[FieldTrip] Combineplanars and timelockstatistics

[Sara Aurtenetxe]

Dear all, 

I would highly appreciate if an expert on the field
could comment on the following questions, or highlight a reference, 
since as far as I am aware of, there are different opinions on it. 

When doing timelockstatistics (ERFs) at the gradiometers level:

- Do the gradiometers need to be combined (ft_combineplanar) before the stats?
  And/or do they need to be combined for visualization of effects?

- Which is the (mathematical) explanation for the answer/s?

- Does apply the same when doing source analysis with 'lcmv'? 

Thanks a lot in advance,
All the best,

Sara