It seems there is a new requirement of the BIDS validator that channel locations should be in the RAS coordinate system.
I was under the impression that we could specify the coordinate system but, apparently, “RAS” is the only coordinate system allowed now (which makes defining the field "EEGCoordinateSystem" useless).
Note that of the 40 EEG datasets on OpenNeuro, NONE uses the RAS system right now (to my knowledge) and all use the ARS coordinate system. This new requirement seems it will create problems in terms of backward compatibility.
I have talked to people who exported some EEG data recently. Since the BIDS validator generated an error on defining the coordinate system as ARS, then simply removed the "EEGCoordinateSystem" JSON field (so now BIDS assumes by default channel locations are in the RAS coordinate system, while they are in fact the ARS one).
@robertoostenveld @sappelhoff please share your thoughts.
It seems there is a new requirement of the BIDS validator that channel locations should be in the RAS coordinate system.
I was under the impression that we could specify the coordinate system but, apparently, “RAS” is the only coordinate system allowed now (which makes defining the field "EEGCoordinateSystem" useless).
Note that of the 40 EEG datasets on OpenNeuro, NONE uses the RAS system right now (to my knowledge) and all use the ARS coordinate system. This new requirement seems it will create problems in terms of backward compatibility.
I have talked to people who exported some EEG data recently. Since the BIDS validator generated an error on defining the coordinate system as ARS, then simply removed the "EEGCoordinateSystem" JSON field (so now BIDS assumes by default channel locations are in the RAS coordinate system, while they are in fact the ARS one).
@robertoostenveld @sappelhoff please share your thoughts.