness not only helps us to understand this practise per se, but has also increased our understanding of plasticity and localization of functions within the adult human brain.

The recent upsurge in interest in mindfulness is reflected in a recent All-Party Parliamentary Report from 2015, which highlighted the potentially beneficial role of Mindfulness in Health, Education, Prisons and Companies. In the current political climate, this cross-party agreement certainly stands out. The report (Mindful Nation, UK) also makes for surprisingly pleasant reading (for a scientist reading a policy paper), because despite the heavy use of anecdotes and obvious advocacy, there is also a substantial body of evidence cited in the report. Indeed, the report also highlights some key limitations in our knowledge in areas where large-scale trials are needed to test whether mindfulness really will benefit certain patient groups or help improve the learning in our classrooms. Before exploring the existing findings, let’s take a step back to ask, what exactly do I mean by mindfulness?

Secular mindfulness without Buddhism

Mindfulness is a relatively recent approach that extracts some of the core teachings from Buddhism and reformulates them as a secular practise to help patients recovering from chronic pain or to deal with stress. This approach was first pioneered by Jon-Kabat Zinn at the Massachusetts University Hospital. Jon-Kabat Zinn had been inspired by his experience of Buddhism and wanted to use it in a clinical setting. It seems however that Buddhism’s broader cultural, philosophical and moral implications proved difficult to bring to the hospital ward!

Jon-Kabat Zinn therefore developed a secular program of mindfulness training that focused on developing some of the key skills involved in Buddhist meditation and awareness training, but left out some of the broader philosophical ideas and values expressed in Buddhism. He formalised this approach as an 8-week Mindfulness-Based Stress Reduction (MBSR) course. This model was then further developed by Mark Williams and colleagues at Oxford, who developed the 8-week Mindfulness-Based Cognitive Therapy (MBCT) course. This 8-week MBCT course was developed over 10 years ago, as a treatment to prevent the relapse of patients who have suffered multiple episodes of depression. Two recent meta-analyses have provided evidence that MBCT offers an effective treatment in preventing relapse for patients who have had depression (Kuyken et al., 2016), and in the treatment of mood and anxiety problems in clinical populations (Hofmann et al., 2010)

At its most simple, mindfulness is about becoming more aware of one’s experience of feelings, emotions, thoughts and mental and bodily state in the present moment. As we will see below however, going into this ‘experiential mode’ requires the recruitment of certain areas of the brain that you may struggle to recruit unless you have already had some mindfulness training. Thus, unless you’ve practised becoming aware of your experience of the present moment it can be hard to understand from a verbal description what exactly that means. Perhaps one of the best ways to get a sense of this is to close your eyes (once you’ve got to the end of this sentence…) and to turn your attention to the feeling of your feet making contact with the floor, and to just try and focus on that for 10 seconds. You might have noticed a sensation of contact with the floor that you simply were not aware of, prior to paying attention to it. You might have also noticed that simply paying attention to nothing but your feet for 10 seconds is actually quite a challenge. All kinds of ideas are likely to jump into consciousness when you try to focus on something as simple as the present moment experience of sensations in your foot. Mindfulness is a training in allowing oneself to focus on such simple aspects of one’s present moment experience. That certainly doesn’t mean that as soon as you start practising, those wandering thoughts will go away, more likely when you first start you’ll realise just how much the mind wanders off when you try and focus on a simple aspect of your present moment experience. Critically however, mindfulness doesn’t mean one starts judging oneself for having a mind that wanders off, rather one seeks to acknowledge one’s wandering mind and patiently learn the skill of bringing it back to the present moment.

To really develop this practise, it can be useful to have extended periods of meditation where you focus on areas of your body, or the sensation of your breathing in a formal meditation posture. Mindfulness isn’t just something you do sitting on a mat on the floor however. You can mindfully eat your dinner, mindfully draw a picture, mindfully read an article about mindfulness.

You don’t have to drive a taxi to change your brain

Except perhaps for Einstein’s oversized parietal lobe, neuroscience has (in the past) tended to ignore individual differences between people’s brains. In fact, it is probably a very reasonable approximation to say all of our brains are very similar. By and large we all have an area dedicated to face perception in the temporal lobes, we all have a hippocampus that plays a key role in memory and spatial navigation, we all have an amygdala that is important in detecting threatening stimuli. I sometimes think that one of the most important and under-communicated (to the general public) findings of the last 50 years is just how remarkably similar our brains are. Not necessarily similar in terms of their exact anatomical structure, but in terms of the way different cognitive or perceptual functions are predictably localised to particular parts
of the brain in different individuals.

