Thanks for your answer. as it is resting state I can have 1 trial or keep the trial existed in the pre-processed signals,147trails, Based on the paper by Sylvain Baillet with title of "The brain resting-state activity is shaped by synchronized cross-frequency coupling of neural oscillations" the covariance matrix is empirically estimated by empty-room recording, therefore as the room noise and participant noise is provided by HCP I don't know which level of noise do I need to take, or I don't need to consider that and just simply did what you have proposed. Thanks
On Mon, Oct 24, 2016 at 4:40 PM Georgios Michalareas < giorgos.michalar...@esi-frankfurt.de> wrote: > Hi , > > I think you can still do it with ft_timelockanalysis. > > I assume that the resting state data you mention has only one trial. > > then if you just do: > > cfg=[]; > > cfg.covariance='yes'; > > pseudoavg=ft_timelockanalysis(cfg, data); > > > then it will just compute the average across trials but as there is only > one trial it will basically produce the exact same data. > > But in the output of timelockanalysis you ll find a field .cov whith > dimension Nchannels x Nchannels which contains the covariance matrix of > the MEG sensors . > > This covariance has been computed from the entire length of the single > resting state trial , so I think this is what you are interested in. > > I hope this helps. > > Best > > Giorgos > > > On 10/24/2016 10:42 PM, mehdy dousty wrote: > > Hello, > > I am using HCP MEG resting state to compute source localization. As it > > is resting state signal and I am using Fieldtirp I have no idea how to > > compute the noise covariance matrix. Mostly this matrix is computed > > with ft_timelockanalysis with the window of [-inf 0] in task-based MEG > > I really appreciate if anybody can help me. > > Thanks > > Mehdy > > > > _______________________________________________ > > HCP-Users mailing list > > HCP-Users@humanconnectome.org > > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > > > > _______________________________________________ > HCP-Users mailing list > HCP-Users@humanconnectome.org > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
