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Results 501 - 550 of 1470
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Sosnik Ronen - - 2007
Previous psychophysical studies have sought to determine whether the processes of movement engagement and termination are dissociable, whether stopping an action is a generic process, and whether there is a point in time in which the generation of a planned action is inevitable ("point of no return"). It is not ...
Ausborn Jessica - - 2007
The sensory system plays a key role in the generation of behavior by providing the nervous system with information about the environment and feedback about body movements such that motor output can continuously be adapted to changing circumstances. Although the effects of sensory organs on nervous system function have been ...
Dean Noah J - - 2008
Experiment 1 was conducted to determine if proportional transfer from "small to large" scale movements is as effective as transferring from "large to small." We hypothesize that the learning of larger scale movement will require the participant to learn to manage the generation, storage, and dissipation of forces better than ...
Chmarra Magdalena K - - 2008
Minimally invasive surgery (MIS) requires a high degree of eye-hand coordination from the surgeon. To facilitate the learning process, objective assessment systems based on analysis of the instruments' motion are being developed. To investigate the influence of performance on motion characteristics, we examined goal-oriented movements in a box trainer. In ...
Carr Sherilene M SM Psychology Department, Monash University, Melbourne, - - 2008
Visual selective attention is thought to underly inhibitory control during pointing movements. Accounts of inhibitory control during pointing movements make differential predictions about movement deviations towards or away from highly salient non-target flankers based on their potential cortical activation and subsequent inhibition: (1) Tipper et al. (Vis Cogn 4:1-38, 1997) ...
Bruzzo Angela - - 2008
It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to ...
Santini Fabrizio - - 2007
In experimental studies of visual performance, the need often emerges to modify the stimulus according to the eye movements performed by the subject. The eye-movement-contingent display (EMCD) methodology enables accurate control of the position and motion of the stimulus on the retina. EMCD procedures have been used successfully in many ...
Meunier Hélène - - 2008
Group members present physical and physiological differences according to their age, sex or social status, which could generate motivation differences among individuals during travel. In spite of these divergences of interest among individuals, the group succeeds more often than not in making a collective decision about departure time and which ...
Franklin David W - - 2007
It has been shown that humans are able to selectively control the endpoint impedance of their arms when moving in an unstable environment. However, directional instability was only examined for the case in which the main contribution was from coactivation of biarticular muscles. The goal of this study was to ...
Goble Jacob A - - 2007
Strategies used by the CNS to optimize arm movements in terms of speed, accuracy, and resistance to fatigue remain largely unknown. A hypothesis is studied that the CNS exploits biomechanical properties of multijoint limbs to increase efficiency of movement control. To test this notion, a novel free-stroke drawing task was ...
Gritsenko V - - 2007
Psychophysical studies have reported an overestimation of limb position in the direction of movement during the early part of active movements. The main hypothesis tested in this study is that the overestimation results from a process of forward prediction of limb state driven by an efference copy of the outgoing ...
Watanabe Katsumi - - 2008
To coordinate our actions with those of others, it is crucial to not only choose an appropriate category of action but also to execute it at an appropriate timing. It is widely documented that people tend to unconsciously mimic others' behavior. The present study show that people also tend to ...
Casellato C - - 2007
The planning and the execution of voluntary movement relies on sensorimotor transformations in which representations of the external environment are integrated into motor programs. We studied executions of Whole Body Pointing movements, in normal and in transient microgravity (parabolic flights) conditions. Three processes could lead to adaptation to the new ...
Janson Charles H - - 2007
We present the theoretical and practical difficulties of inferring the cognitive processes involved in spatial movement decisions of primates and other animals based on studies of their foraging behavior in the wild. Because the possible cognitive processes involved in foraging are not known a priori for a given species, some ...
Obhi Sukhvinder S - - 2007
To investigate the sources of conscious awareness of action, participants made judgments about the initiation times of active and passive key press movements that were either forceful or soft. After each trial, participants made judgments about when they moved by reporting the position of a rotating clock hand at the ...
Esposti Roberto - - 2007
The mechanisms that control the limbs position during rhythmic voluntary oscillations were investigated in ten subjects, who were asked to synchronise the lower peak of their hand or foot rhythmic oscillations to a metronome beat. The efficacy of the "position control" was estimated by measuring the degree of synchronisation between ...
Økland, Finn; Norwegian Institute ...
Movements of and habitat utilisation by radio-tagged threespot tilapia (body length 25–50cm) were studied in the Upper Zambezi River between 23 November 2000 and 8 May 2001. Although utilising a relatively large stretch of river (average 5.4km) during the study period, the fish mainly stayed within defined home ranges, with ...
Khan Michael A - - 2008
The relation between reaction time and the number of elements in a response has been shown to depend on whether simple or choice RT paradigms are employed. The purpose of the present study was to investigate whether advance information about the number of elements is the critical factor mediating the ...
