hello,I want to do a time-frequency of scouts' statistic test between two group subjects(one group has 13 subjects,and another one has 18 subjects),and the scouts's on the MNI standard brain time-frequency maps of all subjuect have been computed ,I want to figure out the difference of power in different frequecy band by statistic test,how should I do it on brainstorm?thank you!
have a nice day!
the most right side of image ,is my t-test result ,I think maybe I did something wrong somewhere
Hello,
What the figure on the right suggests is that there is nothing significantly between the two sets of files you tested.
Go to the Stat tab and increase the statistic threshold if you want to see something in this figure.
What I notice is also that you computed the time-frequency decomposition on source maps from which you have taken the absolute value. This is not something you should do.
For a proper sequence of operations to test differences in power, please refer to the following tutorials:
http://neuroimage.usc.edu/brainstorm/Tutorials/Difference
http://neuroimage.usc.edu/brainstorm/Tutorials/Statistics
http://neuroimage.usc.edu/brainstorm/Tutorials/Workflows
http://neuroimage.usc.edu/brainstorm/Tutorials/VisualGroup
Francois
oh,thank you! speak of the absolute value problem, in the tutorial,it has a absolute values process before project on default anatomy,that's why I computed the time-frequency decomposition on source maps from which I have taken the absolute value,I don't know if absolute values is a must-thing to do before project on default anatomy.......
Take the absolute value before computing the average of source maps between subjects.
Do not take the absolute value before doing any frequency analysis.
Many analysis scenarios are described in this tutorial:
http://neuroimage.usc.edu/brainstorm/Tutorials/Workflows