Brainstorm, comparing the effects between groups

Discussions
1

Hi Francois
We have the data from 2 groups: patients and healthy controls. For time-frequency analysis on signals or sources, I would like to compare 2 conditions within each group (baseline vs. manipulation condition). Then I would like to know if these effects are different across groups (baseline vs. manipulation condition, in the patients VS. baseline vs. manipulation condition, in healthy controls). Would it be possible to do this kind of analysis in Brainstorm (second one, comparison of effetcs between groups) and to get appropriate comparison figures or I should extract the data and do these in statistical software?
Thanks

2

Hello,

As long as you are only comparing files with the tests available in Brainstorm, you should be able to do this.
Guidelines for statistical analysis: http://neuroimage.usc.edu/brainstorm/Tutorials/Workflows

If you are familiar with external statistics software, you can also export everything and process it manually. You might understand better what is happening and how to produce the figures you want

Francois

3

Thanks Francois.

The guide is as follows:
Statistics: Single subject
Parametric or non-parametric two-sample t-test, independent, two-tailed.
Statistics: Group analysis, between subjects
Second-level statistic: Parametric or non-parametric two-sample t-test, independent, two-tailed.

I can run the paired t-test on signals for time-frequency analysis for each group. Let us say, in patients A vs. B is significantly different, and in healthy controls also A vs. B is significantly different. Then is there a test in Brainstorm to test if these effects (A vs. B) are different between groups? Although we have this effect in both groups, I would like to know if there is between group difference in this effect, statistical difference between groups in strength of the effect.

Also, within group. A vs. B is significantly different, and also C vs. D is significantly different. I would like to compare A vs. B VS. C vs. D.

In Statistical software it is possible to do this kind of interaction analyses, just did wonder if we can do it in Brainstorm.

4

is there a test in Brainstorm to test if these effects (A vs. B) are different between groups?

You can test the difference of the two conditions between the two groups: (A-B) for group 1 vs. (A-B) for group 2. Maybe there are other things you can do but I'm not a statistics person...

Also, within group. A vs. B is significantly different, and also C vs. D is significantly different. I would like to compare A vs. B VS. C vs. D. In Statistical software it is possible to do this kind of interaction analyses, just did wonder if we can do it in Brainstorm.

I don't know what kind of statistic you would compute for this.

@Sylvain @pantazis?

5

Thanks a lot Francois, I got it.