A popular theory, touted in the majority of these studies, is that a person’s brain has a limited capacity for attention, and can only focus on one task at a time to operate effectively. When people engage in what they believe to be multitasking, they are probably skimming through most of the projects without much thought.
Psychologist Daniel Goleman, author of “Focus: The Hidden Driver of Excellence,” says that from the viewpoint of cognitive science, multitasking is a “complete fiction” and that it is impossible for humans to focus on two things at once.
Goleman says the mind cannot hold more than one task at a time in its “working memory” ― the storage of transitory information in the mind while it is being manipulated. He says that every time a person breaks focus to do something else, it takes several minutes to return to what one was working on before.
According to Goleman, one needs to be fully focused and free of interruptions in order to work effectively on a problem. While focusing on a single task, scientists can observe a neurological signal that creative ideas are being developed.
Because of this limitation, some scientists say that effective multitasking is impossible.
A joint team of researchers from Tokyo University and Oxford University conducted a study on how well people can simultaneously perform two tasks. They found that doing two things at once often led to dual-task interference, with the result that both the tasks were poorly performed.
Researchers looked at single-neuron activity in monkeys’ lateral prefrontal cortexes while the animals performed tasks that required both spatial attention and memory. The monkeys were stimulated visually, and then were distracted with another task while processing the visual information.
The study showed that the strain of doing multiple task impaired the brain’s ability to hold on to information related to the tasks. Due to dual-task interference, researchers said, it is virtually impossible to carry out two tasks at once with any proficiency.
Believers in multitasking have claimed that some people are just hardwired to be good at multitasking, but the findings of Stanford communications professor Clifford Nass suggest otherwise.
Nass had 262 college students participate in experiments that involved both multiple and single tasks. Contrary to popular belief, students who were frequent multitaskers did considerably worse than the nonmultitaskers in both solitary activities and multitasking, suggesting that frequent multitaskers do not use their brains effectively.
Some scholars say that not only is multitasking inefficient, it is actually harmful to the brain as encountering enormous amounts of data without processing it can blunt one’s mental sharpness.
Bouncing between several projects while being bombarded with information can cause a 10-point fall in a person’s IQ, according to a study at Kings College London. The effects of multitasking were double the 5-point drop that resulted from smoking marijuana, researchers found.
Psychiatrist Glenn Wilson, who conducted the study, said that multitasking “can be incredibly stressful on the brain,” impairing short-term memory and concentration.
Of course, it is also possible that what people often call multitasking is not multitasking at all. For most people, multitasking is paying attention to information from several different sources at the same time. For instance, one can constantly check email while monitoring the TV for breaking news and working on a separate project.
But this is a different process called “continuous partial attention,” or CPA ― being mindful of several sources of incoming information at a superficial level ― according to writer and consultant Linda Stone, who coined the term.
Stone, formerly an executive at Apple and Microsoft, said that CPA and multitasking are based on different motivations. The former is pushed by the urge to be more productive and efficient. It also pairs an automated activity ― such as stirring a stew, which involves very little thinking ― with another that requires more cognition.
CPA, on the other hand, is motivated by the desire to be constantly on alert for new information, according to Stone. This creates an artificial sense of crisis that triggers the fight-or-flight mechanism, which has its upsides but also induces problems such as overstimulation and lack of fulfillment.
Stone says that the fight-or-flight response releases a barrage of stress hormones that leave modern-day people on edge.
By Yoon Min-sik (email@example.com)