Hospod Valérie - - 2007
The aim of the present study was to test whether fusimotor control of human muscle spindle sensitivity changed when attention was selectively directed to the recognition of an imposed two-dimensional movement in the form of a written symbol. The unitary activities of 32 muscle spindle afferents (26 Ia, 6 II) ...
Huang Felix C - - 2007
The authors employed a virtual environment to investigate how humans use haptic and visual feedback in a simple, rhythmic object-manipulation task. The authors hypothesized that feedback would help participants identify the appropriate resonant frequency and perform online control adjustments. The 1st test was whether sensory feedback is needed at all; ...
George, Gerald James
The black drum, Pogonias cromis (Sciaenidae), is a molluscivorous, coastal/estuarine species, often associated with oyster reefs, that is sought in recreational and commercial fisheries. I used a radio-acoustic positioning system and an array of moored receivers to monitor movements of 34 black drum around oyster reefs in Barataria Bay, Louisiana ...
Flash Tamar - - 2007
Humans interact with their environment through sensory information and motor actions. These interactions may be understood via the underlying geometry of both perception and action. While the motor space is typically considered by default to be Euclidean, persistent behavioral observations point to a different underlying geometric structure. These observed regularities ...
Greiner Chieko - - 2007
Videotaping, direct observation, and biomechanical devices have been used to measure the wandering behavior of institutionalized people with dementia and to identify patterns of movement. Owing to technical limitations, the variability in movement patterns or the distance traveled could not be examined. The present study examined the feasibility of an ...
Schutte Anne R - - 2007
The timed-initiation paradigm developed by Ghez and colleagues (1997) has revealed two modes of motor planning: continuous and discrete. Continuous responding occurs when targets are separated by less than 60 degrees of spatial angle, and discrete responding occurs when targets are separated by greater than 60 degrees . Although these ...
Temprado J J - - 2007
The present work investigated the effects of spatial and neuromuscular constraints on the mean states and variability of interlimb coordination patterns performed in the para-sagittal plane of motion in a hand-held pendulum oscillation task. Nine right-handed students had to oscillate two pendulums through wrist adduction-abduction movements. Relative movement direction was ...
Foster Paul S - - 2007
BACKGROUND/HYPOTHESIS: The degree of attention directed to a stimulus and the presence of anisometric representations can alter the perception of the magnitude of a stimulus. We wanted to learn if normal right-handed subjects' estimates of distance traveled are influenced by the right-left direction or hemispace of movements. METHODS: We had ...
Haswgawa, Eiichi
The present study used six carps Cyprinus carpio,about 11cm in average total length,for investigating fish distribution in a funnel net and fish movement between two mountain-shaped nets which set on upper and lower sides or set on both sides. The most important effect to fish distribution in a funnel net ...
Ridderikhoff Arne A Institute for Fundamental and Clinical Human Movement Sciences (IFKB), Faculty of Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands. - - 2007
Although previous studies indicated that the stability properties of interlimb coordination largely result from the integrated timing of efferent signals to both limbs, they also depend on afference-based interactions. In the present study, we examined contributions of afference-based error corrections to rhythmic bimanual coordination using a kinesthetic tracking task. Furthermore, ...
Spencer Rebecca M C RM Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720-1650, USA. - - 2007
We have proposed that the stability of bimanual coordination is influenced by the complexity of the representation of the task goals. Here, we present two experiments to explore this hypothesis. First, we examined whether a temporal event structure is present in continuous movements by having participants vocalize while producing bimanual ...
Horn Robert R - - 2007
We compared the nature and rate of change in intra-limb coordination in participants who observed a video model (model) with those who practised based on verbal guidance only (control). Sixteen male novices threw a ball towards a target with maximal velocity using a back-handed, reverse baseball pitch. Participants in the ...
Bradshaw Corey J A - - 2007
Recent advances in telemetry technology have created a wealth of tracking data available for many animal species moving over spatial scales from tens of meters to tens of thousands of kilometers. Increasingly, such data sets are being used for quantitative movement analyses aimed at extracting fundamental biological signals such as ...
Bouquet C A - - 2007
The perception of a human actor performing movements may involve processes related to action execution. This resonance of the motor system may support observational learning and imitation, and could also explain the fact that observers'/actors' movements are disturbed by the observation of a human model making different movements (Kilner et ...
Arzamarski Ryan R Center for the Ecological Study of Perception and Action, Department of Psychology, U-1020, University of Connecticut, 406 Babbidge Rd, Storrs, CT 06269-1020, USA. - - 2007
Part of understanding how acts are coordinated is identifying the information that guides movements. In the case of catching a ball within arm's reach, that identification has been complicated by empirical disparities concerning hand-movement reversals during catching. Jacobs and Michaels found unilateral reversals in a paradigm in which balls swung ...
