Millisecond Forums

+x

 

elisegrimm - 11/3/2020

Hello, I have modified the instructions  slightly for the SSRT task.

Could you please let me know whether these will be correct and the trials will run appropriately?

Thank you,

Elise

> Could you please let me know whether these will be correct and the trials will run appropriately?

Correct with respect to what?

+x

 

Dave - 11/3/2020

+x

 

elisegrimm - 11/3/2020

Hello, I have modified the instructions  slightly for the SSRT task.

Could you please let me know whether these will be correct and the trials will run appropriately?

Thank you,

Elise

> Could you please let me know whether these will be correct and the trials will run appropriately?

Correct with respect to what?

In the script, it says that the maxssd should not be above 1250? Have I understood and coded things appropriately? I have not changed anything else besides these parameters . ..

+x

 

elisegrimm - 11/3/2020

+x

 

Dave - 11/3/2020

+x

 

elisegrimm - 11/3/2020

Hello, I have modified the instructions  slightly for the SSRT task.

Could you please let me know whether these will be correct and the trials will run appropriately?

Thank you,

Elise

> Could you please let me know whether these will be correct and the trials will run appropriately?

Correct with respect to what?

In the script, it says that the maxssd should not be above 1250? Have I understood and coded things appropriately? I have not changed anything else besides these parameters . ..

The trials' stimulus timing in the script is as follows:
0: fixation
250: the stimulus (left of right arrow)
Then at 1500ms, i.e. 1250ms after the stimulus, the stimulus is erased and the trial ends. So there is a maximum of 1250ms during which a stop signal could occur. At 1250ms, it would occur exactly when the stimulus is erased and the trial ends, so there's not chance to respond. Whether that makes sense is open for debate. What definitely wouldn't make sense is to have a maximum possible ssd greater 1250ms, i.e. after the trial is already over and the next trial has begun.

I cannot answer whether the parameters have been selected appropriately as I have no information about the reasoning and intentions behind those parameter choices.

+x

 

Dave - 11/3/2020

+x

 

elisegrimm - 11/3/2020

+x

 

Dave - 11/3/2020

+x

 

elisegrimm - 11/3/2020

Hello, I have modified the instructions  slightly for the SSRT task.

Could you please let me know whether these will be correct and the trials will run appropriately?

Thank you,

Elise

> Could you please let me know whether these will be correct and the trials will run appropriately?

Correct with respect to what?

In the script, it says that the maxssd should not be above 1250? Have I understood and coded things appropriately? I have not changed anything else besides these parameters . ..

The trials' stimulus timing in the script is as follows:
0: fixation
250: the stimulus (left of right arrow)
Then at 1500ms, i.e. 1250ms after the stimulus, the stimulus is erased and the trial ends. So there is a maximum of 1250ms during which a stop signal could occur. At 1250ms, it would occur exactly when the stimulus is erased and the trial ends, so there's not chance to respond. Whether that makes sense is open for debate. What definitely wouldn't make sense is to have a maximum possible ssd greater 1250ms, i.e. after the trial is already over and the next trial has begun.

I cannot answer whether the parameters have been selected appropriately as I have no information about the reasoning and intentions behind those parameter choices.

At a minimum, I believe, you'll want to adjust the trialduration to compensate for the longer pretrialpause, so

<parameters>
/ resetpracticessd = false
/ leftkey = "D"
/ rightkey = "K"
/ minssd = 50
/ maxssd = 1250
/ adjustment = 50
/ ssd_start = 300
/ pretrialpause = 750
/ trialduration = 2250
/ waitbetweenblocks = 15
/ p = 0.5
</parameters>