scholarly journals Motor cortical beta transients delay movement initiation and track errors

2018 ◽  
Author(s):  
Simon Little ◽  
James Bonaiuto ◽  
Gareth Barnes ◽  
Sven Bestmann
Keyword(s):  
Movement Control ◽  
Monitoring And Evaluation ◽  
Human Movement ◽  
High Amplitude ◽  
Burst Activity ◽  
Beta Activity ◽  
Movement Initiation ◽  
Before And After ◽  
Motor Cortical ◽  
Spatio Temporal

ABSTRACTMotor cortical activity in the beta range (13-30 Hz) is a hallmark signature of healthy and pathological movement, but its behavioural relevance remains unclear. Recent work in primates and human sensory cortex suggests that sustained oscillatory beta activity observed on average, may arise from the summation of underlying short-lasting, high-amplitude bursts of activity. Classical human movement-related event-related beta desynchronisation (ERD) and synchronization (ERS) may thus provide insufficient, non-dynamic, summaries of underlying focal spatio-temporal burst activity, limiting insight into their functional role during healthy and pathological movement.Here we directly investigate this transient beta burst activity and its putative behavioural relevance for movement control, using high-precision magnetoencephalography (MEG). We quantified the subject-specific (n=8), trial-wise (n>12,000) dynamics of beta bursts, before and after movement. We show that beta activity on individual trials is dominated by high amplitude, short lasting bursts. While average beta changes generally manifest as bilaterally distributed activity (FWHM = 25mm), individual bursts are spatially more focal (FWHM = 6 mm), sporadic (1.3 −1.5/s), and transient (mean: 96 ms).Prior to movement (the period of the classical ERD), the timing of the last pre-movement burst predicts movement onset, suggesting a role in the specification of the goal of movement. After movement (the period of the classical ERS), the first beta burst is delayed by ~100ms after a response error occurs, intimating a role in error monitoring and evaluation.Movement-related beta activity is therefore dominated by a spatially dispersed summation of short lasting, sporadic and focal bursts. Movement-related beta bursts coordinate the retrieval and updating of movement goals in the pre- and post-movement periods, respectively.

“Se non scritto, almen dipinto”: The ethos of becoming in Purgatorio 28–33

2021 ◽  
pp. 001458582110225
Author(s):  
Thomas E Peterson
Keyword(s):  
Learning Process ◽  
Perceptual Experience ◽  
The State ◽  
Central Question ◽  
Central Focus ◽  
Cognitive Limitations ◽  
Before And After ◽  
Analogia Entis ◽  
Spatio Temporal ◽  
Divine Beauty

A central question facing the reader of the Paradiso terrestre (Pg 28–33) concerns the selfhood of the protagonist, the character Dante. While the state of Dante’s soul was critical to the poem’s beginning in the dark wood, and remained implicit through the intervening cantos, it is only in the Paradiso terrestre that it becomes the poem’s central focus. This question is explored in cognitive and theological terms in a sequential reading of the six cantos that elucidates the learning process occurring in the character before and after his confession in Pg 31: in his encounter with Matelda, his sensory and perceptual experience of the procession, his dialogues with Beatrice, and his witnessing of her divine beauty as the analogia entis reflecting the beauty of God. The analysis acknowledges the changes in Dante’s style in this interval, which serves as a fulcrum of the entire Commedia, a spatio-temporal threshold in which the transition of one soul, from confession to redemption to instruction on the divine word, is linked to the destiny of humankind and the prospect of universal salvation. Throughout this process of becoming, the character’s cognitive limitations are exposed, not simply as flaws but as signs of his intrinsic humanity.

Does Aerobic Exercise Decrease Brain Activation?

1997 ◽  
Vol 19 (3) ◽  
pp. 291-301 ◽  
Author(s):  
Karla A. Kubitz ◽  
Konstantinos Pothakos
Keyword(s):  
Reaction Times ◽  
Brain Activation ◽  
Vigilance Task ◽  
Beta Activity ◽  
Significant Group ◽  
Eeg Activity ◽  
Time Interaction ◽  
Before And After ◽  
Study Participants ◽  
Group Effects

