Hi,

I have an interesting problem that I was wondering if you could shed some light on. I'm running an experiment where I'm trying to show a picture for 20ms. Because the refresh rate, this translates into 24-26ms (in the log file). However, and this is the problem -- every once in awhile (one in four participants) this 20ms instead gets converted to what must be three refresh rates and all those trials come up as 35-37ms.

Fortunately it is consistent (once it switches to 35 ms it stays for all trials for that participant). But it IS a problem. Why would the same DirectRT script file give me 25ms sometimes and 35ms (consistently) other times?

To my knowledge no other settings have been changing on the computers to mediate this. This SEEMS to be a DirectRT thing/problem. Anyone encountered this before?

It seems like a problem with the script file interpreter. Sometimes it's interpreted as 2 screen refreshes/frames, and sometimes as 3!!

Regards,
Josh Salmon