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Results 401 - 450 of 1496
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Saunter Christopher D - - 2009
The apparently stationary phase of mitochondrial motion was investigated in epithelial cells by spinning disk confocal light microscopy combined with image correlation based single particle tracking using custom software producing sub-pixel accuracy measurements (approximately 5 nm) at 10-12 Hz frame-rates. The analysis of these data suggests that the previously described ...
Conradt L - - 2009
Self-organizing-system approaches have shed significant light on the mechanisms underlying synchronized movements by large groups of animals, such as shoals of fish, flocks of birds, or herds of ungulates. However, these approaches rarely consider conflicts of interest between group members, although there is reason to suppose that such conflicts are ...
Byström A - - 2009
REASONS FOR PERFORMING STUDY: A comprehensive kinematic description of rider and saddle movements is not yet present in the scientific literature. OBJECTIVE: To describe saddle and rider movements in a group of high-level dressage horses and riders. METHOD: Seven high-level dressage horses and riders were subjected to kinematic measurements while ...
Fink Philip W PW Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA. - - 2009
One difference between the excitator model and other theoretical models of coordination is the mechanism of discrete movement initiation. In addition to an imperative signal common to all discrete movement initiation, the excitator model proposes that movements are initiated when a threshold element in state space, the so-called separatrix, is ...
Bradi Ana C AC Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S3G3, - - 2009
A modulation of Fitts's Law occurs when rapid pointing movements are made to targets within a placeholder array. Although Fitts's Law predicts increasing movement times with larger movement amplitudes, with the placeholder array the furthest target is reached faster than the second furthest. This study analyzed the timing of this ...
Cui Rongqing R Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, 645 North Michigan Avenue, Suite 1100, Chicago, IL 60611, - - 2009
Both self-paced movements (internally generated) and movements paced by a fixed interval cue (externally cued) are preceded by a slow-rising movement-related potential (MRP) of similar timing, magnitude and topography. When the timing of the external cue is variable (temporally unpredictable), this MRP is absent. These findings have been interpreted to ...
Kehoe E James - - 2009
The present experiment was aimed at characterizing the timing of conditioned nictitating membrane (NM) movements as function of the interstimulus interval (ISI) in delay conditioning for rabbits (Oryctolagus cuniculus). Onset latency and peak latency were approximately, but not strictly, scalar for all but the smallest movements (<.10 mm). That is, ...
Hammer Georg Philipp - - 2010
The cricothyroid joint (CTJ) plays a key role in pitch adjustment of the human voice. It allows an external elongation of the vocal fold performed by the cricothyroid muscle with a consecutive stretching and increasing of tension. Phonosurgical methods such as cricothyroid approximation need sophisticated investigations on anatomical and functional ...
Li Yong - - 2009
The present study examined the principles underlying inter and intralimb coordination constraints during performance of bimanual elbow-wrist movements at different cycling frequencies (from 0.75 Hz to 2.50 Hz). Participants performed eight coordination tasks that consisted of a combination of in-phase (IN) and/or anti-phase (AN) coordination modes between both elbows and ...
Wolffsohn James S - - 2009
PURPOSE: To determine the critical fitting characteristics of modern soft contact lens fits and from this to devise a simplified recording scheme. METHODS: Ten subjects (aged 28.1+/-7.4 years) wore eight different modern soft contact lenses. Video was captured and analysed of blink (central and up-gaze), excursion lag (up, down, right ...
Hadley Adam S - - 2009
Reduced pollination success, as a function of habitat loss and fragmentation, appears to be a global phenomenon. Disruption of pollinator movement is one hypothesis put forward to explain this pattern in pollen limitation. However, the small size of pollinators makes them very difficult to track; thus, knowledge of their movements ...
Viviani Paolo P Faculty of Psychology and Educational Sciences, University of Geneva, 40, Boulevard du Pont d'Arve 1205, Geneva, Switzerland. - - 2009
An experiment was conducted to contrast the motor performance of three groups (N = 20) of participants: (1) patients with confirmed Parkinson Disease (PD) diagnose; (2) age-matched controls; (3) young adults. The task consisted of scribbling freely for 10 s within circular frames of different sizes. Comparison among groups focused ...
