Multitasking also hits limits with practice, study finds - Science proves the human brain can't truly multitask—no matter how hard you try

New research confirms that the human brain cannot truly handle two tasks at once—even with practice. Scientists from Martin Luther University Halle-Wittenberg and partner institutions explored how the brain manages multitasking through a series of experiments. Their findings challenge the idea of parallel processing and highlight the risks of task-switching in critical situations.

The study involved 25 participants across three carefully designed experiments. Researchers used fMRI scans to monitor brain activity while volunteers tackled different multitasking challenges. Each experiment varied in complexity and the amount of prior practice given to participants.

Training improved speed, but the results showed no evidence of true parallel processing. Instead, the brain optimised the order of individual steps to reduce interference between tasks. Even small changes to tasks led to more mistakes and slower reactions, proving that the brain's ability to juggle multiple actions has clear limits. The team tested scenarios where participants had to switch between tasks quickly. Despite extensive practice, the brain still processed one task at a time rather than simultaneously. This sequential approach, rather than parallel handling, explained why performance dropped when tasks were altered slightly.

The findings suggest that multitasking remains inefficient, even for those with experience. Situations demanding constant task-switching, such as driving or high-pressure jobs, could become riskier due to slower response times and errors. The study underscores the brain's reliance on sequencing rather than true multitasking—no matter how much training is involved.