Force Science News #148:
New studies on multitasking: What’s your risk from brain overload?
New studies of the nature and challenges of multitasking have important implications about the safety of police driving, both on patrol and in high-speed pursuits, according to Dr. Bill Lewinski, executive director of the Force Science Institute.
One research team, at the University of Utah, revisited the often-studied subject of cell phone use while driving—and discovered something new.
Contrary to the researchers’ expectation, there are people who can pay attention to a cell phone exchange while moving through traffic, without experiencing deterioration of their driving skill.
However, these “supertaskers,” as Dr. Jason Watson and Dr. David Strayer of the University’s psychology department term them, comprise a tiny “exceptional” minority—only 2.5% of those tested. The overwhelming majority “showed significant performance decrements” when attempting to multitask.
Watson and Strayer monitored 200 male and female volunteers, ranging in age from 18 to 43, during an exercise with a high-fidelity driving simulator. The subjects were required to brake “in a timely and appropriate manner” during a simulated trip along a 32-mile stretch of multi-lane highway “with on- and off-ramps, overpasses, and 2- and 3-lane traffic in each direction.” If they failed to brake, “they would eventually collide” with another vehicle.
The researchers compared how the subjects performed when they had only to concentrate on driving vs. when they used a hands-free cell phone to hear and respond to math and memory problems that were posed as they tried to maneuver the route.
For 97.5% of the group, “dual-task performance was inferior to single-task performance,” the researchers found. Moreover, both the driving and the unrelated problem-solving via cell phone deteriorated for most subjects when attempted simultaneously.
The impact of cell phone use on driving found in other studies was reconfirmed, Watson and Strayer report: “brake reaction times are delayed, object detection is impaired, traffic-related brain potentials are suppressed, and accident rates are increased…. [C]ell phone conversations lead to a form of inattention blindness causing drivers to fail to see up to half of the information in the driving environment that they would have noticed had they not been conversing on the phone.”
Why the small minority of extraordinary supertaskers were able to perform “both tasks at the same time with high levels of proficiency on each” and with little or no impairment is not known. The researchers hope to study these “strikingly remarkable” individuals in greater depth.
Meanwhile, they caution against the temptation to think that you are among the exceptional few. “A great many people have the belief that the laws of attention do not apply to them,” Watson and Strayer write. However, “the odds of this are against them.”
Lewinski agrees. “In today’s patrol cars, there are many distractions from driving—cell phones, data terminals, radio traffic with dispatchers and other officers, the need to assess information and plan strategy when you’re en route to calls.
“When you’re attending to these things, your ability to perceive and react to what’s happening in your driving environment is in fact impaired, perhaps significantly so, even though you may believe you are monitoring it simultaneously.
“If high speed is added to the mix, you become even more of a hazard to yourself and other drivers or pedestrians.
“To be safer, you need to reduce either the distraction or the challenges of the roadway. That could include driving slower, using a route less traveled, and maintaining significant distance between you and vehicles ahead so you have greater reaction time to help compensate for the ‘performance cost’ of your divided focus.”
[Click here to access the full report of the Utah study.]
In a second new study, researchers in France reached a conclusion about multitasking that Lewinski expresses some caution about.
A report co-authored by Dr. Etienne Koechlin, a professor with the French National Institute for Health and Medical Research in Paris, and widely reported this month [Apr. 2010] in the science news media, finds that the human brain can successfully handle 2 tasks at once but becomes “muddled” when attempting 3.
The researchers used functional MRI scans to study the frontal lobes of the brains of 32 volunteers “while they were performing fairly complicated tasks” involving letter matching and sequencing.”
When the subjects were doing just one task, “there was activity in goal-oriented areas of both frontal lobes,” Koechlin says. “That suggested that the 2 sides of the brain were working together to get the job done.”
When the volunteers took on a second task, the lobes “divided their responsibilities,” each pursuing its own task; the left lobe focused on the first job, while the right focused on the second.
