scholarly journals Neuronal population dynamics during motor plan cancellation in non-human primates

2019 ◽  
Author(s):  
Pierpaolo Pani ◽  
Margherita Giamundo ◽  
Franco Giarrocco ◽  
Valentina Mione ◽  
Emiliano Brunamonti ◽  
...  
Keyword(s):  
Movement Control ◽  
Neuronal Population ◽  
Neuronal Dynamics ◽  
State Spaces ◽  
Reaching Task ◽  
Visuomotor Transformations ◽  
Motor Plan ◽  
Orthogonal Subspace ◽  
Neuronal Computation ◽  
And Control

AbstractTo understand the cortical neuronal dynamics behind movement generation and control most studies focused on tasks where actions were planned and then executed, using different instances of visuomotor transformations. However, to fully understand the dynamics related to movement control one must also study how movements are actively inhibited. Inhibition, indeed, represents the first level of control both when different alternatives are available and only one solution could be adopted and when is necessary to maintain the current position.We recorded neuronal activity from a multielectrode array in the dorsal premotor (PMd) cortex of monkeys performing a countermanding reaching task that requires, in a subset of trials, to cancel a potentially planned movement before its onset. In the analysis of the neuronal state-spaces of PMd we found a subspace in which activities conveying temporal information were confined during active inhibition and position holding. Movement execution required activities to escape from the plane toward an orthogonal subspace and, furthermore, surpass a threshold associated to the maturation of the motor plan.These results revealed further details in the neuronal dynamics underlying movement control extending the hypothesis that neuronal computation confined in an output-null subspace does not produce movements.

Servo Drive Trajectory Design of Three-Axis Laser Processing System

2014 ◽  
Vol 529 ◽  
pp. 139-143
Author(s):  
Wei Hua Jiang ◽  
Yuan Cheng Fan ◽  
Da Zeng
Keyword(s):  
Control System ◽  
Processing System ◽  
Movement Control ◽  
Linear Interpolation ◽  
Numerical Control ◽  
Trajectory Design ◽  
Servo Drive ◽  
Digital Integrator ◽  
Detector Resolution ◽  
And Control

Three-axis processing of laser inner engraving machine control system can carry on multi-axis linkage control. Furthermore, it ensures multi-axis of high feeding speed and trajectory control of high precision. This article introduces the design of laser inner engraving machine movement control system. The core is a digital integrator of linear interpolation algorithm to generate the desired trajectory and control XYZ axis linkage. Wide speed range of servo motor and position detector resolution is adequate to constitute a half-closed loop drive. With integral separation algorithm being introduced in the controller, the speed of numerical control system, track speed and positioning accuracy are guaranteed in order to achieve optimal specification for dynamic and static characteristics of the whole system.

Effect of weightlessness on posture and movement control during a whole body reaching task

1995 ◽  
Vol 36 (8-12) ◽  
pp. 727-732 ◽  
Author(s):  
T. Pozzo ◽  
A. Berthoz ◽  
C. Popov
Keyword(s):  
Movement Control ◽  
Whole Body ◽  
Reaching Task

Dense Circuit Reconstruction to Understand Neuronal Computation: Focus on Zebrafish

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Rainer W. Friedrich ◽  
Adrian A. Wanner
Keyword(s):  
Neuronal Population ◽  
Higher Order ◽  
Order Structure ◽  
Annual Review ◽  
Publication Date ◽  
Population Activity ◽  
Stimulus Features ◽  
Processing And Storage ◽  
Low Dimensional ◽  
Neuronal Computation

The dense reconstruction of neuronal wiring diagrams from volumetric electron microscopy data has the potential to generate fundamentally new insights into mechanisms of information processing and storage in neuronal circuits. Zebrafish provide unique opportunities for dynamical connectomics approaches that combine reconstructions of wiring diagrams with measurements of neuronal population activity and behavior. Such approaches have the power to reveal higher-order structure in wiring diagrams that cannot be detected by sparse sampling of connectivity and that is essential for neuronal computations. In the brain stem, recurrently connected neuronal modules were identified that can account for slow, low-dimensional dynamics in an integrator circuit. In the spinal cord, connectivity specifies functional differences between premotor interneurons. In the olfactory bulb, tuning-dependent connectivity implements a whitening transformation that is based on the selective suppression of responses to overrepresented stimulus features. These findings illustrate the potential of dynamical connectomics in zebrafish to analyze the circuit mechanisms underlying higher-order neuronal computations. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Design and Underwater Tests of Subsea Walking Hexapod MAK-1

