Help for understanding the find_ica_artifacts part of mne_bids_pipeline

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1

I try to recreate the functionality of the mne_bids_pipeline _06a2_find_ica_artifacts step.

Here is my function:

def detect_eog_components(
    ica: mne.preprocessing.ICA,
    raw: mne.io.BaseRaw,
    epochs: mne.Epochs,
    verbose: bool = True
) -> mne.preprocessing.ICA:
    """
    Detect and exclude EOG components from ICA using simulated EOG channels.

    This function creates EOG epochs, finds bad EOG components using ICA,
    and excludes them from the ICA solution.

    Args:
        ica: The ICA object to use for component detection.
        raw: The unfiltered raw MNE data object.
        epochs: The epochs object used for ICA fitting.
        verbose: Whether to output additional information during processing.

    Returns:
        The modified ICA object with EOG components excluded.
    """
    logger.info("\t\tUsing simulated EOG channel to autoselect independent components")

    eog_channels = ["Fp1", "Fp2"]

    # Create EOG epochs
    eog_epochs = mne.preprocessing.create_eog_epochs(raw, ch_name=eog_channels, baseline=(None, -0.2), verbose=verbose)

    if len(eog_epochs):
        if epochs.reject is not None:
            eog_epochs.drop_bad(reject=epochs.reject)

    # Find bad EOG components
    eog_indices, eog_scores = ica.find_bads_eog(
        eog_epochs,
        ch_name=eog_channels,
        threshold=3.0,
        verbose=verbose
    )

    # Exclude detected EOG components
    ica.exclude = eog_indices

    return ica

Somehow I get a different number of eog epochs detected then with the mne_bids_pipeline. @richard Is the assumption correct that in _06a2_find_ica_artifacts create_eog_epochs uses the unfiltered raw data?

2

@richard Sorry for pinging you again but I am still not able to reproduce what the mne-bids-pipeline does in this step despite looking at the source code multiple times.
I really hope for your insights!

Thanks,
Richard