Determining low power frequency range information from spectral data. Rawsignal data can be adjusted to increase dynamic range for power within lowpower frequency ranges as compared to higher-power frequency ranges todetermine adjusted source data valuable for acquiring low power frequencyrange information. Low power frequency range information can be used in theanalysis of a variety of raw signal data. For example, low power frequencyrange information within electroencephalography data for a subject from aperiod of sleep can be used to determine sleep states. Similarly, automatedfull-frequency spectral electroencephalography signal analysis can be usefulfor customized analysis including assessing sleep quality, detectingpathological conditions, and determining the effect of medication on sleepstates.
