Effects of Competitive Activation on Precision Movement Control

1996 ◽  
Vol 83 (3_suppl) ◽  
pp. 1203-1208 ◽  
Author(s):  
F. de Melo ◽  
M. Laurent
Keyword(s):  
Emotional State ◽  
Peak Velocity ◽  
Movement Control ◽  
Peak Acceleration ◽  
Movement Kinematics ◽  
Acceleration Phase ◽  
Movement Sequence ◽  
Movement Parameters ◽  
Competitive Activation

Models of emotional activity consider that the emotional state can have general effects on movement control. This control depends on programmed movement invariants (movement sequence, duration of the relative phases, etc.) and on the setting of the movement parameters (amplitude, velocity, etc.). This study of 14 adults shows an influence of the emotional state upon movement kinematics, namely, the peak velocity and the peak acceleration, the amplitude, and the duration of the acceleration phase.

Representation of hand position prior to movement and motor variability

1995 ◽  
Vol 73 (2) ◽  
pp. 262-272 ◽  
Author(s):  
Michel Desmurget ◽  
Yves Rossetti ◽  
Claude Prablanc ◽  
Marc Jeannerod ◽  
George E. Stelmach
Keyword(s):  
Peak Velocity ◽  
Human Subjects ◽  
Hand Position ◽  
Feedback Process ◽  
Significant Modification ◽  
Movement Kinematics ◽  
Acceleration Phase ◽  
Movement Onset ◽  
Motor Variability ◽  
Deceleration Phase

Pointing accurary of six human subjects was measured in two blocked conditions where the hand was either never visible (T: target only) or only visible in static position prior to movement onset (H+T: hand + target). It was shown in condition H+T that, viewing the hand prior to movement greatly decreased end-point variability compared with condition T. This effect was associated with a significant modification of the movement kinematics: the H+T condition induced a shortened acceleration phase with a corresponding lengthened deceleration phase, compared with the T condition. These results led us to the hypothesis that viewing the hand prior to movement onset allowed a decrease of pointing variability through a feedback process. This hypothesis was further tested by turning the target off during the deceleration phase of the movement at half peak velocity. It was shown that turning the target off had no effect upon the T condition but induced a significant increase of pointing variability in the H+T condition. This result suggests that vision of the static hand enhances the proprioceptive localization of the limb and allows for a better visual to kinesthesic feedback.Key words: proprioception, vision, motor control, pointing, feedback, human.

THE ANALYSIS OF DYNAMICAL RESPONSE OF TRANSVERSELY ISOTROPIC MATERIAL UNDER BLASTING LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1443-1448
Author(s):  
YUE-XIU WU ◽  
QUAN-SHENG LIU
Keyword(s):  
Isotropic Material ◽  
Peak Velocity ◽  
Transversely Isotropic ◽  
Normal Direction ◽  
Dynamical Response ◽  
Transversely Isotropic Material ◽  
Peak Acceleration ◽  
Loading Direction ◽  
Blasting Load ◽  
Explosion Load

To understand the dynamic response of transversely isotropic material under explosion load, the analysis is done with the help of ABAQUS software and the constitutive equations of transversely isotropic material with different angle of isotropic section. The result is given: when the angle of isotropic section is settled, the velocity and acceleration of measure points decrease with the increasing distance from the explosion borehole. The velocity and acceleration in the loading direction are larger than those in the normal direction of the loading direction and their attenuation are much faster. When the angle of isotropic section is variable, the evolution curves of peak velocity and peak acceleration in the loading direction with the increasing angles are notching parabolic curves. They get their minimum values when the angle is equal to 45 degree. But the evolution curves of peak velocity and peak acceleration in the normal direction of the loading direction with the increasing angles are overhead parabolic curves. They get their maximum values when the angle is equal to 45 degree.

Visual Fatigue and Saccadic Eye Movement Parameters

1983 ◽  
Vol 27 (8) ◽  
pp. 728-732 ◽  
Author(s):  
Ted Megaw ◽  
Tayyar Sen
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Peak Velocity ◽  
Cognitive Task ◽  
Saccadic Eye Movements ◽  
Tracking Task ◽  
Frequency Of Occurrence ◽  
Saccadic Eye Movement ◽  
Visual Fatigue ◽  
Movement Parameters

