Dear Freesurfers,
sorry for the additional message but I really need your help.
I'm running the retinotopy analysis to study population receptive fields on healthy subjects. Structurals have been reconstructed using "recon-all -qcache".
The stimuli I used for retinotopy are: rotating wedge (45deg, counter-clockwise) for polar angle and expanding ring (out) for eccentricity.
Each subject underwent retinotopy stimuli in two conditions: free normal sight and narrowed sight. So, each subject has 1 structural and 2 pairs of functionals for each condition (1 rot wedge + 1 expanding ring for each condition).
I
successfully
computed the 1st level analysis for each subject for each condition. Now, I'd like to check the differences in cortical activation between the two conditions to understand if we have significant effects in activations when we narrow the sight (or simply make the subtraction analysis on the 2 conditions in such a way that we can check if we really narrow the sight).
I checked on FREESURFER tutorials but I cannot find anything similar. The
group analysis is for comparison between 2 different subject populations. I opted for
paired analysis but I'm stuck with the FSGD files (I understand two FSGD files are requested)
1)
GroupDescriptorFile 1
Class Main
Input subject6ng Main
Input subject6 Main
Input subject7ng Main
Input subject7 Main
Input subject8ng Main
Input subject8 Main
Input subject9ng Main
Input subject9 Main
Input subject10ng Main
Input subject10 Main
Input subject11ng Main
Input subject11 Main
Input subject12ng Main
Input subject12 Main
Input subject13ng Main
Input subject13 Main
2)
GroupDescriptorFile 1
Class Main
Variables Goggles
Input subject6pair Main normal
Input subject7pair Main normal
Input subject8pair Main normal
Input subject9pair Main normal
Input subject10pair Main normal
Input subject11pair Main normal
Input subject12pair Main normal
Input subject13pair Main normal
Where the "normal" variable means in free view conditions (not narrowed). Is it well done or am I making something wrong?
- I have 1 main folder for structurals, storing all subject structural folders;
- 1 main folder for functionals, storing all subjects two times (normal and narrowed conditions).
Are there any other ways to compare activations on the same subjects in different conditions?
Thank you for your patience and your help,
Marco
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Marco Ninghetto, PhD candidate
Laboratory of Neuroplasticity
Nencki Institute of Experimental Biology
Polish Academy of Sciences
3 Pasteur Street, 02-093 Warsaw, Poland