Changing trigger number for varying stimuli in builder

Builder
1

I am very happy about getting mor involved in using Psychopy, but I struggle a bit. I just got a new brain vision EEG system (from brain products) including a triggerbox that connects my stimulus laptop with the amplifier and recording laptop.
What I want to do is the following: I conduct ERP studies. My first experiment includes 3 word conditions (my, his, a), each word being randomly presented for 500ms and 40 times. Each word presentation is to be identified by study participants. Finally, what I need to calculate ERPs out of raw EEG data are triggers that code for kind of word (a, my or his) and the answer (button press: correct or incorrect).
Now, I know that creating an excel sheet is the basis for psychopy to know what words exist and what answers are correct, but can this this sheet also include a column with condition-dependent trigger codes that psychopy’s builder can read in somewhere?
If this is possible, how and where do I load the excel sheet in so that psychopy correctly understand and uses different trigger numbers for the randomly presented different words?

Any help would be so much appreciated. I love psychopy and I really want to become a skilled user of it.

Cheers,
Peter

2

Hi I am currently trying to figure out how to solve the same problem - did anyone figure it out yet?

3

The table which you connect to a loop creates variables with the name of each column, and on each iteration of the loop the values of these variables are taken from a row of the table (according to the randomisation option you choose in the loop). Because it’s an entire row at a time, if you want to send a specific trigger when the stimulus is a specific word, you just need to add a column of these triggers and make sure the values in each row match. For example, with the table:

stim_word eeg_trigger
a 1
my 2
his 3

You could set the stimulus text to be $stim_word and the trigger’s value to be $eeg_trigger and the two would always be matched together such that when stim_word is a, eeg_trigger is 1.