Monitor and clarify definition code#

tStart and are therefore possibly all ~one frame rate longer than the actual time (ignoring usb delays)Īs above, that is optional.

Monitor and clarify definition code#

this code which is inserted if one selects “sync RT with screen” in Builder: win.callOnFlip(key_resp_2.clock.reset) # t=0 on next screen flipĭo keyboard/mouse reaction times go from the time of the actual screen onset or do they relate to. If you want to know the precise time at which the first image of a component was displayed, then you should pass some function to be executed in the win.callOnFlip() function. 16 ms after the the scheduled end-time, so the total duration of the stimulus should be correct. tStart of the component, but conversely, the offset of the stimulus will be approx. So yes, the actual screen offset time will be approx. tStart and are therefore possibly all ~one frame rate longer than the actual time (ignoring usb delays)Īs you’ve seen, the code for each component inevitably has to run in an inter-frame interval before the first frame on which that component becomes visible. tStart.Īre there any other quantifiable psychopy related aspects I should consider if I want to get as accurate value for stim onset as possible? (I need this for purposes other than getting a precise keyboard reaction time)Īlso, do keyboard/mouse reaction times go from the time of the actual screen onset or do they relate to. I’ve taken a quick look at the value of win.lastFrameT and for me this is typically ~7us (ie tiny) indicating that actual stimulus onset (ignoring hardware lag in the video card and the monitor itself) is typically close to one frame rate after the value of the.

tStart is actually up to one framerate before the actual onset, so on a 60Hz monitor up to ~16.7ms before actual onset. I’ve had a quick look at the code and it seems that. tStart attribute of your component of interest as providing this information. Regarding ‘knowing’ precisely the time of stimulus onset, at least one other forum posting refers to the.