scholarly journals Long-lasting event-related beta synchronizations of electroencephalographic activity in response to support-surface perturbations during upright stance

2020 ◽  
Author(s):  
Akihiro Nakamura ◽  
Yasuyuki Suzuki ◽  
Matija Milosevic ◽  
Taishin Nomura
Keyword(s):  
Upper Extremities ◽  
Support Surface ◽  
Intermittent Control ◽  
Upright Posture ◽  
Upright Stance ◽  
Beta Band ◽  
Ankle Muscles ◽  
Related Potentials ◽  
High Beta ◽  
Postural Recovery

AbstractMovement related beta band cortical oscillations, including beta rebound after execution and/or suppression of movement, have drawn attention in upper extremity motor control literature. However, fewer study focused on beta band oscillations during postural control in upright stance. Here, we examined beta rebound and other components of electroencephalogram (EEG) activity during perturbed upright stance to investigate supraspinal contributions to postural stabilization. Particularly, we aimed to clarify the timing and duration of beta rebound within a non-sustained, but long-lasting, postural recovery process that occurs more slowly compared to upper extremities. To this end, EEG signals were acquired from nine healthy young adults in response to a support-surface perturbation, together with the center of pressure (CoP) and mass (CoM) and electromyogram (EMG) activities of ankle muscles. Event-related potentials (ERPs) and event-related spectral perturbations were computed from EEG data using the perturbation-onset as a triggering event. After short-latency (< 0.3 s) ERPs, our results showed high-beta band power decrease (event-related desynchronization), which was followed by an event-related synchronization at high-beta band and theta band desynchronization. Specifically, beta synchronization (beta rebound) was sustained for as long as three seconds. EMGs of the ankle muscles and the ankle and hip joint torques remained activated in the first half period of the beta rebound. They returned to the steady-state in the remaining phase, where the CoP/CoM were in their final approach to the equilibrium. We propose possible mechanistic causes of the long-lasting beta rebound, which may be related to underlying intermittent control strategy in upright stance.New & NoteworthyBeta rebound cortical activity was identified during postural recovery from a perturbed upright stance. Contrary to upper extremities, it was initiated before the recovery of motion was completed, and sustained for as long as three seconds. Those novel characteristics of the beta rebound might be caused by slow dynamics of the upright posture and by selections of on/off switching in an intermittent feedback controller, which was shown to stabilize upright posture.

scholarly journals Long-Lasting Event-Related Beta Synchronizations of Electroencephalographic Activity in Response to Support-Surface Perturbations During Upright Stance: A Pilot Study Associating Beta Rebound and Active Monitoring in the Intermittent Postural Control

2021 ◽  
Vol 15 ◽  
Author(s):  
Akihiro Nakamura ◽  
Yasuyuki Suzuki ◽  
Matija Milosevic ◽  
Taishin Nomura
Keyword(s):  
Postural Control ◽  
Upper Extremity ◽  
Half Period ◽  
Support Surface ◽  
Intermittent Control ◽  
Upright Stance ◽  
Beta Band ◽  
Active Monitoring ◽  
Related Potentials ◽  
Postural Recovery

Movement related beta band cortical oscillations, including beta rebound after execution and/or suppression of movement, have drawn attention in upper extremity motor control literature. However, fewer studies focused on beta band oscillations during postural control in upright stance. In this preliminary study, we examined beta rebound and other components of electroencephalogram (EEG) activity during perturbed upright stance to investigate supraspinal contributions to postural stabilization. Particularly, we aimed to clarify the timing and duration of beta rebound within a non-sustained, but long-lasting postural recovery process that occurs more slowly compared to upper extremities. To this end, EEG signals were acquired from nine healthy young adults in response to a brief support-surface perturbation, together with the center of pressure, the center of mass and electromyogram (EMG) activities of ankle muscles. Event-related potentials (ERPs) and event-related spectral perturbations were computed from EEG data using the perturbation-onset as a triggering event. After short-latency (&lt;0.3 s) ERPs, our results showed a decrease in high-beta band oscillations (event-related desynchronization), which was followed by a significant increase (event-related synchronization) in the same band, as well as a decrease in theta band oscillations. Unlike during upper extremity motor tasks, the beta rebound in this case was initiated before the postural recovery was completed, and sustained for as long as 3 s with small EMG responses for the first half period, followed by no excessive EMG activities for the second half period. We speculate that those novel characteristics of beta rebound might be caused by slow postural dynamics along a stable manifold of the unstable saddle-type upright equilibrium of the postural control system without active feedback control, but with active monitoring of the postural state, in the framework of the intermittent control.