More recently however, there has been an increasing recognition that our brains sometimes differ in ways that have interesting functional and theoretical consequences. This focus within neuroscience gained particular prominence with an ingeniously simple observation: London taxi drivers have a larger than average hippocampus. This finding highlighted that individual differences in brain anatomy can have functional implications and suggested that even the adult brain has a degree of neuroplasticity that can influence quite large-scale neuroanatomy. The finding that taxi drivers had a larger hippocampus was quickly followed by other similar observations. Violin players have an enlarged area in their motor cortex, and experimental demonstrations showed that a number of weeks’ experience in learning to juggle increased the size of an area of the brain associated with the perception of complex motion.

In 2004, meditation joined the list of factors that were associated with changes in the brain’s structure. Building on work from the previous year, showing that the brains of experienced meditators had higher levels of coherent activity (Lutz et al., 2004), researchers at Harvard, Yale, MIT and Massachusetts General Hospital found that there were also large-scale differences in the structure of certain areas of the brains of experienced meditators (Lazar et al., 2005). These changes were not random, they were found in areas of the brain that could be logically interpreted given the skills practised in meditation. In particular, one of the areas that was larger in experienced meditators was the insula. This is an area of the brain that we know is important in interoception, the perception (visceral, not visual) of our own body. Given that mindfulness often involves the development of a greater awareness of one’s present moment bodily experience, it seems logical that the area of the brain that seems to be involved in that would be one of the areas to be influenced by long-term mindfulness practise.

However, whilst this might seem logical, it isn’t the only plausible interpretation of these findings. Firstly these studies were performed on Buddhist monks, who not only practise mindfulness, but who also live very different lives, providing all manner of potential confounding influences on their brain’s development. Secondly this was a cross-sectional observation (like the first study with taxi drivers and violin players), so it’s possible that those individuals with a larger insula area were more likely to become Buddhist monks in the first place.

The other big limitation to these findings was that these monks had tens of thousands of hours of meditation experience. If mindfulness only brings about changes after thousands of hours of experience, then it is unlikely to be of any practical benefit in the contexts (Health, Education, Prisons and Companies) outlined in the All-Party Report (Mindful Nation, UK).

7 years in Tibet vs 8 weeks of mindfulness

Science thrives on being able to systematically manipulate something and then measure what happens following that manipulation. Typical experimental manipulations in psychology and cognitive neuroscience tend to be rather limited. They involve momentary changes in the task participants are performing or stimuli they are presented with, and then measuring changes in behaviour (often reaction time) or measures of brain activity. The 8-week mindfulness courses developed by Jon Kabat-Zinn and Mark Williams have offered neuroscience a chance to implement a much more substantial manipulation, and measure its effects.

A recent review (Gotink et al., 2016) of over 20 studies argues that the changes observed after a relatively short period of practising mindfulness are closely comparable to those observed following long-term meditative practise. Thus, just as the insula appears to be larger than average following long-term meditative experience, it also appears to be more active, and sometimes larger, after only 8 weeks of mindfulness. For example, one early study found that when asked to go into a more experiential (rather than narrative) mode, novices didn’t show more activity in their insula. After 8 weeks of (a particular form of) mindfulness training, participants showed significantly more activity in their insula when asked to go into an ‘experiential mode’. This finding highlights again that whether you are able to enter into a more experiential mode of being isn’t simply a matter of having a perfect verbal definition of what mindfulness is. Rather like riding a bike, mindfulness is a skill that has to be practised.

One might wonder what are the benefits of a larger or more active insula? Especially given the broader benefits of mindfulness as a treatment for relapse from depression and to deal with anxiety and stress. The answer to this isn’t totally clear, but one potentially important theoretical perspective that could help explain this is Antonio Damasio’s concept of ‘somatic markers’. Somatic markers are visceral (bodily) manifestations of emotions that seem to be able to influence our reasoning and decision making. Thus, whilst we might think of decision making as a purely rational process that only occurs in our head, it seems that the manner in which our brain makes decisions is shaped by the way we experience emotions in our body. It could be that by developing a better awareness of what is going on in our body (a critical role of the insula) we are more conscious of this influence, and potentially have more control over it. One area where this body awareness might prove particularly significant is in the domain of addictions, often maintained by very visceral urges, which might be easier to control if one is more aware of them. Indeed, there is already some promising evidence that mindfulness might offer a useful treatment in reducing certain forms of addiction such as smoking (Tang et al., 2016).

