Is a technique often used in studies investigating sleep patterns. researchers place electrodes at various locations on a person's head in order to record brainwaves?

During a sleep study electrodes are attached to the scalp, near the chin, near the eyes, on the upper chest, and the lower legs. Sensors are also attached to the upper lip and either the finger or the ear. The electrodes on the scalp measure brain waves or EEG to monitor the different stages of sleep. The electrodes near the eyes record eye movement and the electrodes on the chin record muscle activity to also provide data for determining sleep stages. The upper chest electrodes monitor heart activity. The lower leg electrodes show leg muscle activity during sleep. The upper lip sensor monitors breathing. The sensor on the finger or ear tell the doctor about the oxygen levels in the patients blood. Various other sensors may be used for studying specific areas of concern t the discretion of the sleep lab technician.

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