In a study published today in the Proceedings of the National Academy of Sciences, researchers used fMRI machines to record neurological patterns preceding careless errors.via Wired
The recordings revealed a cascade of shifting activity in the parts of the brain associated with focusing attention and maintaining routines. Researchers observed test subjects' minds going on autopilot up to half a minute before the subjects actually made mistakes, even though the subjects weren't aware of their own lapses of attention.
Up to 30 seconds before Eichele's test subjects carelessly said that an arrow pointing in one direction was pointing in another, blood flow decreased in their posterior medial frontal cortex, a brain region associated with sustaining effort and focus.
At the same time, activity increased in the so-called default mode network -- a region of the brain spanning the precuneus, retrosplenial cortex and anterior medial frontal cortex. The default mode network is associated with maintaining baseline routines, and tends to be most active during sleep and sedation.
In short, the conscious brain started to shut down while the system usually responsible for preventing that failed.