How Does Our Brain Work? Brainwave Frequencies Explained
Updated: Oct 27
The brain is a fascinating, complex organ which controls every aspect of our daily life. It is responsible for every thought and action, from the deepest philosophical musing, to remembering a grocery list, down to coordinating the motor skills necessary to brush your teeth. Scientists are discovering new and fascinating information about how the brain works every day.
The brain communicates using electronic signals transferred using neurons, also called brain waves. Brain waves can be measured using a technology called Electroencephalography (EEG), which picks up the electric signals from the brain using sensors in the form of metal electrodes placed on different locations on the head.
Brain waves can be divided into different speeds (fast, medium, slow) and correspond to different types of thought patterns. They are often compared to musical notes, since each type of brain wave has its own “sound” which is distinct from others. When the brain is working well, it is like a symphony in harmony, with the different brain waves occurring in predictable patterns and using fluid jumps between mental states. However, in certain individuals, the brain wave patterns can be dys-regulated and one type of brain wave can dominate too frequently or at the wrong time.
They are further broken down into the following three categories:
Hi-Beta (20.5-28 Hz) - Hi-Beta waves are seen during highly complex, rapid thought including states of excitement and high anxiety.
Beta (16.5-20 Hz) - Beta waves are the intense, focused brain activity when we are working on solving a problem or actively engaging with our environment.
Lo-Beta (12-16 Hz) - Also known as sensorimotor rhythm (or SMR), the Lo-Beta waves have been shown to be very beneficial in reducing anxiety, increasing focus and overall wellbeing and health.
Alpha (8-12 Hz) - Alpha waves are slower and higher in amplitude than Beta waves and represent a calm, relaxed state. It is the resting state of the brain, and occurs during some meditative and mindful activities. Most people can increase their Alpha waves by closing their eyes and taking a few deep breaths.
Theta (4-7 Hz) - Theta waves are very slow, and relate to dreamy, free-flowing, detached unconscious thought, which occurs while doing automatic tasks and sometimes in deep meditative states. It often occurs during dreaming sleep.
Delta (1 - 3 Hz) - Delta waves are low brain waves which occur during dreamless sleep and in deepest meditative states.
The average person experiences all of these types of brain waves at different times over the course of a day. For instance, when solving a difficult crossword, their Beta waves would be most active, while sitting during a relaxing coffee break they may have more Alpha waves, and in bed thinking over the events of the day right before drifting off to sleep their Theta waves would be dominant.