Figure 4

Group statistics on the source waveforms. A: Group mean responses (thick lines) to the speech stimuli during the three MEG recording sessions and the 95% confidence limits (thin lines) for the group mean as estimated by bootstrap resampling. The confidence bands for the three days of MEG recording overlap widely, however, they are separated for all sessions in a latency interval around 200 ms (colored shaded areas), indicating significant differences in the group mean amplitudes during the P2m latency interval. B: Group mean responses and 95% confidence limits for the responses to the noise stimulus. The confidence bands do not overlap during the P2m latency interval for the first and second pre-training sessions only. C: Group mean P2m amplitudes for all experimental conditions. The between subject variability is illustrated with the error bars, depicting the 95% confidence intervals for the mean. D: Mean P2m amplitudes for the three stimuli and the three sessions illustrate the interaction between stimulus and session. E: Main effects of the recording session as revealed by repeated measures ANOVA calculated for each time point separately. The F-ratio took high values around 200 ms exclusively correspondingly to high significance for the effect of the recording session on the response amplitude. F: The time course of the interaction between session and stimulus type shows significance during a latency interval around 200 ms only.