Despite the potential for EEG abnormalities to provide insight into the neurophysiology of disease processes, studies that measure EEG power and coherence in both SZ and BP are rare (for exceptions, see (Clementz et al. 1994). The one study that directly compared these two populations restricted their analyses to frequency amplitudes (i.e. the square root of power) at central electrodes (Clementz et al. 1994). Another study compared SZ with their first-degree biological relatives, and BP with their relatives on frequency amplitudes, but did not directly contrast the two patient groups (Venables et al. 2009). The current study evaluated whether resting EEG power and coherence measures across a wide frequency range can differentiate BP and SZ from NC, and whether EEG measures can distinguish these two psychiatric disorders. Given previous findings, we predicted that both 1) low-frequency EEG power and 2) coherence across frequency bands would be increased in SZ, and 3) inter-hemispheric coherence at alpha and beta would be reduced in BP.
