Naming Error when Trying to do Counterbalancing/Branched experiment

Builder
1

OS (e.g. Win10): Win10
PsychoPy version (e.g. 1.84.x): v2022.1.1
Standard Standalone? (y/n) Y
What are you trying to achieve?: I’ve just started tinkering around with Psychopy today and I want to construct a task with two different counterbalancing conditions. I want participants to only see one of the conditions based on keyboard input by the experimenter. I’m using this tutorial released by Psychopy as basis: How to Make Branched Experiments in PsychoPy: An Example using Consent forms - YouTube

What did you try to make it work?:
I have two conditions placed in separate loops.

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In the showCounterbalance properties for both conditions I have assigned the nreps option to be a variable:

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Prior to these conditions, I have a routine where I ask for input, whether 1 or 2 depending on which counterbalancing condition is wanted.

I then use this input to assign values to the nreps variables in code

if counterbalance_input.keys == 1:
  nReps_A = 1
  nReps_B = 0
  
elif counterbalance_input.keys == 2:
  nReps_A = 0
  nReps_B = 1

The code should assign one of the ‘nReps’ to be 0, thereby suppressing the corresponding condition.

What specifically went wrong when you tried that?:

I’m getting a naming error:

showCounterbalance1 = data.TrialHandler(nReps=nReps_A, method=‘random’,
NameError: name ‘nReps_A’ is not defined

I’ve checked many times through that the names are consistent in the code and in the properties section. Any insight into what might be happening? Thank you.

2

Which tab of the code component have you put your code in? Does it work if you provide some “initialization” of the variable in the begin experiment tab?

e.g.

nReps_A = 0
nReps_B = 0

Thanks,
Becca

3

Hi Becca,

I have a routine called ‘Counterbalancer’ right at the start of the experiment where I’ve put the code in and I put the code itself into the End Routine tab.

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I’ve tried your suggestion, typing nReps_A = 0 and nReps_B = 0 in the Begin Experiment tab, but all that does now is assign both variables to be 0 and neither condition runs when I start the experiment. Psychopy does not seem to be taking the input from the End Routine code. Is there anything else I could try? Thank you!

4

Put the 1 and 2 in quotes. Keys are strings

5

This worked, thank you!