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Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

Lu CF, Liu YC, Yang YR, Wu YT, Wang RY - PLoS ONE (2015)

Bottom Line: Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties.WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only.Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

View Article: PubMed Central - PubMed

Affiliation: Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC; Department of Radiology, School of Medicine, Taipei Medical University, Taipei, Taiwan, ROC; Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan, ROC.

ABSTRACT
In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC), premotor cortices (PMC), and supplemental motor areas (SMA), using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT). Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

No MeSH data available.


Related in: MedlinePlus

The averaged dynamics of HbO (red curves), HbR concentrations (blue curves), and Hbdiff level (green curves) at the left PFC (Channel 1) during (a) WMT and (b) WCT.The horizontal solid lines depict the concentration level of zero, and the vertical solid lines label the time of zero for the task onset. The early and late phases are defined as the periods of 5 to 20 s and 21 to 50 s after the task onset, respectively. The error bars represent the corresponding standard errors of mean.
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pone.0129390.g002: The averaged dynamics of HbO (red curves), HbR concentrations (blue curves), and Hbdiff level (green curves) at the left PFC (Channel 1) during (a) WMT and (b) WCT.The horizontal solid lines depict the concentration level of zero, and the vertical solid lines label the time of zero for the task onset. The early and late phases are defined as the periods of 5 to 20 s and 21 to 50 s after the task onset, respectively. The error bars represent the corresponding standard errors of mean.

Mentions: A block design with a 20–30-second task period is commonly used in fNIRS studies [9, 42, 56, 60]. In this study, a longer task period (60 s) was used to investigate brain activation in the first 20 seconds after task onset as well as in the subsequent 30 seconds. The period between 5 and 20 seconds after task onset was defined as the early phase to reflect the immediate hemodynamic response when performing tasks (Fig 2). The period between 21 and 50 seconds after task onset was defined as the late phase to assess continuous brain activation (Fig 2). The 3 possible patterns of activation were no activation in early and late phases, activation in the early phase but not the late phase (Fig 2A), and activation in early and late phases (Fig 2B). The first 5 seconds and final 10 seconds of each task period were excluded to eliminate the transient periods of hemodynamic responses [25].


Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

Lu CF, Liu YC, Yang YR, Wu YT, Wang RY - PLoS ONE (2015)

The averaged dynamics of HbO (red curves), HbR concentrations (blue curves), and Hbdiff level (green curves) at the left PFC (Channel 1) during (a) WMT and (b) WCT.The horizontal solid lines depict the concentration level of zero, and the vertical solid lines label the time of zero for the task onset. The early and late phases are defined as the periods of 5 to 20 s and 21 to 50 s after the task onset, respectively. The error bars represent the corresponding standard errors of mean.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4469417&req=5

pone.0129390.g002: The averaged dynamics of HbO (red curves), HbR concentrations (blue curves), and Hbdiff level (green curves) at the left PFC (Channel 1) during (a) WMT and (b) WCT.The horizontal solid lines depict the concentration level of zero, and the vertical solid lines label the time of zero for the task onset. The early and late phases are defined as the periods of 5 to 20 s and 21 to 50 s after the task onset, respectively. The error bars represent the corresponding standard errors of mean.
Mentions: A block design with a 20–30-second task period is commonly used in fNIRS studies [9, 42, 56, 60]. In this study, a longer task period (60 s) was used to investigate brain activation in the first 20 seconds after task onset as well as in the subsequent 30 seconds. The period between 5 and 20 seconds after task onset was defined as the early phase to reflect the immediate hemodynamic response when performing tasks (Fig 2). The period between 21 and 50 seconds after task onset was defined as the late phase to assess continuous brain activation (Fig 2). The 3 possible patterns of activation were no activation in early and late phases, activation in the early phase but not the late phase (Fig 2A), and activation in early and late phases (Fig 2B). The first 5 seconds and final 10 seconds of each task period were excluded to eliminate the transient periods of hemodynamic responses [25].

Bottom Line: Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties.WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only.Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

View Article: PubMed Central - PubMed

Affiliation: Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC; Department of Radiology, School of Medicine, Taipei Medical University, Taipei, Taiwan, ROC; Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan, ROC.

ABSTRACT
In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC), premotor cortices (PMC), and supplemental motor areas (SMA), using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT). Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

No MeSH data available.


Related in: MedlinePlus