2016 ◽  
Author(s):  
Vadim V. Chernyshev ◽  
Vladimir V. Arykantsev ◽  
Andrey E. Gavrilov ◽  
Yaroslav V. Kalinin ◽  
Nikolay G. Sharonov
Keyword(s):  
Movement Control ◽  
Experimental Tests ◽  
Energy Usage ◽  
Walking Machine ◽  
Walking Machines ◽  
Sea Bottom ◽  
Different Types ◽  
Robotic Devices ◽  
And Control ◽  
System Power

An important role among machines for sea bottom exploration is assigned to the autonomous ground devices. Some rescue tasks also require subsea robotic devices. The main purpose of the work is to investigate and improve adaptive characteristics, traction properties and control methods of cyclic walking movers in underwater conditions. Traction properties of walking machines, which moves at sea bottom was analyzed. Some experience of development and experimental tests of the walking robot “Vosminog”, designed for work at weak and waterlogged grounds. Dynamic model of a walking machine has been shown. Studied an opportunity to increase adaptive characteristics and shape passableness of walking machines. Also design and results of underwater tests of subsea walking unit MAK-1 are discussed. During tests the performance of a walking unit has been checked and the influence of design features of a walking mover on its traction characteristics and ground passability has been investigated. Some details about control system, power system and energy usage, vertical motions and accelerations for different types of walking and conditions of movement has been given. Also, certain attention was given to testing of methods of standalone movement control of subsea unit in conditions of incomplete and ambiguous vision of current situation. Tests have shown that walking movers in subsea conditions can provide higher traction properties, in comparison with wheeled and tracked ones. The unit can be used for exploration of seabed resources and for rescue tasks.

scholarly journals Integration of allocentric and egocentric visual information in a convolutional / multilayer perceptron network model of goal-directed gaze shifts

2021 ◽  
Author(s):  
Parisa Abedi Khoozani ◽  
Vishal Bharmauria ◽  
Adrian Schuetz ◽  
Richard P. Wildes ◽  
John Douglas Crawford
Keyword(s):  
Multilayer Perceptron ◽  
Visual Information ◽  
General Framework ◽  
Movement Control ◽  
Saccade Target ◽  
Directed Movement ◽  
Visuomotor Transformations ◽  
Multilayer Perceptron Network ◽  
Mlp Model ◽  
Gaze Position

Allocentric (landmark-centered) and egocentric (eye-centered) visual codes are fundamental for spatial cognition, navigation, and goal-directed movement. Neuroimaging and neurophysiology suggest these codes are segregated initially, but then reintegrated in frontal cortex for movement control. We created and validated a theoretical framework for this process using physiologically constrained inputs and outputs. To implement a general framework, we integrated a Convolutional Neural Network (CNN) of the visual system with a Multilayer Perceptron (MLP) model of the sensorimotor transformation. The network was trained on a task where a landmark shifted relative to the saccade target. These visual parameters were input to the CNN, the CNN output and initial gaze position to the MLP, and a decoder transformed MLP output into saccade vectors. Decoded saccade output replicated idealized training sets with various allocentric weightings, and actual monkey data where the landmark shift had a partial influence (R2 = 0.8). Furthermore, MLP output units accurately simulated prefrontal response field shifts recorded from monkeys during the same paradigm. In summary, our model replicated both the general properties of the visuomotor transformations for gaze and specific experimental results obtained during allocentric-egocentric integration, suggesting it can provide a general framework for understanding these and other complex visuomotor behaviors.

scholarly journals Neuronal dynamics of signal selective motor plan cancellation in the macaque dorsal premotor cortex

2020 ◽  
Author(s):  
Giarrocco Franco ◽  
Bardella Giampiero ◽  
Giamundo Margherita ◽  
Fabbrini Francesco ◽  
Brunamonti Emiliano ◽  
...  
Keyword(s):  
Premotor Cortex ◽  
Movement Control ◽  
Behavioral Strategy ◽  
Behavioral Strategies ◽  
Inhibitory Process ◽  
Neuronal Dynamics ◽  
State Space Approach ◽  
Stop Task ◽  
Space Approach

