Search results for "coordination"
showing 10 items of 1282 documents
Serum nitrotyrosine and psychometric tests as indicators of impaired fitness to drive in cirrhotic patients with minimal hepatic encephalopathy
2013
BACKGROUND & AIMS: Cirrhotic patients with minimal hepatic encephalopathy (MHE) show impaired driving ability and increased vehicle accidents. The neurological deficits contributing to impair driving and the underlying mechanisms are poorly understood. Early detection of driving impairment would help to reduce traffic accidents in MHE patients. It would be therefore useful to have psychometric or biochemical parameters reflecting driving impairment. The aims of this work were as follows: (i) to shed light on the neurological deficits contributing to impair driving; (ii) to assess whether some psychometric test or biochemical parameter is a good indicator of driving impairment. METHODS: We a…
''Alterations with Movement Duration in the Kinematics of a Whole Body Pointing Movement''
2013
Casteran, Matthieu | Manckoundia, Patrick | Pozzo, Thierry | Thomas, Elizabeth; International audience; ''Our aim was to investigate how the organization of a whole body movement is altered when movement duration (MD) is varied. Subjects performed the same whole body pointing movement over long, normal and short MDs. The kinematic trajectories were then analyzed on a normalized time base. A principal components analysis (PCA) revealed that the degree of coordination between the elevation angles of the body did not change with MD. This lack of significant differences in the coordination was interesting given that small spatial and temporal differences were observed in the individual kinemati…
Eye-Hand Coordination in Rhythmical Pointing
2009
International audience; The authors investigated the relation between hand kinematics and eye movements in 2 variants of a rhythmical Fitts's task in which eye movements were necessary or not necessary. P. M. Fitts's (1954) law held in both conditions with similar slope and marginal differences in hand-kinematic patterns and movement continuity. Movement continuity and eye-hand synchronization were more directly related to movement time than to task index of difficulty. When movement time was decreased to fewer than 350 ms, eye-hand synchronization switched from continuous monitoring to intermittent control. The 1:1 frequency ratio with stable pi/6 relative phase changed for 1:3 and 1:5 fre…
Motor abnormalities and basal ganglia in first-episode psychosis (FEP)
2020
AbstractBackgroundMotor abnormalities (MAs) are the primary manifestations of schizophrenia. However, the extent to which MAs are related to alterations of subcortical structures remains understudied.MethodsWe aimed to investigate the associations of MAs and basal ganglia abnormalities in first-episode psychosis (FEP) and healthy controls. Magnetic resonance imaging was performed on 48 right-handed FEP and 23 age-, gender-, handedness-, and educational attainment-matched controls, to obtain basal ganglia shape analysis, diffusion tensor imaging techniques (fractional anisotropy and mean diffusivity), and relaxometry (R2*) to estimate iron load. A comprehensive motor battery was applied incl…
An ensemble analysis of electromyographic activity during whole body pointing with the use of support vector machines.
2011
Import JabRef | WosArea Life Sciences and Biomedicine - Other Topics; International audience; We explored the use of support vector machines (SVM) in order to analyze the ensemble activities of 24 postural and focal muscles recorded during a whole body pointing task. Because of the large number of variables involved in motor control studies, such multivariate methods have much to offer over the standard univariate techniques that are currently employed in the field to detect modifications. The SVM was used to uncover the principle differences underlying several variations of the task. Five variants of the task were used. An unconstrained reaching, two constrained at the focal level and two …
Quantifying coordination and coordination variability in backward versus forward running: Implications for control of motion
2015
The aims of this study were to compare coordination and coordination variability in backward and forward running and to investigate the effects of speed on coordination variability in both backward and forward running. Fifteen healthy male participants took part in this study to run forwards and backwards on a treadmill at 80%, 100% and 120% of their preferred running speeds. The coordinate data of passive reflective markers attached to body segments were recorded using motion capture systems. Coordination of shank-foot and thigh-shank couplings in sagittal plane was quantified using the continuous relative phase method. Coordination variability was calculated as the standard deviation of a…
''Modulation of Anticipatory Postural Activity For Multiple Conditions of A Whole-body Pointing Task''
2012
Tolambiya, A. | Chiovetto, E. | Pozzo, T. | Thomas, E.; International audience; ''This is a study on associated postural activities during the anticipatory segments of a multijoint movement. Several previous studies have shown that they are task dependant. The previous studies, however, have mostly been limited in demonstrating the presence of modulation for one task condition, that is, one aspect such as the distance of the target or the direction of reaching. Real-life activities like whole-body pointing, however, can vary in several ways. How specific is the adaptation of the postural activities for the diverse possibilities of a whole-body pointing task? We used a classification paradig…
Frontoparietal cortex and cerebellum contribution to the update of actual and mental motor performance during the day
2016
AbstractActual and imagined movement speed increases from early morning until mid-afternoon. Here, we investigated the neural correlates of these daily changes. Fifteen subjects performed actual and imagined right finger opposition movement sequences at 8 am and 2 pm. Both actual and imagined movements were significantly faster at 2 pm than 8 am. In the morning, actual movements significantly activated the left primary somatosensory and motor areas, and bilaterally the cerebellum; in the afternoon activations were similar but reduced. Contrast analysis revealed greater activity in the cerebellum, the left primary sensorimotor cortex and parietal lobe in the morning than in the afternoon. Im…
Hydroxo Hydrido Complexes of Iron and Cobalt (Sn−Fe−Sn, Sn−Co−Sn): Probing Agostic Sn⋅⋅⋅H−M Interactions in Solution and in the Solid State
2000
Bis(toluene)iron 9 reacts with Lappert's stannylene [Sn[CH(SiMe3)2]2] (4) to form the paramagnetic bis-stannylene complex [[(eta6-toluene)Fe-Sn-[CH(SiMe3)2]2]2] (10). Compound 10 reacts with H2O to form the hydroxo hydrido complex [(eta6-C7H8)(mu-OH)(H)-Fe-[Sn[CH(SiMe3)2]2]2] (12) in high yield; its solid-state structure has been elucidated by X-ray and neutron diffraction analysis. In agreement with the 1H NMR results, 12 contains a hydridic ligand whose exact coordination geometry could be determined by neutron diffraction. The 1H and 119Sn NMR analysis of 12 suggested a multicenter Sn/Sn/H/Fe bonding interaction in solution, based on significantly large values of J(Sn,H,Fe) = 640+/-30 Hz…
Homoleptic heavy alkaline Earth and europium triazenides.
2009
The sigma-bond metathesis reaction between PhSiH(3) and the heteroleptic metal pentafluorophenyl compounds [Dmp(Tph)N(3)MC(6)F(5)(thf)(n)] (Dmp = 2,6-Mes(2)C(6)H(3) with Mes = 2,4,6-Me(3)C(6)H(2); Tph = 2-TripC(6)H(4) with Trip = 2,4,6-(i)Pr(3)C(6)H(2); n = 1, 2; M = Sr, Ba, Eu) supported by sterically crowded, biphenyl- and terphenyl-substituented triazenido ligands afforded the first homoleptic stontium, barium, and europium triazenides [M{N(3)Dmp(Tph)}(2)] {M = Sr (2), Ba (4), Eu (5)}. Crystallization of 2 from an n-heptane/1,2-dimethoxyethane mixture gave the complex [Sr{N(3)Dmp(Tph)}(2)(dme)] (3). All new compounds have been characterized by (1)H and (13)C NMR spectroscopy (not 5), ele…