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Forum Member
 
Group: Forum Members
Last Login: 7/30/2007 6:06:51 PM
Posts: 25,
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| Hello, My intended Onset-Onset is 300 (Duration = 300) , yet it gives me an Onset-Onset of 301... So, I tried making the Duration one or two second(s) shorter (Duration = 299, or Duration = 298), yet it still gives me an Onset-Onset of 301 ! Is this a result of the refresh rate of the monitor ?
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Forum MVP
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Last Login: Yesterday @ 10:30:44 PM
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| My first suspicson would be yes. If you are sync with the vertical blank (default), then no matter what you type in for the duration, the onset to onset will always be divisible by the refresh rate and thus the recommendation that durations be entered as divisible by the refresh rate. Knowing the refresh rate would make things more clear. Assuming 60 hz, then 301 ms would be nearly exactly 18 refreshes. Please note that onset to onset is not the exact same as "time on screen" because a) if the 2nd stimulus does not actually clear (because say the 2nd object paints a 1x1 pixel no where near the stimulus) it then the stimulus would still be there and b) if you are not using a CRT then the rise and fall time could be up to 40ms plus or minus. -Brandon
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Forum Member
Group: Forum Members
Last Login: 7/30/2007 6:06:51 PM
Posts: 25,
Visits: 36
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| Thank you. I'd also like to know what is a "CRT". Have a good day, Guillaume
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Forum MVP
Group: Administrators
Last Login: Yesterday @ 10:30:44 PM
Posts: 549,
Visits: 1,198
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