Electroencephalography Eeg And Magnetoencephalography

Noninvasive human electrophysiology was first accomplished in a systematic way with the electroencephalogram (EEG) in 1929 by the German psychiatrist Hans Berger, who recorded the a rhythm (10-Hz oscillations) from two electrodes placed on the front and back of his son's scalp. A variant of EEG is the event-related potential (ERP), in which changes in electrical activity immediately following the presentation of a stimulus or decision are recorded; ERPs are thus "time-locked," with changes being described relative to a particular event (hence the name, "event-related"). The first magnetic recordings of brain activity, using magnetoencephalography (MEG), were produced only much later in 1971.

Methods for recording EEG, ERP, and MEG provide information about the summed electrical events produced by individual brain cells. EEG and ERPs are recorded from electrodes placed on the scalp (although, very rarely, they can be recorded from within the brain in patients being prepared for surgical treatment of epilepsy). MEG and its time-locked derivative, event-related fields (ERFs, which are the magnetic analogs of ERPs), are recorded from arrays of superconducting quantum interference devices (SQUIDs). These detectors are so cold that tiny fluctuations in magnetic fields can induce slight currents, which can then be amplified and recorded.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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