Mistakes can be predicted by patterns of brain activity
Boring jobs switch our minds to autopilot, say scientists - and it means we can seriously mess up some simple tasks.
Monotonous duties switch our brain to "rest mode", whether we like it or not, the researchers report in Proceedings of National Academy of Sciences.
They found mistakes can be predicted up to 30 seconds before we make them, by patterns in our brain activity.
The team hopes to design an early-warning brain monitor for pilots and others in "critical situations".
The scientists say the device would be particularly suitable for monotonous jobs where focus is hard to maintain - such as passport and immigration control.
"We might be able to build a device (that could be placed) on the heads of people that makes these easy decisions," said Dr Eichele, of the University of Bergen, Norway.
"We can measure the signal and give feedback to the user that your brain is in the state where your decisions are not going to be the right one."
Headsets could be designed to offer "early warning" of mistakes
In the study, Dr Eichele and his colleagues asked participants to repeatedly perform a "flanker task" - an experiment in which individuals must quickly respond to visual clues.
As they did so, brain scans were performed using functional magnetic resonance imaging (fMRI).
They found the participants' mistakes were "foreshadowed" by a particular pattern of brain activity.
"To our surprise, up to 30 seconds before the mistake we could detect a distinct shift in activity," said Dr Stefan Debener, of Southampton University, UK.
"The brain begins to economise, by investing less effort to complete the same task.
"We see a reduction in activity in the prefrontal cortex. At the same time, we see an increase in activity in an area which is more active in states of rest, known as the Default Mode Network (DMN)."
This is not a sign of the brain going to sleep, says Debener.
"Autopilot would be a better metaphor," he explains. "We can assume that the tendency to economise task performance leads to an inappropriate reduction of effort, thus causing errors."
Device could help pilots and air traffic controllers maintain focus
Since this state begins about 30 seconds prior to a mistake being made, it could be possible to design an early-warning system that alerts people to be more focused or more careful, said the researchers.
That could significantly improve workplace safety and also improve performance in key tasks, such as driving, analysis of X-rays, or airport security screening.
But MRI scanners are neither portable enough nor fast enough to be practical for these real life scenarios, so the next step is to see if more mobile EEG devices are able to detect the phenomenon.
A prototype of a wireless, mobile, and lightweight EEG amplifier is currently in development and could be ready for the market in "10 to 15 years", says Dr Debener, who is based at the MRC Institute of Hearing Research, at Royal South Hants Hospital.
"But first, we must establish what is causing these mistakes," he adds.
"We do not know whether the change in brain activity we see has a causal link to the mistakes. After we establish that, we can try to develop monitoring devices."