Tinjust David - - 2009
It has been suggested that temporally-constrained goal directed movements are based on a single submovement control strategy that could be modulated online. On the contrary, spatially-constrained movements might encourage participants to produce very fast, open-loop, but somewhat inaccurate/variable primary movement impulses and, if necessary, to perform a discrete correction. We ...
Yano Ken'ichi - - 2009
People of all ages have suffered impairment in traffic accidents or sport accidents, and these individuals worry about dysfunction of their upper limbs, but they can recover from dysfunction by rehabilitation. In this study, we developed an assistive robot for upper limb movement that has high rehabilitation effectiveness. To achieve ...
Gua?tella Isabelle - - 2009
Following our work on the relationship between eyebrow movements and the fundamental frequency of the voice, this article presents the results of a study on this phenomenon, and also on the temporal location of rapid eyebrow movements with respect to speaking turns during dialogue. We used an automatic movement-acquisition system ...
Simon Ann M - - 2009
Pattern recognition myoelectric control in combination with targeted muscle reinnervation (TMR) may provide better real-time control of upper limb prostheses. Current pattern recognition algorithms can classify movements with an off-line accuracy of approximately 95%. When amputees use these systems to control prostheses, motion misclassifications may hinder their performance. This study ...
Reed-Jones Rebecca J - - 2009
Virtual-reality technology is being increasingly used to understand how humans perceive and act in the moving world around them. What is currently not clear is how virtual reality technology is perceived by human participants and what virtual scenes are effective in evoking movement responses to visual stimuli. We investigated the ...
Heuer Herbert - - 2009
Movements in virtual stereoscopic space tend to be difficult and slow. To shed some light on the origins of these difficulties, we studied open-loop pointing with targets presented in a mirror stereoscope. Whilst targets were placed in a virtual horizontal plane, movement end-points were located in an inclined plane. The ...
Ravichandran Vengateswaran J - - 2009
Stretch reflexes have been considered one of the simplest circuits in the human nervous system. Yet, their role is controversial given that they assist or resist an imposed perturbation depending on the task instruction. Evidence shows that a loud acoustic stimulus applied prior to an impending movement elicits a movement-direction ...
Lommertzen Janneke - - 2009
We investigated here how partly occluded stimuli affect early and late prehension kinematics. Stimuli were pictures of partly occluded cylindrical objects with indentations or protrusions at regular intervals along the contour. They diverged into two plausible completions: a local completion, comprising a linear continuation of the contour, and a global ...
Malcolm Matthew P - - 2009
PURPOSE: Recovery of skilled upper limb movement remains a critical focus of rehabilitation in individuals post stroke. Conventional treatments, however, have demonstrated limited capability to produce substantial improvements in poststroke quality of movement. Recently, rhythmic auditory stimulation (RAS) has emerged as efficacious in improving and normalizing limb movements in neurologically ...
Grierson Lawrence E M - - 2009
Kinematic investigations of rapid goal-directed aiming suggest that the online control of movement occurs via 2 processes. One process involves a comparison of visual information about the relative locations of the hand and target late in the trajectory. A second process has been proposed in which a movement's initial impulse ...
David Nicole - - 2009
In a recent experiment with functional magnetic-resonance imaging, we found that brain activity in the extrastriate body area (EBA) distinguished between observed self- and other-generated movements, being significantly higher during observation of someone else's movement. Here, we investigated further the role of EBA in self-other distinctions using low-frequency repetitive transcranial ...
Ashida I - - 2009
The movement of the larynx in five young men during the swallowing of a liquid was examined by simultaneously recording a video-movie, the trajectory of a piezoelectric sensor, and the surface electromyogram of the suprahyoid muscles (SH). The movies revealed swallowing was associated with four characteristic spatial points of laryngeal ...
