One of the least understood forms of meditation holds great curative potential
Non-dual meditation, also known as non-dual awareness meditation, involves becoming aware of the present moment and letting go of thoughts and beliefs that create a sense of duality or separation from the world. Here are some ways in which non-dual meditation can improve brain function:
Amygdala: Non-dual meditation has been shown to reduce activity in the amygdala, which is the part of the brain responsible for the processing of emotions and stress responses.
Prefrontal cortex: This area of the brain, associated with executive function, working memory, and decision-making, has been shown to become thicker with regular non-dual meditation practice.
Hippocampus: The hippocampus, a region important for learning and memory, has been shown to increase in size with regular non-dual meditation practice.
Default mode network: Non-dual meditation has been shown to alter activity in the default mode network, a network of brain regions that is active when the mind is at rest and inactive during focused attention.
Anterior cingulate cortex: This brain region, associated with self-awareness, empathy, and emotional regulation, has been shown to become thicker with regular non-dual meditation practice.
Insula: The insula, a region of the brain associated with body awareness and interoception, has been shown to become thicker with regular non-dual meditation practice.
So how can non-dual meditation help us?
Reduced stress and anxiety: Non-dual meditation has been shown to reduce stress and anxiety levels, which in turn can improve brain function by decreasing cortisol levels and promoting neuroplasticity.
Increased focus and attention: By promoting mindfulness and awareness, non-dual meditation can help improve focus and attention, leading to improved cognitive functioning and decision-making.
Improved neuroplasticity: Regular non-dual meditation practice has been shown to increase neuroplasticity, which is the brain’s ability to adapt and change in response to new experiences. This can lead to better brain function and improved learning and memory.
Reduced inflammation: Non-dual meditation has been shown to reduce inflammation, which has been linked to cognitive decline and neurodegenerative disorders.
Improved executive function: Non-dual meditation has been linked to improved executive function, including better decision-making, problem-solving, and working memory.
Increased grey matter density: Studies have shown that regular non-dual meditation practice can lead to an increase in grey matter density in the brain, which is associated with better cognitive function and a reduction in age-related cognitive decline.
Overall, non-dual meditation has the potential to improve brain function significantly. By reducing stress and promoting mindfulness, this form of meditation can improve focus and attention, neuroplasticity, executive function and more, leading to better cognitive and mental health.
The scientific history of meditation reveals that we may be overlooking many important findings from the past.
A history of meditation and mindfulness
In the last century, we have seen four or five (it depends on how you categorise the research) waves of engagement between science and spiritual/meditation technologies. Careful attention to the successes and failures of each of these waves gives us important insights into the current crisis in meditation research. Understanding how the curative potential of meditation has been altered by its relocation to science should accelerate the development of more effective interventions. However, there are few reliable accounts of the scientific history of meditation from which to evaluate our progress. This short introduction highlights some of the important and often disregarded progress from past decades.
Buddhist meditation had been migrating for two and a half thousand years. From its conceptual birthplace in Northern India, Buddhism developed many schools and approaches, all loosely tied to foundational theoretical frameworks. Buddhist meditation methods became transnational spiritual practices, frequently adapted to local conditions whenever they established a foothold.
The relocation of Buddhism from Asia to the West gained momentum in the first half of the twentieth century, bringing Buddhist knowledge and meditation to many Westerners for the first time. But as well as introducing Zen Buddhism to many in the West, academic and Zen teacher Daisetsu Teitaro Suzuki was also redrawing the boundaries between psychology and religion. Suzuki’s ideas were shaped by the time he spent living and working with Paul Carus at the start of the twentieth century. Carus was an advocate of monism, a concept expressed through the Religion of Science (RoS).  The RoS held that a positivist symmetry existed between elements of science and religion. By the middle decades of the twentieth century, Suzuki had become increasingly influential with Western academics and opinion formers such as Alan Watts and Erich Fromm.
Fromm drew on Suzuki’s reformed, psychologised version of Zen to develop Zen psychotherapy in the late 1950s. Fromm’s interest in Zen was part of a broader movement, and during the 1960s Eastern spiritual traditions became increasingly important in America and Britain. Promoted by poets, philosophers and global celebrities such as The Beatles, meditation in general and Transcendental Meditation, in particular, expressed the aspirations of a generation. The growing Counter Culture became increasingly suspicious of mechanistic approaches to health and wellbeing. Meditation and spiritual world views were seen by many as an antidote to the restlessness caused by an overbearing ‘technocracy’ and processes of dehumanisation.
