Multitasking: Perspectives from MIT and UofM

Last fall, NPR broadcast a series of reports that covered multitasking. In their September 30th report, correspondent Jon Hamilton interviewed neuroscientists from MIT and the University of Michigan, asking them whether the human brain is capable of multitasking. The short answer: Yes, but only to a limited extent.

Earl Miller, Picower professor of neuroscience at MIT, believes people who think they are good at multitasking are "deluding themselves." That is not to say people are completely incapable of multitasking--only that it doesn't happen as much or as well as people tell themselves. Miller explains that people often think they are multitasking when they are actually switching between tasks very rapidly. Genuine multitasking is extremely difficult because multiple stimuli compete for the attention of the same cognitive resources.

University of Michigan neuroscientist Daniel Weisman says that, by using MRIs, he can "see" the brains of his research subjects switching between tasks. In one experiment, he displayed pairs of red digits and pairs of green digits to subjects in his lab. If the digits were red, the subjects were to select the greater number. If the digits were green, the subjects were to select the number that was printed in the larger point size, regardless of its numerical value. (These instructions are so similar that they are likely to be processed by the same parts of the brain.) Then Weisman observed their brains while they performed the task. Each time the color of the digits changed, the subjects' brains paused, trying to reload the corresponding instructions--they switched tasks. This suggests that their brains could not process simultaneously instructions competing for the same mental resources.

This article lends support to the conclusions of yesterday's post: people possess a limited ability to multitask. How limited--or how great--is that ability? To what extent does modern life coerce people to mulitask? Are people getting better at it by practicing? Is there a correlation between age and multitasking capacity? What sorts of activities can be performed on autopilot? It's time to start foraging for some more answers!