In the present study, participants were randomly assigned to an exercise or a nonexercise group to measure brain activation (spontaneous EEG activity), affect, and cognitive functioning before and after a 15-min treatment period. Exercisers (a) sat quietly for 5 min, (b) exercised for 15 min, (c) recovered for 5 min, and (d) completed a 15-min vigilance task. Nonexercisers did not exercise. There was a significant (a) Condition × Band × Time interaction for EEG activity, (b) Condition × Time interaction for Activation-Deactivation Adjective Checklist (AD ACL) scores, and (c) Condition × Time interaction for reaction times (RTs). Post hoc tests showed (a) no significant group effects at the baseline and 15-min vigilance periods, and (b) significant group effects at the postexercise and 5-min vigilance periods. Exercisers had lower levels of brain activation (i.e., more theta and alpha activity and less beta activity), higher AD ACL scores, and slower RTs than nonexercisers during these periods.

scholarly journals Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 62
Author(s):  
Alberto Alfonso-Torreño ◽  
Álvaro Gómez-Gutiérrez ◽  
Susanne Schnabel
Keyword(s):  
High Resolution ◽  
Sediment Deposition ◽  
Aerial Images ◽  
Valley Bottom ◽  
Erosion And Deposition ◽  
Channel Dynamics ◽  
Check Dams ◽  
Before And After ◽  
Multi Temporal ◽  
Spatio Temporal

Gullies are sources and reservoirs of sediments and perform as efficient transfers of runoff and sediments. In recent years, several techniques and technologies emerged to facilitate monitoring of gully dynamics at unprecedented spatial and temporal resolutions. Here we present a detailed study of a valley-bottom gully in a Mediterranean rangeland with a savannah-like vegetation cover that was partially restored in 2017. Restoration activities included check dams (gabion weirs and fascines) and livestock exclosure by fencing. The specific objectives of this work were: (1) to analyze the effectiveness of the restoration activities, (2) to study erosion and deposition dynamics before and after the restoration activities using high-resolution digital elevation models (DEMs), (3) to examine the role of micro-morphology on the observed topographic changes, and (4) to compare the current and recent channel dynamics with previous studies conducted in the same study area through different methods and spatio-temporal scales, quantifying medium-term changes. Topographic changes were estimated using multi-temporal, high-resolution DEMs produced using structure-from-motion (SfM) photogrammetry and aerial images acquired by a fixed-wing unmanned aerial vehicle (UAV). The performance of the restoration activities was satisfactory to control gully erosion. Check dams were effective favoring sediment deposition and reducing lateral bank erosion. Livestock exclosure promoted the stabilization of bank headcuts. The implemented restoration measures increased notably sediment deposition.

scholarly journals To a Burst of 137Cs Activity in the Air under the “Arch” Object on October 17, 2019

2021 ◽  
Vol 21 (2) ◽  
pp. 107-115
Author(s):  
V. K. Shynkarenko ◽  
◽  
V. A. Kashpur ◽  
G. G. Skorjak ◽  
P. V. Sabenin
Keyword(s):  
Nuclear Power ◽  
Total Activity ◽  
137Cs Activity ◽  
Beta Activity ◽  
Hot Particles ◽  
Safe Work ◽  
Before And After ◽  
Isolation Systems ◽  
October 17 ◽  
The One

The construction of a New Safe Confinement (NSC) is one of the main stages in the transformation of the Chornobyl nuclear power plant 4th power unit into an ecologically safe system. On the one hand, this system is designed to ensure the safety of personnel, the population and the environment, on the other — to allow safe work with the remnants of the unit. At the same time, the project allows quite high levels of bulk activity of radioactive aerosols inside the NSC — up to 210 Bq/m3 for total β-activity. The sharp increase in the volumetric air activity, observed on October 17–19, 2019 in a number of rooms of the Shelter object and in the space under the “Arch” object in the absence of a burst of activity outside these objects, can be considered as a successful kind of spontaneous test of the NSC isolation systems. The chronology of the dynamics of volume activity according to the act of official investigation of the precedent is given. The results of studies of aerosol filters exposed in the near zone of the Chornobyl NPP before and after the burst of activity in the air under the “Arсh” object are presented. Autoradiograms of fragments of these filters demonstrate a significant (≈2 orders of magnitude) increase in the number of hot particles immediately after the fall of the concrete fragment of the floor in the room 402/3. The analysis of features of the hot particles after the collapse indicates a significant contribution to the total activity of a large number of low-activity particles (0.005÷5 Bq), and the low 137Cs/241Am ratio that indicates their fuel nature. Based on the assumption about the fuel nature of hot particles, their minimum possible aerodynamic diameters were calculated, which are in the range 2.91<d<36.7 μm, which does not exclude the presence of smaller hot particles on the filter that are not visible using this method. The contribution of particles with aerodynamic diameters less than 10 μm, determined using the impactor, did not exceed 20% of the total beta activity of the aerosol.

