Given the task definition and input, reply with output. In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

Unexpectedly, cycling speed actually increased during dual tasks, leading to dual task benefits rather than the expected dual task costs for both populations. Further, DTEs of the PD group were less than those of the HOAs, rather than greater. Simultaneously, performance in cognitive tasks in the dual task condition did not differ from single task performance with three exceptions, performance in two cognitive tasks improved (although the difference was not significant when age was covaried) and performance in one cognitive task declined in both groups. These findings cannot be explained by current theories in which dual task effects are attributed to the cognitive demands of the two concurrent tasks exceeding available cognitive resources. We conclude that additional factors must be playing a role in dual task situations. 
  
 Accounting for Dual Task Benefits 
  
 Research on acute exercise, which examines cognitive performance during dual tasks when exercise levels are held constant, offers a partial explanation. The acute exercise literature posits that exercise-related arousal increases the amount of processing resources available for the concomitant, “secondary” cognitive task, sometimes leading to improved cognitive performance during exercise relative to performance with no exercise task [32]. However, because the intensity of the exercise is always controlled in acute exercise research, their findings cannot address the improvements in cycling performance found in the current study. 
  
 To account for the findings of the current study and unify the findings of the acute exercise and the dual task research, these data suggest that a model of dual task performance should incorporate the arousing effects of the cognitive tasks on motor performance as well as physiological arousal due to the exercise itself [33,34]. Specifically, the perception that performing motor and cognitive tasks concurrently will be challenging could increase overall arousal [35]. Crucially, both cognitive and exercise-related arousal have been associated with increases in cognitive resources, improvements in speed, and greater efficiency of cognitive and motor responses [32,33,36]. Moreover, both physiological and cognitive arousal have been attributed to increased release of catecholamines, particularly epinephrine, norepinephrine and dopamine [33–36]. 
  
 Specifically, we hypothesize that when faced with dual tasks, the perception that performing the tasks concurrently will be novel and challenging could increase cognitive arousal [36], triggering the release of dopamine and norepinephrine. This increased production of catecholamines would increase the availability of supplementary cognitive resources that, in turn, facilitates performance in both the cognitive and motor task. Consequently, dual task performance will be based on this increased level of cognitive resources, as modulated by the attentional demands of the concurrent tasks. Based on this reasoning, we posit an expansion of Kahneman’s account of dual task performance [9] and the exercise-related arousal model discussed in the acute exercise literature [10,34], which we call the Arousal and Attentional Demands (AAD) model of dual task performance. According to the AAD model, when the increase in attentional resources due to cognitive and physiological arousal matches the actual demands of the combined dual tasks, performance on both tasks can be maintained with no observable dual task cost. Dual task costs only appear when the additional arousal due to the dual tasks does not provide adequate cognitive resources to maintain performance levels in both tasks. Conversely, according to the AAD model, when the cognitive demands of the combined dual tasks are less than anticipated, the increased arousal can result in dual task benefits on performance rather than dual task costs, as found in the current study. 
  
 The catecholamine-dependent arousal hypothesized by the AAD predicts that people with low levels of dopamine, norepinephrine and epinephrine will show significant differences in dual task effects from control subjects. PD leads to deterioration of dopaminergic input to frontal and subcortical regions [37,38] which would necessarily affect levels of norepinephrine and epinephrine [39]. Therefore, people with PD might be expected to demonstrate limited catecholamine-dependent arousal when challenged with a dual task. This reasoning is consistent with the findings of the current study. The PD group exhibited DTEs below those of HOAs in all 12 tasks in the current study (mean difference 8.1%, range 3.9%–13.5%). In studies with more difficult motor tasks such as walking or maintaining balance, the AAD model would predict that participants with PD would benefit less from dopamine-dependent arousal and, consequently, evince greater dual task impairments than HOAs, which is indeed the typical finding in the literature [13]. 
  
