Validation of new sleep scoring method by comparison with classical methods.

(A) Overlap of manual scoring with OB gamma scoring. Each column gives the percent of time from each state identified using manual scoring (x label) that is classified as NREM (blue), REM (red), and wake (grey), respectively, using OB gamma scoring. For example, the first column can be read as signifying that out of all the data classified as NREM by the manual scorer, 93% was also classified as NREM by the OB gamma scoring, 2% as REM, and 5% as wake (n = 4). (B) Overlap of automatic EMG scoring with OB gamma scoring (n = 6). (C) Correlation of OB gamma power and EMG power for one mouse, with automatically determined thresholds in red. Dots in the upper right and lower left-hand corner are identically classified by both approaches. (D) OB gamma and EMG power triggered on transitions from wake to sleep and sleep to wake determined by the OB gamma, demonstrating tight temporal locking of changes with both indicators (n = 6). (E) Quality of fit of two Gaussians to OB gamma power and EMG power distributions. Both distributions are strongly bimodal, as the average Ashman’s D is larger than 2. However, both mean square error and R2 show that gamma power distributions are better fit by a sum of two Gaussians (n = 15 for gamma, n = 6 for EMG; t test, p = 0.43, 0.0063, 0.0005, respectively, *** p < 0.001). EMG, electromyography; NREM, non-REM; OB, olfactory bulb; REM, rapid eye movement.