Modeling Qualitative Changes in Bimanual Movements

1997 ◽  
Vol 07 (06) ◽  
pp. 1441-1450 ◽  
Author(s):  
C. Scheffczyk ◽  
A. Zaikin ◽  
M. Rosenblum ◽  
R. Engbert ◽  
R. Krampe ◽  
...  
Keyword(s):  
Correction Function ◽  
Coupling Mechanism ◽  
Control Mechanisms ◽  
Rhythmic Movements ◽  
Bimanual Movements ◽  
Iterated Maps ◽  
Essential Properties ◽  
The Central Nervous System ◽  
Level Of Training ◽  
Qualitative Changes

In the cognitive sciences the study of complex rhythmic movements is a challenging problem which is a subject of extensive research. Experiments on bimanual movements are paradigms for studying the ability of humans on timing and coordination. Such experiments give insights into the control mechanisms of the central nervous system and also reflect the functional state and level of training of the person tested. In a recent study on bimanual polyrhythm production the existence of phase transitions in dependence on the speed of performance has been shown. In this paper we present an iterated map model to explain main findings of these experiments. The model consists of two iterated maps describing the dynamics of the finger movements. The essential properties of the model are a nonlinear correction function and a coupling mechanism between the two maps. Numerical simulations show that the model is in qualitative agreement with the experimentally observed phenomena.

Control Mechanisms in Oscillatory Motor Behavior

2013 ◽  
Author(s):  
Davide Piovesan ◽  
Felix C. Huang
Keyword(s):  
Muscle Activation ◽  
Motor Behavior ◽  
Rhythmic Movement ◽  
Control Mechanisms ◽  
Rhythmic Movements ◽  
Movement Trajectories ◽  
Reduced Frequency ◽  
The Central Nervous System ◽  
Human Motor ◽  
Inertial Loading

Studies on unimpaired humans have demonstrated that the central nervous system employs internal representations of limb dynamics and intended movement trajectories for planning muscle activation during pointing and reaching tasks. However, when performing rhythmic movements, it has been hypothesized that a control scheme employing an autonomous oscillator — a simple feedback circuit lacking exogenous input — can maintain stable control. Here we investigate whether such simple control architectures that can realize rhythmic movement that we observe in experimental data. We asked subjects to perform rhythmic movements of the forearm while a robotic interface simulated inertial loading. Our protocol included unexpected increases in loading (catch trials) as a probe to reveal any systematic changes in frequency and amplitude. Our primary findings were that increased inertial loading resulted in reduced frequency of oscillations, and in some cases multiple frequencies. These results exhibit some agreement with an autonomous oscillator model, though other features are more consistent with feedforward planning of force. This investigation provides a theoretical and experimental framework to reveal basic computational elements for how the human motor system achieves skilled rhythmic movement.

Effect of Transcranial Magnetic Stimulation on Bimanual Movements

2005 ◽  
Vol 93 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Jen-Tse Chen ◽  
Yung-Yang Lin ◽  
Din-E Shan ◽  
Zin-An Wu ◽  
Mark Hallett ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Left Hemisphere ◽  
Magnetic Stimulation ◽  
Normal Subjects ◽  
Left Index Finger ◽  
Rhythmic Movements ◽  
Bimanual Movements ◽  
Ipsilateral Stimulation ◽  
The Right

Transcranial magnetic stimulation (TMS) of the motor cortex can interrupt voluntary contralateral rhythmic limb movements. Using the method of “resetting index” (RI), our study investigated the TMS effect on different types of bimanual movements. Six normal subjects participated. For unimanual movement, each subject tapped either the right or left index finger at a comfortable rate. For bimanual movement, index fingers of both hands tapped in the same (in-phase) direction or in the opposite (antiphase) direction. TMS was applied to each hemisphere separately at various intensities from 0.5 to 1.5 times motor threshold (MT). TMS interruption of rhythm was quantified by RI. For the unimanual movements, TMS disrupted both contralateral and ipsilateral rhythmic hand movements, although the effect was much less in the ipsilateral hand. For the bimanual in-phase task, TMS could simultaneously reset the rhythmic movements of both hands, but the effect on the contralateral hand was less and the effect on the ipsilateral hand was more compared with the unimanual tasks. Similar effects were seen from right and left hemisphere stimulation. TMS had little effect on the bimanual antiphase task. The equal effect of right and left hemisphere stimulation indicates that neither motor cortex is dominant for simple bimanual in-phase movement. The smaller influence of contralateral stimulation and the greater effect of ipsilateral stimulation during bimanual in-phase movement compared with unimanual movement suggest hemispheric coupling. The antiphase movements were resistant to TMS disruption, and this suggests that control of rhythm differs in the 2 tasks. TMS produced a transient asynchrony of movements on the 2 sides, indicating that both motor cortices might be downstream of the clocking command or that the clocking is a consequence of the 2 hemispheres communicating equally with each other.

