Performance of prewhitening beamforming in MEG dual experimental conditions

This paper presents an analysis on the performance of the prewhitening beamformer when applied to MEG experiments involving dual (task and control) conditions. We analyze the performance of the prewhitening method under two kinds of realistic scenarios. In the first scenario, we assume that some sources exist only in the control condition but they not in the task condition. In the second scenario, we assume that some signal sources exist both in the control and the task conditions, and that they change intensity between the two conditions. Our analysis shows that the prewhitening method is very robust to these non-ideal scenarios, and the results of this analysis are validated in our experiments.