Dear Michael, Thank you for your reply! I loaded right hand motor task data into Matlab and see the range of z score is from ~-20 to ~29. If I convert those high z scores, the p value will be just 0. Is that normal? also how can I run a cluster-level correction on the surface map?
Best, Xiangyu On Wed, Nov 26, 2014 at 3:42 PM, Harms, Michael <[email protected]> wrote: > > Hi, > The file has "zstat" in its name, so it is the z-statistic from the Level > 3 group model across 440 related subjects ("R440"). You could compute a > p-value from a standard normal distribution, but those p-values will not be > fully accurate, because as we note in the data release manual, the model > for computing the z-stats didn't account for the familial relationships > between subjects (i.e., the R440 subjects are not an independent group of > subjects). You could use the "U100" set of subjects instead, which are 100 > unrelated subjects. In that case, p-values computed from the z-stat should > be accurate, but note that those will be grayordinate-wise p-values, and > will not be corrected for multiple comparisons. > > cheers, > -MH > > -- > Michael Harms, Ph.D. > ----------------------------------------------------------- > Conte Center for the Neuroscience of Mental Disorders > Washington University School of Medicine > Department of Psychiatry, Box 8134 > 660 South Euclid Ave. Tel: 314-747-6173 > St. Louis, MO 63110 Email: [email protected] > > From: Long <[email protected]> > Date: Wednesday, November 26, 2014 6:50 AM > To: "[email protected]" <[email protected]> > Subject: [HCP-Users] How to threshold the task data? > > Dear all, > > I tried to run statistical analysis on the task data, for instance, > HCP_Q1-Q6_R440_tfMRI_ALLTASKS_level3_zstat1_hp200_s2.dscalar.nii. However I > don't know if the data contained z score or beta score, and how to > calculate the p value from the task data. Thank you in advance for helping! > > Best, > Xiangyu > > _______________________________________________ > HCP-Users mailing list > [email protected] > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > > > ------------------------------ > > The materials in this message are private and may contain Protected > Healthcare Information or other information of a sensitive nature. If you > are not the intended recipient, be advised that any unauthorized use, > disclosure, copying or the taking of any action in reliance on the contents > of this information is strictly prohibited. If you have received this email > in error, please immediately notify the sender via telephone or return mail. > _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
