Net amps 200 64 channel eeg amplifier

EEG was acquired using a 64-channel net (HydroCel Geodesic Sensor Net, Electrical Geodesics, Inc., Eugene, OR, USA) and amplified and measured (Net Amps 200 64-channel EEG Amplifier, Electrical Geodesics, Inc., Eugene, OR, USA; Net Station version 4.1.2, Electrical Geodesics, Inc., Eugene, OR, USA). Electrode resistance was maintained at ≤100 kΩ during the experiment, and data were continuously recorded at a sampling frequency of 250 Hz and electrode on Cz was used as the system reference. The hardware band-pass filter was set at 0.1 to 100 Hz. EMSE data editor version 5.2 was used for analysis. Measures of EEGs were transformed using electrodes on mastoids as the offline reference, and a software band-pass filter (0.1 to 30 Hz) was applied. Trials including artifacts above ±40 μV were rejected manually. Face symbol presentation for participants was set as 0 ms, and a −200- to 800-ms range was averaged to obtain an ERP waveform in each of the six conditions: CT-positive, CT-negative, SO-positive, SO-negative, FO-positive, and FO-negative. Baseline correction of ERP was carried out by subtracting the mean value of −200 to 0 ms from the overall waveform. The number of additions to average was set at ≥60 times.

Electroencephalograms (EEGs) were acquired using a 64-channel net (HydroCel Geodesic Sensor Net; Electrical Geodesics, Inc., Eugene, OR, USA), amplified and measured (Net Amps 200 64-channel EEG Amplifier, Electrical Geodesics, Inc.; Net Station version 4.1.2, Electrical Geodesics, Inc.). Electrode resistance was maintained at <100 kΩ during the experiment, and data were continuously recorded at a sampling frequency of 250 Hz, with electrodes on Cz used as the system reference. The hardware band-pass filter was set at 0.1 to 100 Hz. EMSE-data editor version 5.2 (Source Signal Imaging Inc., La Mesa, CA, USA) was used for analysis. Measured EEGs were transformed using electrodes on the mastoid processes as the offline reference, and a software band-pass filter (0.1-30 Hz) was applied. Trials including artifacts above ±40 μV were rejected manually. Gain or loss image presentation for participants was set at 0 ms, and a −200- to 800-ms range was averaged to obtain the ERP waveform. Baseline correction of ERP was carried out by subtracting the mean value of −200 to 0 ms from the overall waveform. The number of additions to average was set at >60 times.