What are brain waves?

What are brain waves?

While reading just a single sentence, you will have experienced thousands of brain waves. These waves of electricity flow around our brains every second of the day, allowing neurons to communicate while we walk, talk, think and feel.

What exactly is a brainwave? The term "brainwave" refers to rhythmic changes in the electrical activity of a group of neurons. When many neurons fire at the same time, we see these changes in the form of a wave, as groups of neurons are all excited, silent, then excited again, at the same time.

All humans display five different types of electrical patterns or “brain waves” across the cortex.
At any one time, a number of brainwaves are sweeping through the brain, each oscillating at a different frequency, classified in bands called alpha, theta, beta and gamma, and each associated with a different task. This rhythmic activity turns out to be the perfect way to organise all the information hitting our senses. Every sensation we feel, from the itch of a sweater to the buzz of a cellphone, triggers a shower of neural signals. Brainwaves may provide clarity in this electrical storm by synchronising all the activity corresponding to a single stimulus - the words on a page, say - to a particular frequency, while neurons attending to another stimulus fire at a different frequency. This would allow brain cells to tune in to the frequency corresponding to their particular task while ignoring irrelevant signals, in much the same way we home in on different waves to pick up different radio stations.

Brains have problems distinguishing signal and noise. In order for neuron A to talk with neuron B, it can better transfer information if it can synchronise its activity.
The importance of signal synchronisation becomes clear when you consider that the different aspects of a sensation - colour and shape in vision, for example - are processed in different parts of the brain before being sent to another region that binds them back together. Imagine you are looking at an apple. The apple's redness and roundness are picked up by different cells in the brain, but you don't see a red thing and a round thing - it's one item.
The rhythmic activity of brainwaves ensures that all the relevant signals relating to the sensation arrive at the binding region at exactly the same time. This allows the receiving neurons to process the signals together, recombining them into a single sensation. If neurons are oscillating at the same frequency, signals from a stimulus would be treated together because the firing came in at the same time, and at the same point on the oscillation, so that the object is perceived as a whole rather than the separate details.
Beyond their role in binding together all aspects of a sensation, however, the properties of brainwaves had remained murky. How, for example, do their specific characteristics, like the timing of each wave's rhythm, influence what we see, hear or remember?
It was discovered not too long ago how the activity of a certain kind of brainwave determines whether something is seen or not. When volunteers were exposed to rapid flashes of light, the type of brainwave that coincided with the flash would predict which ones they would see.
If the flash coincided with the peak of a wave in the alpha or theta frequencies, they saw it, but if it occurred when the wave was at its trough, they didn't. Apparently neurons are more likely to fire in response to visual input if they are already excited.

In another experiment volunteers were exposed to a certain word very briefly, the words were recognized when brainwaves in the gamma frequency range were in sync. Out of sync, the word was not consciously recognized. To consciously perceive a stimulus, you need coordination not only in local activity but also in many different parts of the brain.

Perhaps the most significant function of brainwaves, however, is their role in memory.
Apparently gamma waves are needed to control the flow of stored information with low-frequency gamma waves sending old memories and high-frequency gamma waves sending newer information.

Gamma waves are involved in higher processing tasks as well as cognitive functioning. Gamma waves are important for learning, memory and information processing. It is thought that the 40 Hz gamma wave is important for the binding of our senses in regards to perception and are involved in learning new material. It has been found that individuals who are mentally challenged and have learning disabilities tend to have lower gamma activity than average. A lower gamma activity often also leads to feelings of depression.
Individuals with too much activity of gamma waves often suffer from anxiety and stress.

Beta waves are known as high frequency low amplitude brain waves that are commonly observed while we are awake. They are involved in conscious thought, logical thinking, and tend to have a stimulating affect. Having the right amount of beta waves allows us to focus and complete school or work-based tasks easily. Having too much beta may lead to us experiencing excessive stress or anxiety. The higher beta frequencies are associated with high levels of arousal. When you drink caffeine or have another stimulant, your beta activity will naturally increase. Think of these as being very fast brain waves that most people exhibit throughout the day in order to complete conscious tasks such as: critical thinking, writing, reading, and socialization.
Too much activity of beta waves leads to adrenaline and an inability to relax, while too little results in daydreaming and poor cognition skills.

Alpha waves bridges the gap between our conscious thinking and subconscious mind. Alpha is the frequency range between beta and theta. Alpha waves help us calm down when necessary and promotes feelings of deep relaxation. If we become stressed, a phenomenon called “alpha blocking” may occur which involves excessive beta activity and very little alpha. Essentially the beta waves “block” out the production of alpha because we become too aroused.
Having too many alpha waves results in daydreaming and inability to focus while too little leads to anxiety and insomnia.

Theta waves are involved in daydreaming and sleep. Theta waves are connected to us experiencing and feeling deep and raw emotions. Too much theta activity may make people prone to bouts of depression and may make them “highly suggestible” based on the fact that they are in a deeply relaxed, semi-hypnotic state. Theta has its benefits of helping improve our intuition, creativity, and makes us feel more natural. It is also involved in restorative sleep. As long as theta isn’t produced in excess during our waking hours, it is a very helpful brain wave range.

