Hello everyone! I am in a pickle right now as I attempt to move forward in my research project on neurofeedback. I am trying to calculate the theta/beta ratio for individual subjects and then compare them statistically. The issue I am having is statistically comparing amplitudes of different frequency bands. For example, in the theta category, I have a subject that had his/her frequency range of 2-9 Hz inhibited. For another subject, his/her frequency range of 3-6 Hz was inhibited. I cannot compare the average amplitudes of these two subjects because the wider a frequency band is, the larger the amplitude is (generally). Basically, for the first subject, what would his/her amplitude be if I restricted the bandwidth from 2-9 Hz to 3-6 Hz? The amplitude for the 2-9Hz range is 34.3, so how much would the amplitude decrease by if I restricted that subject’s frequency range to 3-6 Hz? Let me know if this issue is not clear and I will try to adjust my question. Thanks everybody!
Tristan, hi.
I assume you have all the originally recorded raw EEG. You just need to run that through your new filter bands. [quote=“tsguigna, post:1, topic:289”]
The amplitude for the 2-9Hz range is 34.3, so how much would the amplitude decrease by if I restricted that subject’s frequency range to 3-6 Hz?
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You cannot compute the new filter output by applying some function to the original output. You must rerun the raw data. The reason for this is that (in your example), you have no idea how much energy was in the 2-3 hz range or 6-9 hz range, until you refilter the raw data.