reviewer questions

Dear Sir,

I am re-posting this question as I have not yet received an answer.

We have several reviewer questions that I would kindly ask your assistance with and which relate to the use of your very valuable DPARSF toolbox.

1)Using DPARSF we have bandpass filtered at 0.01-0.1 Hz. The reviewer requested to precisely state the 'type of filter". Was the filtering based on a 'discrete cosine transform' as done in SPM with the given frequencies used as cut-off, I believe this is correct, but just wanted to confirm.

2) the other reviewer question was this: "How many degrees of freedom were left in the data after preprocessing"? I am a little lost with this question. We regressed the white matter, CSF and the global signal ( and selected the 'Friston 24'). We also selected the Head motion scrubbing regressors (power option).

In your DPARSF toolbox I selected "motion scrubbing" and selected the FD (power) option.
The reviewer of our manuscript asked what the assumed head radius was? Would you be able to help with this?

I very much appreciate your help in answering these questions,

With kind regards,
Catherine Chong

Comments

Hi Catherine,

1. It's an ideal filter (e.g., http://www.dsprelated.com/freebooks/sasp/Ideal_Lowpass_Filter.html).

2. This is a difficult question. You can estimate the DOF according to Patel, A.X., Bullmore, E.T., 2015. A wavelet-based estimator of the degrees of freedom in denoised fMRI time series for probabilistic testing of functional connectivity and brain graphs. Neuroimage.

3. 50mm for FD Power.

Best,

Chao-Gan