scholarly journals Vigor of reaching, walking, and gazing movements: on the consistency of interindividual differences

2020 ◽  
Vol 123 (1) ◽  
pp. 234-242
Author(s):  
Ombeline Labaune ◽  
Thomas Deroche ◽  
Caroline Teulier ◽  
Bastien Berret
Keyword(s):  
Decision Making ◽  
Motor Control ◽  
Basal Ganglia ◽  
Reaching Movements ◽  
Neural Pathways ◽  
Motor Tasks ◽  
Interindividual Differences ◽  
Arm Reaching ◽  
Highly Correlated ◽  
First Time

Movement vigor is an important feature of motor control that is thought to originate from cortico-basal ganglia circuits and processes shared with decision-making, such as temporal reward discounting. Accordingly, vigor may be related to one’s relationship with time, which may, in turn, reflect a general trait-like feature of individuality. While significant interindividual differences of vigor have been typically reported for isolated motor tasks, little is known about the consistency of such differences across tasks and movement effectors. Here, we assessed interindividual consistency of vigor across reaching (both dominant and nondominant arm), walking, and gazing movements of various distances within the same group of 20 participants. Given distinct neural pathways and biomechanical specificities of each movement modality, a significant consistency would corroborate the trait-like aspect of vigor. Vigor scores for dominant and nondominant arm movements were found to be highly correlated across individuals. Vigor scores of reaching and walking were also significantly correlated across individuals, indicating that people who reach faster than others also tend to walk faster. At last, vigor scores of saccades were uncorrelated with those of reaching and walking, reaffirming that the vigor of stimulus-elicited eye saccades is distinct. These findings highlight the trait-like aspect of vigor for reaching movements with either arms and, to a lesser extent, walking. NEW & NOTEWORTHY Robust interindividual differences of movement vigor have been reported for arm reaching and saccades. Beyond biomechanics, personality trait-like characteristics have been proposed to account for those differences. Here, we examined for the first time the consistency of interindividual differences of vigor during dominant/nondominant arm reaching, walking, and gazing to assess the trait-like aspect of vigor. We found a significant consistency of vigor within our group of individuals for all tested tasks/effectors except saccades.

Two functionally different synergies during arm reaching movements involving the trunk

1995 ◽  
Vol 73 (5) ◽  
pp. 2120-2122 ◽  
Author(s):  
S. Ma ◽  
A. G. Feldman
Keyword(s):  
Motor Control ◽  
Degrees Of Freedom ◽  
Arm Movements ◽  
The Other ◽  
Reaching Movements ◽  
Positional Error ◽  
Trunk Motion ◽  
Arm Reaching ◽  
Trunk Movements ◽  
The Right

1. To address the problem of the coordination of a redundant number of degrees of freedom in motor control, we analyzed the influence of voluntary trunk movements on the arm endpoint trajectory during reaching. 2. Subjects made fast noncorrected planar movements of the right arm from a near to a far target located in the ipsilateral work space at a 45 degrees angle to the sagittal midline of the trunk. These reaching movements were combined with a forward or a backward sagittal motion of the trunk. 3. The direction, positional error, curvature, and velocity profile of the endpoint trajectory remained invariant regardless of trunk movements. Trunk motion preceded endpoint motion by approximately 175 ms, continued during endpoint movement to the target, and outlasted it by 200 ms. This sequence of trunk and arm movements was observed regardless of the direction of the endpoint trajectory (to or from the far target) or trunk movements (forward or backward). 4. Our data imply that reaching movements result from two control synergies: one coordinates trunk and arm movements leaving the position of the endpoint unchanged, and the other produces interjoint coordination shifting the arm endpoint to the target. The use of functionally different synergies may underlie a solution of the redundancy problem.

scholarly journals Cortico-basal-ganglia communication: Temporally structured activity for selective motor control

