Figure 4

Transformation of raw electroencephalogram (EEG) into quantitative EEG (qEEG). The center top panel shows a 10 second segment of raw EEG. This EEG segment can be transformed using mathematical processing to separate the waves into major frequency bins with the height of each bin indicating the relative percentage (that is, power) of that frequency during the 10 second epoch (lower left panel). Each bandwidth can be trended on a minute by minute basis to create a variability histogram for that bandwidth for each channel (lower right panel). The alpha bandwidth variability trend is shown (lower center panel).