Advanced Event-related fMRI Example Data Set ============================================ Repetition priming for famous and nonfamous faces Created R. Henson 8/7/00 WDCN & ICN, UCL r.henson@ucl.ac.uk One subject's data from Henson et al. (in prep) - FOR TEACHING PURPOSES ONLY (to illustrate facilities of SPM99) - PLEASE DO NOT CITE WITHOUT PERMISSION Experiment ---------- 2x2 factorial event-related fMRI One session (one subject) (Famous vs. Nonfamous) x (1st vs 2nd presentation) of faces against baseline of chequerboard 2 presentations of 26 Famous and 26 Nonfamous Greyscale photographs, for 0.5s, randomly intermixed, for fame judgment task (one of two right finger key presses). Parameteric factor "lag" = number of faces intervening between repetition of a specific face + 1 Minimal SOA=4.5s, with probability 2/3 (ie 1/3 null events) Continuous EPI (TE=40ms,TR=2s) 24 descending slices (64x64 3x3mm2), 3mm thick, 1.5mm gap Following images are in the Data directory... sM03953_0005_*.{img,hdr} in RawEPI ---------------------------------- 351 Analyze format functional images (*img contain data, *hdr is Analyze header) 64x64x24 3mmx3mmx4.5mm voxels < View images with button on main SPM window - Note orbitofrontal and inferior temporal drop-out and ghosting (Effects:brighten if necessary) > rsM03953_0005_*.{img,hdr,mat} in Realigned_r -------------------------------------------- Coregister all images to first, and then reslice using sinc interpolation (*mat files contain orientation information) Type: Press in the upper left SPM window 'Number of subjects' - 1 'Num Sessions for subject 1' - 1 Select all sM03953_0005_*.{img} and press 'Done' Pull down menu - select 'Coregister and Reslice' Pull down menu - select 'Sinc Interpolation' Pull down menu - select 'Create All Images + Mean image' 'Adjust sampling errors' - no Output: r* resliced files meanr* mean of resliced files (for normalisation) realignment_params_sM03953_0005_0006.txt movement parameters (6x351 values) spm99.ps (ps file renamed to spm_realign.ps) graphical output of translations and rotations arsM03953_0005_* .{img,hdr,mat} in Interpolated_ar -------------------------------------------------- 351 functional images temporally realigned to middle slice 12 (of 24) using sinc interpolation (top slice = 24 = acquired first) Type: Press in the upper middle SPM window Select all rsM03953_0005_*.img and press 'Done' Pull down menu - select 'Descending (first slice = top)' Prompt - Reference Slice - enter '12' (default) Prompt - Interscan interval (TR) - enter '2.0' Prompt - Acquisition time (TA) - enter '2.0' (default) Output: ar* files interpolated realigned images < Can use to create difference image between arsM03953_0005_0200.img and rsM03953_0005_0200.img to see effect of interpolation about middle slice > narsM03953_0005_*.{img,hdr,mat} in Normalised_nar ------------------------------------------------- Normalised interpolated realigned functional images The normalisation parameters are generated from the mean realigned image, normalised to the EPI template using affine and nonlinear warps Optional: To save filespace, can change default voxel size to 3x3x3, rather than interpolating to 2x2x2: Press in SPM main window Pull down menu - 'Spatial Normalization' Pull down menu - 'Defaults for - writing normalized' Pull down menu: Bounding box - 'Default' Pull down menu: Voxel sizes - '3 3 3' Type: Press near upper, middle SPM window Pull down menu - 'Determine Parameters and Write Normalised' Number of subjects - 1 'Image to determine parameters' - meanrsM03953_0005_0006.img (in Realigned_r dir) 'Images to write Normalised' - meanrsM03953_0005_0006.img (in Realigned_r dir) AND all arsM03953_0005_0006.img (in Interpolated_ar dir) 'Template image' - EPI.img Pull down menu - 'Bilinear interpolation' Output: nar* files normalised, interpolated, realigned functionals nmeanarsM03953_0005_0006.img normalised mean realigned functional meansM03953_0005_0006_sn3d.mat normalisation parameters spm99.ps (ps file renamed to spm_norm.ps) graphical output of normalisation process < View normalised images with button - Note interpolation to new voxel sizes and image dimensions > < View normalisation transformations in spm_norm.ps > < Check registration with button - select nmeanarsM03953_0005_0006.img, EPI.img in SPM Templates dir and single_sub_T1.img in SPM Canonical dir > snarsM03953_0005_*.{img,hdr,mat} in Smoothed_snar ------------------------------------------------- Smoothed normalised realigned images Smoothed with an isotropic Gaussian kernel with FWHM = 8mm (for statistical inference using theory of Gaussian fields) Type: Press in upper right SPM window Prompt - smoothing FWHM - enter '8' Select all narsM03953_0005_*.img and press 'Done' Output: snar* Smoothed normalised images OPTIONAL step: normalising structural image ------------------------------------------- Coregister mean EPI and structural T1 images Type: Press in upper right SPM window Prompt - No. subjects enter - '1' Pull down menu - 'Coregister only' Pull down menu: Modality of target image - 'EPI' Pull down menu: Modality of object image - 'T1' Select target image - 'meanrsM03953_0005_0006.img' Select object image - 'sM03953_0007.img' Select other images - press 'plot' Pull down menu - 'Plots of parametric responses' Pull down menu - 'F' (or 'N')