Hi
I wonder if you can help me. I am using SDM for the first time and am just a bit uncertain about a specific point.
I don't have the t-statistic, z score or p value for some of my study coordinates, so the tutorial suggests writing a p for positive peaks and an n for negative peaks.
First question is, what do you mean by a positive peak and a negative peak? Is positive where activation is greater than the control and negative where is less than controls? Or does it refer to left sided and right sided coordinates?
The second question is where do I put the n or p, would this go before or after the coordinate in the .txt file?

Warm regards
Lara

Dear Lara,

in SDM, a peak is considered to be positive if it reflects the direction of the contrast, e.g. if the activation in patients is higher than in controls. It is not related to the location of the peak.

You should write the coordinates followed by the t-value or p/n, e.g.

6,35,32,p
2,40,-14,n

Hope this helps,

Joaquim

Thank you so much
That is great