ICA components seem to be strange

  • MNE-Python version: 0.23.0
  • operating system:

When I apply ICA on my MEG data (.con) files for artificat detection, I get figures that I feel seem to be strange.


Here is my code:

meg_file_dir = "Con_" + session_date + "_" + session_name + "_BESA[con].con"  #fixme  
raw = mne.io.read_raw_kit(parent_dir_meg + "/" + meg_file_dir)
meg_raw = raw.copy()

ecg_evoked = create_ecg_epochs(meg_raw).average()
ecg_evoked.apply_baseline(baseline=(None, -0.2))
print("ECG Info")
#Filtering to remove slow drifts
filt_raw = meg_raw.copy()
filt_raw.load_data().filter(l_freq=1., h_freq=None)
ica = ICA(n_components=15, max_iter='auto', random_state=97)
ica.plot_sources(meg_raw, show_scrollbars=False)


print("Please enter first component")
c1 = input()
print("Please enter second component")
c2 = input()
print("User components are ")
print(c1, c2)
ica.exclude = [c1, c2]

Do you know what might be wrong?

you seem to have a problem of head position in the device


In the future steps (when we align the MRI with MEG), will this problem be solved or shouId I perform the experiment again?

was the head well positioned in the device during the experiment?

to know if it’s an acquisition problem or a software issue.


1 Like

Sorry for my late reply.
I guess it was positioned correctly. We put some small pillows around the subjects face to avoid movement and I think we always check that the head is completely inside the device