There is 1 channel position not present in the DigMontage ['VREF]

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1
  • MNE version: 1.9
  • operating system: e.g. macOS 15.4.1
# Setup the data montage
montage = mne.channels.make_standard_montage("GSN-HydroCel-129")
             									  
for t1_file,td_file in zip(t1_file_list,td_file_list):
	
	# Get the path to the data file	
	input_fname_t1 = data_path + t1_file
	input_fname_td = data_path + td_file

	# Load the data files 
	raw_data_t1 = mne.io.read_raw_egi(input_fname_t1, eog=None, misc=None, include=None, 
	                               exclude=None, preload=True, channel_naming='E%d', 
	     						   events_as_annotations=True, verbose=None)
	     						   
	raw_data_td = mne.io.read_raw_egi(input_fname_td, eog=None, misc=None, include=None, 
	                               exclude=None, preload=True, channel_naming='E%d', 
	     						   events_as_annotations=True, verbose=None)
	     						   	
	print(f"Channel list for t1:\n {raw_data_t1.ch_names}\n") 
	print(f"Channel types t1: {raw_data_t1.get_channel_types()}")
		
	raw_data_t1.set_montage(montage, match_case=False, on_missing='warn') 
	
	print(f"Channel list for t1:\n {raw_data_t1.ch_names}\n")
	print(f"Channel types t1: {raw_data_t1.get_channel_types()}")

and I am getting the following

RuntimeWarning: DigMontage is only a subset of info. There is 1 channel position not present in the DigMontage. The channel missing from the montage is:

[‘VREF’].

But I can clearly see a channel labeled that. I tried using montage = mne.channels.make_standard_montage(“GSN-HydroCel-256”) as suggested in some other posts but I still get the same error. I looked at the channels being read:

Channel list for t1:
[‘E1’, ‘E2’, ‘E3’, ‘E4’, ‘E5’, ‘E6’, ‘E7’, ‘E8’, ‘E9’, ‘E10’, ‘E11’, ‘E12’, ‘E13’, ‘E14’, ‘E15’, ‘E16’, ‘E17’, ‘E18’, ‘E19’, ‘E20’, ‘E21’, ‘E22’, ‘E23’, ‘E24’, ‘E25’, ‘E26’, ‘E27’, ‘E28’, ‘E29’, ‘E30’, ‘E31’, ‘E32’, ‘E33’, ‘E34’, ‘E35’, ‘E36’, ‘E37’, ‘E38’, ‘E39’, ‘E40’, ‘E41’, ‘E42’, ‘E43’, ‘E44’, ‘E45’, ‘E46’, ‘E47’, ‘E48’, ‘E49’, ‘E50’, ‘E51’, ‘E52’, ‘E53’, ‘E54’, ‘E55’, ‘E56’, ‘E57’, ‘E58’, ‘E59’, ‘E60’, ‘E61’, ‘E62’, ‘E63’, ‘E64’, ‘E65’, ‘E66’, ‘E67’, ‘E68’, ‘E69’, ‘E70’, ‘E71’, ‘E72’, ‘E73’, ‘E74’, ‘E75’, ‘E76’, ‘E77’, ‘E78’, ‘E79’, ‘E80’, ‘E81’, ‘E82’, ‘E83’, ‘E84’, ‘E85’, ‘E86’, ‘E87’, ‘E88’, ‘E89’, ‘E90’, ‘E91’, ‘E92’, ‘E93’, ‘E94’, ‘E95’, ‘E96’, ‘E97’, ‘E98’, ‘E99’, ‘E100’, ‘E101’, ‘E102’, ‘E103’, ‘E104’, ‘E105’, ‘E106’, ‘E107’, ‘E108’, ‘E109’, ‘E110’, ‘E111’, ‘E112’, ‘E113’, ‘E114’, ‘E115’, ‘E116’, ‘E117’, ‘E118’, ‘E119’, ‘E120’, ‘E121’, ‘E122’, ‘E123’, ‘E124’, ‘E125’, ‘E126’, ‘E127’, ‘E128’, ‘VREF’, ‘DIN2’, ‘DIN1’]

Channel types t1: [‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘eeg’, ‘stim’, ‘stim’]

I also checked that the names/types channels were the same length

Channel list for t1:
131 items

Channel types t1:
131 items

I am just trying to figure out how to read the data -in addition to trying to understand what the data itself is, and I ma hitting the wall. Thanks.

2

Hey @Tyrion1803 yes this can be annoying..!

The issue is that in the "GSN-HydroCel-129" montage, the reference channel is named "Cz" (not "VREF"). If you do print(montage.ch_names) you can see what I mean.

MNE-Python can handle that specific mismatch, if you do:

raw_data_t1.set_montage(montage, match_alias=True)

and that should fix your problem!

Scott

1 Like
3

Outstanding, thank you so much. This is a high learning curve project.