Millisecond Forums

avoid flicker between (response) trials

https://forums.millisecond.com/Topic23972.aspx

By juliane_d - 3/7/2018

Hi there,

I am programming an approach-avoidance task in which participants receive visual response feedback - e.g. the background image and stimulus size changes to create the impression of approaching or dtsiancing themselves from the stimulus (by moving within a virtual room)
Unfortunately, the beginning of each trial always comes with a short flicker which highly disturbs the desired visual illusion. this seems to only happen, when i use an image for the background, not when I use shapes defined within inquisit, so it may be related to the loading time of the image (?).
Any idea what I can do to avoid this?

Many thanks!
Juliane
By Dave - 3/8/2018

juliane_d - Thursday, March 8, 2018
Hi there,

I am programming an approach-avoidance task in which participants receive visual response feedback - e.g. the background image and stimulus size changes to create the impression of approaching or dtsiancing themselves from the stimulus (by moving within a virtual room)
Unfortunately, the beginning of each trial always comes with a short flicker which highly disturbs the desired visual illusion. this seems to only happen, when i use an image for the background, not when I use shapes defined within inquisit, so it may be related to the loading time of the image (?).
Any idea what I can do to avoid this?

Many thanks!
Juliane

This sounds like some of your stimulus elements displayed during the trial is not set to /erase = false, thus causing the flicker.
By juliane_d - 3/8/2018

Dave - Thursday, March 8, 2018
juliane_d - Thursday, March 8, 2018
Hi there,

I am programming an approach-avoidance task in which participants receive visual response feedback - e.g. the background image and stimulus size changes to create the impression of approaching or dtsiancing themselves from the stimulus (by moving within a virtual room)
Unfortunately, the beginning of each trial always comes with a short flicker which highly disturbs the desired visual illusion. this seems to only happen, when i use an image for the background, not when I use shapes defined within inquisit, so it may be related to the loading time of the image (?).
Any idea what I can do to avoid this?

Many thanks!
Juliane

This sounds like some of your stimulus elements displayed during the trial is not set to /erase = false, thus causing the flicker.

that was it!
thanks for the quick help!!!
By anon8127365 - 12/6/2020

I know that the problem was already solved, but it did not work for me (Using inquisit 5), so I tried some stuff out and it turns out that if you do this that it fixes the problem completely. 
<trial x>
/ stimulusframes = [
1 = firststim
1 = secondstim
1 = thirdstim
]
</trial>

Just wanted to post this in case the previous answer did not work (I am super new at this, so it may be that this is really obvious, but I posted just in case).