Display calculated variables to subject

I'm working on a program right now where participants will be required to type in a random letter string (6 letters). Ideally, any letter they mistype would trigger an error event (e.g., a sound and a red x). I don't think this can be done, but I am willing to do without the error event. Please correct me if I'm wrong, though :).

However, what is really important, is that participants are presented with their RT to entering the entire letter string. If this RT is higher than the average RT (which would need to be constantly updated/calculated), it is displayed in red; if it is lower than the average RT, it is displayed in green. Is this possible? I've tried messing around with the feedback parameter, but with no luck. This parameter seems to only report a single key-press.

Maybe it would be better to do this in Medialab?


Thanks for any help or suggestions you may have
-Kirk

Sounds like a job for MediaLab. You could use calculated values and variables from the Advanced Features and because of the nature of the task (entering 6-letter strings), I don't think the RT error will hurt your power too much. Feel free to cross post this in the MediaLab how-to area for any questions you have on using the advanced features.