Loop counter variable - Opensesame

Comments

• Dion

  June 2019

  Hi Kian,

  Assuming you have an experimental loop with a sequence called "trial_sequence", you should have an OpenSesame variable called "count_trial_sequence" which keeps track of the current trial sequence iteration. Note that the counter starts at 0.

  You can set whether or not a script runs through the controls by going to the sequence and setting the “Run if” field:

  [count_trial_sequence] > 0

  
  

  Alternatively, you can also edit it through the script using (don’t forget to hit “Apply and close”). In this example, sketchpad_1 always runs and sketchpad_2 only runs after the first trial:

  run sketchpad_1 always

  run sketchpad_2 "[count_new_sequence] > 0"

  
  

  For slightly more complex conditions, it is easier to use Python. You can use Python in an OpenSesame script by starting the condition with an equals sign and access OpenSesame variables using exp.get(). For example, to only run a script during the first and third trial:

  =exp.get('count_new_sequence') in (0, 2)

  Or in the Opensesame script like:

  run sketchpad_1 "=exp.get('count_new_sequence') in (0, 2)"

  
  

  For more info on OpenSesame variables and using them, see: https://osdoc.cogsci.nl/2.9.3/usage/variables-and-conditional-statements/

  Hope this helps,
• Kian

  July 2019

  Thank you very much @Dion.

  Very helpful :)