Arnau et al. (2020) have investigated how mental wandering is reflected in the brain, which usually not only reduces one’s performance but can also be dangerous in risky work. It was suspected that the measurement of alpha activity in the brain is a good indicator of mental wandering. Alpha activity is one of five frequency ranges in which brain activity is measured by electroencephalography, which is predominantly seen when a person’s attention is focused inward.
In the experiment, subjects were given two different simple and rather monotonous tasks in blocks on the computer, but were asked at random times between task blocks whether they were currently concentrating or not. In the absence of concentration, the three most recently completed task blocks were rated as having been completed under digression. This showed that those subjects whose thoughts were absent from the tasks made significantly more errors. However, this had no influence on the reaction time in the tasks, which was also recorded.
Basically, all subjects were faster when they had to solve the same task in one task block as in the previous one. The alpha activity was particularly increased between the task blocks in which the test subjects had digressed mentally.
Tip: If you are unable to concentrate during a task, you should briefly note on a piece of paper where your thoughts stray. Then you can often turn to the actual task again without being disturbed.
Literature
Arnau, S., Löffler, C., Rummel, J., Hagemann, D., Wascher, E. & Schubert, A.?L. (2020). Inter?trial alpha power indicates mind wandering. Psychophysiology, doi:10.1111/psyp.13581.