Auditory and visual stimulus-locked CSD waveforms (400 sample points spanning the time interval from −300 to 1,695 ms around stimulus-onset) and response-locked CSD waveforms (201 sample points spanning the time interval from −700 to 300 ms around response-onset) were submitted to four separate temporal PCA to better account for the modality-dependent ERP/CSD component structure and to isolate their stimulus and response contributions (MatLab emulation of BMDP-4M algorithms; cf. appendix of Kayser and Tenke, 2003). Hence, input data matrices consisted of either 400 or 201 variables and 2,480 observations stemming from 40 participants, 2 conditions (new/old pooled across short and long lags) and 31 electrode sites, including the nose.