Alongside the Carus-Zuzuki-Fromm confluence of psychology and traditional spiritual thought, there was a second, more scientific engagement with Eastern meditation traditions. Early accounts of the effects of meditation on the brain can be found in the electroencephalographic (EEG) literature from the 1930s. The following decades were punctuated with several important peer reviewed papers from philosophical, psychoanalytical, physiological and psychological perspectives. A key breakthrough in the scientific understanding of the effects of meditation came with NN Das’s and Henri Gastaut’s research in 1955. By studying brain wave activity alongside other physiological indicators, Das and Gastaut helped to establish the methodology that dominated meditation research for the following two decades.
EEG studies became much more commonplace during the 1960s. Researchers from several countries (France, Germany, India and Japan in particular) confirmed a correlation between the frequency and strength of alpha brain waves and meditative states. But in 1970, a study of Transcendental Meditation (TM) published in Science took the scientific and public interest in meditation to new levels. Keith Wallace’s claims that alongside a range of potential health benefits, TM practitioners could access a novel state of consciousness, inspired meditation researchers for a decade. The 1970s saw a rapid growth in TM studies in experimental and applied settings. In the early 1970s, Wallace joined forces with the cardiologist and health researcher Herbert Benson. Using novel methodological approaches, Benson and Wallace provided further evidence that the practice of TM could lead to improved health and wellbeing.
By 1974 Benson’s research had changed direction, he went on to describe the relaxation response (RR), a ‘grand theory’ that made sweeping claims for a relaxed cognitive state. Benson aggregated operational elements from many different spiritual practices into four essential components that could deliver the relaxation response. Despite a successful book about the RR (written by Benson and Miriam Klipper), the science underpinning the hypothesis never received universal scientific acceptance. By 1980 the scientific community had begun to evaluate‘progress’ made in the study of meditation. Deep-seated methodological and theoretical issues with TM research led to critical reviews from scientists such as Michael West.
However, setbacks to the reputation of meditation research did not thoroughly dampen enthusiasm for the technology. Several new approaches were delivering positive findings, such as Vikram Patel’s combination of biofeedback and meditation to reduce stress. At the start of 1980, there was a growing acceptance of the curative potential of Eastern non-positivist interventions, such as meditation (as well as yoga and acupuncture). But a critical view of meditation research had raised questions about how psychology might best harness the curative potential of meditation.
When viewed from a history of science perspective, many of the strengths and weaknesses in contemporary meditation research are visible in previous ‘waves’. I acknowledge the Western-centric nature of this account. Some potentially important research originating outside of America and Britain, remains to be fully reviewed. But a clear conclusion from this brief summary is that if we don’t pay attention to reliable science from the past, we risk repeating the same mistakes and also missing important findings from earlier work.
(Based on a history of meditation paper prepared for the ERC BodyCapital conference October 2020).
 Ronkin, Noa, Early Buddhist Metaphysics: The Making of a Philosophical Tradition (London: Routledge, 2005).
 Stephen C. Berkwitz, Buddhism in World Cultures (ABC-CLIO, 2006).
 N Das and H Gastaut, ‘Variations in the Electrical Activity of the Brain, Heart, and Skeletal Muscles during Yogic Meditation and Trance’, Electroencephalography and Clinical Neurophysiology, 6 (1955), 211-219.
A 2020 review of mindfulness research highlights a reluctance to acknowledge potential adverse effects.
Scientists and clinicians, generally speaking, attempt to make the world a better place. Many of us working with mindfulness have confidence that this human technology has significant curative potential. But a health and wellbeing intervention cannot be built on my confidence or compassionate aspiration. It requires objective results produced through reliable scientific methods. Such results should offer a comprehensive understanding, including indications of problematic side effects. This summer, perhaps for the first time, a journal article has summarised adverse events linked to meditation practice (MAE).1
In a recent review of Richard Layard’s manifesto for happiness, I highlighted the tension between wanting mindfulness to be an effective panacea and making the scientific case for its widespread use. This dilemma is well known to psychologists. We direct our research towards a desired outcome, a plausible hypothesis, reliant on the scientific method to ensure our work remains objective and unbiased. Methodologically robust results of experiments and clinical trials should deliver a balanced and replicable set of data. If the data is not objective or if a later investigation cannot repeat the results, the scientific reliability may be open to question. Within the psychological sciences, these conflicting forces have long been a major source of concern.