2018 ◽  
Author(s):  
Petra Fischer ◽  
Witold Lipski ◽  
Wolf-Julian Neumann ◽  
Robert Sterling Turner ◽  
Pascal Fries ◽  
...  
Keyword(s):  
Motor Control ◽  
Basal Ganglia ◽  
Firing Rate ◽  
Structural Connectivity ◽  
Reaction Times ◽  
Spike Timing ◽  
List Type ◽  
Gamma Phase ◽  
Neural Pathways ◽  
Phase Coupling

AbstractDespite the hard-wired structural connectivity of neural pathways, neural circuits allow context-dependent reactions to sensory cues by triggering the desired movement. Cortico-basal-ganglia circuits seem particularly important for flexible motor control as this is impaired in Parkinson’s disease (PD). We analysed subthalamic nucleus (STN) spike and cortical ECoG activity from PD patients performing a visually-cued hand grip task. Fast reaction times were preceded by enhanced STN spike-to-cortical gamma phase coupling irrespective of firing rate changes, suggesting a role of gamma coupling in motor preparation. STN spike timing was offset by half a cycle when comparing ipsilateral with contralateral movements. Additionally, cortical high-frequency activity increased more steeply within each gamma cycle at the sites that showed the strongest coupling with STN spikes. Cortico-basal-ganglia gamma coupling may thus help shape neural activity to facilitate selective motor control. The observation that this effect occurs independent of changes in mean firing rate has far-reaching implications.HighlightsFast RTs were preceded by enhanced STN spike-to-cortical gamma phase couplingSTN spike probability was significantly modulated relative to the gamma cycleDuring ipsilateral movement, spikes were more likely at the opposite part of the cycleSTN output may thus help shape cortical gamma for selective motor control

scholarly journals Optogenetic investigation into the role of the subthalamic nucleus in motor control

2020 ◽  
Author(s):  
Adriane Guillaumin ◽  
Gian Pietro Serra ◽  
François Georges ◽  
Åsa Wallén-Mackenzie
Keyword(s):  
Motor Control ◽  
Basal Ganglia ◽  
Experimental Evidence ◽  
Subthalamic Nucleus ◽  
Motor Coordination ◽  
List Type ◽  
Motor Tasks ◽  
Experimental Support ◽  
Freely Moving

AbstractThe subthalamic nucleus is important achieve intended movements. Loss of its normal function is strongly associated with several movement disorders. Classical basal ganglia models postulate that two parallel pathways, the direct and indirect pathways, exert opposing control over movement, with the subthalamic nucleus part of the indirect pathway through which competing motor programs are prevented. The subthalamic nucleus is regulated by both inhibitory and excitatory projections but experimental evidence for its role in motor control has remained sparse. The objective here was to tease out the selective impact of the subthalamic nucleus on several motor parameters required to achieve intended movement, including locomotion, balance and motor coordination. Optogenetic excitation and inhibition using both bilateral and unilateral stimulations of the subthalamic nucleus were implemented in freely-moving mice. The results demonstrate that selective optogenetic inhibition of the subthalamic nucleus enhances locomotion while its excitation reduces locomotion. These findings lend experimental support to basal ganglia models in terms of locomotion. However, further analysis of subthalamic nucleus excitation revealed grooming and disturbed gait. Selective excitation also caused reduced motor coordination, independent of grooming, in advanced motor tasks. This study contributes experimental evidence for a regulatory role of the subthalamic nucleus in motor control.HighlightsBilateral optogenetic excitation of the subthalamic nucleus in freely-moving mice reduces forward locomotion while optogenetic inhibition leads to its increase.Unilateral optogenetic excitation and inhibition of the subthalamic nucleus cause opposite rotational behavior.Bilateral optogenetic excitation, but not inhibition, of the subthalamic nucleus induces jumping and self-grooming behavior.Engaged in advanced motor tasks, bilateral optogenetic excitation causes mice to lose motor coordination.The results provide experimental support for predictions by the basal ganglia motor model on the role of the subthalamic nucleus in locomotion, and identifies a causal role for the subthalamic nucleus in self-grooming.

