We recorded 64-channel resting eyes-open EEGs using the SynAmps2 amplifier and Scan 4.3 acquisition software (Compumedics Neuroscan Inc., Charlotte NC). The EEG signal was referenced to an electrode between Cz and CPz for online recording, and then re-referenced to the right ear offline. The ground electrode was placed 8 cm above the nasion. Electrode impedances were maintained below 10 kΩ. The sampling rate was 250 Hz, analog filters were 0.3–70 Hz, and 7–8 min of data were recorded. EEG recordings were processed offline using the Edit program in Scan 4.3. Artifacts from eye movements were removed using the ocular artifact reduction algorithm (ARTCOR procedure) in Scan 4.3. The resulting EEG was unusable for three LTAA participants and two NSAC participants due to excessive noise and voltages out of range.
