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Brain Waves (Aromatherapy Series)

Brain Waves

Aromatherapy Series

Welcome to our Aromatherapy Series! Technically, this is the 2nd article in the series, but let’s just act like it’s the first for educational purposes alright? Alright coo.

In order to better explain how each essential oil is used in aromatherapeutic applications, I believe it’s necessary to start with a foundation of what brain waves are, so that I can effectively explain later how they are affected by the inhalation of essential oils.

Types of Waves

There are millions of neurons (brain cells) in the brain which constantly communicate, sending electrical signals back and forth in specific sequences and patterns. The patterns of neuronal electrical activity are called brain waves. The speed of brain waves is called frequency, which is measured in cycles per second or Hertz (Hz). These brain waves can be observed and measured using an electroencephalograph (EEG). There are 5 different types of brain waves displayed by the human brain, and each type of wave is associated with a different state of consciousness. The 5 types of brain waves include: Gamma, beta, alpha, theta, and delta.

Our brain's ability to cycle through different patterns of wave frequencies determines how successful we are at managing stress, getting quality sleep, remembering and focusing. If an imbalance exists in these brain wave patterns, we will see problems in these areas of our lives. 

We will begin the discussion of the different types of brain waves starting with the fastest frequency, or Gamma.


Important for learning, memory, and information processing. It is found that individuals with mental challenges such as learning disabilities have lower gamma activity than average. Gamma is associated with insight, expanded consciousness and peak focus. They are generated when the brain is learning new information and is sharply concentrating or storing new memories.

Frequency range: 40 Hz to 100 Hz (highest)
    • Too much: stress, states of high arousal
    • Too little: ADHD, learning disabilities, depression
    • Optimal amount: Binding our senses in regards to perception, learning new material, cognition, REM sleep
    • How can you increase? Reading, learning new information, daily brain exercises (such as puzzles)

    • Beta

      Known as high frequency low amplitude brain waves, where the term “amplitude” indicates the phase of periodic function. Commonly observed while we are awake, beta waves are involved in conscious thought, and school/work-based tasks such as logical thinking. They dominate our normal waking state of consciousness when attention is directed to the external world, and tend to have a stimulating effect. When you consume a stimulating substance such as caffeine, your beta waves will naturally increase, which can result in anxiety and stress. Conversely, too little beta may result in poor cognition. Beta waves are very fast brain waves that we utilize throughout the day to complete conscious tasks such as: critical thinking, reading, writing and socialization.

      Frequency range: 12 Hz to 40 Hz (high)
      • Too much: High arousal state, inability to relax/stress, anxiety, adrenaline
      • Too little: ADHD, depression, poor cognition, daydreaming
      • Optimal amount: Conscious focus, memory, problem solving/logical thinking
      • How can you increase?: Listening to beta binaural beats is a substance-free way to increase beta waves. Another substance-free way to increase them includes reading books. Stimulants such as caffeine and energy drinks also increase beta waves.

      • Alpha

        These waves bridge the gap between the conscious and subconscious mind. Alpha waves help us to calm down, and promote deep relaxation. They can act as a natural antidepressant as they help promote the release of the neurotransmitter serotonin. They are dominant during quiet, contemplative and in some meditative states.

        Frequency range: 8 Hz to 12 Hz (moderate)
        • Too much: Feeling too relaxed, daydreaming, inability to focus
        • Too little: Anxiety, high stress, insomnia
        • Optimal amount: Relaxation, visualization
        • How can you increase?: A substance-free way to increase alpha waves includes meditation. Cannabis, relaxants and some antidepressants can increase alpha waves as well.

        • Theta

          These waves are associated with deep relaxation and sleep, as well as dreaming and auto-pilot states. A person can be considered “highly suggestible” when theta waves are dominant, due to the person being in a deeply relaxed, semi-hypnotic state. These waves can help improve our intuition, creativity and are involved in achieving deep, restorative sleep. 

          Frequency range: 4 Hz to 8 Hz (slow)
          • Too much: ADHD, depression, inattentiveness
          • Too little: Anxiety, poor emotional awareness, stress
          • Optimal amount: Creativity, emotional connection, intuition, relaxation
          • How can you increase?: Theta breathwork, binaural beats, meditation. Depressants may also increase theta brain waves.

          • Delta

            The slowest of the brain waves in humans, delta waves are associated with the deepest levels of restoration and sleep. We tend to produce higher levels of delta as infants. The amount of delta we produce begins to decrease as we age, even during deep sleep. Delta waves are also involved in autonomic functions such as regulating heart beat as well as digestion. 