Tainmont J - - 2009
"Who are you, Nystagmus?" A semantic and historical approach. Initially, the need to name nystagmus was logically satisfied by the use of the metaphor of a galloping horse, "hippus". Later, nictatio, oeil d'hypocrite and souris embodied the presumed connection between blinking and the rhythmic involuntary movements of the eyeball. Blinking ...
Emmorey Karen - - 2009
Speakers monitor their speech output by listening to their own voice. However, signers do not look directly at their hands and cannot see their own face. We investigated the importance of a visual perceptual loop for sign language monitoring by examining whether changes in visual input alter sign production. Deaf ...
Dummer Timothy - - 2009
When a participant views a rubber hand being stroked by a paintbrush while his/her real hand is unseen and similarly stroked by another paintbrush, a misperception known as the rubber hand illusion occurs whereby tactile sensations are falsely referred to the non-body part. The purpose of the current study was ...
Bradberry Trent J - - 2009
The capacity to decode kinematics of intended movement from neural activity is necessary for the development of neuromotor prostheses such as smart artificial arms. Thus far, most of the progress in the development of neuromotor prostheses has been achieved by decoding kinematics of the hand from intracranial neural activity. The ...
Obayashi Chihiro - - 2009
Acquiring skillful movements of experts is a difficult task in many fields. Since non-experts often fail to find out how to improve their skill, it is desirable to find quantitative indices of skillful movements that clarify the difference between experts and non-experts. If we find quantitative indices, we can develop ...
Battapady Harsha - - 2009
The objective of this research is to explore whether a two-dimensional BCI can be achieved by reliably decoding single-trial magneto-encephalography (MEG) signal associated with sustaining or ceasing right and left hand movements. Seven naïve subjects participated in the study. Signals were recorded from 275-channel MEG and synthetic aperture magnetometry (SAM) ...
Shapiro Adam R - - 2009
William Paley's Natural Theology has experienced a resurgence in popularity in recent decades with the continuing controversies over the teaching of evolution and the emergence of a new "intelligent design" movement. But while both the movement's supporters and detractors agree that Paley is an intellectual forefather of the present-day movement, ...
Shi Ying - - 2009
Numerical simulations were used to explore the consequences of a spatially non-uniform sense of hand position on arm movements in the horizontal plane. Isotropic or anisotropic position errors were introduced into several starting hand positions and the resulting errors in movement direction were quantified. Two separate simulations were performed. In ...
Go Tohshin - - 2009
Patients with Rett syndrome are known to respond well to music irrespective of their physical and verbal disabilities. Therefore, the relationship between auditory rhythm and their behavior was investigated employing a two-dimensional motion analysis system. Ten female patients aged from three to 17 years were included. When music with a ...
Masia Lorenzo - - 2009
In the last two decades robot training in neuromotor rehabilitation was mainly focused on shoulder-elbow movements. Few devices were designed and clinically tested for training coordinated movements of the wrist, which are crucial for achieving even the basic level of motor competence that is necessary for carrying out ADLs (activities ...
Carson Richard G - - 2009
When we move along in time with a piece of music, we synchronise the downward phase of our gesture with the beat. While it is easy to demonstrate this tendency, there is considerable debate as to its neural origins. It may have a structural basis, whereby the gravitational field acts ...
Wang W W University of Pittsburgh, Pittsburgh, PA, - - 2009
In this study human motor cortical activity was recorded with a customized micro-ECoG grid during individual finger movements. The quality of the recorded neural signals was characterized in the frequency domain from three different perspectives: (1) coherence between neural signals recorded from different electrodes, (2) modulation of neural signals by ...
Martin V - - 2008
Outside the laboratory, human movement typically involves redundant effector systems. How the nervous system selects among the task-equivalent solutions may provide insights into how movement is controlled. We propose a process model of movement generation that accounts for the kinematics of goal-directed pointing movements performed with a redundant arm. The ...