A Classification of Postural Sway Patterns During Upright Stance in Healthy Adults and Patients with Parkinson’s Disease

2011 ◽  
Vol 15 (8) ◽  
pp. 997-1010 ◽  
Author(s):  
Tomohisa Yamamoto ◽  
◽  
Yasuyuki Suzuki ◽  
Kunihiko Nomura ◽  
Taishin Nomura ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Postural Sway ◽  
Postural Instability ◽  
Elderly Subjects ◽  
Intermittent Control ◽  
Upright Stance ◽  
Muscle Torque ◽  
Ankle Muscles ◽  
Ankle Muscle

The intermittent control during human quiet upright stance is a new hypothesis which claims that the active neural feedback control generating the ankle muscle torque is switched off and on intermittently at appropriate timings. The intermittent strategy is capable of providing compliant posture while ensuring robust stability. Contrastingly, impairment of postural reflexes in patients with Parkinson’s disease (PD) causes postural instability. Here we hypothesize that the instability in PD patients might be due to a loss of appropriate intermittent activations in the feedback muscle torque during stance. In order to provide evidence for this hypothesis, we characterized stochastic postural sway patterns measured as changes in center of pressure (CoP) and activities of ankle muscles during quiet stance in healthy young and elderly subjects as well as PD patients. To this end, sway patterns and associated ankle muscle activities were quantified by several indices including the CoP sway area, scaling factors of double-power-law power spectra of the sway, as well as levels and patterns of the muscle activations. Hierarchical cluster analysis was performed to suggest that the sway patterns could be classified into two major types. The first type consisted mainly of sway and muscle activation patterns from healthy subjects and some PD patients with the mild level of severity, and they showed features indicating the intermittent control. The second type, consisting mainly of PD patients with relatively severe levels of motor symptoms, was accompanied with non-intermittent but tonic muscle activities and sway areas either smaller or larger than those in the first type. Moreover, the major two types were further classified into several subtypes with distinguishable characteristics. Results suggested that a loss of the intermittent activations in the ankle muscles could be a cause of the postural instability for a population of PD patients.

scholarly journals Bilateral Intracranial Beta Activity during Forced and Spontaneous Movements in a Hemi-PD Rat Model

2020 ◽  
Author(s):  
Soheil Mottaghi ◽  
Sandra Kohl ◽  
Dirk Biemann ◽  
Samuel Liebana ◽  
Ruth Montano ◽  
...  
Keyword(s):  
Beta Activity ◽  
Beta Band ◽  
Motor Impairments ◽  
Beta Oscillations ◽  
Impaired Performance ◽  
Novel Treatments ◽  
Spontaneous Movements ◽  
Electrophysiological Characterization ◽  
New Treatments ◽  
High Beta

AbstractCortico-basal ganglia beta oscillations (13-30Hz) are assumed to be involved in motor impairments in Parkinson’s Disease (PD), especially in bradykinesia and rigidity. Various studies have utilized the unilateral 6-OHDA rat PD model to further investigate PD and test novel treatments. However, a detailed behavioral and electrophysiological characterization of the model, including analyses of popular PD treatments such as DBS, has not been documented in the literature. We hence challenged the 6-OHDA rat PD model with a series of experiments (i.e. cylinder test, open field test and rotarod test) aimed at assessing the motor impairments, analyzing the effects of Deep Brain Stimulation (DBS), and identifying under which conditions excessive beta oscillations occur. We found that hemi-PD rats presented an impaired performance in all experiments compared to the sham group, and DBS could improve their overall performance. Across all the experiments and behaviors, the power in the high beta band was observed to be an important biomarker for PD as it showed differences between healthy and lesioned hemispheres and between PD and sham rats. This all shows that the 6-OHDA PD model accurately represents many of the motor and electrophysiological symptoms of PD and makes it a useful tool for the pre-clinical testing of new treatments and further investigations into this disease.

