Search Results
Results 601 - 650 of 1468
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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 ...
Gayed Bassem A - - 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 ...
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 ...
Chen S C - - 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 ...
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 ...
Fortunov Daniel I - - 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 ...
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 ...
Selen Luc P J LP Faculty of Human Movement Sciences, Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam, The - - 2006
The neuromuscular system is inherently noisy and joint impedance may serve to filter this noise. In the present experiment, we investigated whether individuals modulate joint impedance to meet spatial accuracy demands. Twelve subjects were instructed to make rapid, time constrained, elbow extensions to three differently sized targets. Some trials (20 ...
Frolov A A - - 2006
The viscoelastic properties of the human arm were measured by means of short force perturbations during fast reaching movements in two orthogonal directions. A linear spring model with time delay described the neuromuscular system of the human arm. The obtained viscoelastic parameters ensured movement stability in spite of the time ...
Verdaasdonk B W - - 2006
Humans show great energy efficiency and robustness in rhythmic tasks, such as walking and arm swinging. In this study a mathematical model of rhythmic limb movement is presented, which shows that tight local coupling of Central Pattern Generators (CPGs) to limbs could explain part of this behavior. Afferent feedback to ...
Smits-Engelsman B C M - - 2006
Previous studies suggested that the advantage in speed accuracy trade-off of cyclic over discrete aiming tasks with the upper limbs may be associated with the operation of spinal neural oscillators, as in locomotion. Similar to the locomotor rhythm that is fairly robust and can accommodate changes in loading or stride ...
William E. Cooper Jr.
Studies of lizard foraging modes and their correlates have led to major advances in our understanding of the evolution of lizard taxonomic, morphological, physiological, ecological and behavioral diversity. Although two basic foraging modes, ambush and active foraging, have been recognized, variability in foraging movements among species has led to controversies ...
A. M. Tozetti
Capture/recapture studies significantly increase our knowledge of the natural history of anuran amphibians. Many different methods have been employed in these studies, but a number of new techniques still require experimental validation. During two reproductive seasons in a Cerrado remnant in southeastern Brazil, we investigated the movement patterns and habitat ...
Press Clare - - 2005
Recent behavioural and neuroimaging studies have found that observation of human movement, but not of robotic movement, gives rise to visuomotor priming. This implies that the 'mirror neuron' or 'action observation-execution matching' system in the premotor and parietal cortices is entirely unresponsive to robotic movement. The present study investigated this ...
Yamada Takayoshi - - 2005
The sit-to-stand movement strategy of each subject is different depending on whether the subjects perform voluntary movements or have concrete instructions (i.e., stand quickly), which is strongly reflected in the performance of each sit-to-stand movement phase. Thirty young-adult male subjects participated in this study (M age=20.7 yr; SD=2.6). Subjects performed ...
Tresilian James R JR Perception and Motor Systems Laboratory School of Human Movement Studies, The University of Queensland, 4072, St Lucia, Australia. - - 2006
The results of two experiments are reported that examined how performance in a simple interceptive action (hitting a moving target) was influenced by the speed of the target, the size of the intercepting effector and the distance moved to make the interception. In Experiment 1, target speed and the width ...
Kerwath, SE; Department of ...
The feasibility of using telemetry equipment to study the movements of estuarine-associated fish in South Africa was investigated by conducting a tracking experiment on spotted grunter <i>Pomadasys commersonnii</i> in the East Kleinemonde Estuary. The telemetry equipment comprised two VEMCO V8 transmitters and a VEMCO VR60 receiver linked to a directional ...
Flash Tamar - - 2005
In recent years different lines of evidence have led to the idea that motor actions and movements in both vertebrates and invertebrates are composed of elementary building blocks. The entire motor repertoire can be spanned by applying a well-defined set of operations and transformations to these primitives and by combining ...
Lackner James R - - 2005
Dynamic perturbations of reaching movements are an important technique for studying motor learning and adaptation. Adaptation to non-contacting, velocity-dependent inertial Coriolis forces generated by arm movements during passive body rotation is very rapid, and when complete the Coriolis forces are no longer sensed. Adaptation to velocity-dependent forces delivered by a ...
Bosga Jurjen - - 2005
The authors examined the means by which people vary movement parameters to satisfy more than 1 constraint at a time in a repetitive motor task. The authors expected that when participants (N = 12) were simultaneously confronted with spatial and temporal constraints in an ellipse-drawing task, they would either exploit ...
Salesse Robin - - 2005
The authors hypothesized that the modulation of coordinative stability and accuracy caused by the coalition of egocentric (neuromuscular) and allocentric (directional) constraints varies depending on the plane of motion in which coordination patterns are performed. Participants (N = 7) produced rhythmic bimanual movements of the hands in the sagittal plane ...
Bosco G G Department of Neuroscience, University of Rome, Tor Vergata and IRCCS Fondazione Santa Lucia, Rome, - - 2005
Previous work from this laboratory has shown that activity in the dorsal spinocerebellar tract (DSCT) relates strongly to global hindlimb kinematics variables during passive displacements of the hindlimb. A linear relationship to limb axis orientation and length variables accounts for most of the response variance for passive limb positioning and ...
Hwang Ing-Shiou - - 2006
The intensity and spatial representation of electromyographical (EMG) activity were examined to characterize the effects of limb dominance and movement direction upon global synkinesis (GS). Twenty-two healthy young subjects (11 men, 11 women) with a mean age of 24.7 years participated in this study. Three trials of EMG activities from ...
