The trick to multi-tasking may be training our brain to ‘divide and conquer’ each task separately, Australian researchers have found.
In one of the largest studies of its kind, Professor Paul Dux and Dr Kelly Garner from the University of Queensland’s School of Psychology used real-time brain imaging to look at patterns of activity of 100 volunteers while they attempted to perform two tasks simultaneously.
The study, published today in Proceedings of the National Academy of Sciences, shows the brain can be trained to be better at multi-tasking on a specific set of tasks.
The human inability to multi-task well is something of a conundrum, given our brains’ enormous processing capacity.
“There has been a long serious body of work trying to understand the mechanisms of why we have trouble doing two simple things at once,” the authors said.
It is thought that we have trouble multi-tasking because parts of the brain such as the frontoparietal and subcortical areas have limited capacity to process multiple stimuli at once.
To test how training can improve the capacity of this part of our brain, volunteers were given an auditory-based task – pushing a button with one hand when they heard one of two sounds – and a visual task where they had to push a different button with the other hand when presented with a particular shape.
As well as measuring their speed and accuracy, the volunteers’ brains were also scanned using functional magnetic resonance imaging – which shows the amount of neural activity across the brain – while being tested with the individual tasks separately and then simultaneously.
Over five days, one group of volunteers underwent multi-tasking training with that particular set of tasks while the other group underwent training for a different demanding task.
Both groups were then tested again after five days of training to see if their speed improved.
Will training help improve skills across the board?
Professor Paul Dux said the scans showed people who went through the multi-task training and got better at multi-tasking seemed to do so because their brain dealt with each task separately.
This showed up on the imaging scans as much more distinct pattern of activity in areas of the brain for each individual task.
“If the two activation patterns, for task one and task two, become more separate, what that suggests is that you’re going to be better at multi-tasking because they don’t interfere with one another as much,” Professor Dux said.
“We used this term of ‘divide and conquer’… so people who have more separate representations in these executive brain regions did better at multi-tasking with training, but only if they did the proper training.”
However, we still do not know if training how to multi-task one set of tasks would improve our ability to multi-task generally, he said.
It is a multi-billion dollar question; the brain training industry was recently valued at around $5 billion, said Professor Dux.
But, he said, understanding why humans have limited capacity to multi-task and identifying interventions to improve our skills also have significant health implications for the elderly.
“As people get older their multi-tasking ability gets much, much worse, and their multi-tasking ability is correlated with falls. And one of the big predictions over 80 of mortality is falls.
“In terms of an ageing population in the world at the moment, we’re going to have the situation where we have a lot more people who have these capacity limitations enhanced, and how do we deal with that, and one of the most important ways is through training.”