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vim-1: from Minimally preprocessed data to Estimated BOLD response

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vim-1: from Minimally preprocessed data to Estimated BOLD response

Posted by Dai Zhang at December 02. 2013

I implement the Basis-restricted separable model in the paper "Identifying natural images from human brain activity" to convert Minimally preprocessed EPI data to estimated BOLD responses amplitude on the Sub1_Ses1-5 data. Actually, the deconvolution results have low correlation (low than 0.4) to the data in EstimatedResponse.mat for some voxel (about 40% in V1). This really hinder identification performance. 

Would you provide the codes of Basis-restricted model?  This would be most helpful to my resent work.

 

Best,

Dai.

 

 

 

Re: vim-1: from Minimally preprocessed data to Estimated BOLD response

Posted by Mark Lescroart at December 10. 2013

Hello Dai (and anyone else with the same question),

We will not be providing the code for the basis-restricted separable model.  However, you may find the MATLAB code in GLMdenoise (http://kendrickkay.net/GLMdenoise/) useful, specifically, the GLMestimatemodel.m function.  This function implements a separable model with a FIR basis, and could be relatively easily tweaked to use a different basis (e.g. sines and cosines).  (GLMdenoise itself provides denoising benefits, but that was not used on the 2008 data.)

 

Re: vim-1: from Minimally preprocessed data to Estimated BOLD response

Posted by Dai Zhang at January 15. 2014

Hi, Mark

I found that EPI images and T1 structure images were provided in this data set. It is hard to register EPI images to the T1 structure images cause EPI images was not for the whole brain. Sform matrixes of T1 and EPI were provided in .header file. However, Both of these matrixes match T1 and EPI image to original point in voxel coordinate, which means we could not use inv(Sform_T1)*Sform_EPI transform EPI to T1. How could I match EPI images to T1?

 

Previously Mark Lescroart wrote:

Hello Dai (and anyone else with the same question),

We will not be providing the code for the basis-restricted separable model.  However, you may find the MATLAB code in GLMdenoise (http://kendrickkay.net/GLMdenoise/) useful, specifically, the GLMestimatemodel.m function.  This function implements a separable model with a FIR basis, and could be relatively easily tweaked to use a different basis (e.g. sines and cosines).  (GLMdenoise itself provides denoising benefits, but that was not used on the 2008 data.)

 

 

Re: vim-1: from Minimally preprocessed data to Estimated BOLD response

Posted by Dai Zhang at January 15. 2014

Could you provide the transform matrix match the voxel coordinate in EPI volume to the voxel coordinate in T1 volume?

Re: vim-1: from Minimally preprocessed data to Estimated BOLD response

Posted by Aakash Agrawal at August 29. 2015

Previously Mark Lescroart wrote:

Hello Dai (and anyone else with the same question),

We will not be providing the code for the basis-restricted separable model.  However, you may find the MATLAB code in GLMdenoise (http://kendrickkay.net/GLMdenoise/) useful, specifically, the GLMestimatemodel.m function.  This function implements a separable model with a FIR basis, and could be relatively easily tweaked to use a different basis (e.g. sines and cosines).  (GLMdenoise itself provides denoising benefits, but that was not used on the 2008 data.)

 

Hello Mark,
I tried using GLMdenoise, but this technique assumes that we have at least 2 runs with same experimental conditions (which I believe is not there in vim-1). Further, using  GLMestimate.m I get an error stating 

"Error using olsmatrix2 (line 56) 

Matrix is singular, close to singular or badly scaled. Results may be inaccurate.

RCOND = NaN." 

Is there a mistake in my implementation?

p.s. I have concatenated data and assumed it to be single run.

 

Thank you

 

Aakash

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