help recording participant response

I have created an experiment where the participant has 3.5 seconds to respond, and the next event will not be presented until after that time period is up. When I ran the experiment, I saw that if a participant responded twice in that time period, both responses would be recorded. Is there a way to set it up so that the event ends only after 3.5 seconds has passed, but only one response will be recorded during that time period?

During the 3.5 millisecond time limit, SuperLab will record all the responses until the correct response is pressed. Then, it will stop recording further key presses and wait until the time limit elapses.