The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform

Christopher J. Dakin - One of the best experts on this subject based on the ideXlab platform.

  • Vestibular attenuation to Random-Waveform galvanic vestibular stimulation during standing and treadmill walking
    Scientific Reports, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The ability to move and maintain posture is critically dependent on motion and orientation information provided by the vestibular system. When this system delivers noisy or erred information it can, in some cases, be attenuated through habituation. Here we investigate whether multiple mechanisms of attenuation act to decrease vestibular gain due to noise added using supra-threshold Random-Waveform galvanic vestibular stimulation (GVS). Forty-five participants completed one of three conditions. Each condition consisted of two 4-min standing periods with stimulation surrounding a 1-h period of either walking with stimulation, walking without stimulation, or sitting quietly. An instrumented treadmill recorded horizontal forces at the feet during standing and walking. We quantified response attenuation to GVS by comparing vestibular stimulus-horizontal force gain between conditions. First stimulus exposure caused an 18% decrease in gain during the first 40 s of standing. Attenuation recommenced only when subjects walked with stimulation, resulting in a 38% decrease in gain over 60 min that did not transfer to standing following walking. The disparity in attenuation dynamics and absent carry over between standing and walking suggests that two mechanisms of attenuation, one associated with first exposure to the stimulus and another that is task specific, may act to decrease vestibulomotor gain.

  • Absence of Nonlinear Coupling Between Electric Vestibular Stimulation and Evoked Forces During Standing Balance
    Frontiers in human neuroscience, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The vestibular system encodes motion and orientation of the head in space and is essential for negotiating in and interacting with the world. Recently, Random Waveform electric vestibular stimulation has become an increasingly common means of probing the vestibular system. However, many of the methods used to analyze the behavioral response to this type of stimulation assume a linear relationship between frequencies in the stimulus and its associated response. Here we examine this stimulus-response frequency linearity to determine the validity of this assumption. Forty-five university-aged subjects stood on a force-plate for four minutes while receiving vestibular stimulation. To determine the linearity of the stimulus-response relationship we calculated the cross-frequency power coupling between a 0-25 Hz bandwidth limited white noise stimulus and induced postural responses, as measured using the horizontal forces acting at the feet. Ultimately, we found that, on average, the postural response to a Random stimulus is linear across stimulation frequencies. This result supports the use of analysis methods that depend on the assumption of stimulus-response frequency linearity, such as coherence and gain, which are commonly used to analyze the body’s response to Random Waveform electric stimuli.

Jianping Yao - One of the best experts on this subject based on the ideXlab platform.

  • real time Random grating sensor array for quasi distributed sensing based on wavelength to time mapping and time division multiplexing
    Optics Letters, 2019
    Co-Authors: Jingxuan Liu, Stephen J. Mihailov, Muguang Wang, Jianping Yao
    Abstract:

    A real-time Random grating sensor array for quasi-distributed sensing based on spectral-shaping and wavelength-to-time (SS-WTT) mapping and time-division multiplexing is proposed and experimentally demonstrated. The sensor array consists of multiple Random gratings written in a single-mode fiber (SMF) at different physical locations. When the temperature or strain applied to a particular Random grating is changed, the central wavelength of the reflection spectrum of the Random grating will change, which is converted to the time domain as a time shift based on SS-WTT using a linearly chirped fiber Bragg grating. After detection at a photodetector, an electrical Waveform with the time shift information encoded in the Random Waveform is obtained, which is further compressed by correlation to increase the time resolution. As a demonstration, a real-time quasi-distributed sensing system based on a two-Random-grating array is implemented. The results show that the sensing resolutions for temperature and strain are 0.23°C and 2.5 μϵ, respectively, and the accuracies for temperature and strain are 0.11°C and 1.2 μϵ, respectively. Compared with a conventional quasi-distributed sensor, our proposed sensing system has key advantages, including real-time sensing, high-resolution interrogation, and large scalability.

  • photonic generation of pseudo Random microwave Waveform based on a Random fiber grating
    Optical Fiber Communication Conference, 2018
    Co-Authors: Hong Deng, Stephen J. Mihailov, Jianping Yao
    Abstract:

    A photonic approach to pseudo-Random Waveform generation based on a Random fiber grating is proposed and demonstrated. A pseudo-Random Waveform with a temporal duration of 10 ns and a time-bandwidth product of 322.4 is demonstrated.