Trunk in Stroke

2022 ◽  
pp. 170-180
Author(s):  
Esra Dogru Huzmeli ◽  
Ozden Gokcek
Keyword(s):  
Human Body ◽  
The Body ◽  
Support Surface ◽  
Upright Posture ◽  
Lower Body ◽  
Control Test ◽  
Limb Movements ◽  
Trunk Control ◽  
Body Regions ◽  
And Performance

The trunk is the part of the human body that provides basic mechanical stabilization. It provides strength transmission between the upper and lower body regions. Body control is the ability of the body muscles to maintain the upright posture, to adapt to weight transfers, and to maintain selective trunk and limb movements by maintaining the support surface in static and dynamic postural adjustments. Good proximal trunk control provides better distal limb movements, balance, and functional motion. There are many evaluation methods, devices, and scales for trunk function and performance. 3D kinematic, electromyography, hand-held dynamometer, isokinetic dynamometer, trunk accelerometer are some devices that measure trunk function. The motor assessment scale-trunk subscale, the stroke impairment assessment set- trunk control subscale, trunk control test, trunk impairment scale are the most used scales. This chapter explores the effect of strokes on the trunk.

The role of vestibular and somatosensory systems in intersegmental control of upright stance

2008 ◽  
Vol 18 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Rob Creath ◽  
Tim Kiemel ◽  
Fay Horak ◽  
John J. Jeka
Keyword(s):  
Support Surface ◽  
Light Touch ◽  
Upright Stance ◽  
Rotating Platform ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss ◽  
Eyes Closed ◽  
Intersegmental Dynamics ◽  
Somatosensory Information ◽  
Leg Coordination

Upright stance was perturbed using sinusoidal platform rotations to see how vestibular and somatosensory information are used to control segment and intersegmental dynamics in subjects with bilateral vestibular loss (BVL) and healthy controls (C). Subjects stood with eyes closed on a rotating platform (±1.2° for frequencies ranging from 0.01–0.4 Hz in the presence and absence of light fingertip touch. Trunk movement relative to the platform of BVLs was higher than Cs at higher platform frequencies whereas leg movement relative to the platform was similar for both groups. With the addition of light touch, both groups showed similar trunk and leg segment movement relative to the platform. Trunk-leg coordination was in-phase for frequencies below 1 Hz and anti-phase above 1 Hz. Interestingly, BVLs showed evidence of a "legs-leading-trunk" relationship in the shift from in-phase to anti-phase around 1 Hz. Controls showed no preference for either segment to lead the coordinative shift from in- to anti-phase. The results suggest that the balance instability of BVL subjects stems from high variability of the trunk, rather than the legs. The high trunk variability may emerge from the "legs-leading" intersegmental relationship upon which BVLs rely. Because BVLs derive information about self-orientation primarily from the support surface when their eyes are closed, the legs initiate the shift to anti-phase trunk-leg coordination that is necessary for stable upright stance control. Higher trunk variability suggests that this strategy results in lower overall postural stability. Light touch substitutes for vestibular information, leading to lower trunk variability along with a trunk-leg phase shift similar to controls, without a preference for either segment to lead the shift. The results suggest that vestibulospinal control acts primarily to stabilize the trunk in space and to facilitate intersegmental dynamics.

Recovery of Postural Control After an Acute Unilateral Vestibular Lesion in Humans

1991 ◽  
Vol 1 (4) ◽  
pp. 373-383
Author(s):  
Michael Fetter ◽  
Hans-Christoph Diener ◽  
Johannes Dichgans
Keyword(s):  
Postural Control ◽  
Acute Phase ◽  
Time Course ◽  
Sensory Input ◽  
Characteristic Pattern ◽  
Support Surface ◽  
Upright Stance ◽  
Spinal Balance ◽  
Vestibular Lesion ◽  
Postural Responses

Postural control during stance was investigated using the EQUITEST® system in 10 patients during recovery after an acute unilateral vestibular lesion and was compared to the time course of recovery of the static and dynamic vestibulo-ocular imbalance. During the acute phase the patients showed a characteristic pattern with normal upright stance as long as at least one accurate sensory input (visual or somatosensory) was provided and severe postural disturbances when they had to rely primarily on vestibular afferences. Both static vestibulo-ocular and vestibulo-spinal balance recovered very fast, showing basically normal results on postural testing within about 2 weeks after the lesion. Thereafter, no pathological pattern was detectable during postural testing even in patients with persistent complete unilateral vestibular lesions. Reflexive postural responses to unexpected rapid displacements of the support surface seemed not to be influenced by vestibular imbalance even in the acute phase of the lesion.

