My participants are learning a sequence of key responses. They overlearn the sequence and correctly respond preemptively, so that their correct response is not recorded during the corresponding trial, because it was too early. This results in a loss of data in the form of correct responses and reaction times.
I am experimenting with using the "all keys" option. Unfortunately, when I am dealing with thousands of trials wherein dozens may belong to this category of 'correct, but early', it will be really time-consuming to go through and manually score correct responses that occurred 80 ms too soon.
Is there some way to make the 'begin' value in a key response component have a negative number, or to achieve a similar effect using a different strategy?