Figure 1.

Intensity dependence responses. (A) N1 differential responses. Waveforms for the N1 differential responses (high-intensity standard minus low-intensity standard sounds) and topographical maps of the responses for each group. (B) N1 responses to standards. The grand-averaged waveforms over the frontocentral channel cluster for responses to low- and high-intensity standard sounds and topographical maps of the responses. The rectangles overlaid with the waveforms show the time window applied in the analyses (mean amplitude values between 80 ms and 130 ms after stimulus onset). The topographies represent the average amplitude in the same time window. The channel cluster applied in the analysis is marked in the figure between the topographies. St = response to standard sound, YOUNG = younger adult group, YOUNG-D = younger adult depression group, OLD = older adult group, OLD-D = older adult depression group.