the problem is that when i run recon-all ( in correct syntax) , permission issues appear; it seems that i dont have permissions to go ahead with the freesurfer.

i also used ( as indicated in one of your tutorial ) the sudo chmod -R a+W $SUBJECTS_DIR command, but if i do so, a password is requested in the terminal.

really, i dont know hot to solve this problem, please help me 

Giuseppe

Thank you again
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