Millisecond Forums

present trials with audio of differing lengths without collecting a response

https://forums.millisecond.com/Topic23818.aspx

By angela_grant - 2/2/2018

Hello,

I'm relatively new to Inquisit, so pardon me if this is a naive question. I am programming a script for an EEG study where participants will have to listen to audio files, which all vary in their length because the sentences are unique on each trial. We will be recording EEG and motor movement contaminates the signal, so we want to keep responses to only a subset of the trials. However, what we have found so far is that there doesn't seem to be a way to code for the trial to end after the audio file finishes without including a specified timeout or a valid response. 

Here's an example of what our trial code looks like, but with a spacebar response, as we can't get it to work without a response.

<trial french_unassociated2>
/ frames = [1=fixation, french_unassociated2, trigger_fr_unas]
/ validresponse = (" ")
/ posttrialpause = 1000
</trial>

I'd like to avoid having to create individual trials for each stimulus, so if you have a better solution, I would appreciate it.

Thank you,
Angela
By Dave - 2/2/2018

angela_grant - Friday, February 2, 2018
Hello,

I'm relatively new to Inquisit, so pardon me if this is a naive question. I am programming a script for an EEG study where participants will have to listen to audio files, which all vary in their length because the sentences are unique on each trial. We will be recording EEG and motor movement contaminates the signal, so we want to keep responses to only a subset of the trials. However, what we have found so far is that there doesn't seem to be a way to code for the trial to end after the audio file finishes without including a specified timeout or a valid response. 

Here's an example of what our trial code looks like, but with a spacebar response, as we can't get it to work without a response.

<trial french_unassociated2>
/ frames = [1=fixation, french_unassociated2, trigger_fr_unas]
/ validresponse = (" ")
/ posttrialpause = 1000
</trial>

I'd like to avoid having to create individual trials for each stimulus, so if you have a better solution, I would appreciate it.

Thank you,
Angela

The way to do this is to set the <sound> or <video> element's /playthrough attribute to true and give the <trial> a short /timeout or /trialduration. That will lead to (1) playing the audio or video being played in full, and (2) the trial terminating automatically once the audio or video is over.
By angela_grant - 2/5/2018

Dave - Friday, February 2, 2018
angela_grant - Friday, February 2, 2018
Hello,

I'm relatively new to Inquisit, so pardon me if this is a naive question. I am programming a script for an EEG study where participants will have to listen to audio files, which all vary in their length because the sentences are unique on each trial. We will be recording EEG and motor movement contaminates the signal, so we want to keep responses to only a subset of the trials. However, what we have found so far is that there doesn't seem to be a way to code for the trial to end after the audio file finishes without including a specified timeout or a valid response. 

Here's an example of what our trial code looks like, but with a spacebar response, as we can't get it to work without a response.

<trial french_unassociated2>
/ frames = [1=fixation, french_unassociated2, trigger_fr_unas]
/ validresponse = (" ")
/ posttrialpause = 1000
</trial>

I'd like to avoid having to create individual trials for each stimulus, so if you have a better solution, I would appreciate it.

Thank you,
Angela

The way to do this is to set the <sound> or <video> element's /playthrough attribute to true and give the <trial> a short /timeout or /trialduration. That will lead to (1) playing the audio or video being played in full, and (2) the trial terminating automatically once the audio or video is over.

That worked, thank you!