We have a section in our experiment where participants are supposed to press left or the right arrow key. We would like to send a marker via parallel port whenever the arrow keys are pressed; left arrow= 5, right arrow= 6. We cant seem to tie the marker signal to the key press i.e. the key press is recognized but no markers are sent via parallel port. We have tried utilizing both getKeys, waitKeys.
Please could you share the code snippet that you are using to send the marker? I think you need a conditional that checks on each frame if a key is pressed and “if pressed” then send trigger.