Excellent thanks for your help, 

So if I want to compare leftward FA asymmetry to some measure of interest with a few controls would this work?

Measure | Control1|Control2|

+1                   0              0

And then this for rightward?

Measure | Control1|Control2|

-1                   0              0

And this would obviously be the same for any other DTI measure (MD,AD,RD)?

Thanks,

Matt

On Fri, Oct 23, 2015 at 1:19 AM, Anderson M. Winkler <[log in to unmask]> wrote:

Hi Matt,

There are various ways, and perhaps the simplest is simply swap the sign of the contrast so you don't have to actually make changes to the images. In other words, in the contrasts, where values are positive, replace for negative, and vice-versa.

All the best,

Anderson

On 22 October 2015 at 21:55, Matthew Walton <[log in to unmask]> wrote:

Hello,

I've run through the basic TBSS pipeline, as well as tbss_sym. I'm just a little confused as to how to go about changing symmetry results to test for R>L (or rightward asymmetry if you will). 

The user guide says to "invert the data and rerun randomize".

What data is this referring to? Is there any other steps involved?

Thanks for your help,

Matt

On Thu, Oct 22, 2015 at 12:27 PM, Matthew Walton <[log in to unmask]> wrote:

Hello,

I've run through the basic TBSS pipeline, as well as tbss_sym. I'm just a little confused as to how to go about changing symmetry results to test for R>L (or rightward asymmetry if you will). 

The user guide says to "invert the data and rerun randomize".

What data is this referring to? Is there any other steps involved?

Thanks for your help,

Matt