Alpha rhythm

The Alpha rhythm (pronounced: /ˈælfə ˈrɪðəm/), also known as Berger's wave after the neurologist Hans Berger, is a type of brain wave that oscillates between 8 and 12 Hz. It is detected by electroencephalography (EEG) or magnetoencephalography (MEG) and originates from the occipital lobe during periods of relaxation with closed eyes. Alpha waves are reduced with open eyes, drowsiness and sleep.

Etymology

The term "Alpha rhythm" is derived from the first letter of the Greek alphabet, alpha (α), indicating it was the first brain wave to be detected and studied. The term "Berger's wave" is named after Hans Berger, the first person to record human brain activity and discover the alpha rhythm.

Related Terms

Beta wave: A type of brain wave that oscillates between 12 and 30 Hz, associated with active, busy or anxious thinking and active concentration.
Theta wave: A type of brain wave that oscillates between 4 and 7 Hz, associated with sleep, deep meditation, and hypnagogic states.
Delta wave: A type of brain wave that oscillates between 0.5 and 4 Hz, associated with deep sleep and certain pathological conditions.
Gamma wave: A type of brain wave that oscillates between 30 and 100 Hz, associated with higher mental activity, including perception, problem solving, fear, and consciousness.