A new University of Florida study reports that multi-tasking may not cause one or both activities to suffer. The study of older adults who completed cognitive tasks while cycling on a stationary bike revealed that the participants cycling speed improved while multi-tasking with no loss to their cognitive performance.
The discovery turned out to be a surprise finding for investigators because they originally set out to determine the degree to which dual-task performance suffers in patients with Parkinson's disease. To do that the researchers had a group of patients with Parkinson's and a group of healthy older adults complete a series of increasingly difficult cognitive tests while cycling.
For the study, 28 people with Parkinsons disease and 20 healthy older adults completed 12 cognitive tests performed once while cycling and then again while sitting. The participants were asked to perform such tasks as saying the word go when a blue star was shown on a projection screen. They were also asked to repeat increasingly long lists of numbers in reverse order of presentation.
A video motion capture system recorded all the participants cycling speeds. They noticed that cognitive performance while cycling was similar to baseline across all tasks. It was also noted that the participants cycling speed was faster when performing the cognitive tests. They also saw the most improvement during the six easiest cognitive tests.
The findings suggest that combining the easier cognitive tests with physical activity may be a way to get people to exercise more vigorously.
- Participants' cycling speed was about 25 percent faster while doing the easiest cognitive tasks but became slower as the cognitive tasks became more difficult.
- The hardest tasks only brought participants back to the speeds at which they were cycling before beginning the cognitive tasks.
- Study participants with Parkinson's disease cycled slower overall and didn't speed up as much as the healthy older adults. That could be because arousal that stems from cognitive and physical exercise is dependent on dopamine and other neurotransmitters, which are impaired in people with Parkinson's.
The participants multi-tasking success was attributed to several factors:
- The cognitive arousal that happens when people anticipate completing a difficult cognitive task.
- The increased arousal from exercise in regions of the brain that control movement. Arousal increases the release of neurotransmitters that improve speed and efficiency of the brain, particularly the frontal lobes, thus improving performance in motor and cognitive tasks.
"Every dual-task study that I'm aware of shows when people are doing two things at once they get worse," said Lori Altmann, an associate professor of speech, language and hearing sciences at the College of Public Health and Health Professions. "Everybody has experienced walking somewhere in a hurry when the person in front of them pulls out a phone, and that person just slows to a crawl. Frankly, that's what we were expecting. As participants were doing the easy tasks, they were really going to town on the bikes, and they didn't even realize it. It was as if the cognitive tasks took their minds off the fact that they were pedaling. What arousal does is give you more attention to focus on a task. When the tasks were really easy, we saw the effect of that attention as people cycled very fast. As the cognitive tasks got harder, they started impinging on the amount of attention available to perform both tasks, so participants didn't cycle quite so fast."