Hugh Pickens writes: "Researchers report that brain activity can be used to predict the likelihood of someone making an error about six seconds in advance, with gradual changes starting as much as 30 seconds ahead of time. The team used an imaging machine to scan the brains of a group of volunteers who performed a task in the presence of distracting information. When performing correctly the volunteers' brains showed increased levels of activity in those parts associated with cognitive effort, as would be expected. However, these areas gradually became less active before errors were made and at the same time another set of regions in the brain became more active. These regions are part of a so-called "default mode network" and show increased used when people are resting or asleep (pdf). While imaging machines are far too big and complex to be used in workplaces to monitor the brain activity of people engaged in important tasks, the team hopes to correlate errors to changes in electrical activity in the brain with electroencephalography (EEG), using electrodes placed on the scalp. If EEG features can be found that correspond to the change in brain activity, then a hat that gives warning of an imminent mistake might one day become reality."