When a third task was introduced, however, the brain seemed overwhelmed. “People slowed down and made many more mistakes. That suggests that the frontal lobes can’t maintain more than 2 tasks,” Koechlin says.
Lewinski’s concern is that laymen may interpret this to mean that a human being can in fact simultaneously focus equally on 2 demands for attention. That misleading conclusion could be potentially dangerous if it builds over-confidence and over-dependence on multitasking.
What happened during the experiment, he believes, is that the brains being studied quickly switched back and forth from one task to another, alternately engaging the 2 frontal lobes. But in a stressful, threatening situation, that would no longer be possible, he says.
“It is very clear, both in terms of common sense and scientific documentation, that once something arises that captures your attention, your external focus immediately narrows down to just that 1 area. Yes, you can walk and talk at the same time, one of the most simplistic forms of multitasking. But once you trip, you can no longer carry on the conversation because your full attention is concerned with dealing with your tripping.”
That is why it is so important to hone your skills to the point that most of your performance in a stressful situation is automatic, leaving the cognitive centers of your brain free to focus on factors of life-saving decision-making.
Take pursuit driving. As we’ve reported previously in Force Science News, British police who are permitted to engage in vehicle pursuits receive vastly more training in high-speed driving than their American counterparts. Pursuit drivers for London Metro Police, for example, initially get 6 weeks of intensive instruction and practice conducted in variable weather and lighting conditions on real roads and highways among real traffic at speeds up to 150 mph. Training and practice continue on a regular basis beyond that.
These officers become extremely sophisticated drivers, able to read subtleties like the impact of tree shade on road-surface moisture, to predict traffic patterns far ahead, and to safely control the interplay between their squad car and other vehicles along a pursuit route. “The physical control and maneuvering of their squad car becomes automatic,” Lewinski explains. “They don’t have to think about that, so their mind is undistracted from critical decisions that have to be made.
“On the other hand, an officer who has not trained extensively in driving at high speeds will find his attention torn in many directions during a fast pursuit as he tries to focus simultaneously on controlling his vehicle, watching for traffic hazards, tracking the offender’s moves, monitoring other traffic, communicating and coordinating with other responders, and so on. He doesn’t have the skill at ‘reading the game’ and anticipating events that more experienced and highly trained officers have, so less of his performance can be sublimated to automaticity. He’s forced into very high-risk multitasking, and in short order he exhausts his cognitive resources. Something has to be sacrificed.”
A study released recently by the California POST reveals that 35% of vehicle collisions in which LEOs are injured or killed in that State involve “unsafe speeds (though not always connected to pursuits or hot-call responses). Multitasking is acknowledged to be a likely factor in these and other on-duty accidents, although the exact level of involvement is unknown.
It is at least interesting to note that the rate of serious collisions involving officers has surged dramatically over the decade covered by the POST study, at the same time the amount of multitasking a peace officer is challenged to accommodate while driving has increased significantly as well.
For more than a year, the Force Science Institute has been working with the British company a2om (pronounced “atom”) on a project designed to improve the safety of police driving. This is a computer-based system for “immersion” driver “training that marshals the latest scientific understanding of brain processing to improve scanning ability, hazard anticipation and detection, interpretation of traffic patterns, and decision making.
“This project is moving toward completion,” says Lewinski. “Extensive real-world video footage is being assembled and scripted into a preliminary training program, and we expect to begin pilot testing before the end of this summer.”
Ultimately, he predicts, the result will be “an affordable training package that will help law enforcement agencies sharply reduce officer deaths and injuries, better protect the civilian population, and cut the costs and liabilities of driving mishaps.”
[Our thanks to Tom Aveni, executive director of the Police Policy Studies Council, and Bill Spence, Director of Development at the Force Science Institute, for their assistance with this report.]
Written by Force Science Institute
April 24th, 2010 at 4:33 pm
© 2017 Force Science Institute Ltd.