Hello, 

I used Conn toolbox to preprocess resting state fmri data,  applying a high pass frequency filter above 0.01 Hz. Looking at the preprocessed data in freeview, the signal in the CSF is centered around 190. Is it possible to do the demeaning of BOLD signal using Conn, in order, for example, to have a CSF signal centered around zero? 

Thank you in advance,

Alice

Hi Alice,

Sorry, in the denoised files that are exported from CONN to other software packages the mean BOLD signal at each voxel is explicitly kept there because it contains important tissue-class information (e.g. several algorithms in SPM will use the mean intensity to determine an appropriate brainmask, while others will use the mean intensity for inter- or intra- modality coregistration). 

Best

Alfonso

Originally posted by alicee:

Hello, 

I used Conn toolbox to preprocess resting state fmri data,  applying a high pass frequency filter above 0.01 Hz. Looking at the preprocessed data in freeview, the signal in the CSF is centered around 190. Is it possible to do the demeaning of BOLD signal using Conn, in order, for example, to have a CSF signal centered around zero? 

Thank you in advance,

Alice