Dear Roni, That looks quite strange. Are you using the latest SPM version? It might have to do with the top of the skull being cut in the MRI image but still the code shouldn't misbehave like that. If you can reproduce this in SPM12 release, send me the image and we'll take a look. Best, Vladimir On 18 Jan 2015, at 10:44, Roni Tibon <[log in to unmask]> wrote: Dear all, Could you please help me understand why I get this "unicorn" shaped mesh for some of my participants, when I create an individual head mesh (as part of the coregistration of M/EEG data)? Many thanks, Roni -- /\.../\ ( -- ---)__{} (_.._...._) http://shkafkafim.blogspot.com/ <306.jpg>