Caljouw Simone R - - 2006
On the basis of research in self-paced aiming movements, Glover [S. Glover, Separate visual representations in the planning and control of action, Behav. Brain Sci., 27 (2004) 3-24] proposed a dichotomy between visual systems that accommodate planning and on-line control of action. Specifically, the planning-versus-control model posits that the on-line ...
Page A - - 2006
Functional data analysis techniques provide an alternative way of representing movement and movement variability as a function of time. In particular, the registration of functional data provides a local normalization of time functions. This normalization transforms a set of curves, records of repeated trials, yielding a new set of curves ...
van Roon Dominique - - 2005
People with cerebral palsy (CP) are known to rely heavily on visual guidance when making targeted upper-limb movements. In the present study, we examined whether being able to visually monitor the moving limb forms a precondition for people with CP to make accurate upper-limb movements. Eight participants with tetraparetic CP ...
Rickert Jörn - - 2005
Recent studies showed that the low-frequency component of local field potentials (LFPs) in monkey motor cortex carries information about parameters of voluntary arm movements. Here, we studied how different signal components of the LFP in the time and frequency domains are modulated during center-out arm movements. Analysis of LFPs in ...
Meesen R L J - - 2005
The role of directional compatibility was investigated during the production of in-phase and anti-phase coordination patterns involving the four limbs as well as the head. Our first aim was to compare the quality of interlimb coordination between concordant and discordant coordination patterns across girdles at different cycling frequencies. Concordant implied ...
Osborne Leslie C - - 2005
Suppose that the variability in our movements is caused not by noise in the motor system itself, nor by fluctuations in our intentions or plans, but rather by errors in our sensory estimates of the external parameters that define the appropriate action. For tasks in which precision is at a ...
Bradley Nina S - - 2005
New imaging technologies are revealing ever-greater details of motor behavior in fetuses for clinical diagnosis and treatment. Understanding the form, mechanisms, and significance of fetal behavior will maximize imaging applications. The chick is readily available for experimentation throughout embryogenesis, making it an excellent model for this purpose. Yet in 40 ...
Mosier Kristine M - - 2005
The issue of how the Euclidean properties of space are represented in the nervous system is a main focus in the study of visual perception, but is equally relevant to motor learning. The goal of our experiments was to investigate how the properties of space guide the remapping of motor ...
Ju Ming-Shaung - - 2005
The goal of this study was to design a robot system for assisting in the rehabilitation of patients with neuromuscular disorders by performing various facilitation movements. The robot should be able to guide patient's wrist to move along planned linear or circular trajectories. A hybrid position/force controller incorporating fuzzy logic ...
Rice Aaron N - - 2005
Fishes require complex coordinated motions of the jaws, body and fins during feeding in order to successfully execute the strike or bite and then move away from the predation site. In conjunction with locomotor systems, sensory modalities guide coordinated feeding behavior, with vision playing an important role in many fishes. ...
Brindle Timothy J - - 2006
The objective of this study was to determine if simple, shoulder movements use the dual control hypothesis strategy, previously demonstrated with elbow movements, and to see if this strategy also applies in the absence of visual feedback. Twenty subjects were seated with their right arm abducted to 90 degrees and ...
Heuer Herbert - - 2006
In two experiments, we studied intermanual interactions in bimanual reversal movements and bimanual aiming movements. Targets were presented on a monitor or directly on the table on which the movements were produced. Amplitudes for each hand were cued symbolically or spatially either in advance of an imperative signal or simultaneous ...
Grassi G - - 2005
OBJECTIVES: To develop a method for the three dimensional analysis of body movements and body positions during the performance of circular swings on the competition mushroom, an apparatus used by young gymnasts for pommel horse training. METHODS: Five experienced male gymnasts, all of national level, performed three series of 10 ...
Bolliet Olivier - - 2005
Observing somebody performing an action has been shown to elicit neuronal activity in the premotor cortex. This paper investigated physiological effect of observing an effortful action at the peripheral level. As Autonomic Nervous System responses reflect central nervous system processes such as movement planning and programming, it was expected that ...
Pfau Thilo - - 2005
Biomechanical studies often employ optical motion capture systems for the determination of the position of an object in a room-based coordinate system. This is not ideal for many types of study in locomotion since only a few strides may be collected per ;trial', and outdoor experiments are difficult with some ...
Khan Michael A MA School of Sport, Health and Exercise Sciences, University of Wales, Bangor, George Building, Bangor, Gwynedd, Wales, LL57 2PX, UK. - - 2005
Danckert and Goodale [Exp Brain Res 137:303-308 (2001)] have shown that increases in movement time as target size decreased were greater when movements were performed in the lower compared with upper visual field. On this basis, they suggested that visual feedback processing was more effective in the lower visual field. ...
Kingma H - - 2005
BACKGROUND: Previous attempts to measure otolith function using ocular counter-rolling have shown poor sensitivity and specificity, thereby hindering a useful clinical application. We have conducted a study to investigate whether thresholds for the perception of the direction of linear acceleration might be an alternative for the clinical evaluation of otolith ...
Fishbach Alon A Department of Physiology, Northwestern University, 303 East Chicago Ave., Chicago, IL, 60611, USA. - - 2005
Despite the abundant experimental evidence for the irregular, multipeaked velocity profiles that often characterize rapid human limb movements, there is currently little agreement on how to interpret these phenomena. While in some studies these irregularities have been interpreted as reflecting a continuous control process, in others the irregularities are considered ...
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