The grand average ERP waveforms at Fz, Cz, and Pz electrode sites in response to target stimuli are shown in Fig. 1 for healthy controls, as well as patients with anxiety disorder and patients with depressive disorder, and also the corresponding waveforms to standard stimuli are showed in Fig. 2. Results of P300 parameters at Pz scalp site are presented in Table 1. Specially, the small peaks around P300 observed in depressive patients were probably due to high proportion of eliminated EEG epochs from average calculation. Table 1Amplitudes and latencies of P300 component of healthy controls and patients at Pz electrode (mean ± SD)P300 parameterHealthy controls (n = 30)Anxiety disorder (n = 35)Depressive disorder (n = 32)Latency (ms)356.3 ± 25.1359.7 ± 30.9374.3 ± 35.2Amplitude (μv)15.8 ± 4.513.6 ± 4.89.5 ± 3.7