scholarly journals Cerebellar Dysfunction in Adults with Prader Willi Syndrome

2021 ◽  
Vol 10 (15) ◽  
pp. 3320
Author(s):  
Laura Blanco-Hinojo ◽  
Laia Casamitjana ◽  
Jesus Pujol ◽  
Gerard Martínez-Vilavella ◽  
Susanna Esteba-Castillo ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Function ◽  
Motor Coordination ◽  
Task Demands ◽  
Functional Mobility ◽  
Prader Willi Syndrome ◽  
Pathophysiological Mechanism ◽  
Motor Tasks ◽  
Correlation Pattern ◽  
Motor Processing

Severe hypotonia during infancy is a hallmark feature of Prader Willi syndrome (PWS). Despite its transient expression, moto development is delayed and deficiencies in motor coordination are present at older ages, with no clear pathophysiological mechanism yet identified. The diverse motor coordination symptoms present in adult PWS patients could be, in part, the result of a common alteration(s) in basic motor control systems. We aimed to examine the motor system in PWS using functional MRI (fMRI) during motor challenge. Twenty-three adults with PWS and 22 matched healthy subjects participated in the study. fMRI testing involved three hand motor tasks of different complexity. Additional behavioral measurements of motor function were obtained by evaluating hand grip strength, functional mobility, and balance. Whole brain activation maps were compared between groups and correlated with behavioral measurements. Performance of the motor tasks in PWS engaged the neural elements typically involved in motor processing. While our data showed no group differences in the simplest task, increasing task demands evoked significantly weaker activation in patients in the cerebellum. Significant interaction between group and correlation pattern with measures of motor function were also observed. Our study provides novel insights into the neural substrates of motor control in PWS by demonstrating reduced cerebellar activation during movement coordination.

Deterministic policies based on maximum regrets in MDPs with imprecise rewards

2021 ◽  
pp. 1-16
Author(s):  
Pegah Alizadeh ◽  
Emiliano Traversi ◽  
Aomar Osmani
Keyword(s):  
Decision Making ◽  
Decision Process ◽  
Process Models ◽  
Sequential Decision Making ◽  
Sequential Decision ◽  
Exact Procedure ◽  
Markov Decision ◽  
Intuitive Idea ◽  
First Time ◽  
Maximum Regret

Markov Decision Process Models (MDPs) are a powerful tool for planning tasks and sequential decision-making issues. In this work we deal with MDPs with imprecise rewards, often used when dealing with situations where the data is uncertain. In this context, we provide algorithms for finding the policy that minimizes the maximum regret. To the best of our knowledge, all the regret-based methods proposed in the literature focus on providing an optimal stochastic policy. We introduce for the first time a method to calculate an optimal deterministic policy using optimization approaches. Deterministic policies are easily interpretable for users because for a given state they provide a unique choice. To better motivate the use of an exact procedure for finding a deterministic policy, we show some (theoretical and experimental) cases where the intuitive idea of using a deterministic policy obtained after “determinizing” the optimal stochastic policy leads to a policy far from the exact deterministic policy.

Timing of Vaccine Decision-Making Among First-Time Parents

2021 ◽  
Author(s):  
J. Nathan Yarnall ◽  
Carl Seashore ◽  
Carrie A. Phillipi ◽  
Joseph E. Hatch ◽  
Beth King ◽  
...  
Keyword(s):  
Decision Making ◽  
Vaccine Decision Making ◽  
First Time

scholarly journals An Avian Basal Ganglia-Forebrain Circuit Contributes Differentially to Syllable Versus Sequence Variability of Adult Bengalese Finch Song

