Sent from my iPhone
> On Apr 16, 2015, at 12:54 PM, George Chahine <[log in to unmask]> wrote:
>
> Dear all,
>
> I have a sort of basic question about group ICA design. I wish to run ICA on two groups (control vs patients). We have the following options concerning the group analysis:
>
> 1) do the initial ICA definition on all subjects regardless of group, and then dual regression on each subject in the analysis.
> 2) do the ICA definition only on the control group, and then dual regression on the subjects from both groups. This will decrease false negatives.
> 3) do the ICA definition on a large control group (that does not include the control subjects in the subsequent analysis) and then dual regression on all subjects that will be part of the analysis.
> 4) do ICA on the patients alone and the control group alone, and then do dual regression for each group separetely and carry the second level analysis on matching networks.
>
> 4 is probably the least preferred option, as it will introduce too much bias and false positives. 3 to me seems the best, but I am not sure if it is valid to do the initial ICA on subjects outside the main analysis.
>
> I would greatly appreciate your help on this issue.
>
> Best regards,
>
> George
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