Hi SPMers:<br>&nbsp;<br>&nbsp;There exists a item called Delay in time(defaults:500ms) in Siemens Trio 3.0T Gre-EPI sequence parameter card.TR value does not chang when i change the parameter( for example: 500ms-&gt;300ms).I guess that Delay in time is part of TR and the TA needed in SPM's slice timing equal to TR minus Delay in time(TA = TR -Delay ),but&nbsp; I am not sure. 
<br>&nbsp;Can someone give some explaination about the parameter? and, how the value of the parameter time influence my fMRI, what is the optimum value of it ??<br>&nbsp;<br>&nbsp;thanks<br>&nbsp;<br>Leina