Average of connectivity OR connectivity of average?

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Which is more appropriate depends on your research question, because the two approaches measure slightly different concepts.

  1. Connectivity of trial average: it measures the connectivity only for the phase-locked (evoked) activity, as the non-phase-locked activity (even if it is time-locked) it cancelled out in the trial averaging.

  2. Average of trial connectivity: it measures the connectivity for the phase-locked and non-phase-locked (evoked and induced) activity. This happens as for each trial, its connectivity metric describes both evoked and induced response, so the average across trials reflects both responses.

In terms of methodology, it is very similar to the computation of PSD, it can be done as:

  1. Power spectrum of average (describes evoked power), or
  2. Average of power spectra (describes evoked+induced power)
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