This image demonstrates a 30-second recording (Compumedics) of stage N2 sleep. Most notable are the K-complexes (dashed boxes), maximally seen in the frontal and central EEG leads. The top two leads represent the eyes (right and left), the next lead is the chin, then the following six leads are EEG (right and left frontal, central, and occipital), ECG with heart rate below (R-R), and the leg EMG lead.
