If an epoch contains both stage N1 and N2 qualities, the epoch should be scored as:

If an epoch contains both stage N1 and N2 qualities, the epoch should be scored as:

• A. Stage N1
• B. Whatever stage exists throughout the majority of the epoch
• C. Stage N2
• D. Whatever stage exists in the first portion of the epoch

Answer: (B)

When deciding how to score an epoch that shows both N1 and N2 features, you choose the stage that covers the majority of that epoch. This reflects the overall depth of sleep during that interval rather than giving equal weight to brief intrusions of a lighter stage. If N2 features occupy more than half of the epoch, label it as N2; if N1 features occupy more, label it as N1. This approach keeps sleep staging consistent by summarizing each 30-second window with the predominant state, instead of basing the score on the first portion or on a split within the epoch.

When deciding how to score an epoch that shows both N1 and N2 features, you choose the stage that covers the majority of that epoch. This reflects the overall depth of sleep during that interval rather than giving equal weight to brief intrusions of a lighter stage. If N2 features occupy more than half of the epoch, label it as N2; if N1 features occupy more, label it as N1. This approach keeps sleep staging consistent by summarizing each 30-second window with the predominant state, instead of basing the score on the first portion or on a split within the epoch.