Coherence is a spatial measure of the correlation between two channels and may provide information about functional connectivity between cortical regions. Frontal- posterior (F-P) coherences for left, right, and midline for 2 dominant frequencies: alpha and theta. A lower coherence in these regions has been reported to correlate mild cognitive impairment. Numerous studies have linked coherence to various conditions associated with reduced cognitive function, including trauma and mild cognitive impairment.