CNS Physiology for UPSC CMS: EEG, Sleep, Motor Control and Reflexes Explained

EEG Waves#

Alpha (8-13 Hz): Awake, eyes closed, relaxed. Centroparietal.
Beta (14-30 Hz): Active thinking, anxiety. Frontocentral.
Theta (4-7 Hz): Drowsiness, children. Temporal.
Delta (0.5-3 Hz): Deep sleep, coma. Frontal in adults, normal in children.

Sleep Stages#

NREM: Stage 1 (drowsy), Stage 2 (sleep spindles), Stage 3/4 (delta sleep = deep). REM: Rapid eye movement, dreaming, brain active, body paralyzed.

UMN vs LMN Signs#