On the reflex coactivation of ankle flexor and extensor muscles induced by a sudden drop of support surface during walking in humans

2004 ◽  
Vol 96 (2) ◽  
pp. 604-611 ◽  
Author(s):  
Kimitaka Nakazawa ◽  
Noritaka Kawashima ◽  
Masami Akai ◽  
Hideo Yano
Keyword(s):  
Stretch Reflex ◽  
Stance Phase ◽  
Human Walking ◽  
Heel Strike ◽  
Emg Activity ◽  
Support Surface ◽  
Sudden Drop ◽  
Reflex Responses ◽  
Ankle Muscles ◽  
Extensor Muscles

Recent studies have revealed that the stretch reflex responses of both ankle flexor and extensor muscles are coaugmented in the early stance phase of human walking, suggesting that these coaugmented reflex responses contribute to secure foot stabilization around the heel strike. To test whether the reflex responses mediated by the stretch reflex pathway are actually induced in both the ankle flexor and extensor muscles when the supportive surface is suddenly destabilized, we investigated the electromyographic (EMG) responses induced after a sudden drop of the supportive surface at the early stance phase of human walking. While subjects walked on a walkway, the specially designed movable supportive surface was unexpectedly dropped 10 mm during the early stance phase. The results showed that short-latency reflex EMG responses after the impact of the drop (<50 ms) were consistently observed in both the ankle flexor and extensor muscles in the perturbed leg. Of particular interest was that a distinct response appeared in the tibialis anterior muscle, although this muscle showed little background EMG activity during the stance phase. These results indicated that the reflex activities in the ankle muscles certainly acted when the supportive surface was unexpectedly destabilized just after the heel strike during walking. These reflex responses were most probably mediated by the facilitated stretch reflex pathways of the ankle muscles at the early stance phase and were suggested to be relevant to secure stabilization around the ankle joint during human walking.

scholarly journals Exploring EEG Characteristics to Identify Emotional Reactions under Videogame Scenarios

2021 ◽  
Vol 11 (3) ◽  
pp. 378
Author(s):  
Laura Martínez-Tejada ◽  
Alex Puertas-González ◽  
Natsue Yoshimura ◽  
Yasuharu Koike
Keyword(s):  
Frequency Domain ◽  
Event Related Potentials ◽  
Classification Performance ◽  
Emotional Reactions ◽  
Strong Correlations ◽  
Theta Band ◽  
Beta Band ◽  
Emotional Information ◽  
Related Potentials ◽  
Arousal And Valence

In this article we present the study of electroencephalography (EEG) traits for emotion recognition process using a videogame as a stimuli tool, and considering two different kind of information related to emotions: arousal–valence self-assesses answers from participants, and game events that represented positive and negative emotional experiences under the videogame context. We performed a statistical analysis using Spearman’s correlation between the EEG traits and the emotional information. We found that EEG traits had strong correlation with arousal and valence scores; also, common EEG traits with strong correlations, belonged to the theta band of the central channels. Then, we implemented a regression algorithm with feature selection to predict arousal and valence scores using EEG traits. We achieved better result for arousal regression, than for valence regression. EEG traits selected for arousal and valence regression belonged to time domain (standard deviation, complexity, mobility, kurtosis, skewness), and frequency domain (power spectral density—PDS, and differential entropy—DE from theta, alpha, beta, gamma, and all EEG frequency spectrum). Addressing game events, we found that EEG traits related with the theta, alpha and beta band had strong correlations. In addition, distinctive event-related potentials where identified in the presence of both types of game events. Finally, we implemented a classification algorithm to discriminate between positive and negative events using EEG traits to identify emotional information. We obtained good classification performance using only two traits related with frequency domain on the theta band and on the full EEG spectrum.

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