Brain imaging can predict the mistakes you are about to make.

From Fountain's review of work by Eichele et al.:

...brain patterns start to change about 30 seconds before an error is committed... changes were seen in two brain networks. One, called the default mode region, is normally active when a person is relaxed and at rest. When a person is doing something, like playing the game, this region becomes deactivated...researchers found that in the time leading up to an error, the region became active again — the subject was heading toward a relaxed state...Another network in the right frontal lobe gradually became less active, the researchers found. This is an area in the brain thought to be related to cognitive control, Dr. Eichele said, to keeping “on task.”

...it might be possible someday to develop a warning system — perhaps by monitoring the brain’s electrical activity, which is more practical — that could be used by people doing monotonous or repetitive tasks. Such a system would alert users when they are heading for a harmful or costly, not to mention mindless, mistake.