E-Prime and iView X not matching reaction times

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Memory Development Lab at UNCG

April 10, 2014 20:36

Hello all,

We use E-Prime with our SMI eyetracker (software iView X).

We are running into a problem where the RT in the E-Prime data file is not matching the end time of the target trials in BeGaze (an analysis program to look at iView X eye data).

I attached an image of our E-Prime experiment structure. As you can see, we have the "Start Recording" package call AFTER the "Delay" image screen (a blank screen where participant waits for the target image) but before the TargetRet image screen (our target image). This TargetRet image stays until the participant makes a response. We want the eyetracker to only record the start and end of the TargetRet image. However, when we look at the iView X screen, we see that the program starts recording immediately when the Delay screen appears.

Does anyone know how to tweak the program so that it records only the TargetRet and not the Delay image? We do not understand why the eye-tracker is starting the recording before we call it to. Does anyone have experience with this problem? Any help would be greatly appreciated!

Retrieval Code.jpg

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  David Nicholson April 15, 2014 16:25

  Hello,

  This issue is most likely caused by PreRelease on the Delay ImageDisplay being set to "same as duration". Please see KB2304 - INFO: Using PreRelease to Maintain Millisecond Timing and KB2627 - FEATURE: PreRelease defaults changed to promote better timing accuracy.

  I hope this helps

  -David

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  David Nicholson October 19, 2015 20:26

  Hello,

  Open Codec Config through the Start menu or through E-Studio's Tools menu. Select "Create Default Mappings" from the Codec Config Tools menu, then click the first option button. This will set up the mappings that are most likely to work on your machine. Next, select Render File... from the File menu, find one of your audio or video files and click Open. If you receive errors, please try rendering it again until you see only warnings or success.

  Note that you only need to render one video file of each type (e.g. avi, wmv, etc.) However, if you encode two avi files differently, you would need to render them both.

  I would also make sure that you are using the correct sound API (4347 - INFO: Sound Latency - Windows Vista / Windows 7 (and beyond)).

  If you want very low latency sound, I recommend using Chronos.

  If you need additional assistance, I recommend creating a web support request.

  -David

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