Fishbach Alon - - 2008
Reaching hand movements tend to follow straight paths. Previous work has suggested that when visual feedback is perturbed such that straight hand motions are seen as curved motions, the motor system adapts to restore straight visual motion. We show that under a nonlinear visuomotor transformation, one that maps straight hand ...
Kovacs Attila J AJ Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843-4243, - - 2009
The purpose of the present experiment was to observe the performance of participants attempting to produce a 1:1 bimanual coordination pattern with 90 degrees relative phase between the arms when feedback concerning the movement of the two limbs was integrated within a Lissajous plot and when this information was withdrawn. ...
Maoz Uri - - 2009
One long-established simplifying principle behind the large repertoire and high versatility of human hand movements is the two-thirds power law-an empirical law stating a relationship between local geometry and kinematics of human hand trajectories during planar curved movements. It was further generalized not only to various types of human movements, ...
Getz Wayne M - - 2008
The movement paths of individuals over landscapes are basically represented by sequences of points (x(i), y(i)) occurring at times t(i). Theoretically, these points can be viewed as being generated by stochastic processes that in the simplest cases are Gaussian random walks on featureless landscapes. Generalizations have been made of walks ...
Fryxell John M - - 2008
Recent theory suggests that animals should switch facultatively among canonical movement modes as a complex function of internal state, landscape characteristics, motion capacity, and navigational capacity. We tested the generality of this paradigm for free-ranging elk (Cervus elaphus) over 5 orders of magnitude in time (minutes to years) and space ...
Bartumeus Frederic - - 2008
The movement ecology framework depicts animal movement as the result of the combined effects of internal and external constraints on animal navigation and motion capacities. Nevertheless, there are still fundamental problems to understand how these modulations take place and how they might be translated into observed statistical properties of animal ...
Wittemyer George - - 2008
The internal state of an individual-as it relates to thirst, hunger, fear, or reproductive drive-can be inferred by referencing points on its movement path to external environmental and sociological variables. Using time-series approaches to characterize autocorrelative properties of step-length movements collated every 3 h for seven free-ranging African elephants, we ...
Kagerer Florian A FA Cognitive Motor Neuroscience Laboratory, Department of Kinesiology and Graduate Program in Neuroscience and Cognitive Science, University of Maryland School of Public Health, College Park, MD 20742, USA. - - 2009
A visuo-motor adaptation task was used to investigate the effects of this adaptation on the auditory-motor representation during reaching movements. We show that, following exposure to a rotated screen cursor-hand relationship, the movement paths during auditory conditions exhibited a similar pattern of aftereffects as those observed during movements to visual ...
Gomi Hiroaki - - 2008
Many neuroscience studies of arm control have attempted to explain how aimed movements are planned, generated, and corrected. The mechanisms of subconscious online reaching correction to a target shift are now being widely examined from computational, physiological, and pathological viewpoints. Recent evidence of a quick manual response to surrounding visual ...
Rutkowski Adam J - - 2009
We studied the relationship between vertical and lateral movements during free flight odor plume tracking by male moths, Manduca sexta, in a wind tunnel with the "horizon" set at different altitudes. Three-dimensional recordings revealed that the plume tracking males generated roughly equivalent movements vertically and laterally regardless of horizon height. ...
Wong Teser - - 2009
Motor control relies on multiple sources of information. To estimate the position and motion of the hand, the brain uses both vision and body-position (proprioception and kinesthesia) senses from sensors in the muscles, tendons, joints, and skin. Although performance is better when more than one sensory modality is present, visuomotor ...
McLean David L - - 2008
The classic 'size principle' of motor control describes how increasingly forceful movements arise by the recruitment of motoneurons of progressively larger size and force output into the active pool. We explored the activity of pools of spinal interneurons in larval zebrafish and found that increases in swimming speed were not ...
Herwig Arvid - - 2009
In tool use, the intended external goals have to be transformed into bodily movements by taking into account the target-to-movement mapping implemented by the tool. In bimanual tool use, this mapping may depend on the part of the tool that is operated and the effector used (e.g. the left and ...
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