Combine Stim/Response

Discussions
1

Hello,

I have four conditions in my study. S1A, S1W, S2A, S2W. I need to change the S2A to be either S2AA when it is preceded by S1A or to S2WA when it is preceded by S1W. Then I need to do the same with S2W. I am attempting to use the [B]Events>Combine Stim/Response[/B] process to accomplish this, but I can’t figure out the proper code to make it work. Does anyone have experience with the proper format of the code for the Combine Stim/Response?

Cheers,

Tim

2

For example, I tried putting the following: “S2A_S1AS2A, S1A, S2A”, but it yielded the error “[proccess_evt_combine] Events > stim/response Invalid combinations format”.

I am having a hard time making sense of the instructions which are as follows:
Process options
Example: We have ones stim (A) and two responses (B and C).
We want to create two new pairs of event categories:
[B]A_AB:[/B] Event A (followed by B)
[B]A_AC:[/B] Event A (followed by C)
[B]B_AB:[/B] Event B (preceded by A)
[B]C_AC:[/B] Event C (preceded by C)
For that, we use the following classification:
[B]A_AB, B_AB[/B], A, B
[B]A_AC, C_AC[/B], A, C
To prevent one category to be created, use “ignore”. Example:
A_AB, [B]ignore[/B], A, B
To create an extended event AB between A and B, use “extend”.
AB, [B]extend[/B], A, B
You may add as many combinations as needed, one per line.

3

Hello,

Indeed, you should be able to do this with the process “Events>Combine Stim/Response”, with the syntax:
ignore, S2AA, S1A, S2A
ignore, S2WA, S1W, S2A
ignore, S2AW, S1A, S2W
ignore, S2WW, S1W, S2W

Let’s explain the first line, it means:

  • detect the succession of two events S1A and S2A
  • create one new event S2AA to replace the detected event S2A
  • leave the S1A event unchanged

Note that this process creates new events, it does not replace the existing ones.

Cheers,
Francois

4

Hey Francois,

Thank you very much for this explanation! I now understand the meaning of the coding much better. When I implemented the code above, it ran and didn’t generate an error message. But it also didn’t produce any changes. It didn’t create the new event markers. Not sure why. I will keep working on it and post if I am able to solve it.

Tim

5

Make sure that the duration between your events is shorter than the input parameter “Maximum delay between grouped events”.
And start by simpler tests, with just one line and without “ignore”. For instance: “Test1A, Test2A, S1A, S2A”