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Results 601 - 650 of 1509
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Spencer Rebecca M C - - 2006
Constraints underlying bimanual coordination have traditionally been explained by dynamic interactions between the effectors. However, the present experiments demonstrate that a fundamental constraint on bimanual performance is the manner in which task goals are represented. In Experiment 1, participants vocalized during in-phase and anti-phase bimanual movements. As expected, most participants ...
Puca Rosa Maria - - 2006
The present research is based on the assumption that people differ in their responsiveness to incentives and threats. In two experiments we examined whether the trait corresponding to the responsiveness to threats (avoidance motive) and the trait corresponding to the responsiveness to incentives (approach motive) influence voluntary motor behavior toward ...
Hirai Hiroaki - - 2006
This paper describes the hierarchical architecture for a rhythmic coordination between robots, which suits juggling-like tasks involving sensory-motor coordination. The authors' approach, which is interpreted as a "bidirectional weak coupling" to the environment, does not require either the environmental model or continuously monitoring the environment but can adapt the robots ...
Torres Elizabeth - - 2006
Is the movement duration time known before we move? To answer this question, a new experimental paradigm is introduced that for the first time monitors the acquisition of a new motor skill in rhesus monkeys. Straight reaches were interleaved with reaches around physical obstacles that elicited a different path geometry. ...
Foisy Martin M Neurological Science Research Center, Department of Physiology, Rehabilitation Institute of Montreal, University of Montreal and Center for Interdisciplinary Research Studies in Rehabilitation CRIR, 6300 Darlington Ave, Montreal, QC, - - 2006
We addressed the fundamental questions of which variables underlie the control of arm movement and how they are stored in motor memory, reproduced and modified in the process of adaptation to changing load conditions. Such variables are defined differently in two major theories of motor control (internal models and threshold ...
Heuer Herbert - - 2006
Temporal and spatial movement characteristics are often seen as controlled separately, although they are not independent. Even in the case of simple oscillations mean frequency and mean amplitude covary when one or the other is changed intentionally. The present experiment revealed that in rapid finger oscillations there is also a ...
Bortoletto Marta - - 2006
The present study investigated the role of pre-motion positivity in movement initiation and the reason why it is not reliably detectable in every study participant. Nineteen right-handed participants performed self-initiated simple movements of the right index finger and mouth while electroencephalography activity was recorded. Most of the participants showed a ...
Pinkston Jonathan W - - 2006
Recent research has demonstrated that avian species may show an enhanced locomotor response to repeated drug exposure, a phenomenon called sensitization. Further research in this domain is warranted as such results not only establish the generality of previous findings, but may lend to a better understanding of sensitization in general. ...
Begon M - - 2007
Determination of the hip joint centre (HJC) using a functional approach requires access to the kinematics of various body postures. The present study aimed to determine the combined impact of the nature of the movement, its type and the number of cycles, on the accuracy of HJC estimation. Kinematics noise ...
O'Leary John G - - 2006
Local field potentials (LFPs) recorded from primary motor cortex (MI) have been shown to be tuned to the direction of visually guided reaching movements, but MI LFPs have not been shown to be tuned to the direction of an upcoming movement during the delay period that precedes movement in an ...
Wallace Douglas G - - 2006
Rat exploration is an organized series of trips. Each exploratory trip involves an outward tour from the refuge followed by a return to the refuge. A tour consists of a sequence of progressions with variable direction and speed concatenated by stops, whereas the return consists of a single direct progression. ...
Wallace Douglas G - - 2006
Rat exploration is an organized series of trips. Each exploratory trip involves an outward tour from the refuge followed by a return to the refuge. A tour consists of a sequence of progressions with variable direction and speed concatenated by stops, whereas the return consists of a single direct progression. ...
Sylvestre Pierre A - - 2006
Simple activities like picking up the morning newspaper or catching a ball require finely coordinated movements of multiple body segments. How our brain readily achieves such kinematically complex yet remarkably precise multijoint movements remains a fundamental and unresolved question in neuroscience. Many prevailing theoretical frameworks ensure multijoint coordination by means ...
