Tag: cognitive load

Categories : NeurologyTags :

Psychological Study Shows that Multitasking has Limits

On By ModernMedia
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Even with highly extensive training, the human brain is not really capable of performing two tasks simultaneously. Moreover, even the smallest deviations from trained routines can have a significant impact on how quickly and successfully people complete tasks simultaneously. This is shown by a new study conducted by Martin Luther University Halle-Wittenberg (MLU), the FernUniversität in Hagen and the Medical School Hamburg. It was recently published in the Quarterly Journal of Experimental Psychology.

In three experiments, the researchers investigated how people perform two tasks simultaneously that involve different senses: participants were asked to indicate the size of a circle that was briefly displayed with their right hand and simultaneously to say whether a sound played at the same time was high, medium or low. The speed at which the participants completed the tasks and the number of mistakes they made were measured. The tasks were repeated over a period of up to twelve days. The results showed that the more often the test subjects completed the test, the faster they solved both tasks without errors.

Earlier studies with similar findings had therefore suggested that so-called dual-task costs, ie, performance losses when working on two tasks simultaneously, could almost completely disappear after extensive practice. “This phenomenon, known as virtually perfect time sharing, has long been considered evidence of true parallel processing in the brain and proof that our brain is capable of unlimited multitasking. The results of our study clearly contradict this assumption,” says psychologist Professor Torsten Schubert from MLU.

The new study shows that the underlying cognitive processes still do not run completely in parallel. What’s more, even the smallest changes to the tasks caused the error rate to rise and the participants to take longer to complete the tasks. “Our brain is very adept at sequencing processes so that they no longer interfere with each other. However, this optimisation has its limits. In particularly challenging situations, our cognitive apparatus therefore tires very quickly and becomes error prone,” Schubert continues.

The study also provides new impetus for safety research. “Our results show why multitasking can often be risky in everyday life, despite routine, for example when driving and talking on the phone at the same time. This is also relevant for professions with complex activities where several tasks have to be performed in parallel, such as air traffic controllers or simultaneous translators,” says Professor Tilo Strobach from the Medical School Hamburg. Professor Roman Liepelt from the FernUniversität in Hagen adds: “Our study sheds new light on the limits of human information processing. Understanding such cognitive bottlenecks is crucial for improving work processes, learning environments and safety measures in everyday life.”

The results were published in the Quarterly Journal of Experimental Psychology.

Tom Leonhardt

Source: Martin Luther University Halle-Wittenberg

Categories : General InterestTags :

Message Boards Showing Highway Death Toll Cause More Crashes

On By ModernMedia
Driver at the wheel of a car
Photo by Why Kei on Unsplash

Displaying the highway death toll on message boards (eg, “1669 deaths this year on Texas roads”) is a common awareness campaign, but new research published in Science shows that it actually leads to more crashes.

Their study focuses on Texas, where officials chose to display these messages only one week each month. The researchers compared crash data from before the campaign to after it started as well as examined the weekly differences within each month during the campaign. They found:

  • There were more crashes during the week with fatality messaging compared to weeks without.
  • Displaying a fatality message caused a 4.5% in crashes in the 10km after the message boards. This increase is comparable to raising the speed limit 5–8kph or reducing highway police by 6–14%, according to previous research.
  • The researchers suggest this “in-your-face” messaging approach weighs down drivers’ “cognitive loads,” temporarily impacting their ability to respond to changes in traffic conditions.

“Driving on a busy highway [and] having to navigate lane changes is more cognitively demanding than driving down a straight stretch of empty highway,” said Assistant Professor Joshua Madsen. “People have limited attention. When a driver’s cognitive load is already maxed out, adding on an attention-grabbing, sobering reminder of highway deaths [can] become a dangerous distraction.”

Another finding was that the higher the number in the fatality message, the more harmful the effects. The number of additional crashes each month increased as the death toll accumulated throughout the year, with the most additional crashes occurring in January when the message stated the year’s total. Crashes were also found to increase in areas where drivers experienced higher cognitive loads, such as heavy traffic or driving past multiple message boards.

“The messages also increased the number of multi-vehicle crashes, but not single-vehicle crashes,” said Hall. “This is in line with drivers with increased cognitive loads making smaller errors due to distraction, like drifting out of a lane, rather than driving off the road.”

However, crashes were reduced when the displayed death tolls were low and when the message appeared where the highways were less complex. Madsen said this suggests that at times the messaging was not as taxing on drivers’ attention. However, alternative campaigns should be considered.

“Distracted driving is dangerous driving,” said Madsen. “Perhaps these campaigns can be reimagined to reach drivers in a safer way, such as when they are stopped at an intersection, so that their attention while driving remains focused on the roads.”

Source: University of Minnesota