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Hello Fieldtrippers,<br><br>I am using for the first time the mulitaper analysis for a TMS study where for every 3 sec a TMS-pulse is given for a 3min duration <br>so i have like 100 trials, i would like to calculate the coherence between two EEG channels within a interval of -0.5 s to 1.5 s.<br><br><br>As in the tutorial for the time frequency analysis the function i am using for calculating the coherence is as follows<br><br><br>[event] = read_fcdc_event('JO_single_pulse_no_block_Vorinervat.vmrk');% reading in the marker file<br>hdr = read_brainvision_vhdr('JO_single_pulse_no_block_Vorinervat.vhdr');% reading the header file<br>cfg = [];<br>cfg.dataset = 'JO_single_pulse_no_block_Vorinervat.eeg';% data file<br>cfg.headerfile = 'JO_single_pulse_no_block_Vorinervat.vhdr' ;<br>cfg.trialdef.eventtype='Stimulus';<br>cfg.trialdef.eventvalue='S 64';<br>cfg.trialdef.prestim = 1.000;<br>cfg.trialdef.poststim = 2.000;<br>cfg = definetrial(cfg);<br>cfg.blc = 'yes';<br>cfg.blcwindow=[-1.000 0.000];<br>dataFIC = preprocessing(cfg);<br><br>% For calculating the coherence <br>cfg=[];<br>cfg.output='powandcsd';<br>cfg.method='mtmconvol';<br>cfg.channel = channelselection({'C3','Cz'}, dataFIC.label);<br>cfg.channelcmb = channelcombination({'C3','Cz'}, dataFIC.label);<br>cfg.foi=2:1:22;<br>numfoi=length(cfg.foi);<br>cfg.t_ftimwin=ones(1,numfoi);<br>cfg.t_ftimwin(:)=0.5;<br>cfg.toi=-0.50:0.05:1.500;<br>cfg.taper='hanning';<br>cfg.tapsmofrq=ones(1,numfoi);<br>cfg.tapsmofrq(:)=1;<br>cfg.pad='maxperlen';<br>cfg.keeptrials='no';<br>TFRmult=freqanalysis(cfg,dataFIC);<br>cfg.keeptrials='yes';<br>fdmtmfft=freqdescriptives(cfg,TFRmult);<br><br>I have attached a plot with this mail which contains very high coherence in the interval -0.75s to 0.75s. Any hint on what is going wrong in the analysis<br>would be very helpfull.<br><br>Sorry for the long mail<br><br>Thanking you <br><br>With regards<br>M.Muthuraman. <br><br /><hr />Detailed profiles 4 marriage! Only at Shaadi.com <a href='http://ss1.richmedia.in/recurl.asp?pid=107' target='_new'>Try it!</a></body>
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