How awake are you?

Your brain wave pattern depends on what you are doing. When you are alert and thinking, your brain is very active and gives a beta-wave EEG pattern. If you close your eyes but stay awake, the EEG shows an alpha wave, while theta and delta waves show you are drowsy or asleep. Different stages of sleep also have different EEG patterns. Strangely enough, REM (rapid eye movement) sleep has an EEG pattern very similar to that of your awake brain - it probably occurs when you are dreaming.

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EEGs showing the five stages of sleep.

How does epilepsy affect the brain?

People with epilepsy have seizures caused by unusual electrical activity in part or all of the brain. Doctors can use an EEG to measure this activity, and diagnose epilepsy (as seizures can have other causes). Unusual bursts of electric activity can sometimes be detected between seizures, and are called 'spikes'. The location of these spikes in the brain can help doctors decide what type of epilepsy the person has, and so what treatment to use.

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EEG showing pattern of brain activity during an epileptic seizure.

 

Principal Funder:

Wellcome trust

Major Sponsors:

GlaxoSmithKline life technologies