Dear Eugenio,

Thank you for your quick response. Sorry but I am not completely sure if I understood correctly your response. What do you mean with "demeaning" the eTIV first?.

If I understood, a good choice would be to correct the subic_volume before perform the regression using the folliwng formula:

subic_vol = average_eTIV_allsample * subic_vol / eTIV_subject

Thank you.

Best,

Steve.

El mié., 22 abr. 2020 a las 17:35, Steve Petersen (<marfneuro@gmail.com>) escribió:

Dear Freesurfer experts,

I would like to perform a correlation between the volume of subiculum and some behavioural measures. Before making that correlation, is it necessary to correct the subiculum volume with the eTIV? I have thought of doing it by scaling the subiculum volume as follows:

subic_vol = mean_eTIV_group * subic_vol / eTIV_subject Is correct??

mean_eTIV_group = eTIV average of the group to which the subject belongs.

Thanks in advance.

Best regards,

Steve.