# Negative Reaction Time

**URL:** <https://discourse.psychopy.org/t/negative-reaction-time/35701>\
**Category:** Builder\
**Created:** [July 12, 2023, 6:22pm UTC](https://discourse.psychopy.org/t/negative-reaction-time/35701 "2023-07-12T18:22:29Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Famsytron](https://avatars.discourse-cdn.com/v4/letter/f/b38774/32.png) [@Famsytron](https://discourse.psychopy.org/u/Famsytron)\
**Post date:** [July 12, 2023, 6:22pm UTC](https://discourse.psychopy.org/t/negative-reaction-time/35701/1 "2023-07-12T18:22:30Z")

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**OS** :MacOS - latest  
**PsychoPy version** : V2022.2.5, latest, 3.1.2, 2023 (my “stable” is on V2022.2.5, but I’ve tried the others based on other people’s forum posts)  
**Standard Standalone? (y/n)** If not then what?: y

**What are you trying to achieve?:**  
Participants should see an ITI fixation cross on the screen for 1-1.5 seconds, then be presented with the stimuli (text - numbers 1-9) for 3 seconds, they are to press P/Q to indicate correct/incorrect match (2-back paradigm).

What is happening however, is that the reaction time recorded for the P/Q response can be negative (i.e., recorded during the ITI presentation), and the 3 second keyboard recording window is actually 3 minus the ITI time, even though the stimuli number is still on the screen for a full 3 seconds.

**What did you try to make it work?:**

- Tried $iti.status==FINISHED (doesn’t work, incorrect media, simply throws an error as our ITI is a code snippet and the cross that is paired with it is text stimuli)

- Tried starting the keyboard response to be when the text stimuli is presented and all other possible duration/time/condition combinations, none of them work. They all continue with negative times, no keyboard recording at all, or positive numbers - but these numbers are recorded during the ITI.

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**Author:** ![JensBoelte](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/jensboelte/32/9060_2.png) [@JensBoelte](https://discourse.psychopy.org/u/JensBoelte)\
**Post date:** [July 19, 2023, 7:38am UTC](https://discourse.psychopy.org/t/negative-reaction-time/35701/2 "2023-07-19T07:38:07Z")

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Hello,

do you mind showing us the relevant experiment flow?

Best wishes Jens