Delta waves are the slowest recorded brain waves in human beings. They are found most often in infants as well as young children. As we age, we tend to produce less delta even during deep sleep. They are associated with the deepest levels of relaxation and restorative, healing sleep. They have also been found to be involved in unconscious bodily functions such as regulating heart beat and digestion. Adequate production of delta waves helps us feel completely rejuvenated after we wake up from a good night’s sleep. If there is abnormal delta activity, an individual may experience learning disabilities or have difficulties maintaining conscious awareness (such as in cases of brain injuries). Having too much delta activity leads to an inability to think and severe ADHD while too little results in an inability to revitalize the brain and poor sleep quality. 


So what does GABA (Gamma AminoButyric Acid) have to do with brain waves? GABA is the major inhibitory or relaxing neurotransmitter. Normalisation of brain GABA levels leads to a reduction in stress, anxiety, nervousness and an improvement in insomnia resulting in a more restful night's sleep.
GABA prevents nerve impulses associated with anxiety from reaching the motor centres of your brain by filling benzodiazepine receptors with GABA.
Besides binding to your GABA and benzodiazepine receptors, GABA decreases your beta brainwaves and increases your alpha brainwaves .

Low levels of GABA can cause or contribute to a variety of health issues such as anxiety, panic disorders, depression (including postpartum depression), epilepsy, convulsions, stress, insomnia (especially waking with a racing mind or waking and not being able fall back to sleep), Tourette's syndrome, muscle spasms, hypertension, emotional issues associated with premenstrual syndrome, dry skin and wrinkles. GABA stimulates secretion of your digestive enzymes and low levels of digestive enzymes are associated with poor digestion, bloating, flatulence, poor bowel motions and malabsorption.


Glutamine is the precursor to GABA production. Glutamine is first converted to glutamate, which is your body's most abundant excitatory neurotransmitter. Glutamic acid is responsible for your attention span, memory, brain energy, learning ability, staying awake and the metabolism of carbohydrates. From there it is converted to GABA. For the converting enzyme to work effectively P5P (the biologically available form of B6) is needed as well as taurine and zinc.

Other important nutrients involved in the process that can enhance the production of GABA, like theanine as found in tea and inositol as well as magnesium.


Theanine, a plant-based amino acid found only in tea increases levels of GABA within the brain increases the production of alpha brainwaves and enhances GABA A receptor response. Studies have shown that theanine is useful in the treatment of anxiety due to its ability to sedate the central nervous system as well as improving the quality of sleep and counteract the toxic effects of stress . In general it is smarter to combat stress with tea rather than with coffee. Coffee can be too stimulating and have an opposite effect!


Inositol, a B group vitamin may help alleviate anxiety and depression, by enhancing the ability of GABA to bind to the benzodiazepine receptors within the brain.
Inositol may also help to stimulate poorly sensitive serotonin receptors within the brain and facilitate a good night's sleep.


Magnesium deficiency is common in western society with up to 80% of women and 70% of men having some form of magnesium deficiency. Magnesium binds to and activates GABA receptors. Anxiety, panic disorders, apathy, poor attention span, depression, insomnia, irritability and nervousness may all result from magnesium deficiency. Magnesium may also improve the length and quality of slow wave sleep.


Chamomile, a medicinal herb used for thousands of years and commonly found throughout the world as a tea has been shown to have sedative effects due to the flavonoid apigenin that binds to the benzodiazepine and GABA receptors within the brain. Traditionally chamomile has been used to help alleviate anxiety and improve insomnia by sedating the central nervous system. Chamomile may also assist in normalising moods.

St John's Wort

St John's Wort may inhibit the reuptake of GABA (which leads to increased GABA levels and GABA activity.
Valerian is known to prevent or reduce the breakdown of GABA within the brain.

Ginkgo Biloba

Ginkgo Biloba has been found in to increase GABA in the hippocampus region of the brain. The hippocampus plays an important role in long and short term memory it is also one of the first area affected by Alzheimers disease hence memory loss and disorentation.

Other herbs such as passionflower, skullcap, hops, lemon balm, and magnolia bark are well-known to have calming and relaxing properties that improves moods, insomnia and anxiety, but their mode of action is not exactly known. It is believed that these herbs act either as a GABA receptor agonists (stimulating the receptor) or boost GABA levels directly.

Fermented foods such as fermented cabbage, fermented milk and fermented juice contain naturally occurring GABA. The same is true for fava beans, tomatoes, sunflower seeds and reishi mushrooms.


Glycine, another amino acid, may help with GABA function and alleviate anxiety and panic attacks by reducing the stimulatory effects of noradrenaline within the brain. Glycine functions as a calming neurotransmitter within the nervous system and it does this by causing a relaxing effect when it binds to and activates the glycine receptors within the spinal cord. Glycine may also help alleviate insomnia due to its role as a relaxing neurotransmitter.