An ancient practice that science has been eyeing for decades
Meditation has become ubiquitous: it appears in psychology clinics, mobile apps, and every stress-management course. This popularity coexists with two equally sterile extremes: the mysticism that wraps it in promises of instant enlightenment, and the skepticism that dismisses it as a mere pastime. Between the two lies a more interesting terrain: asking what truly happens in the brain of someone who meditates.
That the practice produces measurable changes is indisputable: variations in pulse, biochemical parameters, and immune markers have all been documented. What remains a subject of debate is the mechanism that explains them. It is worth keeping this in mind, because much of the popular literature on meditation confuses “observed correlates” with “knowing why it works.”
One idea should be established from the start: anyone can sit with their eyes closed; sustaining attention without getting tangled in one’s own mental chatter is another matter entirely. That is why meditation, like almost anything worth doing, requires guidance at the beginning, time, and repetition. No one reaches enlightenment in a weekend, regardless of what the teacher of the moment might claim.
Plasticity: The brain is maintained through use
The most sober hypothesis for understanding why meditation “feels good” is based on neural plasticity: the nervous system’s ability to create, undo, and refine connections between neurons. The decisive factor is not the isolated cell, but the network—millions of connections whose result is more than the sum of their parts. And those networks, like a muscle, are maintained through use. Neural activity promotes the release of factors such as BDNF (brain-derived neurotrophic factor), which is associated with the maintenance and health of these connections.
Serial and parallel: The key to “noise” during meditation
The brain processes information in two complementary ways. Parallel processing handles massive, simultaneous tasks: balance, heartbeat regulation, automatic thoughts, and memories that remain active without us noticing them. Serial processing handles the costly tasks: conscious attention, which can only focus on a few things at once because its resources are very limited.
This distinction illuminates the frustrating experience of beginners. Mental content never disappears—that would be incompatible with life as we know it; it continues to “reverberate” in circuits working in parallel. When we sit in silence, conscious attention, which functions serially, runs out of tasks. In that gap, it is very easy for background content to assault the “screen” of consciousness. Hence the hundreds of thoughts that seem to sprout from nowhere as soon as we close our eyes.
The “void” pursued by meditation is, therefore, not a powered-down brain, but a consciousness freed from work. The hypothesis is elegant: by not fixing attention on any specific content, we stop inhibiting some circuits in favor of others and allow the whole system to self-regulate. It is this self-regulation, rather than any mystical state, that would explain the general improvement described in so many studies. It is a reasonable hypothesis, not a closed certainty.
A classic practice scheme (with a warning)
The following is an illustrative scheme, not a substitute for guidance from someone with experience. If you are truly interested in the practice, go to a center or teacher with a recognized track record; this text only seeks to give shape to a process that otherwise sounds abstract.
Posture. Some schools minimize this and advocate for comfort. Zen tradition, however, places importance on it: a straight back and slightly tucked chin favor concentration and prevent drowsiness. The essential thing is a stable position that does not require you to be preoccupied with your body.
Breath as an anchor. With eyes closed and breathing naturally, bring your attention to the coming and going of the air. After a few breaths, focus on the exhalation: let the inhalation pass and observe how the lungs empty.
What to do with thoughts. They will appear, and many of them. This “chatter” is not a failure; it is the brain performing maintenance. The classic instruction is not to fight it or surrender to it—”do not resist, do not give up”—simply, every time you notice you have become entangled, return to the anchor. Having a thought does not force you to attend to it; we are the ones who decide what we pay attention to.
The gaps. Later on, attention can rest in the brief interval between the end of an exhalation and the start of the next—a minimal instant, difficult to “inhabit” at first—or on a meaningless syllable, like a mental “ah,” which occupies consciousness while other processes continue their course. When a thought arises, a common technique is to ask yourself, without looking for an answer, “And you… where did you come from?”: in the subsequent silence, a fleeting stillness appears. Answering would activate reasoning and break the practice.
All of this can be prolonged as much as you like. The recipe has no shortcuts: practice, repetition, and sustained attention.
Cannabis as a “support”: A critical reading
In cannabis culture, the idea that cannabis “enhances” or “catalyzes” meditation has circulated for decades. The experience described by those who defend it—more absorbed attention, a more vivid perception of the body and breath—is real to them, but it should be viewed with some distance.
First: cannabis does not produce mental stillness. Its most characteristic effect is the exact opposite of what meditation pursues—it tends to multiply associations, disperse attention, and fragment working memory. THC can also intensify anxiety or discomfort in high doses or in sensitive individuals, precisely the type of state that the practice attempts to soothe. What is “deepening” for one person may be, for another, getting lost in a fascinating but empty internal discourse. The original text itself admits this by warning against “filling the mind with fantasies and vain discourses.”
From a harm reduction perspective, some honest considerations:
- Do not confuse intensity with depth. An experience more loaded with content is not a better meditation; it is often the opposite of what the practice seeks.
- Skill is trained while sober. Relying on a substance to “feel something” before knowing how to sustain attention on your own tends to create dependence on the effect, not proficiency.
- Context matters. Mixing a practice oriented toward calm with a psychoactive substance during a bad emotional moment can amplify discomfort instead of dissolving it.
- Personal cautions exist. A history of anxiety, panic attacks, or psychotic vulnerability are strong reasons not to use cannabis as an “aid” at all.
None of this is a moral condemnation of cannabis or those who combine it with their practice. It is, simply, an invitation not to sell as a reliable technique what is a subjective, variable experience with its own risks.
Critical reading
The neuroscientific framework we have used—plasticity, serial and parallel processing—is a useful explanatory analogy, not a closed description of what happens when meditating. Research on meditation is real and abundant (there is literature indexed in databases like PubMed regarding its physiological correlates, and reference works in Spanish such as those by Ramiro Calle on the practice), but it carries known problems: small samples, disparate definitions of “meditation,” a placebo effect that is difficult to control, and publication bias toward positive results. Taking the benefits as proven in detail is going further than the evidence allows. The idea of “lost seconds” or the “background prior to mental content,” for its part, is a suggestive phenomenological metaphor, not a laboratory finding: it is valid as a description of the experience, not as data.