No fear: brain training worth paying for…

One of the other brain areas consistently implicated in the practise of mindfulness is the amygdala. The amygdala is a brain structure that is important in interpreting fear and detecting threat. Indeed, recent research has confirmed that the amygdala can respond differently to threatening stimuli before we are even conscious of the existence of that stimulus. It’s a brain structure that also exists in much simpler mammals, and seems to play a very basic role in signalling threat.

Long-term meditation experience seems to cause a reduction in the size of the amygdala, and even shorter periods of mindfulness training can result in reduced levels of activity in the amygdala in response to threatening stimuli. We have also already seen that mindfulness can influence the insula. There are however numerous other areas of the brain that are influenced by mindfulness training. For example as little as 11 hours of mindfulness can increase the connectivity between the anterior cingulate cortex (ACC) and other areas of the brain (Tang et al., 2010). These changes in the brain are also accompanied by a wide range of behavioural implications, from improved attentional performance in well-controlled experiments, to reduced symptoms in a number of clinical conditions.

This ‘generalisation’ from the practising of a particular skill to a wide range of implications is perhaps one of the most significant findings regarding the cognitive neuroscience of mindfulness. Typically when we train a particular skill, such as riding a bike, we get better at that skill, and that learning will inevitably depend on changes to the neural circuits required to perform that particular skill. With mindfulness however, the practise of bringing one’s focus back to one’s experience of the present moment seems to have much broader implications.

This generalisable effect sits in clear juxtaposition to recent findings with ‘brain training’ games, which have recently attracted some controversy for claiming that they can elicit broader changes in cognition. This claim has proved controversial, because the evidence suggests that whilst one can certainly improve one’s performance on particular brain training games, the impact of that doesn’t always generalise to other aspects of cognition. With mindfulness training however, training one’s attention to return to the present moment seems to have wide-ranging implications.

Mindfulness over matter or mindfulness via matter

Given that mindfulness has a range of measurable impacts on certain forms of behaviour, and improves the outcomes in a number of clinical conditions, we should not be surprised that there are also changes in the brain. In a recent review of Educational Neuroscience, Jeff Bowers concisely reminds us: ‘unless one is a dualist, the brain necessarily changes whenever learning takes place’. Nevertheless, the idea that mindfulness can actually change the physical structure of our brain is probably intuitively surprising to a lot of people.

Indeed, the science of mindfulness brings to life the complexity of some of these causal relationships between the way in which our behaviour is shaped by our brain and our brain is shaped by our behaviour.  Even if one isn’t interested in mindfulness, the extended periods of practise required in mindfulness programs provide scientists with an excellent opportunity to understand the nature and extent of neural plasticity, and provides an additional source of evidence regarding the functional role of the areas influenced by mindfulness practise. From the increased recruitment of the insula and the ACC, to the reduced recruitment of the amygdala, mindfulness can help us to understand what particular parts of the brain do. Moreover, mindfulness can also help us understand the way in which different areas of the brain are connected, and can change their connectivity, and the potential broader implications that can have for the recruitment of networks of brain areas. Understanding exactly how these neural changes are implemented (with an increased density of synapses, or increases in the myelination of white pattern pathways) offers an excellent challenge and opportunity for neuroscientists to understand how the brain learns more generally.

References

Gotink RA, Meijboom R, Vernooij MW, Smits M, Hunink MGM (2016). 8-week Mindfulness-Based Stress Reduction induces brain changes similar to traditional long-term meditation practice – A systematic review. Brain Cogn 108, 32–41 doi:10.1016/j.bandc.2016.07.001

Hofmann SG, Sawyer AT, Witt AA, Oh D (2010). The effect of mindfulness-based therapy on anxiety and depression: a meta-analytic review. J Consult Clin Psychol 78, 169-183 doi:10.1037/a0018555

Kuyken W, et al. (2016). Efficacy of mindfulness-based cognitive therapy in prevention of depressive relapse: an individual patient data meta-analysis from randomized trials. JAMA Psychiatry 73, 565–574  doi:10.1001/jamapsychiatry.2016.0076

Lazar SW, et al. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport 16, 1893–1897.

Lutz A, Greischar LL, Rawlings NB, Ricard M, Davidson RJ (2004). Long-term meditators self-induce high-amplitude gamma synchrony during mental practice. Proc Natl Acad Sci USA 101, 16369–16373  doi:10.1073/pnas.0407401101

Tang YY, et al. (2010). Short-term meditation induces white matter changes in the anterior cingulate. Proc Natl Acad Sci 107, 15649–15652. doi:10.1073/pnas.1011043107

Tang YY, Tang R, Posner MI (2016). Mindfulness meditation improves emotion regulation and reduces drug abuse. Drug Alcohol Depend 163, S13–S18 doi:10.1016/j.drugalcdep.2015.11.041