FIGURE 1. EEG frequency bands investigated in ADHD (adapted from (Ref. 234)).
In quantitative EEG, recordings of brain electrical activity at the scalp are quantified in the frequency range of interest, which usually extends between 1 and 70 cycles per second (Hz). In ADHD research, this frequency range is traditionally separated into four frequency bands Recently ADHD research has further extended to very low-frequency oscillations below 0.5Hz. Figure adapted from Malmivuo and Plonsey (Ref. 49; © 1995 Oxford University Press) by permission of Oxford University Press, Inc. (http://www.oup.com). Abbreviations: ADHD, attention deficit hyperactivity disorder; EEG, electroencephalography; VLF, very low frequency.