Which rhythm is characterized by a surface negative potential in the central regions of the brain?

The mu rhythm is identified by its characteristic surface negative potential, particularly observable in the central regions of the brain, specifically over the sensorimotor areas. It typically oscillates in the frequency range of 8-12 Hz and is associated with sensorimotor activity. The presence of this negative potential is significant as it is linked to the brain's readiness to initiate movement and sensory processing, often diminishing during active motor engagement or observation of movement.

In contrast, theta rhythms are generally found in the hippocampal regions and are associated with memory and drowsiness, while delta rhythms, which oscillate at lower frequencies (1-4 Hz), are indicative of deep sleep. Beta rhythms, occurring in the frequency range of 12-30 Hz, are associated with active thinking and alertness, and do not typically show a central negative potential like the mu rhythm does. This specificity in potential and location is what distinctly characterizes the mu rhythm.