In today’s modern, technologically advanced world, with email and smartphones and Twitter and Facebook demanding all of our attention all of the time — even as we work, socialize, and play — multitasking may seem like the only answer. But science cautions us to restrict multitasking efforts: do not deceive yourself — you are not accomplishing more by multitasking.
Science says that multitasking—the art of doing multiple things at once — is nearly impossible. When you multitask, your brain switches between each task very rapidly to the point that you feel as though you are doing tasks simultaneously.
The anatomical portions of the brain primarily responsible for multitasking-type behaviors have been mapped to sections of the prefrontal cortex (PC), an area well developed in humans compared to other primates. The PC is generally responsible for focusing on input and deciding which response is most ideal. Recently, a paper published by Dr. Earl Miller, Picower Professor of Neuroscience at the Massachusetts Institute of Technology, showed that certain neurons within this portion of the brain are actually capable of multitasking themselves.
So why is it that science maintains that we are still so bad at it?
On the whole, as we make a decision involving a single task, portions of the brain including both frontal lobes are active. According to Miller, when attempting to accomplish two tasks simultaneously, the neuronal circuitry within our brains can suffer from what is known as “interference.” This is in part due to tasks competing for finite resources, sometimes within similar areas of the brain. Furthermore, research by René Marois, a neuropsychology professor at Vanderbilt University, showed that portions of the brain act as information bottlenecks, clogging information transfer from one portion of the brain to another. The results from this study indicated the primary bottleneck occurred when the lateral frontal, superior frontal and prefrontal cortices had difficulties processing two tasks simultaneously. Rather, a “queuing” of the tasks was shown to result as the brain processed them. Marois noted that if tasks were presented with a delay of one second or more between, the bottlenecking effect was eliminated.
Another angle from which one can ponder the negatives of multitasking is through the “Dunning-Kruger effect.” This is a phenomenon of cognitive bias, named after the team from Cornell University that produced the research, in which individuals have the propensity to overrate their abilities and lack the metacognitive ability to realize that the decisions they have made are incorrect. Simply put, we are likely the worst judges of our own abilities. This was exemplified in a research study from Stanford University detailing how certain types of heavy multitaskers believe they are very good at multitasking, but in reality are most often the worst at it. In addition, the study found productivity to be decreased, while further research supported the notion that multitasking impairs and can even harm cognitive performance.
It came therefore as a surprise that a recent article published in Science by a group headed by Etienne Koechlin, a professor at Paris’ École Normale Supérieure, has emerged arguing for the possibility of limited multitasking. When volunteers were asked to complete a single task for monetary reward that researchers had designed, areas of both frontal lobes known as the medial prefrontal cortex (MFC) became involved and appeared to be working in conjunction to solve the problem. When volunteers were then asked to complete two tasks, Koechlin and his colleagues were able to discern that the two frontal lobes appeared to divide their attention, with one pursuing completion of the first task while the other targeted the second. Most interestingly, when accosted with three tasks, completion accuracy dramatically decreased. It appeared that the third task could simply not find the available brain space in which to concurrently process. Koechlin observed that the individuals seemed to perform as if one of the three tasks was forgotten.
While the results of the study seem to indicate that we may be capable of multitasking two things at once, does this truly mean we can dual-task? While some evidence shows that multitasking can be improved and optimized to some degree, this remains a tricky question. Given that our daily to-do lists typically run higher than two and likely also include decisions, this could easily overwhelm our neural circuitry.
Finally, while a recent study indicated that there may be in our midst a small subset (~2.5 percent) of individuals that multitask extremely well (termed “supertaskers”) — it still seems prudent that, given the chances, one should not yet throw caution to the wind when considering whether one should multitask.
In a world plagued with lives that must fit into decreasing amounts of time, people naturally attempt to multitask. However, as science continues to provide us with evidence of our multitasking limitations, perhaps it is best that society attempt a return to the basics: Finish an item, then cross it off. As Publilius Syrus wrote in the 1st century B.C., he “who chases two rabbits catches neither.” (Known today as “To do two things at once is to do neither.”) Sadly, it has taken us until the 21st century to realize that Syrus may have had a point.