Psychology has been locked into a so called replication crisis for several decades.2 Meditation research shares characteristics of this malaise, but scientists working in this field have highlighted several additional concerns. Meditation based mind training ultimately mediates brain function and structure; none of our higher (cortical) brain functions work in isolation. When activity in one area attenuates, we may see a correlated augmentation in an anatomically separate region. Put simply: brain training can simultaneously have different effects, these effects can vary from person to person. This truism of neuroscience should ensure that when meditation based health interventions are studied, both beneficial and adverse potentials are considered.
In August of this year, a research team (Farias, Maraldi, Wallenkampf and Lucchetti) published a strategic review of meditation studies in Acta Psychiatrica Scandinavica. ‘Adverse events in meditation practices’ investigated almost half a century of meditation research, a total of 6,742 citations. Of those papers, only 83 met the project’s inclusion criteria. Across this sample, the study found MAEs in 8.3% of cases. That meditation practice has been scientifically correlated with problems in some practitioners is a significant finding in its own right. But a second issue, the tendency of meditation and mindfulness research to focus on positive outcomes to the exclusion of other considerations also needs to be taken very seriously. When the science of meditation is explored from a historical perspective, this lack of objectivity has been a recurrent problem for a long time, at least fourty years. Its root causes go back to early engagements between non-positivist knowledge systems and psychology.
The Farias et al. paper signposts a potential new trajectory for the science of meditation. It doesn’t, however, offer any explanation of why adverse side effects receive a low research priority. Given the codes of ethics and conduct underpinning experimental and clinical psychology, future research will need to take the question of MAEs more seriously. However, two overarching consideration require urgent attention. Firstly, on the theoretical and operational level what happened to spiritual meditation when it relocated to psychology? And why, despite thousands of experiments over at least eighty years, is our scientific knowledge of meditation still described as ‘preliminary’?
1 Farias, M., Maraldi, E., Wallenkampf, K. C., & Lucchetti, G. (2020). Adverse events in meditation practices and meditation‐based therapies: a systematic review. Acta Psychiatrica Scandinavica.
2 Maxwell, S. E., Lau, M. Y., & Howard, G. S. (2015). Is psychology suffering from a replication crisis? What does “failure to replicate” really mean?. American Psychologist, 70(6), 487.
The default mode network has a crucial but poorly understood role in how meditation influences brain structure and function. This paper sets out some of the current thinking regarding self-generated thought.
Authors: Andrews‐Hanna, J. R., Smallwood, J., & Spreng, R. N.
Title: The default network and self‐generated thought: component processes, dynamic control, and clinical relevance
Summary: It is frequently suggested that neuroscience is still in its infancy, this becomes patently clear when you start to consider how little we know about the default mode network (DMN). The DMN, also known as the default network (DN) or the task-negative network (TNN) is most active when humans are in a resting state. In short, the DMN is the network that takes over when we are not actively engaged in a specific task. Surprisingly it was assumed that the brain was resting when not engaged in an externally focussed activity. This assumption was surprising because scientists know that their brains are capable of complex processes such as mind wandering when they are not reacting to the external environment. However, only when it was demonstrated that functional brain activity could reach similar levels in task and non-task modes did the investigation into the DMN begin in earnest. This has particular relevance for meditators and contemplative science, as the DMN is often the direct and indirect target for meditation methods.
Andrews‐Hanna, Smallwood and Spreng produced a review of the leading findings linked to the DMN, which they describe as an anatomically diffuse global network. Their primary focus is the DMN and self-generated thought, thought that arise without external sensory stimulus. Describing much of the recent research in the field they conclude that the DMN plays an integrated role in a wide range of neurological functions. Thus both normal and abnormal mental health is dependent on activity and functional connectivity within the DMN and links to other neural networks. The paper provides a useful background to contemplative scientists looking for an understanding of how meditation might influence human behaviour.
Not a surprising headline until you consider that Dr Erhan Genç and Christoph Fraenz at Ruhr-Universität Bochum are reported as suggesting that people with higher scores on an intelligence test were found to have smaller brain structures. […]
Not a surprising headline until you consider that Dr Erhan Genç and Christoph Fraenz at Ruhr-Universität Bochum are reported as suggesting that people with higher scores on an intelligence test were found to have smaller brain structures.
Brains are extremely complex organs and many aspects of their function and structure are not yet fully understood. However, we do know that neurons usually gather data from adjacent (presynaptic) neurons through complex tree-like structures containing many dendrites. The dendrites communicate with their own neuron’s cell body. Based on the messages received through the dendrites, a cell may fire (create an action potential) or not. When an action potential is generated, a message is then sent out to other neurons (postsynaptic) through the axon terminal. The reports of this study (I haven’t read the actual paper yet) is suggestive that people with fewer dendrites feeding into certain neurons in the cerebral cortex had higher IQ scores.
