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Results 451 - 500 of 1470
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Varoto Renato - - 2008
Generally, quadriplegic individuals have difficulties performing object manipulation. Toward satisfactory manipulation, reach and grasp movements must be performed with voluntary control, and for that, grasp force feedback is essential. A hybrid system aiming at partial upper limb sensory-motor restoration for quadriplegics was built. Such device is composed of an elbow ...
White Olivier - - 2008
In many nonprimate species, rhythmic patterns of activity such as locomotion or respiration are generated by neural networks at the spinal level. These neural networks are called central pattern generators (CPGs). Under normal gravitational conditions, the energy efficiency and the robustness of human rhythmic movements are due to the ability ...
van Doorn Robert R A - - 2008
Right-handed participants performed aimed, left- and right-hand movements toward a fixed target in speed and precision conditions. The purpose was to determine detailed hand differences in the temporal and spatial control during the course of a movement. The results showed that hand differences pertaining to spatial control of movement direction ...
Maki Yohko - - 2008
Mirror-symmetrical bimanual movement is more stable than parallel bimanual movement. This is well established at the kinematic level. We used functional MRI (fMRI) to evaluate the neural substrates of the stability of mirror-symmetrical bimanual movement. Right-handed participants (n=17) rotated disks with their index fingers bimanually, both in mirror-symmetrical and asymmetrical ...
Lai Shih-Chiung - - 2008
This study investigated the mutual information in the trajectories of discrete aiming movements on a computer controlled graphics tablet where movement time ( 300 - 2050 ms) was manipulated in a given distance (100 mm) and movement distance (15-240 mm) in 2 given movement times (300 ms and 800 ms ...
Kjeldsen Rick - - 2008
Vision-based head trackers have been around for some years and are even beginning to be commercialized, but problems remain with respect to usability. Users without the ability to use traditional pointing devices--the intended audience of such systems--have no alternative if the automatic bootstrapping process fails. There is room for improvement ...
Heath Matthew - - 2008
The authors manipulated the availability of monocular and binocular vision during the constituent planning and control stages of a goal-directed reaching task. Furthermore, trials were completed with or without online limb vision to determine whether monocular- or binocular-derived ego-motion cues influence the integration of visual feedback for online limb corrections. ...
Schaefer Sydney Y - - 2008
The purpose of this study was to examine the mechanisms underlying control of distance during multijoint movements in different directions. The findings revealed 2 sequential muscle torque impulses, which correlated with 2 events in the hand acceleration profile. These 2 events occurred prior to peak velocity, characterizing control in the ...
Mirbagheri Mehdi M - - 2008
OBJECTIVES: To characterize the time-course of changes in motor recovery in the upper extremity of hemiparetic stroke survivors over a 1-year interval after stroke, and to use kinematic and kinetic recordings of elbow voluntary movement at 1 month to predict recovery over this 1-year period. DESIGN: Motor impairment was assessed ...
Pollick Frank E - - 2009
It has long been acknowledged that planar hand drawing movements conform to a relationship between movement speed and shape, such that movement speed is inversely proportional to the curvature to the power of one-third. Previous literature has detailed potential explanations for the power law's existence as well as systematic deviations ...
Pellizzer Giuseppe - - 2009
Children from 8 to 12 years of age drew figure-eights and ellipses at a self-chosen tempo on a digitizing tablet. Global aspects (perimeter and average speed) and local aspects (relation between instantaneous speed and curvature) of performance were analyzed across age groups and types of figures. We tested the predictions ...
Wallace Douglas G - - 2008
Rats use multiple sources of information to maintain spatial orientation. Although previous work has focused on rats' use of environmental cues, a growing number of studies have demonstrated that rats also use self-movement cues to organize navigation. This review examines the extent that kinematic analysis of naturally occurring behavior has ...
Fradet Laetitia - - 2008
Submovements that are frequently observed in the final portion of pointing movements have traditionally been viewed as pointing accuracy adjustments. Here we re-examine this long-lasting interpretation by developing evidence that many of submovements may be non-corrective fluctuations arising from various sources of motor output variability. In particular, non-corrective submovements may ...
Orgs Guido - - 2008
We presented professional dancers and non-dancers with videos of two movement styles, dance movements and everyday movements. Participants were asked to indicate by a button press to which category a movement belonged. We computed event-related desynchronization (ERD) in alpha and beta frequency bands between 7.5 and 25 Hz relative to ...
Perkins M C - - 2008
Understanding the movement of the active ingredient in relation to the other formulation components following application is crucial to an overall understanding of herbicide performance. We describe the novel use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) as a tool for following the movement of herbicide formulation components into and ...
Trempe Maxime M Département de kinésiologie, Université de Montréal, Montreal, Quebec, Canada. - - 2008
One can adapt movement planning to compensate for a mismatch between vision and action. Previous research with prismatic lenses has shown this adaptation to be accompanied with a shift in the evaluation of one's body midline, suggesting an important role of this reference for successful adaptation. This interpretation leads to ...
