run compare dsm¶
Matlab output: run_compare_dsm
%% RSA Tutorial
% Compare DSMs
%
% # For CoSMoMVPA's copyright information and license terms, #
% # see the COPYING file distributed with CoSMoMVPA. #
subjects = {'s01','s02','s03','s04','s05','s06','s07','s08'};
masks = {'ev_mask.nii','vt_mask.nii'};
config=cosmo_config();
study_path=fullfile(config.tutorial_data_path,'ak6');
%%
% In a nested loop over masks then subjects:
% load each dataset
% demean it, get DSM, save it in dsms
n_subjects=numel(subjects);
n_masks=numel(masks);
counter=0;
for m = 1:n_masks
msk = masks{m};
for s = 1:length(subjects)
sub = subjects{s};
sub_path=fullfile(study_path,sub);
% load dataset
ds_fn=fullfile(sub_path,'glm_T_stats_perrun.nii');
mask_fn=fullfile(sub_path,msk);
ds_full = cosmo_fmri_dataset(ds_fn,...
'mask',mask_fn,...
'targets',repmat(1:6,1,10)');
% compute average for each unique target
ds=cosmo_fx(ds_full, @(x)mean(x,1), 'targets', 1);
% remove constant features
ds=cosmo_remove_useless_data(ds);
% demean
% Comment this out to see the effects of demeaning vs. not
ds.samples = bsxfun(@minus, ds.samples, mean(ds.samples, 1));
% compute the one-minus-correlation value for each pair of
% targets.
% (Hint: use cosmo_pdist with the 'correlation' argument)
dsm=cosmo_pdist(ds.samples, 'correlation');
if counter==0
% first dsm, allocate space
n_pairs=numel(dsm);
neural_dsms=zeros(n_subjects*n_masks,n_pairs);
end
% increase counter and store the dsm as the counter-th row in
% 'neural_dsms'
counter=counter+1;
neural_dsms(counter,:)=dsm;
end
end
%%
% Then add the v1 model and behavioral DSMs
models_path=fullfile(study_path,'models');
load(fullfile(models_path,'v1_model.mat'));
load(fullfile(models_path,'behav_sim.mat'));
% add to dsms (hint: use comso_squareform)
v1_model_sf=cosmo_squareform(v1_model);
behav_model_sf=cosmo_squareform(behav);
% ensure row vector because Matlab and Octave return
% row and column vectors, respectively
dsms = [neural_dsms; v1_model_sf(:)'; behav_model_sf(:)'];
%%
% Now visualize the cross-correlation matrix. Remember that 'cosmo_corr'
% (or the builtin 'corr') calculates correlation coefficients between
% columns and we want between rows, so the data has to be transposed.
cc = cosmo_corr(dsms');
figure();
imagesc(cc);
%%
% Now use the values in the last two rows of the cross correlation matrix to
% visualize the distributions in correlations between the neural similarities
% and the v1 model/behavioral ratings. Store the result in a matrix
% 'cc_models', which should have 8 rows (corresponding to the participants)
% and 4 columns (corresponding to EV and VT correlated with both models)
%
% Rows 1 to 8: EV neural similarities
% Rows 9 to 16: VT neural similarities
% Row 17: EV model
% Row 18: behavioural similarities
cc_models = [cc(1:8,17) cc(9:16,17) cc(1:8,18) cc(9:16,18)];
labels = {'v1 model~EV','v1 model~VT','behav~EV','behav~VT'};
figure();
boxplot(cc_models);
set(gca,'XTick',[1:4],'XTickLabel',labels);