EEG Practice Questions And Answers

What is an EEG? correct answer: Measurement of voltage fluctuations at the surface of the scalp generated by the electrical activity of the brain. These voltage fluctuations are called _______ and are recordings of ___________. correct answer: Brain waves Voltage difference versus time How many electrodes are plugged into each amplifier on the EEG machine? correct answer: Two What does the EEG recorder detect? correct answer: The voltage differences between the recording and reference electrode for each channel of detection. The amplifier compares the two electrode signals coming into it and cancels out signals that are the same. Therefore the EEG signal is the difference in electrical activity detected by two electrodes. One electrode pair is referred to as a _____. correct answer: Channel Modern EEg recordings have from 8 to 40 channels to produce a ____________ as shown here. correct answer: Multichannel recording. The closer the electrodes are to each other, the ____ differences in their brain waves. correct answer: Less What happens if the electrodes are too close? correct answer: The EEG channel will display a straight line. Therefore, when recording EEGs, a technician will measure the patient's head to ensure symmetrical and equidistant placement of electrodes. The voltage emitted from the scalp is on the order of ____ correct answer: Microvolts (10^-6) The EEG amplifiers increase this signal by a fac