scholarly journals Cortical Engagement Metrics During Reactive Balance Are Associated With Distinct Aspects of Balance Behavior in Older Adults

2021 ◽  
Vol 13 ◽  
Author(s):  
Jacqueline A. Palmer ◽  
Aiden M. Payne ◽  
Lena H. Ting ◽  
Michael R. Borich
Keyword(s):  
Older Adults ◽  
Balance Control ◽  
Network Activity ◽  
Beta Activity ◽  
Balance Function ◽  
Potential Biomarker ◽  
Beta Power ◽  
Wide Range ◽  
Motor Cortical ◽  
Reactive Balance

Heightened reliance on the cerebral cortex for postural stability with aging is well-known, yet the cortical mechanisms for balance control, particularly in relation to balance function, remain unclear. Here we aimed to investigate motor cortical activity in relation to the level of balance challenge presented during reactive balance recovery and identify circuit-specific interactions between motor cortex and prefrontal or somatosensory regions in relation to metrics of balance function that predict fall risk. Using electroencephalography, we assessed motor cortical beta power, and beta coherence during balance reactions to perturbations in older adults. We found that individuals with greater motor cortical beta power evoked following standing balance perturbations demonstrated lower general clinical balance function. Individual older adults demonstrated a wide range of cortical responses during balance reactions at the same perturbation magnitude, showing no group-level change in prefrontal- or somatosensory-motor coherence in response to perturbations. However, older adults with the highest prefrontal-motor coherence during the post-perturbation, but not pre-perturbation, period showed greater cognitive dual-task interference (DTI) and elicited stepping reactions at lower perturbation magnitudes. Our results support motor cortical beta activity as a potential biomarker for individual level of balance challenge and implicate prefrontal-motor cortical networks in distinct aspects of balance control involving response inhibition of reactive stepping in older adults. Cortical network activity during balance may provide a neural target for precision-medicine efforts aimed at fall prevention with aging.

scholarly journals Neuro-musculoskeletal Upper Limb in-silico as virtual patient

2021 ◽  
Author(s):  
Mallampalli Kapardi ◽  
Madhav Pithapuram ◽  
Raghu Seshadri Iyengar ◽  
Mandayam Rangayyan Yashaswini ◽  
Avinash Kumar Singh ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Upper Limb ◽  
In Silico ◽  
Neural Control ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Human Movement ◽  
Virtual Patient ◽  
Spatio Temporal ◽  
Movement Simulation

Virtual patients and physiologies allow experimentation, design, and early-stage clinical trials in-silico. Virtual patient technology for human movement systems that encompasses musculoskeleton and its neural control are few and far in between. In this work, we present one such neuro-musculoskeletal upper limb in-silico model. This upper limb is both modular in architecture and generates movement as an emergent phenomenon out of a multiscale co-simulation of spinal cord neural control and musculoskeletal dynamics. It is developed on the NEUROiD movement simulation platform that enables a co-simulation of popular neural simulator NEURON and the musculoskeletal simulator OpenSim. In this work, we describe the design and development of the upper limb in a modular fashion, while reusing existing models and modules. We further characterize and demonstrate the use of this model in generating a range of commonly observed movements by means of a spatio temporal stimulation pattern delivered to the cervical spinal cord. We believe this work enables a first and small step towards an in-silico paradigms for understanding upper limb movement, disease pathology, medication, and rehabilitation. Index Terms : co-simulation, in-silico, NEUROiD, neuromusculoskeletal, upper limb, Virtual patient.

scholarly journals RESEARCH ON CONSTRUCTION METHOD OF SPATIO-TEMPORAL DATA MODEL BASED ON BEHAVIOR-EVENT

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 591-594
Author(s):  
J. W. Li ◽  
Y. Ma ◽  
J. W. Jiang ◽  
W. D. Chen ◽  
N. Yu ◽  
...  
Keyword(s):  
Data Model ◽  
Logical Structure ◽  
Physical Structure ◽  
Temporal Data ◽  
Model Based ◽  
Time Space ◽  
Before And After ◽  
Spatio Temporal ◽  
Temporal Objects ◽  
Organic Combination

