function [fr_coeff,lags,lim95]=fr_ccf(ra,rb,dt,MAXLAG,w,option) % get firing rate correlation, and Common Drive Coefficient % Input: % ra and rb: the two firing rates % dt: time resolution (msec) % MAXLAG: maximum time lag (msec) % w: bandwidth of the firing rates (Hz) % option: detrending prior to correlation calculation % Output: % cr: common drive coefficient % lags: time lags % lim95: 95% confidence interval % % %Written by Ning Jiang, Institute of Biomedical Engineering, Univesity of New %Brunswick, NB, Canada, E3B 5A3. %Email: ning.jiang@unb.ca % %Date: Mar 5, 2007 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% if option %detrending... hpass=500; %msec b=ones(1,hpass/dt); b=b/sum(b); rat=filter(b,1,ra); rbt=filter(b,1,rb); ra=ra-rat; rb=rb-rbt; ra=ra(501:length(ra)); rb=rb(501:length(rb)); end if length(ra) > length(rb) ra=ra(1:length(rb)); else rb=rb(1:length(ra)); end [fr_coeff,lags]=xcov(ra,rb,MAXLAG/dt,'unbiased'); fr_coeff=fr_coeff/(std(ra)*std(rb)); lags=lags*dt; lim95=2*sqrt(1/(2*w*dt*length(ra)/1000));