It has been suggested by Bahill and Stark (1975) that visual fatigue can be identified by changes in some of the saccadic eye movement parameters. These include increases in the frequency of occurrence of glissades and overlapping saccades and reductions in the peak velocity and duration of saccades. In their study, fatigue was induced by the same step tracking task that was used to evaluate the changes in saccadic parameters. However, there is evidence that subjects experience extreme feelings of fatigue while performing such a task and that somehow the task is unnatural. The present study was designed to assess whether there are any differences in the various saccadic parameters obtained while subjects perform a step tracking task and a cognitive task involving the comparison of number strings. Both tasks were presented on a VDU screen. The second objective was to establish whether there are any changes in the parameters for either task as a result of prolonged performance. The results showed no major differences in the saccadic eye movements between the two tasks and no consistent changes resulting from prolonged performance.

scholarly journals Chapter 1. Eye-tracking: facts and figures

2018 ◽  
pp. 15-44
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Eye Movement ◽  
Movement Control ◽  
General Information ◽  
Cognitive Research ◽  
Pros And Cons ◽  
Movement Parameters ◽  
Tracking Devices

In chapter 1 we describe the method of eye-tracking and how the interest to studying eye movements developed in time. We describe how modern eye-tracking devices work, including several most commonly used in cognitive research (SR-Research, SMI, Tobii). We also give some general information about eye movement parameters during reading and a brief over- view of main models of eye movement control in reading (SWIFT, E-Z Reader). These models take into account a significant amount of empirical data and simulate the interaction of oculo- motor and cognitive processes involved in reading. Differences between the models, as well as different interpretations allowed within the same model, reflect the complexity of reading and the ongoing discussion about the processes involved in it. The section ends up with the pros and cons of using LCD and CRT displays in eye-tracking studies.

scholarly journals RESEARCH OF THE MOVEMENT STRUCTURE OF THE QUALIFIED WEIGHTLIFTERS IN THE SNATCH AND THE CLEAN AND JERK TAKING INTO ACCOUNT MODELLING OF BIOMECHANICAL COMPONENTS

2016 ◽  
Vol 3 ◽  
pp. 499
Author(s):  
Valentin Oļeško ◽  
Artjom Ivanov ◽  
Leonīds Čupriks ◽  
Aleksandra Čuprika
Keyword(s):  
Vertical Displacement ◽  
Knee Extension ◽  
Technical Training ◽  
Maximum Height ◽  
Acceleration Phase ◽  
Weight Category ◽  
Vertical Speed ◽  
Biomechanical Parameters ◽  
Movement Parameters ◽  
Braking Phase

The research was conducted during the training process of Ukrainian, Russian and Latvian weightlifters and their participation in international competitions (the World and European Championships). The aim of the current study was to identify qualified weightlifters movements development regularities snatch and clean and jerk through the biomechanical component modelling. A total of 442 qualified weightlifters participated in the research: 242 male weightlifters and 200 female weightlifters. All athletes were divided into three groups according to their weight category: male weightlifters: Іst group – 56–69 kg; ІІnd group – 77–94 kg; ІІІrd group – 105 and +105 kg; female weightlifters: Іst group – 48-58 kg; ІІnd group – 63-69 kg; ІІІrd group – 75 and +75 kg. Obtaining the biomechanical parameters of technical training of the qualified weightlifters in the snatch and the clean and jerk during the competitions, biodynamic and biokinematic complex of movement parameters of the interaction between the athletes and the barbell was examined using the electro-optical complex „Weightlifting analyzer 3.0“,produced in Germany. In all weight categories in the final acceleration phase (F3FAP) and supported squat phase (F4SSP) the best efforts in the snatch are made by female weightlifters, although they lift considerably less weight of loads (by 15–25 %) than male weightlifters. In the first group of weight categories the parameters differ by 1,4 and 4,2 % (р ≤ 0,005), in the second group of weight categories – by 8,9 and 3,9 % (р ≤ 0,005), however in the third group of weight categories differences were only observed in the final acceleration phase (F3 FAP) – by 3,7 % (р ≤ 0,005). The results of the research show that in the instant of the first application of the maximum force (v F1) females develop higher speed of the barbell than males (by 44,0 %). The same tendency is observed in the instant of the maximum knee extension (v MAХ KE) – in this phase the vertical speed of the barbell among female weightlifters is by 4,5 % (р ≤ 0,05) higher than among male weightlifters. Females of the Ist and the IIIrd group of weight categories achieve the best results in the final acceleration phase (v MAX) – they are by 6,8 and 5,4 % (р ≤ 0,05) higher than the same parameters of males of the Ist and the IInd group of weight categories. Significant differences have been also observed in biomechanical parameters of the barbell's movement among representatives of different genders and weight categories. Moreover, in the Ist group of weight categories differences mainly exist in the preliminary squat phase (h PR.SQ.), when female parameters are by 4,5 % higher than male parameters; in the instant of the attainment of the maximum height of the barbells' displacement (h MAX) they are by 7,5 % higher respectively; the amount of force in the process of interaction between the athletes and the barbell in the active braking phase (FАBP) is by 5,3 % bigger respectively. In the IInd group essential differences appeared in the vertical displacement of the barbell in the instant of the attainment of the maximum height (h MAX), female parameters are by 7,3 % higher than male parameters; in the supported squat phase (h SQUAT.) the opposite tendency can be observed as parameters among males are by 47,8 % higher than female parameters; the amount of force applied to the barbell in the supported squat phase (FSSP) among females are by 3,4 % higher than among males. In the IIIrd group significant differences are noticed in the vertical displacement of the barbell in the instant of the attainment of the maximum height (h MAX), female parameters are by 6,5 % better than male parameters; the amount of force in the process of interaction between the athletes and the barbell in the active braking phase (F ABP) among females is by 5,7 % higher than among males.Thus biomechanical parameter changes of the execution technique of competitive exercises in the clean and jerk among the weightlifters of different gender and weight categories show more than 62,5 % of differences in respect of biodynamic and biokinematic (speed and spatial) parameters of support interaction of the athletes. In spite of the same phase structure of the exercises, movements of the first method of the clean and jerk considerably differ from the similar parameters of the snatch technique. This indicates individualisation of model parameter formation of technical training of the qualified athletes, performing competitive exercises within the certain group of weight categories, taking into consideration gender differences.  

