What Do We Mean When We Say “Brain Waves” ?
The Brain is made of billions of brain cells called neurons. Neurons are interconnected and communicate with each other by sending electro-chemical signals. When large numbers of neurons send signals at once, a significant (but not too high) electrical activity is generated – and can be measured using sensitive equipment like EEG (See Below). The Brain (collectively by the firing of neurons) can generate up to 10 watts of electrical power.
This electrical power characterizes different brain waves, because it is cyclic. The collective electrical signal has a frequency, which is what helps us ‘classify’ these brain waves into four types. [The frequency is how many cycles per second a certain signal does]
So “How many times the signal goes up and down” is the frequency.
Even though the brain doesn’t have one pure wave, this is our approximation of the electrical activity of the brain.
What Are the Brain Waves, and What Do They Correspond to?
Our classification breaks the types of brain waves into four:
- Around 15 to 40 cycles per second (Hertz) : These are Beta Waves . The most alert and Hyper ones. A strongly engaged mind.
- 9 to 14 cycles per second : These are Alpha Waves. Correspond to basic rest and reflection. Imagine how you would be after finishing a brain-engaging task
- 5 to 8 cycles per second: These are Theta waves. Think about when you’re drowsy or day dreaming. Someone driving for a long distance on a freeway might go to that stage.
- 4 cycles and below per second: This is when the Brain Waves are called Delta waves. It corresponds to the stages of deep sleep.. Below 2 cycles per second the sleep becomes dreamless. Note that the cycles never reach 0 , because that would mean brain death.
Cool Applications of Brain Waves?
To illustrate how our brain activity level changes as we sleep , consider this: When we go to bed and read before attempting sleep, we are usually in low beta. As we put the book down, turn off the lightsm and close our eyes, our brainwaves will descend from beta, to alpha, to theta and finally, when asleep, to delta.
The Theta Brain Wave activity stage is sometimes associated with getting good and creative ideas, for example when running a long distance and alternating between the Alpha and Theta states.
Studies have shown that learning in Alpha State enhances the performance of students, as opposed to being in beta (concentration and alert) the whole time. That makes sense because these short periods of relaxation help recharge and re-energize the mind. Frequent gaps of 2 to 3 minutes after every 30 minute study period relaxes their minds and the alpha state will prove its efficiency with great ease and fun. (See this)
Though Alpha has been mostly agreed upon as best for learning, many would assert that Theta is the best state for memorization and creativity. In the Theta state the brain activity slows below Alpha (at approximately 5-8 Hz) and a greater connection occurs between the conscious and unconscious mind. [See this]
Interestingly , some classical music has been shown to induce Alpha brain wave states in the brain – see this : http://blog.think-grow.biz/right-brain-left-brain-development-language-music/
What does meditation do?
Meditation can lower your brain activity level and allow you to access the Alpha or Theta states. They are associated with being able to raise creativity, relax, and regenerate learning ability. The Key is to focus on the breath. The breath and mind work together, so as breath begins to lengthen, brain waves begin to slow down. (See This )
According to the same source, the attentive or deep relaxation (alpha or theta), produce increases in the levels of beta-endorphin, noroepinephrine and dopamine, linked to feelings of enlarged mental clarity and formation of rememberances. It is ideal for some of the proper functions of the right hemisphere.
A General Thought..
Remember that this ”brainwave frequency” is an approximation of the frequency of the overall electrical activity in the brain – in other terms, it is something we conceptually created, and it somehow serves like an average. So, although one brainwave state may predominate at any given time, depending on the activity level of the individual, the remaining three brain states are present in the mix of brainwaves at all times. In other words, while somebody is an aroused state and exhibits a beta pattern, there can also exist a component of alpha, theta and delta, even though these may be present only at the trace level.
What are Binaural Beats? More Relevant Things?
A further application of this concept of brain waves is what’s known as ‘Binaural Beats’, which provide an interesting insight.
H. W. Dove discovered that when signals of two different frequencies are presented separately for us to hear, one to each ear, the brain detects the phase variation between the frequencies and tries to reconcile that difference. That is done by producing a third – imagined – sound which has the frequency of the difference (heard only inside the mind of the listener).
So for example if you hear – through your headphones – (Note this only works by using a headphone/earphone because otherwise it is very hard to hear two different sounds in each ear), a sound with a fixed frequency of 200 Hz in your right ear, and another sound of fixed frequency of 220 Hz in the left one, the actual sound that you will hear in your mind will be a 20 Hz one… This is the binaural beat.
Research has shown that after some time, the brain starts resonating at a similar frequency of the binaural beat… so effectively by having a binaural beat with a frequency of 10 Hz (for example) , we can help the brain get into a relaxed / meditative state easily by using the binaural beat. Binaural beats are hailed by some as a great tool to help the brain reach certain specific states, and even some specifically defined points within each state (Example: N hz corresponds to dopamine release, etc..)
What is an EEG by the way?
EEG: electroencephalogram. Made of small metal discs with thin wires (electrodes) that are placed on the scalp. These electrodes detect the brain’s electrical activity and send signals to a computer to record the results.