Chen Jessie J Department of Physiology and Neuroscience, New York University School of Medicine, 550 First Avenue, MSB 442, New York, NY 10016, USA. - - 2006
Accuracy of shifting movements between two notes was examined in nine cellists (intermediate-professional skill levels). Three pairs of notes separated by different distances were tested under the same movement rate. Finger position on the string was measured by a circuit. Angular velocities of the left upper arm and forearm were ...
Daprati Elena - - 2007
We tested the hypothesis that our ability to detect fine kinematics variations is tuned to reveal more subtle differences when the motion pattern belongs to the observer compared to another individual. To this purpose, we analyzed the responses of 15 subjects in a same-different task on pairs of movements, which ...
Teixeira Luis Augusto - - 2006
Movement reprogramming in a task requiring timing accuracy was investigated in young and elderly individuals. The task consisted of manually hitting a hemiball in synchrony with the arrival of a moving light stimulus running through an electronic trackway. Movement reprogramming was required by unexpectedly changing the regular stimulus velocity at ...
Mazyn Liesbeth I N - - 2006
In the present study, the limits of human catching behavior were challenged to investigate quantitative and qualitative adaptations of the catching movement when performing under varying ball speeds, implying minor as well as severe temporal constraints. Nine male participants caught balls approaching at speeds ranging from 8.5 to 19.7 m/s ...
Demiris Yiannis - - 2006
Recent computational approaches to action imitation have advocated the use of hierarchical representations in the perception and imitation of demonstrated actions. Hierarchical representations present several advantages, with the main one being their ability to process information at multiple levels of detail. However, the nature of the hierarchies in these approaches ...
Runge M - - 2006
Neuromuscular parameters that describe locomotion are indispensable variables for the diagnosis and treatment of frailty, fall risk and osteoporosis. A scientifically-based standardized locomotor assessment should be an essential part of medical examinations in research and clinical practice. There has been no previous consensus regarding which test procedures should be included ...
Pitsillides Andrew A - - 2006
It has long been appreciated that studying the embryonic chick in ovo provides a variety of advantages, including the potential to control the embryo's environment and its movement independently of maternal influences. This allowed early workers to identify movement as a pivotal factor in the development of the locomotor apparatus. ...
Lyons James J Department of Kinesiology, McMaster University, Hamilton, ON, Canada. - - 2006
Recent studies have shown that the initial impulse associated with goal-directed aiming movements typically brings the limb to a position short of the target. This is because target overshooting is associated with greater temporal and energy costs than target undershooting. Presumably these costs can be expected to vary not only ...
Rand Miya K MK Motor Control Laboratory, Department of Kinesiology, Arizona State University, Box 870404, Tempe, AZ 85287-0404, USA. - - 2006
This study investigates coordination between hand transport and grasp movement components by examining a hypothesis that the hand location, relative to the object, in which aperture closure is initiated remains relatively constant under a wide range of transport speed. Subjects made reach-to-grasp movements to a dowel under four speed conditions: ...
Vernazza-Martin S S Laboratoire Sport et Culture EA2931, Université Paris-X Nanterre, 200 av. de la République, 92001 Nanterre, France. - - 2006
The aim of this investigation was to study the adaptation to an unstable support surface of kinematic synergy responsible for equilibrium control during upper trunk movements. Eight adult subjects were asked to bend their upper trunk forward to an angle of 35 degrees and then to hold the final position ...
Cruz E G EG Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Suite 1406, 345 E. Superior Street, Chicago, IL 60611, - - 2006
The goal of this study was to examine the characteristics of planar fingertip movements with respect to the hand. Ten subjects with no known neuromuscular impairments performed a series of point-to-point movements with their dominant index fingertips. Subjects were instructed to move between five pairs of targets within the workspace ...
Bailey Helen - - 2006
1. Broad-scale telemetry studies have greatly improved our understanding of the ranging patterns and habitat-use of many large vertebrates. However, there often remains considerable uncertainty over the function of different areas or the factors influencing habitat selection. Further insights into these processes can be obtained through analyses of finer scale ...
