Errors to import .mat MEG/EEG files

Discussions
,
1

Hello, I updated the latest version of Brainstorm (24 April 2026), which runs on MATLAB 2024b on a Mac with Apple Silicon. A few months ago, I imported a MEG/EEG files in Brainstorm without any problem.

The structure of the file includes the following folders: filename,tipo, other_channel, th, name, dataout

the latest dataout is made of others subfolders: hdr,fsample,grad, sampleinfo,trial,time,label cfg.

Now, when I try to import this file.mat I receive the error message:

Error: Line 28:  in_fopen_spm (line 28)
** SPM must be in the Matlab path to use this feature.
** Call stack:
** >in_fopen_spm.m at 28
** >in_fopen.m at 153
** >in_data.m at 107
** >import_data.m at 196
** >bst_call.m at 28
** >tree_callbacks.m>@(h,ev)bst_call(@import_data,[ ],[ ],[ ],iStudy,iSubject) at 687

After I add the spm12 in the Matlab path, importing MEG/EEG files I have the new error message:

Error: Line 36:  in_fopen_spm (line 36)
** The two files .dat and .mat must be available in the same folder.
** Call stack:
** >in_fopen_spm.m at 36
** >in_fopen.m at 153
** >in_data.m at 107
** >import_data.m at 196
** >bst_call.m at 28
** >tree_callbacks.m>@(h,ev)bst_call(@import_data,[ ],[ ],[ ],iStudy,iSubject) at 687

how can I solve this problem?

thanks

Carmela

2

Hi @car,

This information suggest that the files that you have at hand come from FieldTrip rather than SPM.

Try to import your data as FieldTrip

3

Dear Raimondo, thank you for your reply.

I’ve tried to import the file as MEG/EEG Fieldtrip, but I obtain this error message:

Error: Line 78: Argument to dynamic structure reference must evaluate to a valid field name.
**
** Call stack:
** >read_fieldtrip_chaninfo.m at 78
** >in_data_fieldtrip.m at 174
** >in_fopen.m at 217
** >in_data.m at 547
** >import_data.m at 196
** >bst_call.m at 28
** >tree_callbacks.m>@(h,ev)bst_call(@import_data,[ ],[ ],[ ],iStudy,iSubject) at 687

In the Plugins window, I set FieldTrip “load “ (green dot) and spm12 installed, but “unload” (red dot). I did not have this problem before the update. Do you have any other suggestions to solve the problem?

thank you again

4

Hi @car,

Thank you for the error report. This was caused by some updates in the FieldTrip code that Brainstorm relies to read FieldTrip data. The issue is now solved: commit f4b64fd

Update your Brainstorm instance to 27-Apr-2026
The FieldTrip data should be imported without troubles