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Dear experts:
I'm using the optseq2 version 2.15 2009/05/26. I have three questions:
1. How does the [PSDmin, PSDmax] relate to the jittered intertrial intervals? 2. I have stimuli of between 12 and 20 seconds, where the part of my stimulus that I want to measure is in the last 5 seconds or so. What should I put my dPSD window to? It's both a matter of that the signal starts later than the stimulus presentation, so I guess I would have a PSDmin of a couple of seconds, but how do I handle the variation in stimuli lengths? 3. As mentioned above I have quite a large variation between my stimuli. When I try to specify them individually (about 25) I always get that all schedules are ill-conditioned. Is this because such schedules are generally hard to optimize? 4. I quite often get that all schedules are ill-conditioned, but there is no information in the log file that tells me what is wrong. Example:
./optseq2 --ntp 1500 --tr 1.86 --psdwin 0 22.32 0.93 --nkeep 3 --nsearch 1000 --o test --ev control_trial_1 16.74 1 --ev control_trial_3 18.6 1 --ev control_trial_7 18.6 1 --ev test_trial_11 16.74 1
I get:
NFO: searched 1000 iterations for 0.010556 hours INFO: 26.3158 iterations per second INFO: 1000/1000 schedules were ill-conditioned ERROR: all schedules found were ill-conditioned. This probably means that you need more scan time (ie, a greater number of time points) or fewer repetitions.
(I'm running on a macOS Mojave version 10.14.3. )
But it's obviously not the ntp that is the problem since I put an extra long time there that cover the event durations by far.
Is there any way I can troubleshoot more efficiently myself? The log file doesn't tell me anything.
Very happy for any advice,
All the best,
Katarina
Katarina Bendtz, Ph.D. (particle physics) Postdoctoral researcher in cognitive neuroscience Department of Psychology, Stockholm University