  • OFC - Photonic Generation of Pseudo Random Microwave Waveform Based on a Random Fiber Grating
    Optical Fiber Communication Conference, 2018
    Co-Authors: Hong Deng, Stephen J. Mihailov, Jianping Yao
    Abstract:

    A photonic approach to pseudo-Random Waveform generation based on a Random fiber grating is proposed and demonstrated. A pseudo-Random Waveform with a temporal duration of 10 ns and a time-bandwidth product of 322.4 is demonstrated.

Kelci B. Hannan - One of the best experts on this subject based on the ideXlab platform.

  • Vestibular attenuation to Random-Waveform galvanic vestibular stimulation during standing and treadmill walking
    Scientific Reports, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The ability to move and maintain posture is critically dependent on motion and orientation information provided by the vestibular system. When this system delivers noisy or erred information it can, in some cases, be attenuated through habituation. Here we investigate whether multiple mechanisms of attenuation act to decrease vestibular gain due to noise added using supra-threshold Random-Waveform galvanic vestibular stimulation (GVS). Forty-five participants completed one of three conditions. Each condition consisted of two 4-min standing periods with stimulation surrounding a 1-h period of either walking with stimulation, walking without stimulation, or sitting quietly. An instrumented treadmill recorded horizontal forces at the feet during standing and walking. We quantified response attenuation to GVS by comparing vestibular stimulus-horizontal force gain between conditions. First stimulus exposure caused an 18% decrease in gain during the first 40 s of standing. Attenuation recommenced only when subjects walked with stimulation, resulting in a 38% decrease in gain over 60 min that did not transfer to standing following walking. The disparity in attenuation dynamics and absent carry over between standing and walking suggests that two mechanisms of attenuation, one associated with first exposure to the stimulus and another that is task specific, may act to decrease vestibulomotor gain.

  • Absence of Nonlinear Coupling Between Electric Vestibular Stimulation and Evoked Forces During Standing Balance
    Frontiers in human neuroscience, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The vestibular system encodes motion and orientation of the head in space and is essential for negotiating in and interacting with the world. Recently, Random Waveform electric vestibular stimulation has become an increasingly common means of probing the vestibular system. However, many of the methods used to analyze the behavioral response to this type of stimulation assume a linear relationship between frequencies in the stimulus and its associated response. Here we examine this stimulus-response frequency linearity to determine the validity of this assumption. Forty-five university-aged subjects stood on a force-plate for four minutes while receiving vestibular stimulation. To determine the linearity of the stimulus-response relationship we calculated the cross-frequency power coupling between a 0-25 Hz bandwidth limited white noise stimulus and induced postural responses, as measured using the horizontal forces acting at the feet. Ultimately, we found that, on average, the postural response to a Random stimulus is linear across stimulation frequencies. This result supports the use of analysis methods that depend on the assumption of stimulus-response frequency linearity, such as coherence and gain, which are commonly used to analyze the body’s response to Random Waveform electric stimuli.

Patrick A. Forbes - One of the best experts on this subject based on the ideXlab platform.

  • Vestibular attenuation to Random-Waveform galvanic vestibular stimulation during standing and treadmill walking
    Scientific Reports, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The ability to move and maintain posture is critically dependent on motion and orientation information provided by the vestibular system. When this system delivers noisy or erred information it can, in some cases, be attenuated through habituation. Here we investigate whether multiple mechanisms of attenuation act to decrease vestibular gain due to noise added using supra-threshold Random-Waveform galvanic vestibular stimulation (GVS). Forty-five participants completed one of three conditions. Each condition consisted of two 4-min standing periods with stimulation surrounding a 1-h period of either walking with stimulation, walking without stimulation, or sitting quietly. An instrumented treadmill recorded horizontal forces at the feet during standing and walking. We quantified response attenuation to GVS by comparing vestibular stimulus-horizontal force gain between conditions. First stimulus exposure caused an 18% decrease in gain during the first 40 s of standing. Attenuation recommenced only when subjects walked with stimulation, resulting in a 38% decrease in gain over 60 min that did not transfer to standing following walking. The disparity in attenuation dynamics and absent carry over between standing and walking suggests that two mechanisms of attenuation, one associated with first exposure to the stimulus and another that is task specific, may act to decrease vestibulomotor gain.