Mechanisms for generating temporal filters in the electrosensory system

1999 ◽  
Vol 202 (10) ◽  
pp. 1281-1289 ◽  
Author(s):  
G.J. Rose ◽  
E.S. Fortune
Keyword(s):  
Nervous System ◽  
Discharge Rate ◽  
Temporal Structure ◽  
Sensory Information ◽  
Gain Control ◽  
Membrane Properties ◽  
Control Mechanisms ◽  
Temporal Features ◽  
Level Of Activity ◽  
The Central Nervous System

Temporal patterns of sensory information are important cues in behaviors ranging from spatial analyses to communication. Neural representations of the temporal structure of sensory signals include fluctuations in the discharge rate of neurons over time (peripheral nervous system) and the differential level of activity in neurons tuned to particular temporal features (temporal filters in the central nervous system). This paper presents our current understanding of the mechanisms responsible for the transformations between these representations in electric fish of the genus Eigenmannia. The roles of passive and active membrane properties of neurons, and frequency-dependent gain-control mechanisms are discussed.

scholarly journals RESPIRATORY MANIFESTATIONS IN ENDOCRINE DISEASES

2016 ◽  
Vol 89 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Codruţa Lencu ◽  
Teodora Alexescu ◽  
Mirela Petrulea ◽  
Monica Lencu
Keyword(s):  
Sleep Apnea ◽  
Central Sleep Apnea ◽  
Regulation Of Respiration ◽  
Control Mechanisms ◽  
Upper Airways ◽  
Respiratory Disorders ◽  
Medical Practitioners ◽  
Endocrine Diseases ◽  
The Central Nervous System ◽  
Pulmonary Arterial

The control mechanisms of respiration as a vital function are complex: voluntary – cortical, and involuntary – metabolic, neural, emotional and endocrine. Hormones and hypothalamic neuropeptides (that act as neurotrasmitters and neuromodulators in the central nervous system) play a role in the regulation of respiration and in bronchopulmonary morphology. This article presents respiratory manifestations in adult endocrine diseases that evolve with hormone deficit or hypersecretion. In hyperthyroidism, patients develop ventilation disorders, obstructive and central sleep apnea, and pleural collection. The respiratory abnormalities in hyperthyroidism as a result of the hypermetabolic action of thyroid hormones are hyperventilation, myopathy and cardiovascular involvement; recent studies have reported pulmonary arterial hypertension in Graves’ disease, as a result of the association of several mechanisms. Thyroid hypertrophy can induce through compression of the upper airways dyspnea, stridor, wheezing and cough. The respiratory disorders in acromegaly are ventilatory dysfunction and sleep apnea, which contribute to an unfavorable evolution of the disease. Respiratory changes in parathyroid, adrenal and reproductive system diseases have been described. Respiratory disorders should be recognized, investigated and monitored by medical practitioners of various specialties (family physicians, internists, endocrinologists, pneumologists, cardiologists). They are frequently severe, causing an unfavorable evolution of the associated endocrine and respiratory disease. 

scholarly journals Mechanisms of spreading depolarization in vertebrate and insect central nervous systems

2016 ◽  
Vol 116 (3) ◽  
pp. 1117-1127 ◽  
Author(s):  
Kristin E. Spong ◽  
R. David Andrew ◽  
R. Meldrum Robertson
Keyword(s):  
Locusta Migratoria ◽  
Model Systems ◽  
Control Mechanisms ◽  
Cellular Mechanisms ◽  
Nervous Systems ◽  
Spreading Depolarization ◽  
Metathoracic Ganglion ◽  
Evolutionarily Conserved ◽  
Central Nervous Systems ◽  
The Central Nervous System

