Setting resting-case-Aaux to []

                    At = [A(:,:,conc) Aaux];

                elseif iscell(rcMap{iBlk}) % channel map: each single regressor corresponds to one channel (nCH groups)

                    lstML = lstMLtmp(find(mlAct(rcMap{iBlk}{conc,iSS})==1));

                    Atcca = Aaux(:,rcMap{conc,iSS});

                    Atcca = Aaux{iBlk}(:,rcMap{conc,iSS});

                    At = [A(:,:,conc) Atcca];

                end

            end

                    end

                    % return the reduced number of available regressors

                    Aaux{iBlk} = REG(:,compindex);

                    Aaux = REG(:,compindex);

                    % return reduced mapping matrix Av, this is the tCCA filter

                    tCCAfilter = ADD_trn.Av(:,compindex);

                    % set channel-regressor map to empty (GLM will use all available regressors for all channels)

                    rcMap{iBlk} = 'all';

                end

                Aaux = []; % we do not want to use regressors for the resting run

                %% save tCCAfilter matrix that was learned from resting state data.

                fprintf('hmrR_tCCA: run idx = %d. Generated and Saved tCCAfilter\n', runIdx)

                save(filterFilename, '-ascii', 'tCCAfilter');