Context

This experiment examines the brain correlates of facial muscle contractions in patients with hemifacial palsy. The onset of facial movements is measured with electromyograms (EMG). Activity during motor preparation is localized at the cortical level. The topographic spatial organisation of the premotor activity is compared between patients and healthy controls.

Technology

Patients and healthy controls are equipped with facial EMG and their brain activity is recorded with MEG while they perform systematic motor tasks.

Pipeline

After noise cancellation (maxfilter) of the MEG signal, the onset of each movement is marked manually by the experimenter, the data is then processed with a focus on activity just prior to these onsets. Source localization is performed using a weighted minimum norm estimate (wMNE). Premotor activity peaks are marked manually, and their position is used as a dependent variable for statistical analysis. A mixed within- between-groups experimental design is used.

There are two processing branches at the beginning:

processing of the resting-state data, used to create the noise covariance matrix used for source reconstruction
processing of task data,

Preprocessing: resting-state data

	Operation	Input format	Software	Output format	Comment / Link
1	Maxfilter	.fif	maxfilter	.fif	maxfilter
2	Mark bad data segments	.fif	Muse	.fif	Review data with Muse
3	Use ICA to remove blinks and cardiac activity	.fif	Matlab (FieldTrip)	.fif	Use ICA to subtract blink and cardiac activity.
4	Data import in Brainstorm	.fif	Brainstorm	Brainstorm	We use a single step of this tutorial. We import the cleaned data from previous step. Do not ignore epochs of different length.
5	Compute noise covariance	Brainstorm	Brainstorm	Brainstorm	Compute noise covariance in Brainstorm. Note that we use a resting-state segment (and not an empty room recording). This is ok and is because we are interested in source activity deviating from rest, rather than just any brain activity.

Preprocessing: task data

Operation

Input format

Software

Output format

Comment / Link

1

Maxfilter

.fif

maxfilter

.fif

maxfilter

2

Data import in Brainstorm

.fif

Brainstorm

Brainstorm

We use a single step of this tutorial. We import the cleaned data from previous step. Do not ignore epochs of different length.

Reading events channel, time period: 0-48000 ms

If necessary, delete the second epoch of each kind.

3

Mark the onset of each movement

Brainstorm

Brainstorm

Brainstorm

This part is undocumented so far. Please edit the link below.

Mark movement onsets with EMG

Source estimation

	Operation	Input format	Software	Output format	Comment / Link
1	MRI segmentatoin	dicom	freesurfer	freesurfer	Freesurfer segmentation
2	Import anatomy	freesurfer	Brainstorm	Brainstorm	Brainstorm tutorial
3	Create a head model	Brainstorm	Brainstorm	Brainstorm	Brainstorm tutorial. Right click subject, compute head model.
4	Source estimation (wMNE)	Brainstorm	Brainstorm	Brainstorm	Brainstorm tutorial

Measures

	Operation	Input format	Software	Output format	Comment / Link
1	Finding the premotor peaks	Brainstorm	Brainstorm	Brainstorm	This part is undocumented so far. Please add!

Statistics

	Operation	Input format	Software	Output format	Comment / Link
1	ANOVA on peak positions	Table (xls)	Rstudio	HTML page	Running a repeated measures ANOVA on the distances between peaks. Interest in interaction effect between within & between factors. Typical script: to be linked
2

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