RE: Multiple covariates and scanner-correction

Dear Conn users,

Thankyou Alfonso et al.,  for providing such a wonderful software and regularly customising it on the basis of user requirements.

I have come across different opinions regarding putting categorical variable as covariate in the design. What would be everybody's opinion regarding Question 1 in this thread on  the below statements

1. Putting '0' and '1' or 8 channel and 32 channel in this case for the variable 'scanner Type'
or
2. Putting '1' and '2' for 8 channel and 32 channel in this case for the variable 'scanner Type'
or
3. Putting '1' for for the subjects scanned with 8 channel and '0' for the subjects scanned with 32 channel for the variable 'Eight channel' and similarly  putting '1' for for the subjects scanned with 32 channel and '0' for the subjects scanned with 8 channel for the variable 'Thity-two channel'

and then how would be the correction procedure in second level model for all the these three cases. I feel the contrast to be entered like 

for case 1 AllSubjects, Iron, Amyloid, IronAmyloid, and ScannerType as [0 0 0 1 0]

for case 2 AllSubjects, Iron, Amyloid, IronAmyloid, and ScannerType as [0 0 0 1 0]

for case 3 AllSubjects, Iron, Amyloid, IronAmyloid, Eight channel and Thirty-two channel as [0 0 0 1 0 0]

Which of the three option is recommended for analysis. Your suggestions are valuable 

Regards
Himanshu Joshi