2009 ◽  
Vol 101 (6) ◽  
pp. 3235-3245 ◽  
Author(s):  
Cara M. Hampton ◽  
Jon T. Sakata ◽  
Michael S. Brainard
Keyword(s):  
Basal Ganglia ◽  
Syllable Structure ◽  
Skill Learning ◽  
Behavioral Variability ◽  
Neural Pathways ◽  
Sequence Variability ◽  
Social Modulation ◽  
The Social ◽  
Learned Behaviors ◽  
Magnocellular Nucleus

Behavioral variability is important for motor skill learning but continues to be present and actively regulated even in well-learned behaviors. In adult songbirds, two types of song variability can persist and are modulated by social context: variability in syllable structure and variability in syllable sequencing. The degree to which the control of both types of adult variability is shared or distinct remains unknown. The output of a basal ganglia-forebrain circuit, LMAN (the lateral magnocellular nucleus of the anterior nidopallium), has been implicated in song variability. For example, in adult zebra finches, neurons in LMAN actively control the variability of syllable structure. It is unclear, however, whether LMAN contributes to variability in adult syllable sequencing because sequence variability in adult zebra finch song is minimal. In contrast, Bengalese finches retain variability in both syllable structure and syllable sequencing into adulthood. We analyzed the effects of LMAN lesions on the variability of syllable structure and sequencing and on the social modulation of these forms of variability in adult Bengalese finches. We found that lesions of LMAN significantly reduced the variability of syllable structure but not of syllable sequencing. We also found that LMAN lesions eliminated the social modulation of the variability of syllable structure but did not detect significant effects on the modulation of sequence variability. These results show that LMAN contributes differentially to syllable versus sequence variability of adult song and suggest that these forms of variability are regulated by distinct neural pathways.

Motor Subcircuits Mediating the Control of Movement Velocity: A PET Study

1998 ◽  
Vol 80 (4) ◽  
pp. 2162-2176 ◽  
Author(s):  
Robert S. Turner ◽  
Scott T. Grafton ◽  
John R. Votaw ◽  
Mahlon R. Delong ◽  
John M. Hoffman
Keyword(s):  
Motor Control ◽  
Basal Ganglia ◽  
Right Hemisphere ◽  
Movement Velocity ◽  
Rate Effects ◽  
Regression Slopes ◽  
The Right ◽  
Parietal Cortices ◽  
Linear Contrasts ◽  
Rate Of Movement

Turner, Robert S., Scott T. Grafton, John R. Votaw, Mahlon R. DeLong, and John M. Hoffman. Motor subcircuits mediating the control of movement velocity: a PET study. J. Neurophysiol. 80: 2162–2176, 1998. The influence of changes in the mean velocity of movement on regional cerebral blood flow (rCBF) was studied using positron emission tomography (PET) in nine healthy right-handed adults while they performed a smooth pursuit visuomanual tracking task. Images of relative rCBF were obtained while subjects moved a hand-held joystick to track the movement of a target at three different rates of a sinusoidal displacement (0.1, 0.4, and 0.7 Hz). Significant changes in rCBF between task conditions were detected using analysis of variance and weighted linear contrasts. The kinematics of arm and eye movements indicated that subjects performed tasks in a similar manner, particularly during the faster two tracking conditions. Significant increases in rCBF during arm movement (relative to an eye tracking only control condition) were detected in a widespread network of areas known for their involvement in motor control. The activated areas included primary sensorimotor (M1S1), dorsal and mesial premotor, and dorsal parietal cortices in the left hemisphere and to a lesser extent the sensorimotor and superior parietal cortices in the right hemisphere. Subcortically, activations were found in the left putamen, globus pallidus (GP), and thalamus, in the right basal ganglia, and in the right anterior cerebellum. Within the cerebral volume activated with movement, three areas had changes in rCBF that correlated positively with the rate of movement: left M1S1, left GP, and right anterior cerebellum. No movement-related sites had rCBF that correlated negatively with the rate of movement. Regressions of mean percent change (MPC) in rCBF onto mean hand velocity yielded two nonoverlapping subpopulations of movement-related loci, the three sites with significant rate effects and regression slopes steeper than 0.17 MPC⋅cm−1⋅s−1 and all other sites with nonsignificant rate effects and regression slopes below 0.1 MPC⋅cm−1⋅s−1. Moreover, the effects of movement per se and of movement velocity varied in magnitude independently. These results confirm previous reports that movement-related activations of M1S1 and cerebellum are sensitive to movement frequency or some covarying parameter of movement. The activation of GP with increasing movement velocity, not described in previous functional-imaging studies, supports the hypothesis that the basal ganglia motor circuit may be involved preferentially in controlling or monitoring the scale and/or dynamics of arm movements. The remaining areas that were activated equally for all movement rates may be involved in controlling higher level aspects of motor control that are independent of movement dynamics.

