Multitasking and Productivity: Studies on Task Attention

How many tasks can you effectively perform at the same time?

By Peter M. Vishton, PhDWilliam & Mary
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily

Multitasking is common—and some would even argue necessary—in our modern age. Researchers have been exploring the pros and cons for many years, though. Dr. Vishton describes an early study revealing unexpected insights about a human’s ability to focus on multiple tasks simultaneously.

Woman multitasking while eating
Over several decades, research has waffled on the issue of multitasking and how many things a person can efficiently do at the same time. Photo by Estrada Anton / Shutterstock

Task Attention and Typing

A large body of research exists now on task attention—assessments measuring how well humans do or don’t do multitasking—along with studies observing how the brain implements multitasking behaviors. A large body of older literature explored one question in particular: With practice, just how many things can someone learn to do at the same time?

When you first learn to perform a new task, it typically requires your full attention—for example, typing. Imagine that you have a handwritten page of text, and you’re given the task of typing it into a word processor. 

Beginning typists must engage in a lot of intentional effort when they’re starting out. You read the next word that you’re going to type, search the keyboard for the first letter of that word, and then press the button. You repeat this for all the letters of the word, and then repeat with the next word that you want to type.

Trying to multitask while first learning to type presents a problem. Imagine someone was talking in the background while you hunted and pecked your way through your typing job. Now imagine that you were supposed to monitor that conversation and press a separate button anytime that person mentioned something about the human brain. 

As the person talked and you continued to type, one of two things would happen. One, you’d have to stop typing every few seconds to listen to the conversation, or two, you would focus completely on the typing and miss some of those spoken comments about the brain.

This is all when you’re new to typing, however. As you practice typing, it becomes more and more automatic, requiring fewer of your mental resources in order to proceed quickly and accurately. If you’re practiced enough, maybe you can do both of these tasks at the same time, without either of them suffering in performance. 

Testing the Limits of Cognition

In a classic study that still gets discussed by researchers in this area, expert typists were given a document to type. At the same time, the experimenters played an audio recording of a voice reading some text aloud. 

The job of the typists was to verbally shadow that audio recording while continuing to type the document. Verbal shadowing is a task in which you repeat what the speaker says while they’re saying it.

The expert typists were able to easily accomplish this task, typing quickly and accurately while simultaneously performing verbal shadowing. Researchers believe that the typing was so automatic that the typist could devote attention to the shadowing, and both tasks could proceed at the same time.

What if the typist practiced the verbal shadowing for a few hundred hours, maybe over the course of several weeks or months? Presumably, the typists would eventually become an expert at typing and verbal shadowing. 

If they became expert enough, perhaps you could add a third task. Maybe someone could type, verbally shadow, and solve arithmetic problems at the same time. Maybe you could eventually add a fourth and fifth task.

“I remember reading these original papers and wondering if there might be no upper limit to this, except perhaps that we only have two hands and two feet,” Dr. Vishton said. “All that would be needed would be enough practice, and maybe you could organize your brain to perform completely separate tasks in parallel.

“Maybe you could write one paper with one hand while simultaneously writing another paper with the other hand on a different keyboard. As an overscheduled college student, this really sounded great to me.”

Of course, it’s hard to think of a situation where one would want to type, verbally shadow, and solve math problems. These were arbitrary tasks that experimenters came up with to test the limits of human cognition and action control. 

Modern-Day Multitasking

Although the tasks in the multitasking study were impractical, we often engage in multitasking behaviors. We perform one primary task such as writing a paper while also engaging in a secondary task and a tertiary task. 

For example, you might answer the phone when it rings and talk with a coworker. Your computer periodically makes a beep, indicating that an email has arrived.

A little pop-up window appears, showing who the email is from and what the subject of the message is. Thus, you’re also monitoring this incoming information and making decisions about whether or not you should stop writing and respond to it.

The older research on task attention with typists showed that with practice people can learn to do multiple tasks at the same time. Current research has been showing that it is not beneficial for the human brain to be multitasking, although our modern world put demands on us to try. It seems far more efficient for productivity and far more beneficial for our brains when we concentrate on one task at a time.

This article was edited by Kate Findley, Writer for Wondrium Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for Wondrium Daily.
Image of Professor Peter Vishton

Peter M. Vishton is an Associate Professor of Psychology at William & Mary. He earned his PhD in Psychology and Cognitive Science from Cornell University. Before joining the faculty of William & Mary, he taught at Northwestern University and served as the program director for developmental and learning sciences at the National Science Foundation.