Table 3.
Characteristics of sleep spindles detected only by the CWT detector and the SIESTA detector, whose length was at least 0.7 s in stage 2 sleep.
| Only CWT (N = 398) Mean (SD) | Only SIESTA (N = 250) Mean (SD) | |
|---|---|---|
| Spindle amplitude (μV)a | 8.21 (2.44) | 7.80 (3.41) |
| Spindle frequency (Hz) | 11.90 (1.77) | 13.02 (1.41) |
| Spindle length (s) | 1.01 (0.48) | 1.10 (0.38) |
| Delta (μV)b | 9.91 (7.20) | 6.28 (3.83) |
| Theta (μV)b | 6.13 (3.84) | 4.02 (2.12) |
| Alpha (μV)b | 4.74 (2.21) | 3.63 (2.45) |
| Spindle to background ratioc | 1.23 (0.60) | 1.73 (0.72) |
Sleep spindles were scored in the C3A2 EEG channel. aComputed from amplitude spectrum as described in “Computation of Sleep Spindle Amplitude and Frequency” Section. bMean amplitude in chosen frequency from amplitude spectrum (delta: 2–4.5 Hz, theta: 4.6–7.5 Hz, alpha: 7.6–11 Hz). cSpindle amplitude divided by mean amplitude in 2–11 Hz background frequency computed from amplitude spectrum.