Neuroscience of Meditation
We can be in one of two states: either the mind is running us or we are running our mind. For the latter, we need to understand the composition of our mind and their physical components like our brain.
WHAT ARE BRAINWAVES?
At the root of all our thoughts, emotions and behaviours is the communication between neurons within our brains. Brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. Brainwaves are detected using sensors placed on the scalp. They are divided into bandwidths to describe their functions (below), but are best thought of as a continuous spectrum of consciousness; from slow, loud and functional - to fast, subtle, and complex. Our brainwaves change according to what we’re doing and feeling.
Meditation enables us to move from higher frequency brain waves to lower frequency and calm the mind. Slower wavelengths allows for more time between thoughts which then offers us more opportunities for to skillfully choose the thoughts we invest in.
CATEGORIES OF BRAINWAVES
There are five major categories of brain waves, each corresponding to different activities we do. The descriptions that follow are only broad descriptions - in practice things are far more complex, and brainwaves reflect different aspects when they occur in different locations in the brain. Brainwave speed is measured in Hertz (cycles per second). Studies have shown that the brain releases different neurotransmitters in each of these frequency bands – affecting our physiology and how we feel.
DELTA WAVES (.5 TO 4 HZ)
Delta brainwaves are slow, loud brainwaves (low frequency and deeply penetrating, like a drum beat). They are generated in deepest meditation and dreamless sleep. Delta waves suspend external awareness and are the source of empathy. Healing and regeneration are stimulated in this state, and that is why deep restorative sleep is so essential to the healing process. Tibetan monks that have been meditating for decades can reach this in an alert, wakened phase but most of us reach this final state during deep, dreamless sleep.
THETA WAVES (4 TO 8 HZ)
Theta brainwaves occur most often in sleep but are also dominant in deep meditation. Theta is our gateway to learning, memory, and intuition. In theta, our senses are withdrawn from the external world and focused on signals originating from within. It is that twilight state which we normally only experience fleetingly as we wake or drift off to sleep. In theta we are in a dream; vivid imagery, intuition and information beyond our normal conscious awareness. It’s where we hold our ‘stuff’, our fears, troubled history, and nightmares. The Theta state is associated with the sixth chakra (third eye), so in this state we are able to practice visualization.
ALPHA WAVES (8 TO 13 HZ)
This is the state where brain waves start to slow down out of thinking mind. Alpha brainwaves are dominant during quietly flowing thoughts, and in some meditative states. Alpha is ‘the power of now’, being here, in the present. Alpha is the resting state for the brain. Alpha waves aid overall mental coordination, calmness, alertness, mind/body integration and learning. We often find ourselves in an alpha state after an intense yoga / mediation class, a walk in the woods or during any activity that helps relax the body and mind. This is often accompanied by an inner and/or outer glow. The hemispheres of the brain are more balanced.
BETA WAVES (13 TO 40 HZ)
Beta brainwaves dominate our normal waking state of consciousness when attention is directed towards cognitive tasks and the outside world. This is where we function for most of the day. Beta is associated with the alert mindstate of the prefrontal cortex. Beta is a ‘fast’ activity, present when we are alert, attentive, engaged in problem solving, judgment, decision making, or focused mental activity.
Beta brainwaves are further divided into three bands; Lo-Beta (Beta1, 13-15Hz) can be thought of as a 'fast idle', or musing. Beta (Beta2, 16-22Hz) is high engagement or actively figuring something out. Hi-Beta (Beta3, 22-40Hz) is highly complex thought, integrating new experiences, high anxiety, or excitement. Continual high frequency processing is not a very efficient way to run the brain, as it takes a tremendous amount of energy.
GAMMA WAVES (40 TO 100 HZ)
Gamma brainwaves are the fastest of brain waves (high frequency), and relate to simultaneous processing of information from different brain areas. Gamma brainwaves pass information rapidly and quietly. The most subtle of the brainwave frequencies, the mind has to be quiet to access gamma. Gamma was dismissed as 'spare brain noise' until researchers discovered it was highly active when in states of universal love, altruism, and the ‘higher virtues’. Gamma is also above the frequency of neuronal firing, so how it is generated remains a mystery. It is speculated that gamma rhythms modulate perception and consciousness, and that a greater presence of gamma relates to expanded consciousness and spiritual emergence.
A simple meditation to use to begin the transition from Beta or Alpha to the Theta State is to focus on the breath. The breath and mind work in tandem, so as breath begins to lengthen, brain waves begin to calm and slow down.
Consistency is key—try to do breath meditation for minimum 15 minutes first thing in the morning and/or at night. Be consistent with your meditation practice. Shorter meditation sessions on a regular basis are more productive than long sessions every few weeks.