 |
 |
Thank you, yes, makes sense. cheers Martin ________________________________ From: FSL - FMRIB's Software Library <[log in to unmask]> on behalf of Prof Stephen Smith <[log in to unmask]> Sent: 03 June 2018 06:09 To: [log in to unmask] Subject: Re: [FSL] "that" tICA question again.. Hi - to be clear - you're talking about tensor-ICA option in MELODIC, right? This relatively small amount of variation (compared to block length) should not prevent the tensor-ICA from finding the dominant modes in the data - but you may of course find some modes that explain this variability, and the variability will mean that you can't expect cross-subject variations in response timing (HRF etc) to be well modelled (in further components) as a well-identifiable separate thing from the stimulus timing variability. Cheers. On 3 Jun 2018, at 03:52, Martin M <[log in to unmask]<mailto:[log in to unmask]>> wrote: Hi, I'm trying to run tICA on a block design (30s ON 30s OFF). The design is the same for all sessions/subjects, however, due to the instrumentation we are using, which is not quite up to snuff yet, there is a little bit of random variance in their onset/offset across sessions/subjects (I'm guessing the range is at most 1-2s; with my TR being 700ms). I know the recommendation is to only use tICA when the timeseries/events are the same across sessions/subjects, is this degree of jitter (in some participants) enough to kill the whole point of doing a tICA? (I realize it will, to the very least, affect the participants for whom there was more jitter) Cheers Martin ________________________________ To unsubscribe from the FSL list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=FSL&A=1 --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Head of Analysis, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask]<mailto:[log in to unmask]> http://www.fmrib.ox.ac.uk/~steve --------------------------------------------------------------------------- Stop the cultural destruction of Tibet<http://smithinks.net> ________________________________ To unsubscribe from the FSL list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=FSL&A=1 ######################################################################## To unsubscribe from the FSL list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=FSL&A=1