On Sat, 26 Sep 2009, Asaf Kaftory wrote:
Hello list,
I'm new to optseq, and would like your help with the following issues:
- What exactly does DPSD mean? and why does the TR has to be an integer of it?
Delta Post-Stimulus Delay. The time between samples in the FIR. Usually, it is just the TR. If you want to do sub-TR estimation, you can make it less than the TR. It has to be an integer divisor of the TR because it forms the basic "tick" of the clock.
- My experiment design uses jitter - both ITI (i.e., between
trials) and ISI (i.e., between stimulus within a compound event). As i understood, optseq can only supply me with the ITI jitter but no the ISI jitter. is that right? do you happen to know a computerized method to introduce a jitter within a compound event?
That is right. Sorry, don't know of anything that will give you with-in event jitter.
- Is it true that jitter in optseq is made by inserting "NULLS",
and that the DPSD determines the "steps" of the jitter (for e.g., if DPSD equals 1, Nullmin equals 2 and Nullmax equals 4, the NULL events will be 2 3 or 4). Did i understand it right?
Yes.
doug
hope to hear from you soon, Asaf.