Hi,
Perhaps a basic question but it puzzled me a lot so hope someone could help.
To illustrate the time-course change in an ROI during an EV of interest, I need to extract the time-course data from every subject and then average them to plot the graph.
Here is my first question:
Please see Figure 1 for trial structure and Figure 3 for extracted time course data in this example article:
goo.gl/GaC5oj
Figure 1: http://imgur.com/a/3UUHk
Figure 3: http://imgur.com/a/Aic67
In this study, they depict the time course data during the inter-stimulus interval (ISI), which is 6, 8 or 10 s (Figure 1 is with an 8-s ISI). My question is, since figure legend of Figure 3 said "the red box illustrates the expected time period of peak BOLD responses associated with the ISI, after taking into consideration the delay of the hemodynamic response function", which hemodynamic delay interval should I use if I have a trial with fixed EVs like this Figure 3? 6 s? 7 s?
For this article, my second question is, since ISI is 6, 8, or 10 s, why in Figure 3 the red box is with a fixed duration?
Then is my third question:
In the article above, their fMRI TR is 2 s. With a trial structure containing fixed EV duration and a total trial duration that times 2 s (i.e., 40 s), the extracted time-course data are always at fixed time point within ISI (i.e., since cue is always 4 s and stimulation1 is always 6 s, regarding the extracted data for ISI, the data point is always at time point 0, 2, 4, 6... s within ISI epoch). If today the cue is randomly jittered between 3-5 s, is it possible to plot the time course data like Figure 3, given now the extracted time-course data won't be at fixed time point within ISI?
Thanks a lot. Mike
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