1. A method for determining the probability of an electroencephalogram (EEG) pattern within an EEG test record of a subject having occurred in sections of reference EEG records scored previously as awake or EEG arousals, said method employing a computer/microprocessor that: performs frequency domain analysis of one or more discrete sections of the EEG test record to determine EEG test record power at specified frequencies, calculates EEG test record power over specified frequency-bands, assigns, for each specified frequency band, a rank to the calculated power-in each discrete section of the specified frequency band, each rank being determined based on values of power encountered in a plurality of the previously scored reference EEG records, assigns a code to each discrete section that reflects the ranking of the calculated powers in different frequency bands, incorporates a database/lookup table constructed from previously scored reference EEG records that indicates the probability of each code to occur in sections of said reference EEG records scored previously as awake or EEG arousals, determines, for each assigned code, the probability indicated in the database/lookup table that corresponds to the assigned code, and reports the determined probabilities that reflect the probability of the electroencephalogram (EEG) pattern within the EEG test record of the subject having occurred in sections of reference EEG records scored previously as awake or EEG arousals.