Fiorio Mirta - - 2007
Perception of limb position and motion is abnormal in Parkinson's disease (PD). Despite the fact that the processing of proprioceptive inputs is inherently temporal, most studies have assessed spatial aspects of proprioception in PD patients. Here, we use a recently described method to test whether deficits also exist in temporal ...
de Freitas Sandra Maria Sbeghen Ferreira - - 2007
This study examined the hypothesis that the degree to which motor redundancy is used to coordinate joint motions for reaching is influenced by motor planning and enhanced when the task requires greater movement flexibility. Subjects reached at arm's length to the same centrally placed target under conditions where the target ...
Scheidt Robert A - - 2007
We characterized how hemiparetic stroke survivors and neurologically intact individuals adapt reaching movements to compensate for unpredictable environmental perturbations. We tested the hypotheses that like unimpaired subjects, hemiparetic stroke survivors adapt using sensory information obtained during only the most recent movements and that the reliability of target acquisition decreases as ...
Meulenbroek Ruud G J RG Nijmegen Institute for Cognition and Information, Radboud University Nijmegen, PO Box 9104, 6500 HE Nijmegen, The Netherlands. - - 2007
Here we report a study of joint-action coordination in transferring objects. Fourteen dyads were asked to repeatedly reposition a cylinder in a shared workspace without using dialogue. Variations in task constraints concerned the size of the two target regions in which the cylinder had to be (re)positioned and the size ...
Mazyn Liesbeth I N - - 2007
Two experiments were conducted in order to investigate the adaptability and associated strategies of the human perceptuo-motor system to deal with changing constraints. In a catching task, perceptual-motor constraints were internally controlled by coupling movement onset of the catch and the illumination circuit in the lab: upon the first movement ...
Tricon Veronique - - 2007
The present study focuses on the organization of kinematic synergy and its adaptation to an unstable support surface during upper trunk movements in aging adults. Seven healthy aging adults (49-66 years old) were instructed to bend the trunk forward (the head and the trunk together) by about 40 degrees and ...
Bhatt Dimple H - - 2007
Animals can produce movements of widely varying speed and strength by changing the recruitment of motoneurons according to the well-known size principle. Much less is known about patterns of recruitment in the spinal interneurons that control motoneurons because of the difficulties of monitoring activity simultaneously in multiple interneurons of an ...
Hayes Spencer J - - 2007
We required two groups of participants to observe an end-point model (ENDPT) while another two groups viewed a full-body, point-light model (FULL) to determine the role of relative motion information in acquisition of a multi-limb, whole-body action. One ENDPT and one FULL group also bowled a ball. Following retention, all ...
Warren Paul A - - 2007
A moving observer needs to be able to estimate the trajectory of other objects moving in the scene. Without the ability to do so, it would be difficult to avoid obstacles or catch a ball. We hypothesized that neural mechanisms sensitive to the patterns of motion generated on the retina ...
Pawar Tanmay - - 2007
Ambulatory ECG analysis is adversely affected by motion artifacts induced due to body movements. Knowledge of the extent of motion artifacts facilitates better ECG analysis. In [1], an unsupervised method using recursive principal component analysis (RPCA) was used to detect transitions between body movements. In this paper, we endeavour to ...
Cohen Rajal G - - 2007
Taking a cue from recent discoveries of directional bias in microsaccades during visual fixation, we investigated directional bias in tremor during manual pointing. Subjects memorized and then performed patterns of alternating postures and voluntary movements. The directions of the tiny movements occurring during periods of intended stillness were predictive of ...
Balslev Daniela - - 2007
During visually guided movements both vision and proprioception inform the brain about the position of the hand, so interaction between these two modalities is presumed. Current theories suggest that this interaction occurs by sensory information from both sources being fused into a more reliable, multimodal, percept of hand location. In ...
Huang Jian - - 2007
This paper deliberates the spatial cognitive ability of the moving distance of the human hand, which is measured by using motion capture. Before the movement begins, the subject is shown a standard length. Then, both horizontal and vertical blindfold hand movements were measured using the proposed protocol for six right ...
Vaidyanathan Ravi - - 2007
The goal of this work is to discover and extract critical features from pressure signals in the aural canal resulting from actions (tongue movements) within the oral cavity. Its scope encompasses the identification of critical features of pressure signals sensed in the ear resulting from tongue motion and the development ...
Christe Blaise - - 2007
In this study, we developed a digitizing tablet-based instrument for the clinical assessment of human voluntary movements targeting motor processes of planning, programming and execution. The tool was used to investigate an adaptation of Fitts' reciprocal tapping task [10], comprising four conditions, each of them modulated by three indices of ...
Hansen Steve - - 2007
We examined the spatial and temporal limitations of the visual corrective process in goal-directed aiming, as well as gender differences in online control. An initial experiment was conducted to test the utility of a monocular switch procedure as a method of rapidly introducing a visual perturbation. The results revealed minimal ...
Jonas M - - 2007
The posterior inferior frontal gyrus (pIFG) and anterior inferior parietal lobule (aIPL) form the core regions of the human "mirror neuron system" that matches an observed movement onto its internal motor representation. We used event-related functional MRI to examine whether simple intransitive finger movements evoke "mirror activity" in the pIFG ...
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