<div dir="ltr"><div>Dear EEGLABers,<br><br>I would like to know whether or not the particular pre-processing steps listed are recommended for ERP analysis, time-frequency analysis (wavelet amplitude spectrograms or DFT spectrograms, ITPC), and source localization analysis. <br><br></div><div>In particular, I am uncertain about the ordering of steps such as interpolating bad channels before or after re-referencing or ICA, or if particular steps work for some analysis strategies but not others (e.g. if a preprocessing step would work fine for time-frequency analysis but not be appropriate for source localization). Any feedback is much appreciated!<br></div><div><br>0. Start with 128-channel EEG from EGI HydroCel Geodesic Sensor
Net, with flags indicating events and epochs around events predefined (-0.1s to 0.9s around the events).<br></div><div>1.
Keep all valid (even if lots of line noise) channels in dataset, only
remove channels which clearly have no physiological information.<br></div><div>2. Epoch the data, reject bad epochs by eye (significant movement or rare, not-stereotyped artifacts)<br></div><div>3. Run ICA on epoched data. </div><div>4. Reject components related to blinks, stereotypical muscle activity, and 60 Hz noise, and EKG artifacts.<br></div><div>5. Reconstruct sensor-level signals from remaining ICA weights<br></div><div>6. Re-reference all cleaned EEG channels to the average reference<br></div><div>7. Interpolate (using spherical splines from neighboring electrodes) any channels that were rejected in step 1.<br></div><div>8. Calculate ERPs, time-frequency analysis, source localization<br></div><div><br></div><div>Best and many thanks,<br></div><div>Michael<br></div></div>