Millisecond Forums

Inquisit will pick the closest possible value (i.e. frame) to the times you entered, i.e. stimuli might be shown a little earlier or later than the specified time. Stimuli falling within the same frame by that logic will effectively be presented at the same time. I suggest you generate some test data and inspect the stimulusonset columns closely.

Hope this helps,

~Dave

Thanks Dave - I assumed this is probably what it would do, and just pick the closest frame. However, when I run test data, the stimulus onset columns all tend to say zero, which is somewhat confusing. Any ideas (without me posting my whole code) if there's something obvious I might be doing wrong that might be causing this not to record?

I am therefore struggling to work out whether the very short stimuli gets presented at all - especially as they are all centred around the same spot, so I suspect if it is trying to display two at the same time then one will be overwritten by the other anyway?

Thanks

Sarah

Not sure about the prevalence of 0s in your stimulusonset columns. Normally, you should have one such column for every stimulus element displayed in a given trial with the value reflecting the time in ms when Inquisit initiated the display of the respective stimulus (measured from the onset of the trial). You might want to check if your version of Inquisit is up-to-date and do the same for your graphics system (driver, DirectX, etc.). BTW, related timing questions have been discussed at greater length in these threads (beware partly technical reading):

• http://www.millisecond.com/forums/Topic3649.aspx#3649


• http://www.millisecond.com/community/forums/p/1224/3664.aspx#3664


• http://www.millisecond.com/community/forums/p/1443/4797.aspx#4797

If the stimuli indeed end up being displayed in the same frame (do the math), then the ones on the "bottom" (i.e. listed first) will effectively not be displayed.

~Dave