Millisecond Forums

Editing Trial Duration

https://forums.millisecond.com/Topic20098.aspx

By liznik - 11/11/2016

Hey, I know this is a pretty basic question but I was wondering how to add specific timing within a trial. 

I want to show a fixation for 1s and then a image for 1s, once it disappears I want to get the subject to respond to it (but there is no duration for how long they can take to respond).  I'm not sure what type of parameters/attributes I need to add to the trial element to make that happen. 
By Dave - 11/11/2016

liznik - Friday, November 11, 2016
Hey, I know this is a pretty basic question but I was wondering how to add specific timing within a trial. 

I want to show a fixation for 1s and then a image for 1s, once it disappears I want to get the subject to respond to it (but there is no duration for how long they can take to respond).  I'm not sure what type of parameters/attributes I need to add to the trial element to make that happen. 

You display the fixation stimulus at t=0; you then display the picture stimulus at t=1000; at t=2000, you overwrite the picture with a blank shape (cf. the "How to erase stimuli" topic in the Inquisit documentation).

<trial sometrial>
/ stimulustimes = [0=fixation; 1000=picturestimulus; 2000=erasepicturestimulus]
...
</trial>

By default, Inquisit starts accepting responses once the stimulus presentation sequence has been completed, i.e. once the picture is overwritten / erased at 2000ms, which is what you want here. If no /timeout or /trialduration is specified, the participant has as much time to respond as s/he wants.