The debate about whether multitasking improves performance has been going on for more than a decade. Those on one side, maintain that their ability to do two, three, or even four things at once gives them an edge on the day. Those on the other side, argue that focusing on one task at a time produces a better outcome for each endeavor.
Based on interviews with hundreds of decision makers and my own experience, I’ve come down on the one-task-at-a-time side. In reviewing some brain science research, I have become even more convinced that those who claim to successfully multi-task are really deceiving themselves.
Neuroscientist, Daniel J. Levitan, author of The Organized Mind, explains it this way: “Multitasking has been found to increase the production of the stress hormone cortisol as well as the fight-or-flight hormone adrenaline, which can overstimulate your brain and cause mental fog or scrambled thinking. Multitasking creates a dopamine-addiction feedback loop, effectively rewarding the brain for losing focus and for constantly searching for external stimulation.”
Levitan goes on to say that, “Asking the brain to shift attention from one activity to another causes the prefrontal cortex and striatum to burn up oxygenated glucose, the same fuel we need to stay on task. And the kind of rapid, continual shifting we do with multitasking causes the brain to burn through fuel so quickly that we feel exhausted and disoriented even after a short time.”
Relatedly, Torkel Klingberg, M.D., Phd., author of The Overflowing Brain, observes, “How well we manage to multi-task can be related to the information load on working memory. Often, we can do the tasks if one of them is automatic, such as walking. For an activity to be designated “automatic,” it no longer demands any activation of the frontal lobes. However, a working memory task can never be automatic, as the information it contains always has to be encoded through the continual activation of the frontal and parietal lobes. This is why it can be so difficult to do two working memory tasks at once.” In other words, you can’t attend to more than one task at the same time.
There are those who will argue that regardless of the research, they have no choice but to multi-task. “It’s the only way I can keep up,” they’ll say. Or, “My boss claims she does it and expects everyone else to do the same.” Those people have my sympathy. Well established beliefs die hard. But as Levitan puts it, “You’d think people would realize that they’re bad at multitasking and would quit. But a cognitive illusion sets in, fueled in part by at dopamine-adrenaline feedback loop, in which multitaskers think they are doing great.”
So, if you can’t multi-task, how do you keep up? By focusing on one task at a time to completion or until you can’t progress due to a missing element, resource or decision. Yes, that requires concentration and the discipline to resist the temptations to do more. How do the best decision makers do this? I’ll cover that in the next post.