[Mne_analysis] question about LCMV

[daisy]

Hi, experts

I have some questions  when I computed LCMV beamformer on evoked data. Could anyone help me? 

(1)I use this command：stc=lcmv(evoked_con1,forward,noise_cov,data_cov,reg=0.01). Then I can plot the source time courses(stc). The xlabel is time(ms). But what is the ylabel? Because the beamformer weight was normalized by noise, according to the paper of Van Veen in 1997, the ylabel should be neural activity index. But for one example in the gallery(http://martinos.org/mne/stable/auto_examples/inverse/plot_lcmv_beamformer_volume.html?highlight=lcmv), the ylabel is LCMV value. Is the ‘lcmv value’ same with ’neural acitvity index’ or ‘pseudo-z value’(Robinson and Vrba 1999)?
(2) If I apply LCMV beamformer on evoked data of two conditions, then I can get two stc files. Can I compare them directly? For example, calculate the difference of time course of these two conditions in given time and location? Is it meaningful?

Thank you!

-Best
 Xiaoxu