A brainwave, also known as an EEG (electroencephalogram), is a electrical activity of the brain in response to various stimuli. This activity can be measured by electrodes placed on the scalp, and it is typically recorded using a machine called an electroencephalograph.
The different types of brainwaves are categorized according to their frequency. The four main categories are delta, theta, alpha, and beta waves. Delta waves have the lowest frequency and are associated with deep sleep. Theta waves have a higher frequency than delta waves and are associated with light sleep or drowsiness. Alpha waves have an even higher frequency than theta waves and are associated with wakeful relaxation. Beta waves have the highest frequency of all four types of brainwaves and are associated with active mental states such as concentration or anxiety.
There is some evidence that certain types of brainwaves can be beneficial for health. For example, research suggests that alpha wave training may help improve memory and cognitive performance in people with Alzheimer’s disease or other forms of dementia. Additionally, beta wave stimulation has been shown to improve symptoms of attention-deficit/hyperactivity disorder (ADHD). However, more research is needed to confirm these findings.