Calibrate opensesame frames to monitor

Nottchris

Good morning,

I hope you can be of some assistance. I am creating a visual experiment that presents words rapidly (23, 35, 47ms; multiples of 85hz). I want to be sure that these words are being presented at the set variable durations. I've set my monitor to 85hz and have set durations of other screens (sketchpads etc) to multiples of 85hz. How can i be sure that these durations are being presented at the set timings?

Best wishes,

Roelof

Hi Nott,
Your set up seems like a good start, in order to find out the duration of the sketchpads make sure to use the timestamps for each sketchpad and check the total duration by subtracting the time stamp of sketchpad2 from sketchpad1.
There are a lot more things involved in getting the timing to work out accurately in all situations, for example if you want yout timing to be 47ms make sure to set the actual duration a bit lower since these duration are rounded up.
It might be worthwhile to check out the following pages:
http://osdoc.cogsci.nl/3.1/manual/timing/
http://docs.expyriment.org/Timing.html#visual

Good luck, let us know if you have any other questions,
Roelof