scholarly journals Developmental Differences in the Prospective Organisation of Goal-Directed Movement Between Children with Autism and Typically Developing Children: A Smart Tablet Serious Game Study

2021 ◽  
Author(s):  
Yu Wei Chua ◽  
Szu-Ching Lu ◽  
Anna Anzulewicz ◽  
Krzysztof Sobota ◽  
Christos Tachtatzis ◽  
...  
Keyword(s):  
Peak Velocity ◽  
Movement Time ◽  
Developmental Differences ◽  
Serious Game ◽  
Movement Kinematics ◽  
Directed Movement ◽  
Mixed Effect ◽  
Feedback Mechanisms ◽  
Time To Peak ◽  
Movement Unit

Movement is prospective. It structures self-generated engagement with objects and social partners and is fundamental to children’s learning and development. In autistic children, previous reports of differences in movement kinematics compared to neurotypical peers suggest its prospective organisation might be disrupted. Here, we employed a smart tablet serious game paradigm to assess differences in the feedforward and feedback mechanisms of prospective action organisation, between autistic and neurotypical preschool children. We analysed 3926 goal-directed finger movements made during smart-tablet ecological gameplay, from 28 children with Childhood Autism (ICD-10; ASD) and 43 neurotypical children (TD), aged 3-6 years old. Using linear and generalised linear mixed-effect models, we found the ASD group executed movements with longer Movement Time (MT) and Time to Peak Velocity (TTPV), lower Peak Velocity (PV), with peak velocity less likely to occur in the first movement unit, and with a greater number of Movement Units After Peak Velocity (MU-APV). Interestingly, compared to the TD group, the ASD group showed smaller increases in PV, TTPV and MT with an increase in Age (ASD x Age interaction), together with a smaller reduction in MU-APV and an increase in MU-APV at shorter target distances (ASD x Dist interaction). Our results are the first to highlight different developmental trends in anticipatory feedforward and compensatory feedback mechanisms of control, contributing to differences in movement kinematics observed between autistic and neurotypical children. These findings point to differences in integration of prospective perceptuomotor information, with implications for embodied cognition and learning from self-generated action in autism.

Peak acceleration, velocity, and displacement from strong-motion records

1980 ◽  
Vol 70 (1) ◽  
pp. 305-321
Author(s):  
David M. Boore ◽  
William B. Joyner ◽  
Adolph A. Oliver ◽  
Robert A. Page
Keyword(s):  
Regression Analysis ◽  
Peak Velocity ◽  
Strong Motion ◽  
Western North America ◽  
Peak Acceleration ◽  
Motion Data ◽  
Horizontal Acceleration ◽  
Large Structures ◽  
San Fernando ◽  
Peak Horizontal Acceleration

abstract Strong-motion data from earthquakes of western North America are examined to provide the basis for estimating peak acceleration, velocity, and displacement as a function of distance for three magnitude classes, 5.0 to 5.7, 6.0 to 6.4, and 7.1 to 7.6. Analysis of a subset of the data from the San Fernando earthquake shows that small but statistically significant differences exist between peak values of horizontal acceleration, velocity, and displacement recorded on soil at the base of small structures and values recorded at the base of large structures. The peak acceleration tends to be less and the peak velocity and displacement to be greater at the base of large structures than at the base of small structures. In the distance range used in the regression analysis (15 to 100 km), the values of peak horizontal acceleration recorded at soil sites in the San Fernando earthquake are not significantly different from the values recorded at rock sites, but values of peak horizontal velocity and displacement are significantly greater at soil sites.

