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.
The Science of Meditation and Mindfulness 