Hi Arman,
It’s worth noting that as your design is different to Manuel’s ( correlating a single behavioural measure with FA ) that -D does need to be used ( and the measure demeaned ).
Kind Regards
Matthew
--------------------------------
Dr Matthew Webster
FMRIB Centre 
John Radcliffe Hospital
University of Oxford

On 4 Oct 2017, at 12:42, Arman Bordbar <[log in to unmask]> wrote:

Thanks Matthew.

On Oct 4, 2017 11:54, "Manuel Blesa" <[log in to unmask]> wrote:
Hi Matthew,

Thanks for your quick reply, it was super useful.

Regards,

Manuel