            Frequency range: 0 Hz to 4 Hz (slowest)
            • Too much: Inability to think, learning issues, severe ADHD, brain injuries
            • Too little: Inability to rejuvenate body or revitalize brain, poor sleep
            • Optimal amount: Strong immune system, natural healing, restorative/deep sleep
            • How can you increase?: Sleep, depressants

            • It is important to note that, when mentioning that the brain is functioning on a certain wave, that wave is dominant. The brain has been shown to function on multiple waves at once. 

              Stress & Brain Waves

              Meditation can induce alpha and theta waves which are brain waves related to relaxation. As a result, beta waves tend to decrease. This can be seen on the EEG. In addition to relaxation, alpha and theta waves are also two of the most important for enhancing creativity and problem-solving abilities. It is postulated that after practicing meditation for long enough, alpha frequencies can become the brain’s dominant brain wave. With alpha waves as the brain’s dominant wave, the following could be experienced: improved quality of sleep, reduction in anxiety, depression and stress, and enhanced learning and memory. Habitual meditation can change your brain wave activity for years to come, leading to increased alpha and theta wave frequencies associated with enhanced overall mental well-being.

              Sleep & Brain Waves

              We descend into sleep in stages. The first stage, Stage I, is the drowsy period - a transitional phase from wakefulness to sleep. We start to shift into this feeling of drowsiness as our brain waves begin slightly increasing in amplitude. Alpha waves are produced in early Stage I sleep. The brain wave activity resembles that of someone who is very relaxed, yet awake. As we progress through Stage I sleep, our dominant brain wave slows down to theta. It is relatively easy to wake someone from Stage I sleep. In Stage II sleep, the body goes into a deep state of relaxation. Our brain waves are still dominated by theta waves, but we begin to see something called “sleep spindles” during this stage, which are periodic bursts of higher frequency wave activity around mid-high beta range (10-12 Hz) for about 1-2 seconds at a time. These arise due to interactions between the thalamic and cortical neurons, and are thought to be important for learning and memory. In addition, something called a “K-Complex” may also be observed during Stage II sleep. A K-complex is a very high amplitude pattern of brain activity that may occur due to environmental stimuli. Stage III represents moderate to deep sleep. This stage is characterized by the presence of delta waves - these brain waves have the lowest frequency and the highest amplitude. In this stage, the sleep spindles begin to decrease. It is much more difficult to wake someone who is in Stage III, and individuals who have increased levels of alpha brain activity during this stage of sleep usually report that they do not feel refreshed upon awakening, regardless of how long they slept. These 3 stages of sleep are called non-rapid eye movement (non-REM or NREM) sleep. 

              The brain produces theta waves during sleep, and during deep restorative sleep, the brain produces rejuvenating delta waves. As we begin to slowly wake, the brain produces more alpha and beta waves. 

              Stage IV of sleep is rapid eye movement, or REM sleep, and is associated with beta waves. The presence of beta waves is what makes us have vivid dreams during this stage due to the brain being more active. It is characterized by darting eye movements under closed eyelids. The previously mentioned stages of NREM are reversed, and the brain activity observed is remarkably similar to that observed whilst a person is awake. The REM stage usually lasts about 10 minutes before the brain cycles back through the non-REM sleep stages.

              Memory & Brain Waves

              A study was conducted by neuroscientists at MIT’s Picower Institute for Learning and Memory, on brain waves and working memory. Working memory is sometimes used interchangeably with the term “short-term memory”. However, there are some subtle differences. For example: Working memory involves temporary storage of information that is being mentally manipulated, such as a telephone number, a looming appointment that day, or ingredients needed to bake that pie for dessert tonight. We are able to hold on to this information from a few minutes to several hours, as working memory enables us to choose what we pay attention to, what decisions to make and when to take action. Short-term memory involves remembering the name of a new acquaintance, a statistic, or current temperature. There are many other types of memory as well, including: episodic memory, semantic memory, procedural memory, sensory memory, and prospective memory. 

              In a 2016 study conducted by MIT neuroscientists Earl Miller and Mikael Lundqvist, it was found that gamma waves are associated with encoding and retrieving sensory information. Gamma waves are conversely related to beta waves meaning when gamma waves increase in intensity, beta waves decrease and vice versa. This led them to theorize that beta waves act as a control mechanism that determines what pieces of information will be allowed to be read out from working memory. It is the brain function that allows control over conscious thought.

