Multitasking performance stems from the speed of information exchange between inner and outer regions of the brain, according to new research in eNeuro.

Doing two things at once courts disaster, as multitasking requires outer cortical brain regions to rapidly communicate with each other. The speed of this information exchange limits multitasking capability yet can improve with practice. But that's not the whole story: multitasking also depends on the striatum, a previously overlooked region deep inside the brain.

Garner et al. compared the brain activity of 100 healthy adults before and after a week of multitasking practice. The participants completed two different tasks, first separately and then at the same time.

The putamen—a brain region in the striatum involved in habitual behavior—and two cortical regions were activated by the tasks separately and increased activity during multitasking.

After testing a variety of potential models, the research team found that multitasking ability hinged on how effectively the putamen could exchange information with the cortical areas.

A week of practice improved the participant's task performance in concert with an increase in communication rates between the putamen and the cortex.

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