Can meditation slow cognitive decline?

Might mindfulness meditation be used to slow brain ageing by regulating connectivity between brain networks?

The relationship between brain networks can be enhanced with meditation

As we get older, we experience an inevitable decline in physical and mental functions. However, the rate of this reduction is dependent on several factors, both genetic and environmental.  It has long been contended that there is a relationship between how we use our brains and mental capacity loss. Mind-training, particularly in the form of meditation, has the potential to mediate how we age. There is a great deal of anecdotal evidence that long term meditators retain good mental function throughout their lives; I have even researched the possible link between meditation and resilience to neurodegeneration (dementia). However, progress in this area is limited by two main problems; poor understanding of the mental processes underpinning meditation and the presence of confounding variables.

Despite over eighty years of meditation research, we know relatively little about how long term meditation changes our brain. This problem is compounded because most long-term meditators are found in spiritual traditions; their lifestyles tend to be atypical. For example, committed Buddhists generally eat healthier diets, take less alcohol and are less likely to be found in stressful occupations than the general population; all factors likely to influence health. Despite these problems, some preliminary research suggests that meditation might slow ‘mental ageing’ (age-related mental decline).

One of the more convincing hypotheses is that meditation plays a role in regulating the brain’s intrinsic and extrinsic networks (I-ENs). The scientific understanding of the I-ENs is still pretty basic. But neuroscience has illustrated that two main brain networks are responsible for our internal perspectives (intrinsic) and external task-based capacities (extrinsic). These are overarching structures connected to anatomically separate parts of the brain. The default mode network (DMN) is a significant component of the intrinsic network. It includes all of those ‘default’ functions that are more active when we’re not undertaking demanding tasks, for example, daydreaming about the past or thinking about our values. The extrinsic network encompasses the task-positive network (TPN). As the name implies, it includes task-oriented and performance systems that allow us to coordinate and carry out attention-demanding activities. But the point I want to make here is that these networks are negatively correlated. Significant activity in the intrinsic network may lead to less activity in the extrinsic, and vice versa. Thus these networks are heavily interdependent; what happens in one is linked to the other.

We can be reasonably confident that abnormally low levels of activity in either the intrinsic or the extrinsic networks leads to problems with our mental functioning and mental health. Meditation research often focuses on attenuating or augmenting function or structure in one of these networks, but typically fails to take into account any relational effect in the other network. For example, meditation and mindfulness experiments have illustrated improvement in cognitive tasks linked to meditation practice. But the increased TPN functionality may also be reducing activity in the DFN; unfortunately, this is an underresearched area.

“While more clinical and basic research is needed to establish the modulation of the DMN and TPN through meditation, and to understand the impact of modulation on ageing and mental disease, the data indicate that meditation may influence different cognitive processes, thus increasing attentional focus and cognitive flexibility.”

Ricardo Ramírez-Barrantes et al.1

Ricardo Ramírez-Barrantes and colleagues published a paper in 2019 that drew attention to the relationship between mental training and meta-awareness.1 Meta-awareness, also known as metaconsciousness or metacognitive awareness, can mediate activity across the I-ENs. That by using meditation to integrate functions in these networks, the rate of cognitive decline in middle and old age might be reduced.

Because of the limitations in meditation and mindfulness research, claims about the regulation of I-ENs through mind-training are still speculative. However, there is a good deal of data,  some presented in this paper, that suggests meditation may have an essential role in maintaining brain function and structure through the lifecycle.

Notes

1 Ramírez-Barrantes, R., Arancibia, M., Stojanova, J., Aspé-Sánchez, M., Córdova, C., & Henríquez-Ch, R. A. (2019). Default mode network, meditation, and age-associated brain changes: what can we learn from the impact of mental training on well-being as a psychotherapeutic approach?. Neural plasticity.

Who you really are; the default mode network

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.

Meditation and the defaulyt mode network.
What is your brain doing when you are day dreaming?

Authors: Andrews‐Hanna, J. R., Smallwood, J., & Spreng, R. N.

Year: 2014

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.

Link:  www.ncbi.nlm.nih.gov

Brain health in middle age; the science of meditation and mindfulness

Meditation and mindfulness may help to keep your brain young

man sitting on chair beside table

 

Authors: Fotuhi, M., Lubinski, B., Trullinger, M., Hausterman, N., Riloff, T., Hadadi, M., & Raji, C. A.

Year: 2016

Title: A personalized 12‐week ” Brain Fitness Program” for improving cognitive function and increasing the volume of hippocampus in elderly with mild cognitive impairment.

Summary: The idea that brain function inevitably declines as people grow older is firmly established in both clinical and cognitive branches of psychology. This particular study is one of only a handful that I have seen to suggest, that even in retirement, people can maintain and even increase both structure and function in the brain. Participants of retirement age with a diagnosis of mild cognitive impairment (MCI) were asked to engage in a number of activities linked to brain health. They included: cognitive stimulation, Omega 3 supplements, some physical exercise, a change in diet and mindfulness meditation. Participant undertook a range of cognitive tests before the interventions and at the end of the experiment.

Results showed that 84% of participants saw an improvement in their cognitive performance. Further neuroimaging examinations revealed that a majority of a sample of the participants also demonstrated no decline or an actual increase in the volume of the hippocampus. Although this was a preliminary study with a number of methodological problems, it is suggestive that people may have a lot more control over brain structure and function than is generally assumed. This kind of ‘shotgun’ approach can support general theories but adds little to our understanding of the extent to which particular interventions (or combination of interventions) may offer benefit. It also makes the establishment of robust scientific theory a challenge, as no single theory can incorporate such a wide range of activities. For example with a new diet, can cognitive changes be attributed to the food that was no longer being eaten or the new food? Or a combination of the two? However simply to demonstrate that older adults can experience increased structure in certain brain regions is an important contribution to our understanding of the human brain.

Link: https://neurogrow.com