Parents around the world are divided on this. Half watch their teenagers sitting among a pile of books, ear buds in, computer on, TV humming in the background and think, "I wish I could multi-task like that." The others stride across the room, pull the plug on the distractions, and ask the age-old question - "How can you study with that on?"

Somewhere along the line we seem to have absorbed the idea that teenagers can multi-task perfectly because they're digital natives. Perhaps we read it somewhere or heard it on the TV - can't have been paying full attention though, because no-one's really sure where it came from. (Perhaps we were multi-tasking at the time - and that's a big clue where this is going.)

Can they multi-task? Absolutely. Will the results be the same as if they were fully focused on their study? Maybe not.

The University of Oxford's Institute for the Future of the Mind recently looked at the impact on students who were constantly interrupted by digital technologies while trying to learn.

During the study, two groups (18- to 21-year-olds and 35- to 39-year-olds) were asked to perform tasks which required 'a significant level of concentration'. Both groups were interrupted during the task with a telephone call, an SMS text message on their mobile or an instant message (IM) to a desktop computer.

Now conventional wisdom tells us that the younger group, being the generation who grew up multi-tasking with technologies, would have had a distinct advantage over the older group.

Indeed, the 18 to 21-year-olds did perform the task better - until the interruptions were introduced. Organisers of the study say "the 18 to 21-year-olds lost this advantage over the older group, for whom the interruption did not significantly change performance."

The older group was more able to switch attention between the task and the interruption and back again.

Similar studies have been conducted using Magnetic Resonance Imaging (MRI), which registers brain activity. The study by the Center for Integrative and Cognitive Neurosciences, Vanderbilt University, suggests the human brain shuts down one task when asked to do another at the same time.

Researchers could identify activity in the corresponding part of the brain for each task, but noted the activity occurred first in one part of the brain and then in another - not both at the same time.

Explaining this experiment, Professor of Neuroscience and author Bill Klemm says the delay is likely to also impact memory and learning.

"If you try to memorise the first task and the brain immediately switches to the second task, performance of the second task interferes with consolidation of the memory of the first task."

Professor Klemm points out that kids are often juggling several distractions at once, which probably makes it even less likely they'll remember all the details of what they're studying.

Californian researcher and UCLA Associate Professor of Psychology Russell Poldrack, PhD, says when distractions force you to pay less attention to what you are doing, you simply just don't learn as well.

"Even if you learn while multi-tasking, that learning is less flexible and more specialised, so you cannot retrieve the information as easily," he adds.

We also now know the teenage brain is still developing the ability to think and analyse information. The question is whether poor study habits now will affect their future ability to learn efficiently.

The question isn't "should we multi-task?" - life is full of multi-tasking moments for us all. It's more a matter of when we should 'power down' and focus.

Rather than pulling the plug on every possible distraction, ask your child to schedule some focused study time each day, at least for their most challenging subjects.   

Multi-tasking is an essential skill to have, but when you really need to study, it could be working against you.