Beginning Again
Fr Thomas Keating used to say that if in meditation one is struggling with intrusive thoughts, every distraction is an opportunity to begin again, to turn again to the Presence. Like many things.
There is a tendency, for me anyway, maybe for you as well, to rate oneself during practice. That was a good meditation, I could say, when there was a maintained state of connection and focus, or conversely if time seems to go very… slowly… I don’t feel I did as well.
Practice is practice, though. Some days one sits down to the piano or the flute or works on the voice and it feels all wrong. There’s no flow. Some days it goes swimmingly.
The important thing is to remain consistent. To keep at it regardless of whether I feel it is going well or not. It’s true of meditation, singing, relationships, walking, and maybe everything.
This article outlines the four related processes the brain meditates neuroplasticity: ‘synaptic plasticity, structural plasticity, neurogenesis, and functional reorganization that enable the brain to adapt to both internal and external changes throughout the lifespan.’
Synaptic Plasticity
Synaptic strength is modulated through long term potentiation (LTP) and long-term depression (LTD). This article explains the mechanisms whereby both LTP and LTD act on neural circuits and contribute to cognitive flexibility. Repeated practice of a skill consolidates the strengthened connections as it reinforces the neural circuits, for example in practising music or learning a new language. On the minus side too much LTP in path pathways can lead to conditions like fibromyalgia or neuropathic pain.
The balance between LTP and LTD seems vital. For example, too much LTD in hippocampal circuits has been shown to contribute to cognitive impairment in disorders like Alzheimer’s.
Structural plasticity
This refers to changing neural architecture, like synaptogenesis, dendritic branching, and the elimination of weak or underused synapses in the teenage and adult years, which helps optimize neural pathways. Forming new synapses and increasing dendritic complexity in the motor cortex are seen when people learn to play a musical instrument, so refining and improving motor control.
On the other hand, though, abnormal dendritic growth can occur as a result of drug addiction, as reward-related circuits are over-stimulated through excessive drug use. There is also the connection between excessive synaptic pruning and disorders like schizophrenia, in which important synaptic bonds are disrupted.
Neuronal plasticity and network adaptations
Individual neurons can change their intrisic properties as responses to learning and environmental input. They adapt through their intrisic plasticity, changing electrophysiological properties, as well as how on a large scale their networks and patterns of connecting are altered. Again this can be positive in learning, consolidation of memory and recovery after an injury like a stroke, but when dysregulated lead to conditions like epilepsy, addictions, or psychiatric illnesses.
Neurogenesis
People continue to generate new neurons over the course of our lives, though of course the rate of generation slows with age. This are generated mostly in the hippocampus and subventricular zone (important for example after brain injury). Neurogenesis is enhanced in enriched environments with complex spatial tasks, exercise, and social interaction, improving cognition and helping regulate stress. But chronic stress or too high cortisol levels can decrease hippocampal neurogenesis, which may contribute to depression and anxiety. There is also the caveat that new neurons may not integrate into existing circuits well enough through several factors.
Neuroplasticity keeps evolving
Not only age, but gender, hormonal changes, and the environment have an ongoing effect on neuroplasticity. ‘Epigenetic modifications, which dynamically regulate gene expression in response to environmental influences, also contribute to these lifespan changes in neuroplastic potential (Nayak et al., 2022).’
The bottom line is that we are learning more about both adaptive and maladaptive ways that neuroplasticity affects us and about how it changes over the course of our life. It is far from perfectly understood and there are confounding contradictory results of studies.
But the encouraging takeaway for those of us who are at or approaching the winter phase of life is that through practice and good habits like regular exercise, good diet, meditation, developing better relationships with people around us, and other positive ways of building good pathways, and by doing our best to avoid harming ourselves through poor mental health or addictions, we can continue to enhance our neuroplasticity throughout our lives.
