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Hi - you can certainly plot std across the mask, for any given test statistic such as PE% - just be clear exactly what this is that you're plotting! It's not very common though, I would think. Cheers. On 6 May 2014, at 12:47, Yang, Daniel <[log in to unmask]> wrote: > Thanks! I am just wondering what the common practice is for reporting the variation of the % signal change for a given ROI mask. My statistic is the PE converted to %, block design. Is it commonly accepted to report and plot +/- std dev as the variation in this situation? > > Best, > Daniel > > On May 6, 2014, at 7:24 AM, "Stephen Smith" <[log in to unmask]> wrote: > >> Hi - I think you're misunderstanding what this std is - in the Featquery table this is the standard deviation of a given statistic across the mask - so it doesn't relate to what I think you're intending to use it for - e.g., mixed-effects cross-subject uncertainty on the values within the mask. >> >> Cheers. >> >> >> >> >> >> On 6 May 2014, at 12:17, Yang, Daniel <[log in to unmask]> wrote: >> >>> Hi Mark, >>> >>> Thanks! My understanding is that standard error should be used in error bars, and yes, it should be mean +/- stderr (sorry for the typo!) So my question is then how to find the standard error information of the % signal change for a given ROI in the featquery output. Thanks! >>> >>> Best, >>> Daniel >>> >>> On May 6, 2014, at 2:39 AM, "Mark Jenkinson" <[log in to unmask]> wrote: >>> >>>> Hi, >>>> >>>> There is a difference between standard error and standard deviation and any textbook on stats (or many pages on the internet) will explain this in detail. What you plot depends on what you want to show, and you should make it clear in your caption what you are doing. And never do stddev (or stderr) +/- mean, but instead do mean +/- stddev (or stderr). >>>> >>>> All the best, >>>> Mark >>>> >>>> On 5 May 2014, at 12:14, "Yang, Daniel" <[log in to unmask]> wrote: >>>> >>>>> Dear FSL developers and users, >>>>> >>>>> In featquery, there is a column named "stddev" (standard deviation?) and there is a column named "mean". >>>>> When I plot the error bars, should I use 1 "stddev" +/- the mean? >>>>> I learn that error bars should be standard errors instead of standard deviation but I don't see stderr in the columns. >>>>> Can you please advise what to do here? >>>>> >>>>> Thanks! >>>>> Daniel >>>>> >>>>> -- >>>>> Daniel (Yung-Jui) Yang, Ph.D. >>>>> Postdoctoral Researcher >>>>> Yale Child Study Center >>>>> New Haven, CT >>>>> Tel: (203) 737-5454 >>>>> E-mail: [log in to unmask] >>>> >> >> >> --------------------------------------------------------------------------- >> Stephen M. Smith, Professor of Biomedical Engineering >> Associate Director, Oxford University FMRIB Centre >> >> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK >> +44 (0) 1865 222726 (fax 222717) >> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve >> --------------------------------------------------------------------------- >> >> Stop the cultural destruction of Tibet >> >> >> >> --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Associate Director, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask] http://www.fmrib.ox.ac.uk/~steve --------------------------------------------------------------------------- Stop the cultural destruction of Tibet