Primates adopt various strategies to interact with the environment. Yet, no study has examined the effects of behavioral strategies with regard to how movement inhibition is implemented at the neuronal level. We modified a classical approach to study movement control (stop-task) by adding an extra signal – termed the Ignore signal – which influenced movement inhibition only under a specific strategy. We simultaneously recorded multisite neuronal activity from the dorsal premotor (PMd) cortex of macaque monkeys during a task and applied a state-space approach. As a result, we found that movement generation is characterized by neuronal dynamics that evolve between subspaces. When the movement is halted, this evolution is arrested and inverted. Conversely, when the Ignore signal is presented, inversion of the evolution is observed briefly and only when a specific behavioral strategy is adopted. Moreover, neuronal signatures during the inhibitory process were predictive of how PMd processes inhibitory signals, allowing the classification of the resulting behavioral strategy. Our data corroborate the PMd as a critical node in movement inhibition.

scholarly journals Air Quality Impact during COVID-19: A Case Study in One Institute of Higher Learning (IHL) in Malaysia

2021 ◽  
Vol 56 (3) ◽  
pp. 72-82
Author(s):  
Farrah Anuar ◽  
Norzila Othman ◽  
Wahid Ali Hamood Altowayti ◽  
Nurina Fitriani
Keyword(s):  
Particulate Matter ◽  
Movement Control ◽  
Higher Learning ◽  
Air Contamination ◽  
Control Order ◽  
Novel Coronavirus ◽  
Spread Of Infection ◽  
Particulate Matter 2.5 ◽  
And Control

Novel coronavirus pneumonia (COVID-19) was first detected in Wuhan, China, soon its rapid escalation in global and become global spread of infection including Malaysia. The principal cases in Malaysia were distinguished on 25th January 2020. The number of cases keeps on ascending since March 2020 until Malaysia has the highest number of cases in Southeast Asia. Therefore, to respond and control the COVID-19 pandemic in the country, the 2020 Movement Control Order (MCO) is implemented. The MCO actualizes a movement of reasonable steps to control advance flare-ups of COVID-19 within the country, counting closing down all organization and private premises aside from those related with "fundamental administrations" and several parts with government permission, and travel disallowances on all outsiders entering Malaysia and on Malaysians taking off the country. Correspondingly, this MCO has brought about the decrease of air contamination as the number of engine vehicles and the activity of businesses is suspended. This study aims to determine the concentrations of particulate matter 2.5 at the selected monitoring stations in UTHM and to correlate environmental factor which is wind speed and wind direction with the Particulate Matter 2.5. This study uses PM2.5 fixations to explain the air pollution before to MCO, stages I, II, III, and IV, where the contingent MCO is actualized. Such outcomes relate to the air contamination list as it was discovered that the PM2.5 fixations showed a high decrease of up to -74 μg/m3 during Phase IV MCO.

Decoupling the actions of the eyes from the hand alters beta and gamma synchrony within SPL

2014 ◽  
Vol 111 (11) ◽  
pp. 2210-2221 ◽  
Author(s):  
Patricia F. Sayegh ◽  
Kara M. Hawkins ◽  
Bogdan Neagu ◽  
J. Douglas Crawford ◽  
Kari L. Hoffman ◽  
...  
Keyword(s):  
Local Field ◽  
Rhesus Macaques ◽  
Motor Task ◽  
Field Potential ◽  
Low Frequency ◽  
Movement Control ◽  
Reaching Movements ◽  
State Planning ◽  
Hand Orientation ◽  
Visuomotor Transformations

Eye-hand coordination is crucial for our ability to interact with the world around us. However, much of the visually guided reaches that we perform require a spatial decoupling between gaze direction and hand orientation. These complex decoupled reaching movements are in contrast to more standard eye and hand reaching movements in which the eyes and the hand are coupled. The superior parietal lobule (SPL) receives converging eye and hand signals; however, what is yet to be understood is how the activity within this region is modulated during decoupled eye and hand reaches. To address this, we recorded local field potentials within SPL from two rhesus macaques during coupled vs. decoupled eye and hand movements. Overall we observed a distinct separation in synchrony within the lower 10- to 20-Hz beta range from that in the higher 30- to 40-Hz gamma range. Specifically, within the early planning phase, beta synchrony dominated; however, the onset of this sustained beta oscillation occurred later during eye-hand decoupled vs. coupled reaches. As the task progressed, there was a switch to low-frequency and gamma-dominated responses, specifically for decoupled reaches. More importantly, we observed local field potential activity to be a stronger task (coupled vs. decoupled) and state (planning vs. execution) predictor than that of single units alone. Our results provide further insight into the computations of SPL for visuomotor transformations and highlight the necessity of accounting for the decoupled eye-hand nature of a motor task when interpreting movement control research data.

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