Practice makes a man a ‘multi-tasker’

Training and practice can significantly improve our ability to multitask, say researchers.

"We found that a key limitation to efficient multitasking is the speed with which our prefrontal cortex processes information, and that this speed can be drastically increased through training and practice, said Paul E Dux, a former research fellow at Vanderbilt, and now a faculty member at the University of Queensland in Brisbane, Australia, and co-author of the study.

The researchers found that with training, the ''thinking'' regions of the brain become very fast at doing each task, thereby quickly freeing them up to take on other tasks.

To reach the conclusion, the researchers trained seven people daily for two weeks on two simple tasks selecting an appropriate finger response to different images, and selecting an appropriate vocal response (syllables) to the presentation of different sounds. The tasks were done either separately or together (multitasking situation).

They also scanned the individuals brains three times over the two weeks using functional magnetic resonance imaging (fMRI) while they were performing the tasks.

Before practice, the participants showed strong dual-task interference slowing down of one or both tasks when they attempted to perform them together.

However with practice and training, the individuals became very quick not only at doing each of the two tasks separately, but also at doing them together. In other words, they became very efficient multitaskers.

"Our results imply that the fundamental reason we are lousy multitaskers is because our brains process each task slowly, creating a bottleneck at the central stage of decision making," said Rene Marois, associate professor of psychology at Vanderbilt University and co-author of the study.

Practice enables our brain to process each task more quickly through this bottleneck, speeding up performance overall.

"Our findings also suggest that, even after extensive practice, our brain does not really do two tasks at once. It is still processing one task at a time, but it does it so fast it gives us the illusion we are doing two tasks simultaneously," she added.

The findings are published in journal Neuron.