Yoga Nidra, hypnosis, meditation
Neuroscience and Modified States of Consciousness
Science and MSC
Numerous scientific studies have focused on the waves emitted by the different areas of the brain in the different states of consciousness encountered in our daily lives. Progress in medical imaging has been very impressive in recent decades in general, and in the neurosciences in particular.
This has led to a better understanding, albeit still very patchy, of what are known as Modified States of Consciousness (MSC).
The different states of consciousness
The Ordinary States of Consciousness (OSC) are very familiar to us: waking, deep sleep, REM sleep (dreams). The altered states of consciousness, a little less familiar, correspond to psychiatric disorders or intoxications due to psychotropic substances (alcohol, drugs, etc.). Finally, the Modified States of Consciousness (MSC) are much more mysterious: they appear during meditations, hypnotic trance, yoga practices, shamanistic trance, mystical ecstasies… or even during near-death experiences, comas, or for example the sensation of slowed-down, called “flow”, experienced by top-level sportsmen and women in situations of extreme concentration.
In these MSC, certain areas of the brain are activated, others are not, but the frequency of the brain waves is also important to take into account. And all this has an effect on the hormones released in our blood, and therefore on the messages sent throughout the body, to the organs and to each of our cells.
Frequencies emitted by the brain
Correlations between the state of consciousness (voluntarily triggered MSC or OSC), brain activity and hormonal activity have been scientifically demonstrated. For example, a Danish team was interested in Yoga Nidra: an increase in Theta waves (typical of meditative states) and in the secretion of certain hormones (65% more dopamine!)* was observed.
Areas of the brain: Altered state of consciousness
Another study has shown that regular Zen meditation practitioners experience less pain due to regular activation of a specific area of the brain, the anterior cingulate cortex (ACC). This area is known in neurology to play a role in pain perception, and was thicker in the meditators and therefore “muscular “**.
Hypnosis can also alter the activity of this area of the brain, resulting in a very powerful anaesthetic effect and is increasingly used for surgical operations as a substitute for pharmacological solutions.***.
Traditional knowledge did not benefit from all the modern technology to directly observe the effects on the brain. Nevertheless, we can understand, a posteriori, the benefit of the different meditative exercises: for example, visualisations make specific areas work, attention on the posture or on the different parts of the body activates the famous CCA. To go into more detail, we can even see that the abstract and concrete visualizations, both encountered in Yoga Nidra, do not activate the same areas of the brain, and are therefore each interesting, for different benefits.
Hormone and DNA: Consciousness
All these observations on the brain might make you think that it’s all “in the head”, but the physiological consequences of MSC encompass the whole body, thanks to hormones, and even go as far as repairing our DNA. For several decades now, it has been noticed that the levels of dopamine (motivation hormone), melatonin (sleep hormone) and many others have been altered, regulated by meditative-type practices. But science is only just beginning to understand the direct influence of these practices on our genome.
Even identical twins live differently, undergo a different environment, and their DNA will age differently, due to chemical processes related to exposure to psychological stress. A French team from the CNRS recently demonstrated that a single day of meditation can reveal measurable changes in the DNA of practitioners****, particularly at sites related to metabolism and the ageing of immune cells.
Outlook
The more science advances, the more it discovers the therapeutic benefits (and associated mechanisms) related to Modified States of Consciousness. The good news is that we don’t need to be a neurologist or biochemist to live and experience all these benefits, but only to open ourselves to traditional practices, to practice them, and thus take care of ourselves at a level that science did not even dream of until recently.