Spreading depolarization (SD) is generated in the central nervous systems of both vertebrates and invertebrates. SD manifests as a propagating wave of electrical depression caused by a massive redistribution of ions. Mammalian SD underlies a continuum of human pathologies from migraine to stroke damage, whereas insect SD is associated with environmental stress-induced neural shutdown. The general cellular mechanisms underlying SD seem to be evolutionarily conserved throughout the animal kingdom. In particular, SD in the central nervous system of Locusta migratoria and Drosophila melanogaster has all the hallmarks of mammalian SD. Locust SD is easily induced and monitored within the metathoracic ganglion (MTG) and can be modulated both pharmacologically and by preconditioning treatments. The finding that the fly brain supports repetitive waves of SD is relatively recent but noteworthy, since it provides a genetically tractable model system. Due to the human suffering caused by SD manifestations, elucidating control mechanisms that could ultimately attenuate brain susceptibility is essential. Here we review mechanisms of SD focusing on the similarities between mammalian and insect systems. Additionally we discuss advantages of using invertebrate model systems and propose insect SD as a valuable model for providing new insights to mammalian SD.

scholarly journals Shared Bimanual Tasks Elicit Bimanual Reflexes During Movement

2009 ◽  
Vol 102 (6) ◽  
pp. 3142-3155 ◽  
Author(s):  
Pratik K. Mutha ◽  
Robert L. Sainburg
Keyword(s):  
Hand Position ◽  
Electromyographic Activity ◽  
Control Mechanisms ◽  
Reactive Control ◽  
Reflex Responses ◽  
Task Goal ◽  
Bimanual Movements ◽  
The Right ◽  
Made In ◽  
Bimanual Tasks

Previous research has suggested distinct predictive and reactive control mechanisms for bimanual movements compared with unimanual motion. Recent studies have extended these findings by demonstrating that movement corrections during bimanual movements might differ depending on whether or not the task is shared between the arms. We hypothesized that corrective responses during shared bimanual tasks recruit bilateral rapid feedback mechanisms such as reflexes. We tested this hypothesis by perturbing one arm as subjects performed uni- and bimanual movements. Movements were made in a virtual-reality environment in which hand position was displayed as a cursor on a screen. During bimanual motion, we provided cursor feedback either independently for each arm (independent-cursor) or such that one cursor was placed at the average location between the arms (shared-cursor). On random trials, we applied a 40 N force pulse to the right arm 100 ms after movement onset. Our results show that while reflex responses were rapidly elicited in the perturbed arm, electromyographic activity remained close to baseline levels in the unperturbed arm during the independent-cursor trials. In contrast, when the cursor was shared between the arms, reflex responses were reduced in the perturbed arm and were rapidly elicited in the unperturbed arm. Our results thus suggest that when both arms contribute to achieving the task goal, reflex responses are bilaterally elicited in response to unilateral perturbations. These results agree with and extend recent suggestions that bimanual feedback control might be modified depending on task context.

Topical issues of interaction of psychotropic drugs

2021 ◽  
pp. 27-38
Author(s):  
Artur Udalisovich Karimov ◽  
Maxim Leonidovich Maximov ◽  
Dmitry Germanovich Semenikhin ◽  
Linar Arturovich Karimov
Keyword(s):  
Mental Disorders ◽  
Psychotropic Drugs ◽  
Review Article ◽  
Internal Organs ◽  
Pharmacodynamic Interactions ◽  
Number Of Patients ◽  
The Central Nervous System ◽  
Practical Information ◽  
Somatic Diseases ◽  
Qualitative Changes

In mental patients with concomitant somatic pathology, psychotropic drugs are prescribed in combination with other drugs used in the treatment of various somatic diseases. As well as a large number of patients with somatic diseases, they receive therapy aimed at correcting mental disorders. At the same time, it is important to take into account the possibility of cross-influence of such pharmacotherapy on the functions of the central nervous system and internal organs, as well as the peculiarities of drug interactions between drugs. According to the mechanism of development, there are pharmaceutical, pharmacokinetic and pharmacodynamic interactions of drugs. The result of the interaction of drugs is more often a change in the intensity of the effect of drugs, less often there are qualitative changes in their action. The review article provides up-to-date practical information on the interaction of drugs for the treatment of mental disorders with drugs of other groups.

