Impacts of multi-tasking
Scientists are still working out the impacts of multi-tasking on our brains, our mental health and our productivity.
What happens in our brain when we multi-task?
While the human brain is capable of pursuing multiple goals at once, how they are divided by the brain is still a mystery.
Researchers have imaged human brains using MRI and watched them try to multi-task as subjects performed a set of variously interrupted tasks. The brains can divide resources fairly easily for two tasks, but have a much harder time juggling three or more.
When single-tasking, researchers found subjects used both of their frontal lobes to manage the work. When there were two tasks in play, each half of the brain was devoted to managing each task. However, when a third task interrupted the second task, subjects' brains started crashing: error rates shot up and response times plummeted. Researchers say this suggests a strong physical limitation on how many things we can think about at once, namely, how many brain hemispheres we have. The study's authors note the results may clarify many of the limitations in our decision-making and reasoning abilities.
What impact does multi-tasking have on mental health?
Macquarie University's Dr Irwin says multi-tasking makes it harder to derive satisfaction from performing tasks. The interruptions can make work unsatisfying and, she suspects, lead workers to not perform a job as well as they would if they did not have to switch often between tasks and just focus on one at a time.
By its very nature, multi-tasking is stressful. Long-term stress can have serious health impacts.
It is known that the area in the brain most involved with multi-tasking is the one most likely to be affected by stress. The pre-frontal cortex helps to assess tasks, prioritise them and assign mental resources. It also marks the spot where we left off a task so we can return to it later. This area is affected by prolonged stress.
Stress can also affect other regions of the brain, such as the hippocampus which helps form new memories and accesses existing ones. Damage to it can make it difficult for people to acquire new skills and facts. Stress hormones can also reduce short-term memory.
Scientists say juggling e-mail, phone calls and other incoming information can change how people think and behave. And while the information plays to a primitive impulse to respond to immediate opportunities and threats, it also provokes excitement. The accompanying squirt of dopamine, released into the human bloodstream, can be addictive. Without it, people feel bored.
Is it dangerous to talk on the phone while driving a car, effectively multi-tasking?
Research shows the answer is an overwhelming yes, even suggesting that multitasking can be more dangerous than drink-driving.
A 2006 study by University of Utah psychologists showed motorists who talk on mobile phones are as impaired as drunk drivers. Mobile phone users were five times more likely to be involved in accidents than undistracted drivers - the same level as someone with a 0.08 per cent blood-alcohol level. Drivers who talked on mobile phones were also shown to have slower reactions than those who did not.
Talking and driving are mutually exclusive because the same part of the brain is used to focus on the phone conversation and the road. When talking, drivers withdraw their attention from the road in order to formulate responses. Because the brain cannot focus on two sources of input at once, driving and also listening or talking on the phone are known to distract the brain and increase the likelihood of accidents.
In some states of the US, mobile phones are banned from cars.
In Australia, mobile phone use has not been banned while driving. However, only hands-free devices are legally allowed to be used by people while driving a car.
How does multi-tasking affect human IQ?
UK research shows distracted workers suffer a greater loss of IQ than people who smoke marijuana.
Dr Glenn Wilson, a psychiatrist at King's College London University, monitored the IQ of workers throughout the day in 80 clinical trials in 2005.
His study found the average worker's functioning IQ, a temporary qualitative state, drops 10 points when multitasking. That is more than double the four-point drop that occurs when someone smokes marijuana.
What are the short-term impacts of multi-tasking?
Many psychologists claim among the negative "side effects" of multi-tasking is an increase in short-term memory loss.
Dr David Meyer, a psychology professor at the University of Michigan, agrees with another US psychologist Dr John Arden, that when humans multitask too much, they can experience short-term memory problems or difficulty concentrating.
University of California research has shown that people interrupted by e-mail report significantly increased stress compared with those left to focus. Gary Small, a psychiatrist at the Los Angeles University, says stress hormones have been shown to reduce short-term memory.
What is the long-term impact of multi-tasking?
The jury is still out because multi-tasking is such a relatively new phenomenon and much research is being undertaken. Only time will tell.
Will the critical/analytical thinking of the younger generation be affected?
Research is continuing into these aspects of multi-tasking and there is not enough evidence to make meaningful conclusions at this stage. We'll just have to wait and see.
Why is research into multi-tasking important?
Dr Meyer says understanding how the brain establishes priorities between tasks and allocates resources may help solve "fundamental problems associated with the design of equipment and human-computer interfaces for vehicle and aircraft operation, air traffic control, and many other activities in which people must monitor and manipulate the environment through technologically-advanced devices."
It may also aid personnel selection, training, assessment and diagnosis of brain-damaged patients, rehabilitation, and formulation of government and industrial regulations and standards.
Results may also improve general understanding of how the brain and human consciousness work.
Are multi-taskers bad at multi-tasking?
Research reported in the Proceedings of the National Academy of Sciences suggests this may be the case. Professor Cliff Nass of Stanford University was a co-author of the study which found that those who engage in multitasking are least able to do so well.
Professor Cliff Nass, of Stanford University, showed in a study that those who engage in media "multi-tasking" are least able to do so well. Two groups
were defined: those who routinely consumed multiple media such as internet, television and mobile phones, and those who did not. In psychology tests
for attention and memory, the "low multi-taskers" consistently outdid their highly multitasking counterparts.
"The shocking discovery of this research is that [high multi-taskers] are lousy at everything that's necessary for multitasking," Professor Nass said.
"The irony here is that when you ask the low multi-taskers, they all think they're much worse at multitasking and the high multi-taskers think they're gifted at it."
Results from the research could be profound, potentially suggesting new means of teaching and even reporting news for those given to a multi-media feed of information.