Miyakawa T - - 2006
The purpose of the present study was to determine the appropriate reference facial expression and to examine the reproducibility of our system using two commercially available video cameras in consideration of functional diagnosis of perioral muscles. The following items were investigated: 1) influence of forward and backward movements and the ...
Motiei-Langroudi Rouzbeh - - 2006
Temporal information is an embedded feature of our sensory and motor experiences. How is temporal information encoded in the brain? In the two-stage theory of timing, an explicit representation of timing is responsible for the movement initiation while movement duration is coded implicitly. We investigated the correlation of movement duration ...
Heuer Herbert - - 2006
In almost all studies of bimanual movements with same and different amplitudes, the difference between amplitudes has been confounded with a difference between endpoint locations. The present authors varied those parameters orthogonally. In addition, they presented target locations on the surface on which the movements were produced (direct cues) and ...
Levit-Binnun Nava N Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, POB 26, Rehovot, 76100, - - 2006
In an earlier study, Viviani and Stucchi (J Exp Psychol Hum Percept Perform 18:603-623, 1992) have introduced a visual illusion, whereby it was shown that when subjects are asked to determine what movement of a light spot, when tracing an elliptical trajectory, appears to be most uniform, they tend to ...
Zacks Jeffrey M - - 2006
People perceive ongoing activity in terms of discrete temporal events. Distinctive changes in the movement of objects or actors may contribute to the perception that one event has ended and another has begun. However, little is known about the quantitative contribution of movement information to the processing of events. This ...
Ridderikhoff Arne - - 2006
This study examined if and how phase entrainment by movement-related afference-- induced by passive movements of the contralateral hand-- contributes to the coordinative stability of rhythmic bimanual movements. The results revealed that phase-shifted passive movements of the dominant or the nondominant hand induced similar entrainment effects on the active movements ...
Ma Yingliang - - 2006
We present the methods that were used in capturing a library of human movements for use in computer-animated displays of human movement. The library is an attempt to systematically tap into and represent the wide range of personal properties, such as identity, gender, and emotion, that are available in a ...
Pozzo Thierry - - 2006
How do we extrapolate the final position of hand trajectory that suddenly vanishes behind a wall? Studies showing maintenance of cortical activity after objects in motion disappear suggest that internal model of action may be recalled to reconstruct the missing part of the trajectory. Although supported by neurophysiological and brain ...
Albert Frederic F Laboratoire de Neurobiologie Humaine, UMR 6149, Université de Provence, 3 Place Victor Hugo, Marseille, France. - - 2006
The aim of the present study was to further investigate the contribution of primary muscle spindle feedback to proprioception and higher brain functions, such as movement trajectory recognition. For this purpose, complex illusory movements were evoked in subjects by applying patterns of muscle tendon vibration mimicking the natural Ia afferent ...
Lee Irwin H - - 2006
Tonically active neurons (TANs) of the primate striatum are putative interneurons that respond to events of motivational significance, such as primary rewards, and to sensory stimuli that predict such events. Because TANs influence striatal projection neurons, TANs may play a role in the initiation and control of movement. To examine ...
Huveneers, C
Passive acoustic telemetry was used to assess the localised movements of seven individuals of the wobbegong shark Orectolobus halei for about two years at Fish Rock, NSW, Australia. Four of the seven sharks were detected for less than 40 days only; this was most likely due to tag loss, although ...
Khan Michael A - - 2006
Vision plays an important role in the planning and execution of target-directed aiming movements. In this review, we highlight the limitations that exist in detecting visual regulation of limb trajectories from traditional kinematic analyses such as the identification of discontinuities in velocity and acceleration. Alternative kinematic analyses that involve examining ...
van Doorn Robert R A - - 2006
The present study showed that movement execution depends on the direct visual environment. We replicated findings of an earlier study that showed a difference between real time information via a trace of the unfolding trajectory, and cursor feedback constituting real time information about the changing movement location. Detailed analyses involving ...
