The 5 Types of Brain Waves
The human brain is one of the great mysteries in science. Although we don’t know much about it, it’s also true to say that we understand some of its functions very well. For example, we know that the best way to define it is as an electrochemical organ. We find proof for this in the types of brain waves that we’re going to talk about in this article.
We all know that the brain generates electrical impulses continuously. For example, the analogy that it uses as much energy as a 10-watt light bulb is well known (albeit debatable). All this is carried out through different types of brain waves. If you want to understand what they are and what processes they’re related to, keep reading and we’ll tell you all about them.
What are brain waves?
You won’t understand what the different types of brain waves are if you don’t first understand what a brain wave actually is. The key is in the neurons. All your emotions, thoughts, and actions are possible thanks to them.
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Neurons are cells in the nervous system that respond to stimuli through a nerve impulse. They form a vast network in the brain and other parts of the body. The average adult has 86 billion neurons, and all of these either generate or receive the nerve impulses that govern what you think, feel, or do.
Brain waves are nothing more than the synchronized electrical impulses of a chain of neurons. Not all waves are the same, as they differ in speed or frequency. We can measure them with the help of an electroencephalogram by placing sensors on the scalp.
All types of brain waves are measured in Hertz (Hz). A hertz is a unit that measures the frequency of a wave, based on cycles per second. For example, five Hertz is five cycles in one second. In very simple terms, brain waves are a reflection of the function of the central nervous system at that moment.
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5 types of brain waves
Now that you have a general idea of what a brain wave is, you’ll be able to understand what the types are a lot better. Your brain activity varies according to the activity you actually do.
For example, the brain manifests different waves when you’re at rest and silent than when you’re active and talking. Let’s look at the five types of brainwaves.
1. Delta brainwaves
These are the slowest brainwaves – the ones with the highest amplitude and the lowest frequency. They oscillate between 1 and 3 Hz, although sometimes they can reach 4 Hz. They’re the characteristic waves that are produced when we’re asleep and were first cataloged in 1930 thanks to Grey Walter.
They manifest themselves mainly in stage 3 of sleep, and come to dominate almost the entire brain in stage 4 (see sleep stages). They originate in the thalamus or cortex and, according to researchers, there are differences in production between men and women (from the age of 30-40, women produce more).
2. Theta brain waves
Theta brain waves are those that oscillate between 4 and 8 Hz. They’re associated with stage 1 and 2 sleep, so they develop when you’re in a dreamy or even meditative state.
These aren’t the only contexts in which you can develop theta waves, as they can also appear when carrying out automatic activities. For example, brushing your teeth, combing your hair, and even playing sports (when it involves a repetitive, automatic movement, free of danger or surprises). We’re talking about states that are between waking and dreaming, and are the activities you carry out on autopilot.
3. Alpha brainwaves
We’re starting to leave behind the waves associated with sleep and we’ll now talk about those involved in wakefulness. Alpha brain waves are those that serve as a type of hinge. They oscillate between 8 and 12 Hz. They appear when you’re relaxed, but when you’re still awake and potentially alert.
They originate in the occipital lobe and, according to some researchers, are related to ideas or creative processes. You develop alpha waves when you close your eyes quietly and think about something relaxing. You’re awake and attentive to an external stimulus, but at the same time disconnected enough to let your mind wander.
4. Beta brainwaves
These are types of brain waves that appear during wakefulness. They range from 13 to 38 Hz and are related to states of full consciousness. When you’re concentrating on something, doing some kind of intellectual activity (reading, studying, building), or making a decision, you produce these brain waves.
They’re sometimes divided into three subtypes: beta 1, 2, and 3. For example, a person suffering from generalized anxiety disorder will develop an unusual amount of beta 2 and 3 brainwaves. These demand a great deal of energy, so they can’t be sustained for too many hours without producing consequences (such as stress or fatigue).
5. Gamma brainwaves
Finally, we find the gamma brainwaves, which are the fastest and the highest frequency. They oscillate between 39 and 42 Hz and are related to activation processes in different parts of the brain. They’re thought to modulate perception and consciousness, although they also develop in the face of very complex activities (solving mathematical puzzles, for example).
They’re known to develop around 4-5 years of age and are related to states of alertness or sensory stimulation (such as epilepsy). Apart from this, the function of these waves is unknown. Some think they are a by-product, others think they’re involved in more complex mechanisms that we don’t yet know about.
So, these are the five types of brain waves you develop according to context. As you can see, none of them are 0 Hz, as this is associated with brain death (as no electrical signals are produced). Although there’s some controversy about this, it’s believed that we can control brain waves through electroencephalographic feedback.
This type of treatment is still under experimentation, and the results should be treated with caution. Since some brain wave states or phases are related to a certain behavior (anxiety, insomnia, attention deficit, hypervigilance, and so on), this is a productive field to explore.