ERP analyses of responses to standard and deviant tones
TD
Neural responses to each stimulus condition were examined without subtraction. The ERP waveforms were averaged as a function of the stimulus condition and the drug administration for TD and ASD. We focused on two prominent ERP components in the grand average waveforms: (i) The P1 (P50) component—a positive peak within [50, 100] ms post-stimulus onset; (ii) The N1 component following P1 as a negative valley in the range [100, 200] ms. In response to the duration deviant, there was another negative valley (N2) in the range of [200, 300] ms, with an amplitude similar to N1 evoked by the frequency deviant and the combined deviant, larger than the N1 component of the duration deviant. The temporal range of this N2 component was aligned with the duration MMN. Thus, the window for individual measurement of the negative component of the duration deviant was set as [200, 300] ms (not [100, 200] ms for other stimuli), to ensure the same neural component contributing to the MMN was measured across stimulus conditions. The amplitudes of the P1 and N1 were extracted for each participant for statistical analysis.