Valls-Solé Josep J EMG unit, Neurology Department, Hospital Clínic, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain. - - 2008
The startle reaction (SR) is usually understood as an involuntary reaction to an unexpected sensory input. However, there is evidence that the mechanisms involved in the SR contribute also to the execution of actions that we consider voluntary. We need to exert a fine control of the motor output, which ...
Woolley Daniel G - - 2008
Previous studies have attempted to identify sources of contextual information which can facilitate dual adaptation to two variants of a novel environment, which are normally prone to interference. The type of contextual information previously used can be grouped into two broad categories: that which is arbitrary to the motor system, ...
Godoy Rolf Inge - - 2008
From our studies of sound-related movement (http:musicalgestures.uio.no), we have reason to believe that both sound-producing and sound-accompanying movements are centered around what we call goal-points, meaning certain salient events in the music such as downbeats, or various accent types, or melodic peaks. In music performance, these goal-points are reflected in ...
Roshier David A - - 2008
Most ecological and evolutionary processes are thought to critically depend on dispersal and individual movement but there is little empirical information on the movement strategies used by animals to find resources. In particular, it is unclear whether behavioural variation exists at all scales, or whether behavioural decisions are primarily made ...
De Marco Rodrigo J - - 2008
A honeybee's waggle dance is an intriguing example of multisensory convergence, central processing and symbolic information transfer. It conveys to bees and human observers the position of a relatively small area at the endpoint of an average vector in a two-dimensional system of coordinates. This vector is often computed from ...
Bose Arpita - - 2008
Most existing models of language production and speech motor control do not explicitly address how language requirements affect speech motor functions, as these domains are usually treated as separate and independent from one another. This investigation compared lip movements during bilabial closure between five individuals with mild aphasia and five ...
Biermann-Ruben Katja - - 2008
Our motor and perceptual representations of actions seem to be intimately linked and the human mirror neuron system (MNS) has been proposed as the mediator. In two experiments, we presented biological or non-biological movement stimuli that were either congruent or incongruent to a required response prompted by a tone. When ...
Schneider Axel - - 2008
A closed kinematic chain, like an arm that operates a crank, has a constrained movement space. A meaningful movement of the chain's endpoint is only possible along the free movement directions which are given implicitly by the contour of the object that confines the movement of the chain. Many technical ...
Missaka Reinaldo - - 2008
This study aimed to present a wireless mandibular motion tracking device and optoelectronic data acquisition system developed to analyze the real-time spatial motion of the entire mandible during mouth opening and closing with no restriction of any movement. The procedures were divided into three phases: confection of a kinematic arch, ...
Izawa Jun - - 2008
Adaptation is sometimes viewed as a process in which the nervous system learns to predict and cancel effects of a novel environment, returning movements to near baseline (unperturbed) conditions. An alternate view is that cancellation is not the goal of adaptation. Rather, the goal is to maximize performance in that ...
Eckert Scott A - - 2008
Adapting state-space models (SSMs) to telemetry data has been helpful for dealing with location error and for modeling animal movements. We used a combination of two hierarchical Bayesian SSMs to estimate movement pathways from Argos satellite-tag data for 15 juvenile loggerhead turtles (Caretta caretta) in the western Mediterranean Sea, and ...
Field Evelyn F - - 2008
Sex differences in the kinematic organization of non-reproductive behavior are often relegated to byproducts of sex differences in body morphology. We review evidence showing not only that male and female rats organize their posture and stepping differently during a variety of actions, but that these differences arise from sex differences ...
Casadio Maura - - 2008
In MS subjects with no clinical disability, we assessed sensorimotor organization and their ability to adapt to an unfamiliar dynamical environment. Eleven MS subjects performed reaching movements while a robot generated a speed-dependent force field. Control and adaptation performance were compared with that of an equal number of control subjects. ...
Tsunoda Yoshiaki - - 2008
Anticipating the timing of behaviorally relevant events is crucial for organizing movement. The time to initiate actions based on events (i.e., reaction time (RT)) is a useful measure to quantify states of anticipation. Few studies have examined how anticipation affects the timing of limb movements. We addressed this question behaviorally ...
Makimoto Kiyoko - - 2008
BACKGROUND: The availability of increasingly sophisticated technology has meant that ambulation can be measured with precision over an extended period. METHODS: An integrated circuit tag-monitoring system was set up to measure the distance moved in a dementia care unit in Korea in 2006. Various indicators were developed to measure temporal ...
Hansen Steve - - 2008
This study examined the spatial and temporal limitations of the visual corrective process in the control of upper limb movements. Real-time calculation of kinematic data was used to trigger a prismatic displacement of the movement environment during manual aiming. Using an OptoTrak motion tracking system, a data acquisition unit, and ...
Noguchi K - - 2008
This study was designed to evaluate the relationship between the temporal anticipation effects and motor control on repetitive tooth tapping movements (tooth tapping produced by open-close jaw movements) commanded by six frequencies of acoustic signals. Ten dentulous young adults were asked to perform tooth tapping movements to acoustic command signals ...
