Multitasking Interferes With Brain Activity Temporal Continuity


Previous research has shown that multitasking – performing several tasks at the same time – reduces productivity by as much as 40 percent. Now a group of brain imaging researchers has found that changing tasks too frequently interferes with brain activity.

The study may explain why the end result is worse than when a person focuses on one task at a time.

The team used functional magnetic resonance imaging to measure different brain areas of 18 research participants while they watched short segments of the Star Wars, Indiana Jones and James Bond movies, said professor Iiro Jääskeläinen of Aalto University in Finland.

Cutting the films (Star Wars: Episode IV — A New Hope, Indiana Jones: Raiders of the Lost Ark and Golden Eye) into segments of approximately 50 seconds fragmented their continuity. In the study, the subjects’ brain areas functioned more smoothly when they watched the films in segments of 6.5 minutes.

Brain Efficiency And Overloading

The posterior temporal and dorsomedial prefrontal cortices, the cerebellum and dorsal precuneus are the most important areas of the brain in terms of combining individual events into coherent event sequences. These areas of the brain make it possible to turn fragments into complete entities.

According to the study, these brain regions work more efficiently when it can deal with one task at a time.

Jääskeläinen recommends completing one task each day rather than working on a dozen of different tasks simultaneously:

“It’s easy to fall into the trap of multitasking. In that case, it seems like there is little real progress and this leads to a feeling of inadequacy. Concentration decreases, which causes stress. Prolonged stress hinders thinking and memory."

The neuroscientist also sees social media as a challenge.

“Social media is really nothing but multitasking, with several parallel plots and issues. You might end up reading the news or playing a game recommended by a friend. From the brain’s perspective, social media only increases the load,” he said.

Lahnakoski, J. M., Jääskeläinen, I. P., Sams, M. and Nummenmaa, L. (2017)
Neural mechanisms for integrating consecutive and interleaved natural events
Hum. Brain Mapp.. doi: 10.1002/hbm.23591