Hi. I'm planning to find temporal envelope correlation between brain signal (gamma) and stimuli signal (music). How can I extract the time series of my ROI (eg. hippocampus) at certain time (eg. 10-20s) from Brainstorm to do this? Is it absolute value more preferable than relative value for this purpose? I have finished doing pre-processing up until source estimation so far. Thank you for your help.
Estimate the sources, then extract the ROI time series with process Extract > Scouts time series.
What difficulties are you facing?
Hi Francois. Thank you for the fast response.
I have done estimating source & scout time series. I then proceeded with averaging time series across subjects (the setting as picture below, are they correct?).
So an averaged file appears under group analysis with all 170 regions for 3 minutes recording (picture below).
So now I plan to export this averaged time series into SPSS to correlate its envelope with stimuli envelope. For the analysis, I will only choose gamma range (30-80Hz), 30 ROIs and first 2 minutes from the whole recording.
How can I perform this step? Is it possible to have them exported as numerical values? Since I'm not familiar with programming & coding eg. Matlab, Python etc.
It seems OK described like this, but I can't tell you if what you did is actually correct.
So now I plan to export this averaged time series into SPSS to correlate its envelope with stimuli envelope.
Is it possible to have them exported as numerical values?
You can right-click on any file > File > Export as file.
Change the file format to set the type for output file you want.
If you want to export all the individual results (instead of the average) in the same file, you can use the processes Extract > Extract values or Standardize > Concatenate signals to create one single file before exporting as a text file to SPSS.
Thank you, it works well! It goes like this;
So now I have all the values of each time frame for all regions & all brainwave frequency (0.5-80Hz). But is it possible to extract the values for specific range of frequency only ie. gamma 30-80Hz?
But is it possible to extract the values for specific range of frequency only ie. gamma 30-80Hz?
You need to filter the signals at some point, using the process "Pre-process > Band-pass filter", if you want to do this. Or extract the magniture of the envelope of the Hilbert transform (see time-frequency tutorial)