‍Hello everyone, in this video I will show you how to preprocess your signal.

‍Several preprocessing functionalities are available within the software.

You can, for instance, launch a power spectrum density from the Preprocessing menu. This window will appear, and you will be able to modify the start and stop time of the analysis or keep the default parameters. After clicking on “launch power spectrum” you can visualize the results for both micro- and macro- channels separately.

‍In this window, you can filter by electrode or channel. You can select multiple channels by holding a right click and dragging the mouse over them . The selected channels will appear on the right side of the window. You can mark them as bad by clicking on “mark selected as bad”. These changes will be synchronized with the main viewer.

Another option within the preprocessing menu is to filter your signal. Clicking on “Permanent filters” opens a toolbar which allows you to apply high-pass, low-pass, band-pass and notch filters. This can be done for macro and micro channels separately. You can enter the low and high frequencies of your choice. If you enter a single value in the low-frequency field, it will turn the filter into a high-pass, and if you enter a single value in the high-frequency field, it will turn the filter into a low-pass. In the advanced parameters option, you can choose the type of filter you want to use and the frequency for the notch filter. ‍

In this case, we have entered both low and high values to apply a bandpass filter but np notch filter.

Once the filters are applied, all subsequent operations on the signal will be performed on the filtered data. This is why these filters are called permanent. You should apply them in a monopolar montage, before re-referencing your signal.

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The re-referencing option is now available in the preprocessing menu. You have several options for re-referencing: monopolar, bipolar, average, median and a common re-reference using the channel of your choice. ‍

You should filter and re-reference your signal before you launch your detectors.

Now it’s your turn to preprocess your signal—good luck!