If you're caught up in multitasking, your brain is more prone to making a decision you'll soon regret. Flickr/sunshine city The human brain is easily thrown off by outside influences, but it takes only a fraction of a second to shut out distractions, which can greatly improve your decision-making.

Studies have previously shown that multitasking can lead to poor decision-making, but a new study published by PLOS ONE measures exactly how long it takes the brain to focus on something, proving how powerful selective attention can be.

The report, "Humans Optimize Decision Making by Delaying Decision Onset," was conducted by Tobias Teichert of the University of Pittsburgh and Vincent P. Ferrera and Jack Grinband of Columbia University.

The team found that it takes at least 120 milliseconds for the brain to switch its attention from task to task. That's roughly the time it takes to quickly double-click a mouse, but in the realm of neuroscience, it counts.

"This may not seem like very much," Teichert told Business Insider, but each time the brain adjusts its focus, it is expending energy.



Teichert's team conducted experiments in which subjects needed to determine which way dots on a screen were moving while a second set of brighter dots (distractors) moved separately. They measured how long it took for the subjects to accurately ignore distractors moving in the opposite direction and arrived at the average of 120 milliseconds.

Teichert said that these findings can be used practically. If you spend your day constantly switching focus from the task at hand to irrelevant distractions or other tasks, it confuses and exhausts your brain. "By the end of the day you may end up making worse decisions just because your attentional system can’t keep up," Teichert said.

Next time you're confronted with a decision, then, take a moment to clear your head and consciously focus on the task in front of you. Waiting just a split second allows the decision-making part of your brain to catch up.