Higher-Order Spectrum in Understanding Nonlinearity in EEG Rhythms

Table 1

Time series	𝜒^2	𝑃	𝑅-estimated	𝑅-theoretical	𝜆
Lorenz system	8469.61	0.0	589.87	46.87	301.35
Mackey-Glass system	5765.88	0.00	408.36	38.49	203.02
White Gaussian noise	2.07	1.00	0.08	2.25	0.07
Filtered noise 1.5 Hz	270.08	0.00	16.31	8.67	9.93
Filtered noise 3 Hz	627.06	0.00	46.60	12.99	22.74
Filtered noise 9 Hz	359.46	0.00	19.83	9.95	13.20
Filtered noise 30.0 Hz	120.05	0.00	5.80	5.89	4.40
Filtered noise 300 Hz	55.68	0.21	0.61	4.03	1.84
Alpha EEG activity	9731.75	0.00	390.91	35.75	175.05
Beta EEG activity	34794.08	0.00	1407.53	67.65	628.16
Theta EEG activity	4442.43	0.00	118.94	23.49	75.33
Delta EEG activity	14962.96	0.00	602.83	44.29	269.02
Indeterminate EEG activity	3178.88	0.00	114.14	20.06	54.83

χ ² value, 𝑃: probability of the time series being Gaussian, 𝑅: interquartile range, 𝜆: noncentrality parameter, 𝑑.𝑜.𝑓=271.