              ​​“Working memory is the sketchpad of consciousness, and it is under our control. We choose what to think about,” he says. “You choose when to clear out working memory and choose when to forget about things. You can hold things in mind and wait to make a decision until you have more information.” - Earl Miller

              To test this hypothesis, brain activity was recorded from the prefrontal cortex of the brain (the seat of working memory) in animals trained to perform a working memory task. The animals first saw one pair of objects (A followed by B). Then they were shown a different pair and had to determine whether the new pair matched the first. The animals released a bar if they determined the two sequences matched. The researchers found that brain activity varied depending on whether the two object pairs matched or not. As an animal anticipated the beginning of the second sequence, it held the memory of object A, which was represented by gamma waves. If the next object seen was indeed A, beta waves then went up, which the researchers believe clears object A from working memory. The brain then switched to holding information about object B, as this was now relevant information to determine if the sequence matched. As a result, gamma waves then went up again. However, if the first object shown was not a match for A, beta waves went way up, completely clearing out working memory, because the animal already knew that the sequence as a whole could not be a match.

              “Beta is acting like a signal that gates access to working memory. It clears out working memory, and can act as a switch from one thought or item to another.” Miller says.


              Entrainment is the synchronization of brain waves with external stimuli. This can include pulses of light and sound at specific frequencies. This has been likened to getting a musical band to play together at slower or faster tempos. Entrainment is a safe and gentle way to guide the brain into specific brain wave patterns. A study was done that showed theta waves increase just before a person remembers something correctly. So, two experiments were conducted to see if memory could be improved by boosting theta brain waves. In one experiment (a group of 40 people in total - 22 females and 18 males aged 18-26 years), a boost of theta waves was compared to a boost of beta waves, while in the other experiment (a group of 50 people in total - 26 females and 24 males aged 18-25 years), a boost of theta waves was compared to a boost of white noise (random patterns, like static heard on a radio station) and this group was used as the control group. In both experiments, the participants were asked to study a list of 200 words, one-by-one. They were then given a memory test in which 100 new words were introduced in addition to the previously studied 200. The participants were asked to recall whether each word had been studied. An EEG was used to measure the electrical activity produced by the brain waves, and it was shown that the group receiving the theta waves had better memory than the group receiving the white noise. The group receiving the beta stimulation had boosted beta waves, but showed no improvements in memory. 

              Focus & Brain Waves

              Beta waves are associated with something called “top-down” information and determine which pieces of information can be extracted from working memory. Top-down information includes information such as a current goal, how to achieve it as well as the rules of a task. The prefrontal cortex of the brain sends top-down signals to lower level regions of the brain. The prefrontal cortex, which is a region of the brain thought to control “higher” thought processes, constructs an internal model of the world. It uses the top-down signals to convey this information to the lower level regions. The other regions of the brain send raw sensory input, or “bottom-up” signals, to the prefrontal cortex. These two signals (top-down and bottom-up) help the brain to figure out what it is experiencing, and therefore, tweak its internal model accordingly.

              An internal model refers to a model of the external world constructed within our brain. It is a representation of space that maintains a consistent relationship with objects in the external world as the body moves within it, and must be continuously updated. This is why our world remains stationary in spite of eye, head, and body movements; this is also why we are able to turn and point directly at objects that were originally outside of our range of vision. Our internal model supports perception, prediction, and action in the external world. 

              This internal model would also explain how a person can focus on two things at once, such as focusing on a picture and ignoring noise in the background or cycling between information in the brain whilst trying to creatively solve a problem.


              Can You Change Brain Waves at Will?

              Yes! You can try and change your brain waves at will by using the following methods:

              • Meditation - can help you enter a different state of consciousness (i.e., changing brain waves).
              • Breathing exercises or breathwork - Can help change brain waves by reducing stress and anxiety. Breathwork can also help induce sleep
                • It is sometimes used to induce states of hallucination. 
                • Brain-training games - Different games designed to train and exercise your brain can help stimulate different types of brain waves. Learning new material can also help with neurogenesis (production of new brain cells). 
                • Entrainment - Can train the brain to work at different frequencies. There are several videos on YouTube which play music in specific frequencies to target different brain waves.
                  • This method has not been tested on children or those with epilepsy, and may not be safe in these populations.
                • High intensity workouts - These can release endorphins, giving you an exercise “high” and promoting alpha waves as you rest.
                • Binaural beats and music - Two different sound frequencies played in each ear. Used to train your brain waves to a particular frequency during a specific task. 

                Note: The methods listed above are just a few ways you can try and change your brain wave patterns. This list is by no means exhaustive.

                Thanks for reading! What did you know about brain waves before reading this article? Will you be attempting to change your brain waves? If so, do you plan on using one of the methods listed above or something different? Let us know in the comments!

                Later, we will discuss a study that showed a reduction in beta waves when certain essential oils were inhaled, which led to reduced systolic blood pressure and stress. Stay tuned and follow us on Instagram to stay in the loop about our newest articles!

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