volume conduction
The spread of electrical activity through tissue from its source to recording electrodes, affecting signal amplitude and morphology.
Full Definition
Volume conduction refers to the passive spread of bioelectrical signals through the conductive medium of body tissues from the site of generation to the recording electrodes. In neurophysiology, this phenomenon affects both EEG and EMG recordings. The amplitude and morphology of recorded potentials depend on the distance from the source, the conductivity of intervening tissues, and the electrode configuration. Understanding volume conduction is crucial for proper interpretation of neurophysiological signals and explains why distant electrical activity can influence recordings.
Usage
Usage note: Important concept for understanding artifact and signal interpretation in all neurophysiological recordings.
In Context
- "The apparent muscle activity was likely due to volume conduction from nearby actively firing motor units." — EMG interpretation note