  • Absence of Nonlinear Coupling Between Electric Vestibular Stimulation and Evoked Forces During Standing Balance
    Frontiers in human neuroscience, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The vestibular system encodes motion and orientation of the head in space and is essential for negotiating in and interacting with the world. Recently, Random Waveform electric vestibular stimulation has become an increasingly common means of probing the vestibular system. However, many of the methods used to analyze the behavioral response to this type of stimulation assume a linear relationship between frequencies in the stimulus and its associated response. Here we examine this stimulus-response frequency linearity to determine the validity of this assumption. Forty-five university-aged subjects stood on a force-plate for four minutes while receiving vestibular stimulation. To determine the linearity of the stimulus-response relationship we calculated the cross-frequency power coupling between a 0-25 Hz bandwidth limited white noise stimulus and induced postural responses, as measured using the horizontal forces acting at the feet. Ultimately, we found that, on average, the postural response to a Random stimulus is linear across stimulation frequencies. This result supports the use of analysis methods that depend on the assumption of stimulus-response frequency linearity, such as coherence and gain, which are commonly used to analyze the body’s response to Random Waveform electric stimuli.

Nicole J. Pearson - One of the best experts on this subject based on the ideXlab platform.

  • Vestibular attenuation to Random-Waveform galvanic vestibular stimulation during standing and treadmill walking
    Scientific Reports, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The ability to move and maintain posture is critically dependent on motion and orientation information provided by the vestibular system. When this system delivers noisy or erred information it can, in some cases, be attenuated through habituation. Here we investigate whether multiple mechanisms of attenuation act to decrease vestibular gain due to noise added using supra-threshold Random-Waveform galvanic vestibular stimulation (GVS). Forty-five participants completed one of three conditions. Each condition consisted of two 4-min standing periods with stimulation surrounding a 1-h period of either walking with stimulation, walking without stimulation, or sitting quietly. An instrumented treadmill recorded horizontal forces at the feet during standing and walking. We quantified response attenuation to GVS by comparing vestibular stimulus-horizontal force gain between conditions. First stimulus exposure caused an 18% decrease in gain during the first 40 s of standing. Attenuation recommenced only when subjects walked with stimulation, resulting in a 38% decrease in gain over 60 min that did not transfer to standing following walking. The disparity in attenuation dynamics and absent carry over between standing and walking suggests that two mechanisms of attenuation, one associated with first exposure to the stimulus and another that is task specific, may act to decrease vestibulomotor gain.

  • Absence of Nonlinear Coupling Between Electric Vestibular Stimulation and Evoked Forces During Standing Balance
    Frontiers in human neuroscience, 2021
    Co-Authors: Kelci B. Hannan, Makina K. Todd, Nicole J. Pearson, Patrick A. Forbes, Christopher J. Dakin
    Abstract:

    The vestibular system encodes motion and orientation of the head in space and is essential for negotiating in and interacting with the world. Recently, Random Waveform electric vestibular stimulation has become an increasingly common means of probing the vestibular system. However, many of the methods used to analyze the behavioral response to this type of stimulation assume a linear relationship between frequencies in the stimulus and its associated response. Here we examine this stimulus-response frequency linearity to determine the validity of this assumption. Forty-five university-aged subjects stood on a force-plate for four minutes while receiving vestibular stimulation. To determine the linearity of the stimulus-response relationship we calculated the cross-frequency power coupling between a 0-25 Hz bandwidth limited white noise stimulus and induced postural responses, as measured using the horizontal forces acting at the feet. Ultimately, we found that, on average, the postural response to a Random stimulus is linear across stimulation frequencies. This result supports the use of analysis methods that depend on the assumption of stimulus-response frequency linearity, such as coherence and gain, which are commonly used to analyze the body’s response to Random Waveform electric stimuli.