A significant positive T/Z statistic means that as your numeric scale goes up, the activity also goes up. As the numeric scale goes down, the activity also goes down.

A signficant negative T/Z statistic means that as your numeric scale goes up, the activity goes down. As the numeric scale goes down, the activity goes up.

For conversion of T-statistics to R, search for

Conversion of Common Test Statistics to r and d Values Statistic

95% CI:
mean+/-1.96*SEM

SEM is computed as standard deviation divided by the square root of N, where N is the number of subjects.

T=con/SEM.

Putting these together, SEM=conimage/T-statistic.
95% CI would be conimage-1.96*conimage/T-statistic to conimage+1.96*conimage/T-statistic.

Best Regards, Donald McLaren
=================
D.G. McLaren, Ph.D.
Postdoctoral Research Fellow, GRECC, Bedford VA
Research Fellow, Department of Neurology, Massachusetts General Hospital and
Harvard Medical School
Office: (773) 406-2464
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On Wed, Feb 8, 2012 at 3:47 PM, Miguel Ferreira <[log in to unmask]> wrote:

Dear SPMers

I've performed a multiple regression study in SPM8 to study the influence 3 numeric scales on fMRI activation pattern. I have positive and negative correlations, and I would like to know what can I conclude from the T and Z statistic of activated voxels. Is it possible to calculate the r-squared and the 95% CI for each voxel in SPM?

Thanks in advance,
Miguel.