You may have heard brainwaves referred to in a casual, colloquial sense. For instance, when two people have the same idea we often refer to it as being on the same brainwave or wavelength. These expressions didn’t come from just anywhere – our brains buzz with electrical activity at all times of the day. Whether you are asleep, working on a project, exercising or daydreaming, our neurons are constantly firing and sending signals to each other. Eventually, these neurons form networks of cells to synchronize the sending of signals, resulting in a patterned rhythm of communication. These patterns are what we commonly refer to as brainwaves.
Neural scientists more formally refer to these brainwaves as neural oscillations. These organized patterns of electrical activity are strong enough that they can be detected by electrodes attached to the scalp. Maybe you remember that metal helmet used in the film “Ghostbusters” when they scan Rick Moranis’ character to confirm he has transformed into the Keymaster. Well, that’s not exactly how it works in real life, of course, but it gives those of you who aren’t neural scientists a conceptual reference point. Electroencephalography, more commonly referred to as EEG, is a method used to monitor electrical activity in the brain to help us make more sense of the brain’s processes.
While most of the electrical activity in the brain is still a mystery, there have been strides made in correlating brainwaves to states of consciousness, memory function and potentially even diseases.
Types of brainwaves are distinguished by their frequency, or the number of times the neurons are firing per second. Brainwaves also vary in amplitude. Amplitude is a measure of a wave’s distance from its base line. Think of amplitude as a measurement of the height of the wave’s crest in relation to sea level. Higher amplitudes correspond with lower wave speed, and lower amplitudes with faster speeds.
There are five main types of brainwaves. Although there are no hard and fast rules about their function, they can be used to predict corresponding states of consciousness. Generally speaking, higher-frequency waves indicate higher levels of alertness.
The slowest wave with the higher amplitudes are delta waves, usually seen in states of deep sleep. The next fastest are theta waves, which are often recorded during daydreaming or meditation. Higher in frequency than that are alpha waves, which indicate an awake but relaxed state, such as when you wake up but still have your eyes closed. Beta waves are the next highest in frequency and correspond when you are awake and thinking about something. The waves with the highest frequency and lowest amplitude of all are gamma waves, which typically indicates a state of focused thought.
All of these generalizations do not mean your brain experiences one type of oscillation at a time. All types of brainwave activity are constantly occurring, there just happen to be times when one type of wave is dominant. Different regions of the brain are more commonly linked with certain wavelengths due to having specific functions.
Sure, this is all interesting, but what use does this have in day-to-day life?
Gamma waves have become interesting to neural scientists because studies have show Alzheimer’s patients don’t seem to use them much. Recent studies have shown the stimulation of gamma waves in mice effectively reduces the amount of Alzheimer’s-related proteins, called beta-amyloid. This suggests brainwaves can change the biology of the brain. The key would be to figure out a way to trigger specific waves as treatment.
Nobody has figured out how to achieve this, nor has anyone proven that this technique would actually work to treat Alzheimer’s in humans, but there are compelling studies that show that individuals with high levels of practice in meditation have higher levels of gamma waves overall. Most average people experience bursts of gamma waves for a half second or so in correspondence with sensory input, or even imagined sensory input. For example, biting into a strawberry or imagining biting into a strawberry. Individuals with a lifetime of practice in meditation showed strong levels of gamma waves all of the time, with significant jumps in their level of gamma waves during meditation.
Nobody can define what this means experientially, but it is incredibly compelling to have proof that the states of our minds and how we manipulate those states can have a strong effect on our neural electrical activity. This evidence doesn’t make specific conclusions, but it does provide some credence to the importance of mental practices such as mindfulness as an influence on our cognition, perception, neuroplasticity and emotional processing.
This may not inspire you to dedicate your life to meditation, but it is difficult to not be in awe of the mysterious powers of the brain that our scientific knowledge is only just beginning to unveil.
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