EEG VOCABULARY LIST 1 QUESTIONS AND ANSWERS

Attenuation - Reduction of EEG activity. An example is reduction or disappearance of the alpha following eye opening. (also referred to as Blocking) Background. - The underlying activity of the brain. Not synonymous with the alpha that itself is seen against the background Bisynchronous. - Occurring simultaneously in the two hemispheres. Really the same as synchronous, which is preferred. Blocking - The same as attenuation as, the alpha is blocked with eye opening. Also used to describe an amplifiers response to a temporary voltage overload during which there is wide excursions of the write out or display preempting recording of EEG activity Channel. - Refers to the input of an amplifier that displays electrical information. The number of channels on an EEG apparatus varies, but often is in the order of 20. Derivation. - Recording from an electrode pair with the output displayed in one channel of the recording Diffuse. - Occurring generally over the two hemispheres usually used to describe slowing. Contrast with focal slowing. Focus - Refers to location of maximum potential Interelectrode Distance - Distance between pairs of electrodes. Lateralized - Used to indicate activities that are recorded in both hemispheres but are more prominent, of higher amplitude on one side Montage - Term used to indicate the pattern of display of EEG activity. Paroxysm - Term used to indicate a waveform that arises suddenly from the background, for example, a spike discharge, or a burst of drowsiness Periodicity. - Refers to recurrent focal of generalized