What is recorded by EEG?

What is recorded by EEG?

An EEG records the electrical activity of your brain via electrodes affixed to your scalp. EEG results show changes in brain activity that may be useful in diagnosing brain conditions, especially epilepsy and other seizure disorders.

What is purpose of EEG?

An EEG is a test that detects abnormalities in your brain waves, or in the electrical activity of your brain. During the procedure, electrodes consisting of small metal discs with thin wires are pasted onto your scalp. The electrodes detect tiny electrical charges that result from the activity of your brain cells.

What is the principle of EEG?

EEG uses the principle of differential amplification, or recording voltage differences between different points using a pair of electrodes that compares one active exploring electrode site with another neighboring or distant reference electrode.

What do EEG and MEG measure?

The first obvious difference is that EEG records the electrical activity and MEG records magnetic activity of the brain. MEG primarily detects the magnetic fields induced by intracellular currents, whereas scalp EEG is sensitive to electrical fields generated by extracellular currents.

What is a drawback of having an EEG scan?

One of the big disadvantages of EEG/ERP is that it’s hard to figure out where in the brain the electrical activity is coming from. By putting lots of electrodes all over the scalp (in our lab we use 64 or 128 electrodes), we can get some idea of where the ERP components are strongest.

What can MEG diagnose?

MEG can be used either to evaluate the brain’s spontaneous activity (e.g., for epilepsy) or to check its response to specific external stimuli (e.g., for mapping motor and sensory areas, language, vision and other functions).

Is EEG invasive?

Invasive EEG recordings are those recordings that are made with electrodes that have been surgically implanted on the surface or within the depth of the brain. Occasionally, the patient’s epilepsy syndrome may require the use of invasive EEG recordings before epilepsy surgery can be considered.

What is a normal EEG result?

Most waves of 8 Hz and higher frequencies are normal findings in the EEG of an awake adult. Waves with a frequency of 7 Hz or less often are classified as abnormal in awake adults, although they normally can be seen in children or in adults who are asleep.