Hi Jason,
Attached is the input file with the practice trials. As you will see, on trial 4, if letter L (code 38) is pressed, a participant skips to trial 5. Otherwise, trial 4 continues and they have to press letter L again; after two mistakes they move on to trial 5 anyway. The key trials here are 9 through 13. I want trial 9 be displayed only if the participant made two mistakes on trial 4 - that is, he/she failed to press letter L on trial 4 twice in a row. However, if the participant did not make a mistake or made only one mistake, I want to skip trial 9. The same association would be between trial 5 and 10, 6 and 11, 7 and 12, as well as 8 and 13. I hope that makes sense.
Thank you in advance for your help.