 Interestingly, the mechanism that we hypothesize is responsible for our findings, the release of dopamine and/or norepinephrine due to challenging, exogenous stimuli, is a similar mechanism to that postulated to underlie kinesia paradoxica in PD [40,41]. Kinesia paradoxica is the phenomenon in which motor performance is facilitated by a threatening event, such as moving to avoid an approaching object. Kinesia paradoxica effects are believed to be due to arousal mediated primarily by stress, leading to increased production of noradrenaline and epinephrine [34]. Alternatively, contextual or psychological factors may also trigger a release of striatal or mesolimbic dopamine that facilitates motor performance [40,42]. Importantly, these accounts are not mutually exclusive; both may play a role in the phenomenon [35]. It is possible that kinesia paradoxica and dual task performance may represent different instances of similar arousal-related, catecholamine-dependent, physiological phenomena that differ primarily in magnitude. 
  
 While we have adopted Kahneman’s approach to dual task performance, in which processing resources are shared between the ongoing motor and cognitive tasks [9, 10], as the foundation for the AAD, other explanations for dual task effects have been offered. In particular, it has been suggested dual task performance involves switching attention between tasks [43], so dual task costs actually represent switch costs in this explanation. To account for the current findings, this conceptualization of dual task performance would also need to invoke the effects of cognitive and exercise-related arousal; however, it would have more difficulty accounting for the changes in cycling performance with increasing task difficulty. Thus, accounting for the findings of the current study, as well as findings from the acute exercise and dual literatures, would be a significant challenge for the task-switching account of dual task performance. ||||| Who says you can't do two things at once and do them both well? 
  
 A new University of Florida study challenges the notion that multi-tasking causes one or both activities to suffer. In a study of older adults who completed cognitive tasks while cycling on a stationary bike, UF researchers found that participants' cycling speed improved while multi-tasking with no cost to their cognitive performance. 
  
 Results of the study, which was supported by a grant from the National Institute on Aging, were published May 13 in the journal PLOS ONE. 
  
 The discovery was a surprise finding for investigators Lori Altmann, an associate professor of speech, language and hearing sciences at the College of Public Health and Health Professions, and Chris Hass, an associate professor of applied physiology and kinesiology in the College of Health and Human Performance. They originally set out to determine the degree to which dual task performance suffers in patients with Parkinson's disease. To do this, 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. 
  
 "Every dual-task study that I'm aware of shows when people are doing two things at once they get worse," Altmann said. "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." 
  
 Participants' cycling speed was about 25 percent faster while doing the easiest cognitive tasks but became slower as the cognitive tasks became more difficult. Yet, the hardest tasks only brought participants back to the speeds at which they were cycling before beginning the cognitive tasks. The findings suggest that combining the easier cognitive tasks with physical activity may be a way to get people to exercise more vigorously. The researchers plan to make this a topic for future research. 
  
 "As participants were doing the easy tasks, they were really going to town on the bikes, and they didn't even realize it," Altmann said. "It was as if the cognitive tasks took their minds off the fact that they were pedaling." 
  
 During the study, 28 participants with Parkinson's disease and 20 healthy older adults completed 12 cognitive tasks while sitting in a quiet room and again while cycling. Tasks ranged in difficulty from saying the word 'go' when a blue star was shown on a projection screen to repeating increasingly long lists of numbers in reverse order of presentation. A video motion capture system recorded participants' cycling speed. 
  
 Their cycling speed was faster while performing the cognitive tasks, with the most improvement during the six easiest cognitive tasks. Cognitive performance while cycling was similar to baseline across all tasks. 
  
 The reasons for participants' multi-tasking success most likely include multiple factors, the researchers say, but they hypothesize that one explanation could be the cognitive arousal that happens when people anticipate completing a difficult cognitive task. Similarly, exercise increases arousal 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. 
  
 "What arousal does is give you more attention to focus on a task," Altmann said. "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." 
  
 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. 
  
 Altmann and Hass are currently studying whether multi-tasking benefits will extend to other types of exercise, including use of an elliptical trainer. They hope to eventually examine whether pairing mental tasks with exercise can lead to both cognitive and fitness improvements in older adults. 
  
 ### ||||| Trying to do multiple things at once can have mixed results; you may accomplish more, or you may not get anything done. When it comes to exercising, though, multitasking may be a good idea, a new study suggests. 
  
