What normal activity would be seen most prominently at the C3 or C4 electrode position?

The prominence of Mu rhythms at the C3 or C4 electrode positions is well-established in EEG studies. Mu activity is associated with motor areas of the brain, specifically localized to the sensorimotor cortex, which corresponds to these electrode placements. This rhythm typically appears as a rhythmic, waxy, 8-12 Hz activity, and is often evident when a person is at rest, especially when they are not engaged in active motor tasks. Understanding that this normal brain activity is specific to areas involved in motor function is vital for EEG technologists, as it helps in differentiating between various brain activities and phenomena that may occur in other contexts.