Some of the variable's started time are missing

Hello. I 've been trying to fix the Stop Signal task and constantly finding some missing time in the csv. ouput file.

I need left/right_image_started time and stop_image started time to calculate the stop signal time delay, which is essential part in my experiment. but as you can see in the pircture, there are some time not recorded at all.

what could be the issue?

the pic below is my GUI where i sturctured my experiment.

if anyone got any idea, please share some.

thank you.

Are you controlling their onset with the code elements? That can sometimes mess with recording the start times because the builder code looks for an update to a status property, which code elements don’t necessarily touch. Alternately, are those trials in which those elements are not presented?

1 Like

yes the onset time is controlled by the code because the start time needs to be updated based on how participants react to the stop stimuli. (for example, if they respond, the onset time in next trial would be 50 ms later, if they don’t respond, it would be 50 ms faster) the picture below is the snippet of the code. And the start time are not recorded even when the stimuli are presented so i don’t think the latter one is the case.

That doesn’t look like the whole story.

I assume current_SSD is the stop_image_right and sound_1 start time. What happens is key_resp.keys isn’t None?

Are there any issues with Current_SSD or Next_SSD in the data file?

You are right. if the key_resp.keys is not None, the current_SSD becomes 50 ms faster like the picture below.


I uploaded the relative files for the better understanding.
938912_SST_v2_2025-03-27_13h08.24.428.csv (19.1 KB)
SST_test_v4.psyexp (146.8 KB)
Thanks