There are typically large numbers of dendrites communicating with each neuron in the cerebral cortex. There is a putative logic which could argue that smaller dendrite trees could be more efficient. Leading to a greater number of relevant action potentials being created more quickly. Given our limitations in understanding the mechanisms that lead to the generation and maintenance of dendrites, some caution needs to be expressed here. Without an appreciation of what the extra dendrites (in the participants with lower IQ scores) do, and why they are there, the picture is incomplete. Intelligence tests in general and IQ tests, in particular, are regarded by many experts as being reductive. It is possible that people with a history of IQ testing could have developed dendritic structures able to support this activity. But has anything been lost in the process? Are the extra dendrites in the lower IQ scored participants simply inefficient, and of no real benefit?
So what has this got to do with meditation? I wrote recently about structural changes in the brains of meditators. A conclusion from my own investigations was that increases and decreases in brain structures are likely to be the result of intense and sustained meditation practice. So the demonstration that neurological structures become bigger or smaller is probably an unhelpful oversimplification. The relationship between the alteration in structural size in different (interrelated) regions of the brain needs to be understood and then correlated to cognitive functionality if the understanding of the significance of changes is to be approached.
Rather than increasing or decreasing brain structures, meditators should probably think about their practice in terms of its deliverable goals in relation to behaviour. Brain imaging technology is still in its infancy and there are many significant problems still to overcome. We are probably decades away for being certain of the impact of complex human behaviours (like meditation) on brain structure, but we have for centuries been able to relate certain practices with behavioural changes. There are two obvious exceptions to these generalizations, age-related structural decline and changes due to neurodegeneration.
It should reiterate that I haven’t seen the full report of the Genç and Fraenz paper but a report is available at Eureka Alert.
The brain is plastic, to what extend does it undergo structural changes during meditation?
Authors: Kieran C.R. Fox, Savannah Nijeboer, Matthew L. Dixon, James L. Floman,
Melissa Ellamil, Samuel P. Rumak, Peter Sedlmeier, Kalina Christoff
Title: Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners
Summary: Like almost every contemplative scientist will point out, our understanding of what meditation can do for us in its infancy. However, this investigation sets out the progress made in understanding meditation related to structural changes in the brain. The researcher identified 21 studies that imaged the brains of meditators, looking for structural changes. Although most of the research was cross-sectional in nature some ‘before and after’ examples are included.
This project reviewed research that used any of the six leading measures of structural changes in the brain (volumetry, concentration, thickness, fractional anisotropy (FA), diffusivity (axial and radial) and gyrification). The selected papers were qualitatively reviewed and also subject to an anatomical likelihood estimation (ALE) meta-analysis. Qualitative results highlighted nine brain areas that might have undergone structural alteration as a result of meditation practice. Seven areas of grey matter: anterior/mid-cingulate cortex, fusiform gyrus, hippocampus, inferior temporal gyrus, insular cortex, rostrolateral prefrontal cortex, somatomotor cortices and two white matter pathways: corpus callosum, superior longitudinal fasciculus.
Although Lazer et al. made efforts to link the results of morphometric neuroimaging to a range of functional studies there are a number of problems in this approach. There is little structure in how meditators and meditation methods are grouped together, both in creating the meta-analysis and explanations for alterations in brain structures. This in part reflects the limitations of the 21 neuroimaging studies used, it is also linked to the widely documented problems in the theoretical frameworks used by contemplative science. For example, common features are looked for in diverse experiments using different forms of meditation, both secular and spiritual. Although the participants from the experimental groups cited in the studies had all meditated, they often differ significantly in the methods they use, frequency and duration of practice and time spent in intensive meditation retreat.
Despite the limitations, which are in large part symptomatic of meditation research in general, this remains an influential study fo0r both cognitive psychology and neuroscience.
Scientific understanding of meditation and mindfulness
Blogging about a related issue at Meditation for Health prompted me to think about how much does science really know about meditation and mindfulness. Leading scientists in the field state that empirical meditation research is at a relatively early stage. But relative to what? Surely not the efforts of the scientific community, thousands of scientific studies have already been published that explored meditation and/or its presumed operationalised components. It should also be considered that there is a vast body of traditional texts available, documenting many aspects of contemplative sciences over the last two thousand years. Contemporary research should also have benefited from the millions of current practitioners, including meditation masters with great experience of practice and underlying theoretical frameworks. It is hard to imagine more auspicious conditions for the study of meditation, so why is the research struggling to make significant progress?