Jian Fuji - - 2006
Vertical movement and distribution of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) adults in stored wheat and corn were studied in small (0.1 x 0.1 x 1 m) and large (0.6 m diameter and 1.12 m high) columns. The adults were introduced at the top, middle, and bottom of the small columns with ...
VanDoorn George H - - 2006
When the right index fingertip of twelve subjects was moved across a cold (15 degrees C) tile by a machine (passive-guided condition), the subjects rated the temperature of the tile as being colder than when they moved the finger across the stimulus themselves (active condition). Results confirmed that active movements ...
Jastorff Jan - - 2006
The recognition of complex body movements and actions is a fundamental visual capacity very important for social communication. It seems possible that movement recognition is based on a general capability of the visual system to learn complex visual motion patterns. Alternatively, this visual function might exploit specialized mechanisms for the ...
Magescas F - - 2006
The ability to perform accurate limb movements may require learning mechanisms that continually tune the motor system. In the current study, we isolate a form of pure limb motor plasticity. Participants reached to targets that were turned off just after the onset of an initial eye movement, reappearing at a ...
Nams Vilis O - - 2006
Johnson et al. (Journal of Animal Ecology, 2002, 71, 225-235) have proposed a new technique for identifying scales of movement in animals. Animals are located at certain time intervals, and movement rates between successive animal relocations are calculated. The null model of a nonscalar response predicts a decreasing linear relationship ...
Schmidt Karen L - - 2006
Previous research suggests differences in lip movement between deliberate and spontaneous facial expressions. We investigated within participant differences between deliberately posed and spontaneously occurring smiles during a directed facial action task. Using automated facial image analysis, we quantified lip corner movement during periods of visible Zygomaticus major activity. Onset and ...
Poirrier Jean-Etienne - - 2006
BACKGROUND: Measurement of locomotor activity is a valuable tool for analysing factors influencing behaviour and for investigating brain function. Several methods have been described in the literature for measuring the amount of animal movement but most are flawed or expensive. Here, we describe an open source, modular, low-cost, user-friendly, highly ...
Scobeyeva Victoria A - - 2006
The investigation of natural variability of metric morphological characters in frog gastrulation revealed that in genetically and environmentally homogeneous samples of embryos their variability is of a higher order of magnitude than that known for quantitative metric characters in adult organisms. Matching the coefficients of variation of characters under consideration ...
Ketcham Caroline J - - 2006
The authors investigated whether visual fixations during a continuous graphical task were related to arm endpoint kinematics, joint motions, or joint control. The pattern of visual fixations across various shapes and the relationship between temporal and spatial events of the moving limb and visual fixations were assessed. Participants (N=16) performed ...
Gayed Bassem A BA Dept. of Biomed. Eng., New Jersey Inst. of Technol., Newark, NJ, - - 2006
Vergence eye movements are the inward (convergence) or outward (divergence) turning of the eyes which allows humans to view images in depth. This study compares converging responses where the stimuli are approaching the subject to diverging responses where the stimuli are moving away from the subject from 10, 6, and ...
Chen S C SC Graduate Sch. of Biomed. Eng., New South Wales Univ., Sydney, NSW, - - 2006
Recipients of vision prosthesis prototypes have reported electrically elicited visual perceptions as discrete dots of light (phosphenes). Phosphenes construct the scenery in discontinuous small isolated patches, resulting in visual information deficit to a large portion of the visual field. Visual scanning therefore plays an important role in the utility of ...
Fortunov Daniel I DI The School of Systems Engineering, Reading University, Whiteknights, Reading, UK. - - 2006
This study investigates the human response to impulse perturbations at the midpoint of a haptically-guided straight-line point-to-point movement. Such perturbation response may be used as an assessment tool during robot-mediated neuro-rehabilitation therapy. Subjects show variety in their perturbation responses. Movements with a lower perturbation displacement exhibit high frequency oscillations, indicative ...
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