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June 11, 2019 05:19AM
Hi, Sam-

For most RSFC parameters, one needs to specify a range of frequencies that define the "low frequence fluctuations" (LFFs) of interest. A typical range of LFFs in resting state might be approx. 0.01 - 0.1 Hz, for example.

fALFF is a ratio:
(the sum of amplitudes of those LFFs) / (sum of amplitudes of all frequencies in time series).

Bandpassing is the mechanism for selecting out the LFFs, and so it is necessary to bandpass your data to calculate LFF. You don't have to use the output bandpassed time series later, but you have to do it beforehand. Note that if you are calculating RSFC parameters, then you can*not* have bandpassed your time series earlier, nor censored your data (e.g., removed volumes of high motion).

I suppose you could use 3dTrproject to get rid of orts, but have you processed these time series already, for example using afni_proc.py? Then your data should already have been detrended, likely.

--pt
Subject Author Posted

switch off bandpass filter in 3dRSFC?

samw June 10, 2019 06:44PM

Re: switch off bandpass filter in 3dRSFC?

ptaylor June 11, 2019 05:19AM

Re: switch off bandpass filter in 3dRSFC?

samw June 13, 2019 06:00PM

Re: switch off bandpass filter in 3dRSFC?

ptaylor June 14, 2019 05:59PM

Re: switch off bandpass filter in 3dRSFC?

samw June 18, 2019 03:11PM

Re: switch off bandpass filter in 3dRSFC?

ptaylor September 23, 2019 11:31AM

Re: switch off bandpass filter in 3dRSFC?

samw March 22, 2021 05:14AM

Re: switch off bandpass filter in 3dRSFC?

ptaylor March 22, 2021 09:24AM

Re: switch off bandpass filter in 3dRSFC?

samw September 18, 2019 07:10PM

Re: switch off bandpass filter in 3dRSFC?

ptaylor September 23, 2019 11:39AM

Re: switch off bandpass filter in 3dRSFC?

samw March 22, 2021 05:52AM

Re: switch off bandpass filter in 3dRSFC?

ptaylor March 22, 2021 09:31AM

Re: switch off bandpass filter in 3dRSFC?

samw April 20, 2022 07:43AM

Re: switch off bandpass filter in 3dRSFC?

samw April 29, 2022 08:34AM

Re: switch off bandpass filter in 3dRSFC? Attachments

ptaylor April 30, 2022 07:47PM



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