It’s no secret that long-term meditators find that the grip of their internal pessimistic voice— their pejorative “self”—becomes weaker and weaker over time. In its wake, they are left with a greater, more open and optimistic view of the world around them, and are less obsessed with their own selfhood altogether.
We all have a baseline level of self-centeredness, as well as an emotional baseline which governs our thoughts and behaviours day-to-day. And if you haven’t noticed yet, we have this repetitive, noisy internal dialogue which rehashes the most random of memories and the most incoherent string of ideas, otherwise known as our monkey mind . Our emotional baseline (the mood we usually find ourselves in) is known as our usual physiological bias.
Somehow, meditation changes both of these: over time, it quiets chatter of the monkey mind and shifts our stubborn physiological bias. Quite like magic. Except, it’s long-term magic: meditation erodes and weakens the strength of our negative thoughts, cognitive dissonances, and painful longings.
But how is this reflected in the brain? Now, that’s the juicy bit.
Stick with me. This is where it gets neuroscience-y. Use your brain to understand the brain. Ha! The irony.
Neural correlates of self-centeredness
In the brain, we have the limbic system which is also known as the paleomammalian cortex (it’s the oldest structure of the brain which governs our instinctual emotions, behavioural responses, particularly the four Fs: feeding, fight, flight, and reproduction. Impulses that arise from the limbic system rise up to other parts of our cortex and have a strong influence on our ultimate behaviour. The trouble is, limbic impulses all have survival as the end goal, so emotions arising here tend to orient us towards threat, fear and anger. So they make us kind of negative.
These impulses then travel up to be processed in the limbic nuclei of the dorsal thalamus. From there, they rise up to the higher cortex. When this thalamocortoical partnership is activated, we get cognitive dissonances, emotional valences, and behaviours that arise from hard-wired instinctual drives. These neurological interactions are what generate our self-centered memories and life narratives that are deeply rooted in our psyche. They subconsciously bias our perception of reality and trap us in repetitive, negative thougths and attitudes.
“Well, so what? It’s easy to acknowledge that we have a Self, and to be flattered into believing that its assets greatly outweigh its liabilities. So what good is a map that shows some of its anatomical and physiological correlates?…[Loosening this grip] requires a major source of deactivation, a way to dampen the ordinary oscillations that reverberate between the thalamus and the cortex.”James Austin, Zen and the Meditative Transformations of Consciousness, p.92
How Meditation Dampens the Thalamocortical Connection
Happily, frontoparietal target regions can be deactivated, with the help of GABA nerve cells. GABA nerve cells act as a blanket of inhibitory neurons that cover all nuclei of the thalamus and prevents their nerve cells from firing strongly. They work to shift the frequency at which impulses from the thalamus reach the cortex.
In short, GABA nerve cells can shift our usual physiological bias.James Austin, Zen and the Meditative Transformations of Consciousness, p.92
Our typical way of operating is self-centered because there is no mitigation of the thalamus-cortex oscillations. But with meditative practice, this firing is weakened such that we shift our focus more towards the outside world; more towards others, more towards greater receptivity, openness, and less towards threat. It becomes an other-consciousness rather than a self-referential consciousness.
These [thalamocortical] deactivations could cause a significant decrease in the maladaptive influences of the Self. Ideally, a person who underwent repeated states of [dampening] could evolve into a sage who was free from unfruitful overconditionings, unattached to Self-centered conceits, unburdened by habitual indulgences and heart-aching resentments.James Austin, Zen and the Meditative Transformations of Consciousness, p.92