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How to have stimulus remain on screen during presentation of video

pjotre — Sun, 03 Jul 2016 14:35:58 GMT

Hi,

I'm quite new with INQUISIT ad, have problems with a stimulus that is presented on screen and needs to remain on screen during presentation of a .gif-video.

Here's how I do it:

<text STIM>
/ numitems = 1
/ items = "STIMULUSNAME"
/ fontstyle = ("Arial Black", 18pt, false)
/ txbgcolor = (0,0,0)
/ txcolor = (255,255,255)
/ erase = false
</text>

<picture up_pic>
/ numitems = 1
/ items = ("up.bmp")
/ position = (50%, 70%)
/ erase=false
</picture>

<video up>
/ items = ("up.gif")
/ position = (50%, 70%)
</video>

<trial up>
/ pretrialpause = 100
/ validkeys = (200)
/ correctresponse = (200)
/ stimulustimes = [0=up_pic;500=STIM]
/ branch = [trial.up_B1]
/ beginresponsetime = 500
</trial>

<trial up_B1>
/ stimulustimes = [0=up]
/ posttrialpause = 100
/ responseinterrupt = trial
/ recorddata = false
/ timeout = 1000
</trial>

Problem is: stimulus is erased as soon as video begins.

Of course I can change stimulusframes so that the stimulus is presented again:
/ stimulustimes = [0=up,STIM]
but then I have a flicker problem.
Is there any solution for this?

RE: How to have stimulus remain on screen during presentation of video

Dave — Sun, 03 Jul 2016 14:35:58 GMT

I am unable to reproduce this. I'm using the attached code (derived from the excerpts in your initial post) and the latest Inquisit 4 Lab version available from https://www.millisecond.com/download/. When sized and positioned such that the <text> and <video> stimuli do not overlap, the static text stimulus remains visible during the presentation of the video (an animated gif) as expected for me.

(1) If your Inquisit 4 installation is not up to date, please update.
(2) If the issue persists, please provide the image and gif files you are using (you can attach files to a post via +Insert -> Add File). Please also report your operating system type and version.
(3) If the issue persists, could you please check and report if the result is identical when using a different video format (e.g. mpg instead of an animated gif).

Thanks.

RE: How to have stimulus remain on screen during presentation of video

pjotre — Sun, 03 Jul 2016 11:05:24 GMT

Hi Dave,

Thank you for your answer.

If I understand correctly I should try to put the static word stimulus in a different area than the video.
However, the video and the word stimulus now already appear in a different place.
The word is in the center of screen and the video is at (50%,70%)
Just to try, I changed the video so that it was smaller: /size =5%,5% (and definitely should not be in the same place) and it didn't change anything.
Also changing the location of video to (50%,90%) didn't change the fact that the word still disappeared when video appeared.
Is there another way to put the word stimulus in a different area than the video?

Thanks,

Pieter

RE: How to have stimulus remain on screen during presentation of video

Dave — Sun, 03 Jul 2016 08:59:53 GMT

Displaying a video means constantly re-drawing the screen area occupied by the video. Hence any static stimuli also occupying that same area will be overwritten / disappear as soon as the area is redrawn for the video for the first time.

Two options:
(1) Display any static stimuli *outside* of the screen area occupied by the video. Those sections of the screen will not have to be redrawn constantly and any static stimuli will remain visible.
(2) If you need to display some kind of stimulus *on top* of the video, your only option is to have that stimulus be a video as well (not a static <text> or <picture> stimulus). Then both the video in background and the video on top of it will be re-drawn and the stimulus will remain.

Hope this helps.