Schematic sections of an human brain where F = frontal lobe (centre
What are the effects of meditation on the brain?
The human brain is the product of 3.5 billions years of evolution when the life started on Earth. Its functions requires a fairly inconceivable 100 billion neurons, interconnected via over 100 trillions of synapses (connections) and over 100 billions non-neuronal cells. A single firing neuron might communicate to thousands of others in a single moment. No computer comes close to the complexity of these communicating bits of organic matter. The capability of the brain to change morphologically and functionally automatically based on its needs is also a significant difference with the computer (see at the end).
One may consider the brain as the hardware and the mind the software. What is consciousness remains a very controversial issue regarding its origin.
Mindfulness meditation has been used for many purposes for at least 15,000 to 20,000 years. Westerns civilizations have discovered non-religious mindfulness meditation only two century ago.
Thanks to the huge progress of neuro imaging over the last decade such as functional MRI (FMRI), Positron Emission Tomography (PET) https://en.wikipedia.org/wiki/Positron_emission_tomography and neuro electrophysiology https://en.wikipedia.org/wiki/Quantitative_electroencephalography we are starting to explore and understand the remarkable effects of meditation of the brain. Without these modern technologies the well-known effects of meditation described thousands years ago could not have been confirmed.
The very schematic A & B diagrams represent a section of the brain with only 3 marked areas:
- The frontal lobe (F) is the area controlling our cognitive functions, concentration and probably also consciousness/awareness. This is the equivalent of our control panel.
- The limbic lobe (L) is the area controlling our emotions. It is also called the reptilian brain or primitive
brain which appeared around 500-600 millions years ago or sooner. It is localized deep in the middle
of the brain. Our emotional mind process input information and output results around x 25 faster than
our rational one. This is why we are reacting emotionally before thinking rationally.
- The occipital lobe (O) is responsible of our vision.
Many more areas non-illustrated here have other specific functions such as motricity, sensitivity, balance, all body functions, etc.
Positron Emission Tomography (PET) imaging showed that:
- If subject A is submitted to various emotional triggers at different degree (pictures, sounds, souvenirs, etc.).
- F is cooling down (blue color). The low activity reflects low concentration, low awareness and low cognitive functions. Our rational response is somewhat “frozen”.
- L is hot (red color). This reflects hyper emotional activity.
- Levels of stress hormones such as cortisol and adrenaline increased with concomitant stress response (emotions, heart rate, respiration, sweat, etc.)
- If subject B is in Zen meditation state for at least 30 minutes:
- F is hot. The high activity reflects high concentration and high awareness.
- L is cooling down. This reflects low emotional activity.
- Stress hormones levels are low or nil.
Quantitative electroencephalography (with cortical sensors on the skull):
Depending on our level of awareness the brain is emitting 5 different types of electrical waves classified by their frequencies in Hz. (# of cycles per sec.) from the lowest to the highest level of alertness.
- Delta waves (0.5-3Hz) are produced during deep sleep.
- Theta waves (3-8 Hz) are produced during deep relaxation.
- Alpha waves (8-12 Hz) are produced during usual alertness & flowing thoughts. Daydreaming and daily activities are an example.
- Beta waves (12-38 Hz) are produced during high alertness and concentration such as during problem solving (analysis, deduction, etc.)
- Gamma waves (38-42 Hz) are produced during intense alertness and concentration such as during deep meditation.
During normal daily activity we are producing mostly alpha and beta waves.
Note: Using invasive micro probes each area can emit their own type of waves based on their current activity.
These two tests are part of a larger scientific arsenal confirming that meditation is not a technique of global mental relaxation but rather an exercise where consciousness is at its highest whereas emotional status is at its lowest.
Finally due brain unique capacity of remodeling called neuroplasticity mentioned previously meditation does affect quantity and quality of many brain keys areas. In others words our brain does modulate its anatomy and functions based on the needs it is facing.
From neuroscience findings this short introduction describes very succinctly what meditation does but we still don’t know how meditation produces these changes.
This meditation-based intense concentration effort explains why meditation can be very difficult and demanding.
Meditation is a real “mental work out” and not a relaxation exercise as described everywhere and perceived by many.
Thank you Ven. Ji Gong Sept 2015
1) “Harvard neuroscientist: Meditation not only reduces stress, here’s how it changes your brain”
Sara Lazar, a neuroscientist at Massachusetts general Hospital and Harvard medical School, was one of the first scientists to take the anecdotal claims about the benefits of meditation and mindfulness and test them in brain scans. What she found surprised her – the meditation can literally change your brain.
2) The healing power of meditation: Shambhala edit. 2013. 20 contributors.
Leadings experts on Zen Buddhism, psychology and medicine explore the health benefits of meditation.