Wendy Wolfson
Newswire21.org

Multitasking may not be a good idea after all.

So suggests a trio of Stanford scientists, who found that those bombarded with information from multiple media sources tend to make more errors.

Their first series of experiments focused on college students. The researchers next plan to study pilots over 50 to gauge the effects on older people.

It's been well established that the human brain doesn't deal well with divided concentration associated with handling multiple tasks at once. But the researchers wanted to know how uber-multitaskers like media-savvy students really fared in an increasingly media-rich world.

Not that fabulously well, it turns out. In a paper published in PNAS this month, professors Clifford Nass and Anthony Wagner, along with researcher Eyal Ophir, reported the heavy multitaskers were more prone to distraction and were worse at switching tasks. People who did one thing at a time were better at filtering out irrelevant stimuli.

"Multitasking leads to more errors for everyone," said Nass. "Errors occur because of the difficulties of managing memory, switching problems and interference, i.e., information from one task interfering another." 

What's Different?
The trio wanted to find out how chronic heavy media multitaskers process information differently than other people.

So they measured a group of 262 students to determine the champions at simultaneously reading, listening to music, texting, checking their email and websurfing with the TV on. They compared the heaviest multitaskers to the light multitaskers in a series of cognitive control studies to determine distractability, working memory and how well they responded to stimuli and tasks.

Students were tested on their ability to filter distractions. The first test was to determine whether a red triangle on a computer screen changed its orientation without being distracted by the appearance of blue rectangles. The more blue triangles appeared, the worse the heavy multitaskers performed. The light multitaskers were unaffected by distractions.

Next, 30 students participated in a continuous performance task to test working memory. They had to identify pairs of letters despite the sudden appearance of distracting letters of different colors. Both groups were equally accurate, but the heavy multitaskers were an average 77 milliseconds slower to react. 

In another test to see how well they could hold multiple representations in working memory, the high multitaskers had a higher false alarm rate.  

Distraction Delays
In a switching test, 32 students, half multitaskers and half single taskers were shown a letter and number on the screen, and told to decide whether the number was even or odd or the letter was a vowel or consonant. It took 167 milliseconds  longer for the heavy multitaskers to switch between letter and numbers than light multitaskers. The researchers attributed the slower response time to interference from distractions.

The researchers concluded that the high multitaskers were less able to filter out irrelevant distractions. They made sure that the two groups did not differ cognitively by testing students on their level of media multitasking, working memory, SAT scores, creativity, and personality, as well as gender.

The researchers wonder if heavy media users are simply more distracted by the sheer volume of input, or alternatively, the light multitaskers can simply focus better.

"We don’t know whether they are born or created. This is a huge question for the next 3-6 months," said Nass.