Event-related electrophysiological data for the target stimulus from the visual oddball task yielded measures of total power in the theta (3.0-7.0 Hz) oscillation at the frontal midline channel (Fz). This measure was estimated for 1560 individuals from the signals in the 300-700 milliseconds time window, which corresponded to the time window of the P300 component in the event-related waveforms. The mean power in the theta band for the frontal midline channel was 30.2 ± 18.7 μV2 (males = 28.2 μV2; females = 32.0 μV2).