Abstract. Starting from the object-oriented idea, this paper analyses the existing event-based models and the logical relationship between behavioral cognition and events, and discusses the continuity of behavioral cognition on the time axis from the perspective of temporal and spatial cognition. A geospatial data model based on behavioral-event is proposed. The physical structure and logical structure of the model are mainly designed, and the four-dimensional model of “time, space, attribute and event” is constructed on the axis. The organic combination of the four models can well describe the internal mechanism and rules of geographical objects. The expression of data model based on behavior-event not only elaborates the basic information of geospatial objects, but also records the changes of related events caused by the changes of geographic Entities' behavior, and expresses the relationship between spatial and temporal objects before and after the changes of behavior cognition. This paper also designs an effective method to organize spatio-temporal data, so as to realize the effective management and analysis of spatio-temporal data and meet the requirements of storage, processing and mining of large spatio-temporal data.

Research on Correction Algorithm for Print-Scan Resistant Digital Watermarking Algorithms Based on DWT

2012 ◽  
Vol 262 ◽  
pp. 172-176
Author(s):  
Zhen Jie Zhang ◽  
Zhen Liu ◽  
Hui Yu
Keyword(s):  
Frequency Domain ◽  
Digital Watermarking ◽  
High Amplitude ◽  
Correction Coefficient ◽  
Correction Algorithm ◽  
Before And After ◽  
Kolmogorov Smirnov ◽  
Contrast Stretching ◽  
Smirnov Test

On the basis of the analysis of the second layer of DWT high amplitude coefficients before and after printing and scanning, we propose a correction algorithm for Print-scan resistant Digital Watermarking Algorithms Based on DWT. This correction algorithm corrects in the frequency domain, multiplying the coefficients by a correction coefficient and determining the best correction coefficient by Kolmogorov-Smirnov test. Contrast with two common methods to correct the distorted pixels: brightness transformation and contrast stretching transformation, this correction algorithm has the character of less calculation and takes the influence of print and scan on the surrounding pixels into account. At last, after applying it to several test images and all the NC values becoming bigger, the proposed correction algorithm is proved to be effective and universal.

scholarly journals A Data Driven Change-point Epidemic Model for Assessing the Impact of Large Gathering and Subsequent Movement Control Order on COVID-19 Spread in Malaysia

2020 ◽  
Author(s):  
Sarat C. Dass ◽  
Wai M. Kwok ◽  
Gavin J. Gibson ◽  
Balvinder S. Gill ◽  
Bala M. Sundram ◽  
...  
Keyword(s):  
Change Point ◽  
Movement Control ◽  
Disease Spread ◽  
Time Period ◽  
Before And After ◽  
Quantitative Understanding ◽  
Control Order ◽  
Short Time ◽  
The Impact ◽  
Second Wave

AbstractThe second wave of COVID-19 in Malaysia is largely attributed to a mass gathering held in Sri Petaling between February 27, 2020 and March 1, 2020, which contributed to an exponential rise of COVID-19 cases in the country. Starting March 18, 2020, the Malaysian government introduced four consecutive phases of a Movement Control Order (MCO) to stem the spread of COVID-19. The MCO was implemented through various non-pharmaceutical interventions (NPIs). The reported number of cases reached its peak by the first week of April and then started to reduce, hence proving the effectiveness of the MCO. To gain a quantitative understanding of the effect of MCO on the dynamics of COVID-19, this paper develops a class of mathematical models to capture the disease spread before and after MCO implementation in Malaysia. A heterogeneous variant of the Susceptible-Exposed-Infected-Recovered (SEIR) model is developed with additional compartments for asymptomatic transmission. Further, a change-point is incorporated to model the before and after disease dynamics, and is inferred based on data. Related statistical analyses for inference are developed in a Bayesian framework and are able to provide quantitative assessments of (1) the impact of the Sri Petaling gathering, and (2) the extent of decreasing transmission during the MCO period. The analysis here also quantitatively demonstrates how quickly transmission rates fall under effective NPI implemention within a short time period.

Sign in / Sign up

Export Citation Format

Share Document