IN FOCUS: Meditation research (Part Two)

Spa still life with white flowers

There’s been a boom in interest in meditation recently – among laypersons and the scientific community alike. Neuroscientists, in particular, have begun using their training and technology to learn more about what happens when people meditate, chant mantras, or take part in mindfulness training. This is part two of a two-part article examining a cross-section of recent scientific publications on meditation and its effects on people’s brains, bodies, and lives.

Not all the recently published research on meditation has exclusively to do with brain parts and cerebral blood flow. In fact, some of the most interesting research has focused on mindfulness and its effects on people’s general well-being. One study, published by Shauna Shapiro (Santa Clara University) and colleagues in the Journal of Clinical Psychology, found that people with higher natural levels of mindfulness benefited even more from mindfulness training than those who were naturally less mindful. Mindfulness, a state in which experience is non-judgmentally observed, catalogued, and engaged rather than judged or evaluated using conceptual frameworks, is often associated with better mental health and more adaptive decision-making.

The researchers made use of Mindfulness-Based Stress Reduction (MBSR) therapy, a therapeutic technique designed by University of Massachusetts meditation expert Jon Kabat-Zinn, to build mindfulness skills in one group of undergraduate students. Another group wasn’t given any particular training. Mindfulness levels were assessed prior to the experiment, right after the single training session, and then at two- and 12-month follow-up meetings. Shapiro and her colleagues found that members of the intervention group who tested highly for mindfulness before the training showed even greater proportional increases in subjective well-being, empathy, and hope than their fellow trainees – effects that lasted for a full year afterward. Likewise, while all MBSR trainees showed decreases in stress and rumination, the decreases were more pronounced in those with high initial levels of mindfulness.

As implied in the Shapiro’s study, mindfulness is usually considered to have a positive effect on well-being. But why? Laurie Hollis-Walker (York University, Toronto) and Kenneth Colosimo (Brock University, Ontario) conducted a study, published in January in the journal Personality and Individual Differences, that examined exactly this question. What they found was that a particular type of self-compassion helped mediate the effect of mindfulness on psychological well-being. Hollis-Walker and Colosimo avoided using experienced meditators for their study, instead opting to investigate mindfulness in the general population. They assessed participants for mindfulness using a 5-facet scale that measured participants’ ability to observe, describe, refrain from judging, and refrain from reacting to experience, as well as their ability to act with awareness. The researchers also assessed participants’ self-reported psychological well-being, levels of neurosis, and self-compassion.

They found that people who rated themselves as more mindful also rated themselves as generally happier, and that mindfulness was strongly correlated with conscientiousness, extraversion, agreeableness, and openness – and negatively correlated with neurosis. Interestingly, the aspect of mindfulness with the strongest effect on these personality traits was the ability to describe experiences. For some reason, subjects who were most skilled at accurately assessing their experiences seemed to have the least trouble with negative emotions.

Hollis-Walker and Colosimo postulated that this relationship could be explained using self-determination theory, which states that a clear awareness and understanding of reality and our circumstances is vital for making decisions that lead not just to happiness. The researchers also found that one particular type of self-compassion, lack of isolation – a feeling of connectedness with others – substantially mediated the relationship between mindfulness and well-being. Between getting a clear window onto reality and helping people connect with others, mindfulness in this study appeared to predictably engender happiness – even though it didn’t come from meditative practice.

Holley S. Hodgins (Skidmore College) and Kathyrn C. Adair (Boston Healthcare System) probed even deeper into the possible connection between meditation and accurate perception of reality with a paper published in December in Consciousness and Cognition. They theorized that, since Zen meditation is designed to help people clearly perceive both inner and outer reality, experienced meditators should be able to, quite literally, see better. To that end, the researchers administered a series of visual perception tests to a large group of experienced meditators and non-meditators. The tests measured participants’ ability to notice subtle changes in photographs, selectively pay attention to cues, and parse out irrelevant data in a visual field. (One interesting test can be seen here – see if you notice anything unusual in the video.)

What Hodgins and Adair found was the Zen meditators were significantly better at visually apprehending their environment. They made fewer errors on the tests, noticed changes more quickly, and attended better to relevant cues. The authors themselves wrote that their “findings show that (Zen) practice is associated with literally seeing more accurately.” Like Hollis-Walker and Colosimo, they also suggested that the ability to accurately perceive reality is a major requirement for psychological well-being, hypothesizing that people with better visual perception skills may, in the long run, also be able to avoid “higher order delusions” that interfere with life decisions.

While a wealth of research has recently been published on meditation, the brain, and well-being, one thing that is often missing in such studies is an effective measure of causality. For example, in Hodgins and Adair’s study, it’s impossible to tell whether the Zen practitioners were better at visual perception tasks because they had meditation experience, or because people with better perceptual skills naturally gravitate toward Zen. In other words, there have been relatively few longitudinal studies on the effects of meditation, particularly when it comes to supposed physical changes in the brain.

However, the final study examined here, published by Britta K. Hölzel (Massachusetts General Hospital, Justus Liebig University of Giessen, Germany) and colleagues in Psychiatry Research: Neuroimaging, addressed that lack. Hölzel et al. recruited a small sample of 16 non-meditators and provided them with eight weeks of MBSR training. The training consisted of eight weekly meetings, plus one full-day training and meditation session. Brain scans were taken of both the meditation group and a 17-person control group before and after the meditation training period.

Having hypothesized that they would find gray matter increases in both the hippocampus and the insula, the researchers were stymied in one of their hypotheses when no growth was found in meditators’ insulas. However, significant gray matter growth in the hippocampus was exhibited among the MBSR training group over the eight-week period. Other areas that showed increase in gray matter density and volume were the tempero-parietal junction, posterior cingulate cortex, and the cerebellum.

The areas that Hölzel et al. found to have increased in mass during the meditation training together form a subsystem of the brain that is used for self-oriented processing such as drawing up memories of the past, thinking about future events, and taking alternative, hypothetical viewpoints. The authors suggested that the increase in gray matter in these areas might mean that meditation helps people develop the ability to use personally relevant data in order to imagine or perceive different perspectives on situations. These effects could include feeling compassion for others and empathizing with their experiences – in other words, thinking about things from viewpoints other than one’s habitual, self-oriented one.

Hölzel’s study is groundbreaking in proving fairly conclusively that extensive meditation training actually leads to alterations in brain structure, an effect long hypothesized but not proved. In light of the work recently published by her and other researchers, it’s becoming easier and easier to see the brain as, in fact, a type of muscle – one that responds and grows with exercise, both physically as well as metaphorically.

The research studies presented above are only a small sample of the dozens, even hundreds, of studies published in recent years. While it’s clear that certain areas of the brain are more clearly linked to meditation than others – such as the hippocampus, limbic system, and frontal cortex – it seems likely that many more studies will need to be done to get a firm handle on how meditative practice specifically affects the brain. For example, different meditative styles obviously have different subjective effects, and it seems they alter the brain differently as well. Furthermore, linking changes in cranial structure and gray matter density to behavioral and psychological effects is not going to be a simple task. Individual brains are different, and there’s some evidence to suggest that people from different cultures literally use the parts of their brains in different ways.

Still, it’s also evident that meditation is a force to be reckoned with. Whether it’s mindfulness meditation helping people reframe their life events in new ways, Zen practice training people to perceive reality more accurately, or matra chanting building gray matter in the parietal cortex, the galaxy of directed mental and spiritual exercises we call meditation can have profound effects on human life and well-being. Studying exactly how they can have these effects is the blending of spirituality and science at its finest.

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