> On May 18, 2016, at 1:25 PM, Manousos Klados <[email protected]> wrote:
> 
> 
> 
> Dear HCP community,
> 
> I send you a question of one of my students, because he cannot subscribe in 
> the mailing list. His email is the following: 
> 
> I am currently studying tfMRI data and especially I am interested in the 
> Working Memory task. However, I came up with a question regarding the onsets 
> of the WM condition blocks. For example, in Subject 100307 the EV directory 
> (path:100307/MNINonLinear/Results/tfMRI_WM_LR/ EVs) contains the .txt files 
> with the onsets and durations of various conditions and trials (as already 
> stated in the manual). Lets assume that we want to study the 2-bk face task 
> (2bk_faces.txt). The onset is at 79.208 sec with a duration of 27.5 sec. 
> 
> The first part of my question is how to retrieve this information from the 
> BOLD time-series (405 frames/run)? I mean, is there a fixed way to retrieve 
> those frames of interest in the specific interval?


Traditionally, a GLM is used to estimate activation in response to each task 
condition. We used FSL’s FEAT (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/FEAT) to 
estimate activation. We have provided the parameter estimates for each subject 
(averaged over the two task runs) available for download in the ConnectomeDB.


> The last part of my question concerns the onsets of the correct trials in 
> this task. More specifically, the file 2bk_cor.txt contains the onsets of the 
> correct trials however I would expect the onsets to be on the interval 
> [79.208, 79.208+27.5] since those trials are executed within the condition 
> block. Is there a way to match this information according to the 2-bk face 
> onset?

If you want to run your own GLM using different predictors, you will need to 
create those predictors and GLMs on your own. You could extract the 
2bk-face-specific correct trials from the file containing all correct 2bk 
trials (i.e., 2bk_cor.txt). Or you could code your predictors in any variety of 
ways by processing the information in TAB.txt files directly. See the 
documentation at: 
http://www.humanconnectome.org/documentation/S900/HCP_S900_Release_Appendix_VI.pdf
 .

Running a custom GLM will be a little trickier, since it will require some 
custom modification to the TaskfMRIAnalysis pipeline within the HCP Pipelines. 
The pipelines and some documentation is located in GitHub.
https://github.com/Washington-University/Pipelines

An example of how these scripts might be modified was provided in Practical #7 
at last year’s HCP Course
https://www.humanconnectome.org/courses/2015/exploring-the-human-connectome.php

Hope this helps!
--Greg

____________________________________________________________________
Greg Burgess, Ph.D.
Staff Scientist, Human Connectome Project
Washington University School of Medicine
Department of Neuroscience
Phone: 314-362-7864
Email: [email protected]


> 
> Best regards,
> Bill.
> Manousos Klados, PhD
> Max Planck Institute for Human Cognitive & Brain Sciences
> Research Group of Neuroanatomy and Connectivity
> Phone: +49(0)-341-9940-2507 
> Mobile: +49(0)-176-6988-1781
> Email: [email protected] 
> Website: http://www.mklados.com
> Skype: mklados | Twitter: @mklados  
> Address: Stephanstraße 1a PC D-04103 Leipzig Germany 
> 
>  Join us at our next event:SAN 2016 Conferece
> 
> 
> 
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