Hi Jennifer,

I'm unable to answer your second question definitively, although I've been doing the summing after Talairaching. It seems to me that, as long as whatever operation you're doing is within subjects, as it would be in the case of summing over the betas in the response lags, it shouldn't make a noticeable difference whether you Talairach first or sum first. I think the only thing that matters is that you Talairach before you do any combining of data at the group-level. (And I don't smooth my iresp files directly, but rather the epis that I run 3dD on. So I'm not sure what to say about that.)

To answer your first question, here are the basic steps that I've been using to get the averaged response curves for each condition in particular ROIs (Rick or anyone else please feel free to correct me if any of these steps are incorrect):

1.) Get iresp datasets from 3dD
2.) Talairach the iresp datasets (adwarp)
3.) Average the datasets from step 2 across subjects to get one dataset for each condition (3dcalc)
4.) Create an ROI mask that defines the regions for which you want to view the averaged response (probably using 3dmerge on your group results)
5.) Use 3dROIstats with the averaged datasets from step 3 and the mask from step 4 to get the averages over each ROI for each condition

For a quick view of the resulting response curves, use 1dplot on the output from step 5. To view multiple curves plotted on the same graph, use 1dplot -one. Note that you can use index numbers with 1dplot to plot different columns of the 3dROIstats output (i.e., the activity in different ROIs over time). For example, assuming you just went with the default 3dROIstats output that gives you columns for the name of the dataset that was used to create the file and the sub-brick numbers in that dataset, the following command would give you the response curve for the first ROI of condition 1 plotted on the same graph as the response curve for the first ROI of condition 2:

1dplot -one cond1[2] cond2[2]

Note that cond1 and cond2 are files output from 3dROIstats. Also note that index number 2 is the first ROI because the first column in those files corresponds to index 0 (the filename), the second column corresponds to index 1 (the sub-brick), and the third column corresponds to the first ROI.

Of course, you can take the numbers that 3dROIstats output and load them into your favorite graph-making program to make prettier time courses. But 1dplot will suffice for a quick view.

-Joe