After I had been meditating for five years I asked a traditional meditation teacher what the goal of my particular practice was. She stripped away the esoteric imagery in which the practice was framed and explained the likely result of my efforts. In particular, she emphasized the importance of my motivation. The idea that the method alone is not the practice is central to many forms of meditation and contemplation. In fact, traditional literature from Tibetan Buddhism makes it clear that progress in a particular method may require the application of significant levels of compassion or non-attachment. It is not my suggestion that a western scientific approach cannot fully understand the processes engaged in different forms of meditation. But rather it might be time to start to think about the phenomena underpinning meditation in a more complete way, even within cognitive psychology or neuropsychology. In some traditional schools, meditators are discouraged from evaluating the progress of others. But when you meditate cheek by jowl in a community of meditators for years, you may inevitably observe differences in the effects of the same meditation practice on different people.
Whilst the capacity of practitioners (individual differences) is a known factor in the experience of meditation. An individual’s motivation is also central to the benefits of a practice. This is a paradigm for all meditators and mindful practitioners in all settings. Unless a scientist can integrate the enthusiasm, scepticism and goals of the meditator into the input part of the equation, great uncertainty regarding the output is inevitable. In a survey of meditators and mindfulness practitioners (Morris, 2017) that included both types of practice and reasons for commencement. The motivation of practitioners was very varied. Among the cited reasons for beginning meditation or mindfulness were:
To improve my health
To improve my general well-being
For spiritual/religious reasons
As a lifestyle choice
Because of the influence of others
Any other reasons
There are reasons to suppose that the motivation of a meditator is a significant influencer on the results of a practice. The empirical approach has a great deal to offer the investigation of meditation, it can help to construct reductionist models able to identify the elements contemplative practice. But we are perhaps at a point when a fuller understanding of meditation and meditators needs to evolve.
Morris, S. (2017), An exploration of the relationship between wellbeing and meditation experience amongst meditators and mindfulness practitioners. The Open University, Milton Keynes. Unpublished
The experience of the meditator in meditation research
Title: Investigating the Phenomenological Matrix of Mindfulness-Related Practices from a Neurocognitive Perspective
Authors: Antoine Lutz, Amishi P. Jha, John D. Dunne, Clifford D. Saron
Summary: This review of research into mindfulness summarises a significant amount of recent nonclinical investigation into the subject. It presents mindfulness as a series of different but related practices which cover diverse phenomena. It highlights the broad spectrum of mindfulness and how it is understood from both spiritual and secular perspectives. This paper expresses the complex nature of mindfulness meditation within ‘a multidimensional phenomenological matrix which itself can be expressed in a neurocognitive framework’. Opportunities and approaches for new research in the general area of mindfulness are suggested. Several important and under researched concerns are raised in this investigation, and calls for a greater understanding of the ethical and axiological contexts are particularly welcome. This work may in due course prove to be an important milestone in the research of meditation in general and mindfulness in particular.
Problems in the scientific research of meditation and mindfulness.
Authors: Richard J. Davidson, Alfred W. Kaszniak
Title: Conceptual and Methodological Issues in Research on Mindfulness and Meditation
Summary: As western psychological investigation into meditation and mindfulness increases, concerns are being raised about how to understand and integrate the wide ranging findings that are being published. Mindfulness is a very general term for one meditative approach which can include a number of distinct psychological phenomena. This paper discusses the conceptual and methodological difficulties in researching this area. Addressing the challenges of creating and subsequently evaluating findings, which by their very nature may only be fully appreciated in the first person.
Authors: Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W
Title: Mindfulness practice leads to increases in regional brain grey matter density
Summary: An investigation into the neural mechanisms underpinning that may be impacted by the Mindfulness Based Stress Reduction (MBSR) form of mindfulness meditation. Sixteen participants with no prior experience of meditation were put through an eight-week MSBR training programme. Any observed changes to grey matter concentration within the MBSR group were investigated and compared to a control group. Analyses indicated the MBSR group experienced increased grey matter in the left hippocampus, posterior cingulate cortex, the temporo-parietal junction and the cerebellum. These findings suggest a potential relationship between the practice of MBSR and changes to the concentration of grey matter in parts of the brain connected to learning and memory processes, emotion regulation, self-referential processing, as well as perspective-taking. The number of participants in the control group is low (16), so replication with a larger number of people is essential. It would also be interesting to know if any parts of the brain suffered reduced concentration of grey matter.