Have you ever thought, when you are happy or in a dreamy state or in deep sleep, what exactly happens to your brain? Here comes the concept of BRAINWAVES.
Whenever you are doing some activity, like watching a movie or playing cricket or when you are reading this blog, your brain is abuzz with activity. Your brain is made up of cells called neurons. There are millions of electrical pulses passing between neurons, that are sending signals to each other. When those signals spread, clusters of neurons start getting feedback from each other, and it becomes a repeating cycle or rhythm: A BRAINWAVE or as Neuroscientists call them neural oscillations. With EEG (electroencephalograph) these brainwaves can be measured by placing Electrodes on the scalp.
Different types of brainwaves are classified as cycles or the number of times the neurons are firing per second. Generally the higher frequency the wave, the more alert and awake you are. A frequency is the number of times a wave repeats itself within a second.
There are 5 categories of these brainwaves, ranging from being on the most active state to doing the least activity.
Below table shows the brainwave frequencies:
|Frequency band||Frequency||Brain states|
|Gamma (γ)||>35 Hz||Concentration|
|Beta (β)||12–35 Hz||Anxiety dominant, active, external attention, relaxed|
|Alpha (α)||8–12 Hz||Very relaxed, passive attention|
|Theta (θ)||4–8 Hz||Deeply relaxed, inward focused|
|Delta (δ)||0.5–4 Hz||Sleep|
Brief on different Brain Waves:
DELTA (0.5 to 4 Hz)
It tends to be the highest in amplitude and the slowest in frequency with deep, dreamless sleep. These brainwaves are detected more often in infants or in young children
THETA (4-8 Hz)
It is seen in connection with creativity, intuition, daydreaming, and fantasizing and is a repository for memories, emotions, and sensations.Theta waves are strong during internal focus, meditation, prayer, and spiritual awareness. These waves are visible in both light sleep stages as well as during focused tasks is what makes them so interesting.
ALPHA (8-12 Hz)
Alpha brain waves (8–13 Hz) may be considered a bridge from the external world to the internal world, and vice versa. Before sleep or when you just woke up, it is the alpha state of mind.
BETA (above 12 Hz)
When you are doing the normal daily works, or interacting with someone, or in a meeting room, or when you are reading this, your mind is in Beta state.
GAMMA (above 30 Hz)
These waves are with small amplitude and higher oscillations. It indicates that you’ve achieved the peak level of concentration.
So in brief, when we close our eyes to sleep, our brainwaves will descend from beta, to alpha, to theta and finally, when we fall asleep, to delta.
And similarly, when we wake up from a deep sleep, the brainwave frequencies will increase through the different stages of brainwave activities, like from delta to theta and then to alpha and finally, when the alarm goes off, into beta.
Here in Silva you can develop the power to control the different brain states by practicing the Silva active meditation techniques.