scholarly journals Perspectives on classical controversies about the motor cortex

2017 ◽  
Vol 118 (3) ◽  
pp. 1828-1848 ◽  
Author(s):  
Mohsen Omrani ◽  
Matthew T. Kaufman ◽  
Nicholas G. Hatsopoulos ◽  
Paul D. Cheney
Keyword(s):  
Motor Cortex ◽  
Upper Limb ◽  
Sensory Feedback ◽  
Primary Motor Cortex ◽  
Movement Control ◽  
Movement Kinematics ◽  
Movement Dynamics ◽  
Upper Limb Movements ◽  
High Level

Primary motor cortex has been studied for more than a century, yet a consensus on its functional contribution to movement control is still out of reach. In particular, there remains controversy as to the level of control produced by motor cortex (“low-level” movement dynamics vs. “high-level” movement kinematics) and the role of sensory feedback. In this review, we present different perspectives on the two following questions: What does activity in motor cortex reflect? and How do planned motor commands interact with incoming sensory feedback during movement? The four authors each present their independent views on how they think the primary motor cortex (M1) controls movement. At the end, we present a dialogue in which the authors synthesize their views and suggest possibilities for moving the field forward. While there is not yet a consensus on the role of M1 or sensory feedback in the control of upper limb movements, such dialogues are essential to take us closer to one.

The Analysis on Rigid Core Pile Composite Foundation Dynamic

2014 ◽  
Vol 638-640 ◽  
pp. 601-604
Author(s):  
Wei Yu Wang
Keyword(s):  
Dynamic Response ◽  
Field Test ◽  
Dynamic Characteristics ◽  
Seismic Waves ◽  
Peak Velocity ◽  
Composite Foundation ◽  
Test Results ◽  
Peak Acceleration ◽  
Rigid Core ◽  
Load Peak

Through studying the field test results of rigid core pile composite foundation, Analyzing dynamic characteristics and dynamic response from peak acceleration and frequency duration, peak velocity and seismic waves. The following conclusion were got: Along with the rising of the upper load, peak acceleration of rigid core pile decrease, The frequency of Rigid core pile was between 6Hz-44Hz, Peak rate in the bottom of core pile have obvious change.

scholarly journals Are reaching and grasping effector-independent? Similarities and differences in reaching and grasping kinematics between the hand and foot

2021 ◽  
Author(s):  
Yuqi Liu ◽  
James Caracoglia ◽  
Sriparna Sen ◽  
Ella Striem-Amit
Keyword(s):  
Peak Velocity ◽  
Object Size ◽  
Body Parts ◽  
Acceleration Phase ◽  
Grip Aperture ◽  
Deceleration Phase ◽  
Neural Representations ◽  
Maximum Grip Aperture ◽  
Similarities And Differences ◽  
Maximum Grip

While reaching and grasping are highly prevalent manual actions, neuroimaging studies provide evidence that their neural representations may be shared between different body parts, i.e. effectors. If these actions are guided by effector-independent mechanisms, similar kinematics should be observed when the action is performed by the hand or by a cortically remote and less experienced effector, such as the foot. We tested this hypothesis with two characteristic components of action: the initial ballistic stage of reaching, and the preshaping of the digits during grasping based on object size. We examined if these kinematic features reflect effector-independent mechanisms by asking participants to reach toward and to grasp objects of different widths with their hand and foot. First, during both reaching and grasping, the velocity profile up to peak velocity matched between the hand and the foot, indicating a shared ballistic acceleration phase. Secondly, maximum grip aperture and time of maximum grip aperture of grasping increased with object size for both effectors, indicating encoding of object size during transport. Differences between the hand and foot were found in the deceleration phase and time of maximum grip aperture, likely due to biomechanical differences and the participants' inexperience with foot actions. These findings provide evidence for effector-independent visuomotor mechanisms of reaching and grasping that generalize across body parts.

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