I think if you start doing a lot of HPF you start picking up structured artifacts in the data, which may make distinguishing between signal and noise more difficult for the ICA. I'm not aware of any other tests than the one that Steve and I did between hp2000 (essentially linear detrend) and hp200. hp2000 performed better with ICA+FIX classification and convergence, but the confounding variable was that I classified all of the hp2000 and Steve all the hp200, so it is possible that I did a better job with the classification too.
Matt. From: <[email protected]<mailto:[email protected]>> on behalf of Keith Jamison <[email protected]<mailto:[email protected]>> Date: Thursday, October 6, 2016 at 1:35 PM To: "Xu, Junqian" <[email protected]<mailto:[email protected]>> Cc: HCP Users <[email protected]<mailto:[email protected]>>, "Ely, Benjamin" <[email protected]<mailto:[email protected]>> Subject: Re: [HCP-Users] MELODIC denoising vs. released ICA-FIX datasets Steve, Have you found an obvious downside to a shorter HPF cutoff of, say, 200 seconds? Would the HCP FIX training data still apply or would the classifier need to be retrained? -Keith On Thu, Oct 6, 2016 at 12:43 PM, Xu, Junqian <[email protected]<mailto:[email protected]>> wrote: > On Oct 4, 2016, at 9:03 PM, Ely, Benjamin > <[email protected]<mailto:[email protected]>> wrote: > > Thanks Steve, that's good to keep in mind. Our acquisition is a single > "HCP-like" 15 minute run at MB6, 2.1mm isotropic resolution, TR=1s, AP phase > encoding, 32-channel head coil on a 3T Skyra; hopefully that gives us a > similar temporal profile. It's not much about the acquisition protocol (though in the multiband era, MB is now related to scanner transmitter stability), but rather the scanner stability itself. > Sounds like I should compare our temporal stability against the HCP's - is > there a measure you recommend? HCP Connectom Skyra scanner has quite small temporal drift and a very linear trend (specific to the gradient and body coil hardware characteristics), which a typical Skyra can't match. To determine what detrending cutoff you should use for your site-specific data, you could run a 5-10min fBIRN phantom scan with your fMRI protocol and look at the scanner stability. _______________________________________________ HCP-Users mailing list [email protected]<mailto:[email protected]> http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list [email protected]<mailto:[email protected]> http://lists.humanconnectome.org/mailman/listinfo/hcp-users ________________________________ The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail. _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
