On 7/29/16 3:17 AM, 連 志浩 wrote:
Hello all,
I'm a new user of Optseq2, and I have 2 questions about optseq2 after I got some sequences and read Dale (1999).
I'll be grateful to anyone can provide help.
- I'm curious about why optseq2 arranged the order of conditions,
does anyone can provided some references to me?
Dale (1999) just discussed about mean ISI and fixed/randomizes ISI design, I wonder what's the difference if I just keep the duration order of null condition (jitter) and randomly present different conditions.
It tries a bunch of random orders until it finds one that is optimum in terms of efficiency (you can also specifically optimize with respect to counter balancing, use the --focb switch; I usually choose 100 for n). With jittering (instead of a fixed ISI), you get more temporal randomization (ie, differential overlap between adjacent events).
- This question is about the total duration of experiments. I'm used
to execute experiments by E-Prime 2.0, and the presentation may delay in E-Prime (I know this situation can be deal with "Pre-release"). If there's a fixation period (15s) after my trials is over (but participants are still scanned), and the delay just affect the duration of the fixation period. Should I reduce the duration of delayed stimulus in terms of the delayed time? Or I don't need to care about the delay, because the key point is the order of conditions and null/jitter?
I'm not sure what you mean. How can it be a delay if it is after the trial is over?
Thanks for your reading.
Best regards,
Chih-Hao
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