hi Dennis and Gang

Is this a case where instead of having PE and LR as separate regressors, the values of PE and LR for each event should be specified using stim_times_AM2?

From the help:

-stim_times_AM1 and -stim_times_AM2 now take files with more
than 1 amplitude attached to each time; for example,
33.7*9,-2,3
indicates a stimulus at time 33.7 seconds with 3 amplitudes
attached (9 and -2 and 3). In this example, -stim_times_AM2 would
generate 4 response models: 1 for the constant response case
and 1 scaled by each of the amplitude sets.

So in this case there would be one -stim_times_AM2 argument to 3dDeconvolve with the times for each trial and the values for PE and LR would be married to them?

The collinearity error I think stems from the fact that, as Gang noted, these things are being assigned using separate -stim_times arguments.

James