Developmental Changes in Sleep Spindle Characteristics and Sigma Power across Early Childhood

Table 2

Descriptive statistics (M, SD) of sleep spindle measures at ages 2, 3, and 5 years for each derivation (C3A2, C4A1, O1A2, and O2A1). Significant post hoc paired -tests (2-tailed) are denoted as (2 years versus 3 years), (2 years versus 5 years), and (3 years versus 5 years).

	2 years		3 years		5 years		Statistics
	M	SD	M	SD	M	SD
Duration (s)
C3A2	0.85	0.13	0.91	0.25	1.11	0.21	9.6	0.26	0.002
C4A1	0.79	0.18	0.92	0.29	1.21	0.26	23.5	0.37	<0.001
O1A2	0.64	0.05	0.69	0.08	0.94	0.22	12.0	0.51	<0.001
O2A1	0.65	0.05	0.67	0.08	0.89	0.17	14.2	0.54	<0.001
Frequency (Hz)
C3A2	13.10	0.20	13.05	0.34	12.77	0.25	13.5	0.25	<0.001
C4A1	13.32	0.37	13.00	0.35	12.72	0.27	11.5	0.39	0.001
O1A2	13.35	0.37	13.10	0.35	12.80	0.26	6.3	0.36	0.010
O2A1	13.25	0.32	13.12	0.35	12.77	0.23	7.9	0.34	0.005
ISA (µV)
C3A2	805.5	156.4	905.1	207.8	1253.7	358.2	10.5	0.40	0.002
C4A1	704.2	260.9	973.0	512.9	1357.6	454.3	13.5	0.32	<0.001
O1A2	436.4	86.0	626.5	191.5	815.5	228.5	7.4	0.46	0.006
O2A1	436.8	67.7	547.0	136.0	778.2	228.1	13.6	0.48	<0.001
Density (#/min)
C3A2	0.98	0.27	1.08	0.33	0.98	0.21	0.4	0.03	0.67
C4A1	0.93	0.31	1.02	0.40	1.06	0.16	0.7	0.04	0.49
O1A2	0.83	0.47	0.67	0.33	0.55	0.17	1.7	0.11	0.22
O2A1	0.71	0.34	0.54	0.22	0.56	0.19	1.5	0.09	0.25