Features of assimilation of knowledge by students at the process of studying the discipline “Functional anatomy of the central nervous system”

2016 ◽  
Vol 7 (1) ◽  
pp. 163-166
Author(s):  
Natalia Yu Zavarzina ◽  
Olga S Kulbakh ◽  
Elena R Zinkevich
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional Anatomy ◽  
Object Allocation ◽  
Essential Properties ◽  
Third Stage ◽  
The Central Nervous System ◽  
Preparatory Stage ◽  
Estimate Quality ◽  
Medical University

In the article the process of assimilation of knowledge when studying discipline "Functional anatomy of the central nervous system" at faculty of clinical psychology of GBOU VPO "St. Petersburg State Pediatric Medical University" of the Ministry of Health of Russia is analyzed. In the course of assimilation the preparatory stage of studying of a subject is of great importance. The teacher focuses attention of students that anatomy as the descriptive discipline is subjective in the basis. It causes need of development of the uniform principles and approaches to the description of a structure of various anatomical structures. At the first stage of assimilation of knowledge there is a perception of a certain anatomic object; allocation of its properties and qualities on the offered algorithm is carried out. At the second stage the judgment of the most essential communications and the relations of the object of studying is made. At the third stage there is a process of imprinting and storing of features of a structure of the studied object, and also its communications and functions allocated as a result of repeated visualization and repetition. At the fourth stage active reproduction by a student of acquired knowledge and understanding of its essential properties and the relations is carried out. Only at this stage the teacher can estimate quality of the acquired knowledge by students. The fifth stage assumes active use of the acquired knowledge, its creative transformation, application in studying of other subject matters.

Strategies for the Control of Balance During Locomotion

2018 ◽  
Vol 7 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Hendrik Reimann ◽  
Tyler Fettrow ◽  
John J. Jeka
Keyword(s):  
Degrees Of Freedom ◽  
Neural Control ◽  
Control Strategies ◽  
Mechanical Effect ◽  
Space Representation ◽  
Control Mechanisms ◽  
Step Width ◽  
Foot Placement ◽  
The Central Nervous System ◽  
Phase Space Representation

The neural control of balance during locomotion is currently not well understood, even in the light of considerable advances in research on balance during standing. In this paper, we lay out the control problem for this task and present a list of different strategies available to the central nervous system to solve this problem. We discuss the biomechanics of the walking body, using a simplified model that iteratively gains degrees of freedom and complexity. Each addition allows for different control strategies, which we introduce in turn: foot placement shift, ankle strategy, hip strategy, and push-off modulation. The dynamics of the biomechanical system are discussed using the phase space representation, which allows illustrating the mechanical effect of the different control mechanisms. This also enables us to demonstrate the effects of common general stability strategies, such as increasing step width and cadence.

scholarly journals Education of medical students in Bitola on tobacco use and their role in health promotion activities

2011 ◽  
Vol 64 (11-12) ◽  
pp. 529-532
Author(s):  
Tanja Jovanovska ◽  
Viktorija Prodanovska-Stojcevska
Keyword(s):  
Health Promotion ◽  
Tobacco Use ◽  
Cross Sectional Study ◽  
Educational Process ◽  
Cross Sectional ◽  
Quit Smoking ◽  
Level Of Knowledge ◽  
Level Of Training ◽  
Harmful Effects ◽  
Qualitative Changes

Health professionals should have a key role in health promotion activities regarding reduced tobacco use. This study was aimed at presenting students? level of knowledge on harmful effects of smoking and the level of training they had gained in order to quit smoking. The research was done as an epidemiological, cross sectional study according to the standardized methodology of Global Health Professional Survey. The study sample consisted of a hundred college students. During the educational process, 77.5% of females, and 93.1% of males were educated on harmful and dangerous effects of smoking and 59.2% of females and 62.1% of males were instructed how to give up smoking and the age of 86.6% of them was from 18 to 24 years. It has been concluded that some qualitative changes are needed in the current curricula and syllabi.

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