 In the study of older adults, researchers found that, when people completed easy cognitive tasks while they were cycling on a stationary bike, their cycling speed increased. 
  
 The investigators said the results surprised them. "Every dual-task study that I'm aware of shows that, when people are doing two things at once, they get worse" at those tasks, study author Lori Altmann, an associate professor of speech, language and hearing sciences at the University of Florida, said in a statement. "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." 
  
 In the study, the researchers looked at 20 healthy adults whose average age was 73, and 28 people with Parkinson's disease, whose average age was 66. The participants completed 12 cognitive tasks while they were sitting in a quiet room, and then they did the tasks again as they were cycling. The easiest tasks included saying the word "go" whenever a blue star appeared on a projection screen, and the most difficult tasks involved repeating long lists of numbers in the reverse order in which they were given. The researchers recorded the people's cycling speed using a video motion-capture system. 
  
 In the healthy group, the participants sped up by about 25 percent on average when they were doing the easiest tasks. "Some of the people in that group actually doubled their speed during that task," Altmann told Live Science. 
  
 The people with Parkinson's disease also sped up while performing the easiest tasks, but not as much as the people in the healthy group, the study found. [10 Ways to Keep Your Mind Sharp ] 
  
 However, all of the participants decreased their speed as the tasks became more difficult. Still, the speeds at which the people cycled while doing the most difficult cognitive tasks were about the same as the speeds at which they cycled before they began the tasks, the researchers said. 
  
 It is not exactly clear why doing an easy task appeared to help people cycle faster, but the explanation may have something to with the release of certain neurotransmitters in the brain, the researchers said. During exercise, the brain releases two such neurotransmitters, dopamine and noradrenaline, which speed up people's thinking and reaction times, Altmann said. 
  
 Research also has shown that those same neurotransmitters are released when a person is exposed to novel and challenging tasks. The researchers think that these two venues of neurotransmitter release may improve the efficiency of the brain, and thus boost both motor and cognitive performance, they said. 
  
 In the future, the researchers would like to see if they could use their findings to get older adults to exercise more intensely, Altmann said. A lot of older adults have started exercising in recent years, and some may be encouraged by research showing that exercise may improve people's thinking skills. But some people do not exercise intensely enough to gain health benefits from aerobic exercise because they don't like to get sweaty, Altmann said. 
  
 The people in the study did not even realize they were cycling faster, and therefore exercising more intensely, when they were doing the cognitive tasks, she said. If researchers could figure out a way to convert the concept of the study into a game format, they could perhaps get older people to increase the intensity of their workouts, Altmann said. 
  
 The study was published May 13 in the journal PLOS ONE. 
  
 Follow Agata Blaszczak-Boxe on Twitter. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science. |||||

That person reading a book on the treadmill may be on to something. A University of Florida study published last month in PLOS ONE showed that older people may be able to exercise more intensely—and gain the benefits associated with that—by doing two things at once. The scientists examined 20 healthy people with an average age of 73, and 28 people with Parkinson's disease who were 7 years younger on average, per LiveScience. The participants completed a dozen cognitive tasks while sitting in a room and while pedaling a stationary bike. They healthy participants sped up their pedaling an average of 25% (some hit 50%) when they were completing the simplest tasks, like saying "pa" as many times as they could in 10 seconds, or saying the word "go" when a blue star flashed on a projection screen. (Never mind that the word "go" might prod one to do anything faster...) When the tasks became more difficult, the participants slowed—but in healthy adults, their speeds were, on average, never less than 2.6% faster than their baseline speed. The researchers propose that cognitive tasks release the neurotransmitters dopamine and noradrenaline, which can make the brain's frontal lobes speedier and more efficient; in turn, motor and cognitive performance improve. Those with Parkinson’s disease pedaled slower than the healthy adults (but still faster, on average, than their baseline speed while completing 9 of the tasks), which researchers believe is due to deficits in their neurotransmitters. Researcher Lori Altmann was surprised by the findings: "Every dual-task study that I'm aware of shows when people are doing two things at once they get worse," she says in a press release. (Could the "thunder god vine" end obesity?)