Wilson Cassie - - 2008
The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic ...
Abernethy Bruce - - 2008
Three experiments were undertaken to ascertain the extent to which expertise in natural anticipatory tasks is characterised by superior attunement to the biomechanical (kinematic) constraints of the movement pattern being observed. Twelve world-class and twelve non-expert badminton players were required to predict the depth of an opponent's stroke from either ...
Wilson Margaret - - 2008
This review introduces different techniques used in biomechanics that have been used in analyzing dance movement. Biomechanics provides information not only for analysis of motion, but for understanding muscle use, forces acting on the body, issues of motor control, and the interaction between any one body part and the body ...
Farrer C - - 2008
It has been hypothesized that an internal model is involved in controlling and recognizing one's own actions (action attribution). This results from a comparison process between the predicted sensory feedback of the action and its real sensory consequences. The aim of the present study is to distinguish the respective importance ...
Cesqui Benedetta - - 2008
In the past, several research groups have shown that when a velocity dependent force field is applied during upper limb movements subjects are able to deal with this external perturbation after some training. This adaptation is achieved by creating a new internal model which is included in the normal unperturbed ...
Liebermann Dario G - - 2009
BACKGROUND: Nociceptive withdrawal reflexes (NWR) are subject to supraspinal modulation. Therefore, awareness about a noxious stimulation may affect its characteristics. The goal of this study was to investigate the effect of different degrees of awareness on the NWR. METHOD: Eight subjects performed back and forth hand movements from a common ...
Francis Joseph T JT Department of Physiology and Pharmacology, State University of New York Downstate School of Medicine, 450 Clarkson Ave., Brooklyn, NY 11203, USA. - - 2008
Our sensory-motor control system has a remarkable ability to adapt to novel dynamics during reaching movements and generalizes this adaptation to movements made in different directions, positions and even speeds. The degree and pattern of this generalization are of great importance in deducing the underlying mechanisms that govern our motor ...
Walsh Eammon E Department of Psychology, University College London, 17 Queen Square, London, WC1N 3AR, UK. - - 2007
An important aspect of everyday behaviour is the ability to cancel a prepared movement. In Experiment 1, subjects prepared a response, and then either executed it in response to a subsequent Go signal, or cancelled the movement if a NoGo signal occurred. Subjects had to detect weak shocks, which were ...
van Vliet Paulette M - - 2007
OBJECTIVE: To investigate the coordination of reach-to-grasp components in hemiparetic and healthy subjects. DESIGN: Split-plot repeated-measures design with 3 factors (group, object size, movement speed). SETTING: Movement laboratory. PARTICIPANTS: Twelve hemiparetic and 12 age-matched healthy subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We used motion analysis to collect information on ...
Black David P - - 2007
The authors conducted two experiments that served as a test bed for applying the recently developed uncontrolled manifold (UCM) approach to rhythmic motor coordination, which has been extensively investigated from a coordination dynamics perspective. The results of two experiments, one investigating within-person and one investigating between-persons rhythmic movement coordination, identified ...
Pereanu Wayne - - 2007
Larval behavioral patterns arise in a gradual fashion during late embryogenesis as the innervation of the somatic musculature and connectivity within the central nervous system develops. In this paper, we describe in a quantitative manner the maturation of behavioral patterns. Early movements are locally restricted "twitches" of the body wall, ...
Kerr A - - 2007
BACKGROUND: The principle of specificity in muscle training requires the training mode to reflect the desired outcome. The observed similarity of lower limb movements during recumbent cycling to the functional movements sit-to-stand and step-up presents the possibility of using recumbent cycling in a rehabilitation context. This may reduce the need ...
Burgess Jamie Kaye - - 2007
Recent studies on intermanual transfer of reaching movements suggest that this transfer is conducted over an "extrinsic" coordinate system. We hypothesize that training reaching movements in a force field with both hands at the same time, in the same position (bimanual grip) will be more beneficial in promoting transfer of ...
Schorer Jörg - - 2007
The authors examined the movement patterns of 5 left-handed handball players (ranging from beginner to national level) who threw a handball to different sections of a goal as if a goalkeeper were present. The authors used time-continuous, 3-dimensional kinematic data to assess interindividual movement patterns and considered participants' intraindividual differences ...
Vasil'eva O N - - 2007
The central mechanism of motor programming was studied using a model of precise horizontal flexion of the arm at the elbow joint. Training was performed in the dark to ensure that formation of the motor program was based predominantly on the use of proprioceptive afferentation. The target was not demonstrated ...
Abernethy Bruce - - 2007
In a series of 3 experiments, the authors examined the ability of badminton players of different skill levels (12 experts and 12 nonexperts) to anticipate the direction of badminton strokes. Participants viewed either film or point-light displays under a range of temporal or spatial occlusion conditions. World-class players were able ...
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