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 Modified for SPM2 by R. Henson 13/5/03 One subject's data from Henson et al. (2002) Cerebral Cortex - FOR TEACHING PURPOSES ONLY (to illustrate facilities of SPM) - PLEASE DO NOT CITE WITHOUT PERMISSION Experiment ---------- 2x2 factorial event-related fMRI One session (one subject) (Famous vs. Nonfamous) x (1st vs 2nd presentation) of faces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,mat} ------------------------ 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) > usM03953_0005_*.{img,hdr,mat} ----------------------------- Coregister all images to first, and then unwarp and reslice using sinc interpolation (*mat files contain orientation information) Type: Select in the upper left SPM window 'Number of subjects' - 1 'Num Sessions for subject 1' - 1 Select all 351 sM03953_0005_*.{img} and press 'Done' Pull down menu - 'Model field changes w.r.t'- select 'Pitch & Roll' Pull down menu - select 'Create what?' - select 'All images + mean' Output: u* resliced, unwarped files mean* mean of resliced files (for normalisation) rp_sM03953_0005_0006.txt movement parameters (6x351 values) spm2.ps graphical output of translations and rotations ausM03953_0005_* .{img,hdr,mat} ------------------------------- 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 'Number of subjects/sessions' - 1 Select all usM03953_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 '1.9...' (default) Output: au* files interpolated realigned images < Can use to create difference image between ausM03953_0005_0100.img and usM03953_0005_0100.img to see effect of interpolation about middle slice > wausM03953_0005_*.{img,hdr,mat} ------------------------------- 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 - 'Preserve concentrations' Pull down menu: Bounding box - 'Default' Pull down menu: Voxel sizes - '3 3 3' Pull down menu: Interpolation - 'Trilinear' Pull down menu: To wrap images - 'no wrap' Type: Press near upper, middle SPM window Pull down menu - 'Determine Parameters and Write Normalised' Select 'Template image' - EPI.img Select 'Source image, subj1' - meanusM03953_0005_0006.img Select 'Images to write' - meanusM03953_0005_0006.img AND all 351 ausM03953_0005_*.img Select 'Source image,subj2' - press Done (ie select nothing; tells SPM no more subjects) Output: wau* files normalised, interpolated, realigned functionals wmeanusM03953_0005_0006.img normalised mean realigned functional meanusM03953_0005_0006_sn3d.mat normalisation parameters spm2.ps graphical output of normalisation process (appended) < View normalised images with button - Note interpolation to new voxel sizes and image dimensions > < View normalisation transformations in spm2.ps (second page) > < Check registration with button - select wmeanusM03953_0005_0006.img, EPI.img in SPM Templates dir and single_sub_T1.img in SPM Canonical dir > swausM03953_0005_*.{img,hdr,mat} -------------------------------- 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 wausM03953_0005_*.img and press 'Done' Output: swaus* 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' Select target image - 'meanusM03953_0005_0006.img' Select object image - 'sM03953_0007.img' Select other images - - note coordinates close to CatStats repetition effect> press 'plot' Pull down menu - 'Plots of parametric responses'