scholarly journals A consumer perspective of advertising by attorneys

1991 ◽  
Vol 17 (1) ◽  
Author(s):  
C. Boshoff
Keyword(s):  
South Africa ◽  
Decision Making ◽  
Information Needs ◽  
Communication Strategies ◽  
Legal Services ◽  
Marketing Communication ◽  
Advertising Agencies ◽  
The Public ◽  
Consumer Perspective ◽  
First Time

Attorneys in South Africa may soon be permitted to advertise their services for the first time. This recommendation put forward by the Association of Law Societies, though still to be ratified by the four provincial law societies, has come amid increasing competition between attorneys and non- professionals. The marketing fraternity is, however, uncertain as to how members of the public are likely to react to legal services advertising. This study attempts to provide some tentative guidelines for decision-making on advertising by attorneys. Interested parties like attorneys, marketing consultants, and advertising agencies could use the researched information to structure marketing communication strategies which will not transgress the ethical code of the attorneys' profession, but which will satisfy the information needs of consumers. The study reports the findings of a survey conducted among 1 000 members of the public. Indications are that consumers not only think that advertising should be permitted, but also that it will benefit both themselves and the legal profession. Opsomming Prokureurs mag moontlik binnekort toegelaat word om hul dienste te adverteer. Die aanbeveling van die Vereniging van Prokureursordes, wat nog deur die vier provinsiale wetsgenootskappe bekragtig moet word, is geneem as gevolg van toenemende mededinging tussen prokureurs en nie-professionele praktisyns. Bemarkingsdeskundiges is egter onseker oor wat die publiek se reaksie sal wees. Die studie poog om enkele tentatiewe riglyne voor te stel vir bemarkingskommunikasiestrategieë wat nie die regsprofessie se etiese kode sal oortree nie, maar tog voldoende inligting aan verbruikers sal beskikbaar stel. Die bevindinge van 'n opname onder 1 000 lede van die publiek dui daarop dat reklame nie alleen verwelkom sal word nie, maar dat dit moontlik tot voordeel van sowel die publiek as die regsprofessie sal strek.

scholarly journals Adoption of management decisions based on programming methods as a subgroup of methods for optimizing performance indicators

2019 ◽  
Vol 4 (9) ◽  
pp. 34-44
Author(s):  
А. Тебекин ◽  
A. Tebekin
Keyword(s):  
Decision Making ◽  
Performance Indicators ◽  
Management Decision ◽  
Management Decisions ◽  
General Classification ◽  
Managerial Decisions ◽  
Management Decision Making ◽  
First Time

The author's classification of management decision-making methods, including twenty-five classes of methods, is presented for the first time. As part of the general classification of management decision-making methods, the role and place of a group of methods for making managerial decisions based on the optimization of performance indicators was demonstrated. In the group of methods for making managerial decisions based on the optimization of performance indicators, a subgroup of programming methods (linear, nonlinear and dynamic) is considered in detail. The features of use and application are shown when making managerial decisions of a subgroup of programming methods.

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