Small-object manipulation is essential in numerous human activities, although its neural bases are still essentially unknown. Recent functional imaging studies have shown that precision grasping activates a large bilateral frontoparietal network, including ventral (PMv) and dorsal (PMd) premotor areas. To dissociate the role of PMv PMd control hand finger movements, we produced, by means transcranial magnetic stimulation (TMS), transient virtual lesions these two areas both hemispheres,...

<h3>Objective</h3> To investigate associations between takeaway meal consumption and risk markers for coronary heart disease, type 2 diabetes obesity in children. <h3>Design</h3> A cross-sectional, school-based observational study. <h3>Setting</h3> 85 primary schools across London, Birmingham Leicester. <h3>Participants</h3> 1948 UK school children year 5, aged 9–10 years. <h3>Main outcome measures</h3> Children reported their frequency of consumption, completed a 24-hour dietary recall, had...

Previous research has shown that grip and load forces are modulated simultaneously during manipulation of a hand-held object. This close temporal coupling suggested both controlled by an internal model within the CNS predicts changes in tangential force on fingers. The objective present study was to examine how would compensate for loss cutaneous sensation through local anesthesia index thumb. Ten healthy adult subjects (5 men 5 women aged 20–57 yr) were asked grasp, lift, hold stationary,...

In humans, both clinical and functional imaging studies have evidenced the critical role played by posterior parietal cortex, particularly anterior intraparietal area (AIP), in skilled hand movements. However, exact contribution of AIP to precision grasping remains debated. Here we used transcranial magnetic stimulation (TMS) induce virtual lesions left and/or right subjects performing a grip-lift task with either hand. We found that, during movement preparation, lesion had distinct...

Through highly precise perceptual and sensorimotor activities, the human tactile system continuously acquires information about environment. Mechanical interactions between skin at point of contact a touched surface serve as source this information. Using dedicated custom robotic platform, we imaged deformation area finger flat during onset tangential sliding movements in four different directions (proximal, distal, radial ulnar) with varying normal force speeds. This simple event evidenced...

The dynamics of fingertip contact manifest themselves in the complex skin movements observed during transition from a stuck state to fully developed slip. While investigating this transition, we found that it depended on hydration. To quantify dependency, asked subjects slide their index glass surface while keeping normal component interaction force constant with help visual feedback. Skin deformation inside region was imaged an optical apparatus allowed us relative sizes slipping and...

The temporal evolution of surface strain, resulting from a combination normal and tangential loading forces on the fingerpad, was calculated high-resolution images. A customized robotic device loaded fingertip with varying force, direction speed. We observed strain waves that propagated periphery to centre contact area. Consequently, different regions area were subject degrees compression, stretch shear. spatial distribution both strains energy densities depended stimulus direction....

The aim of the study was to survey use outcome measures in rehabilitation within Europe. It envisaged that this would provide basis for further studies on cross-cultural validity measures. A postal questionnaire distributed November 1998 866 units providing rehabilitation. In total, 418 questionnaires were returned, corresponding a response rate 48%. These centres treated an estimated 113,000 patients annually, undertaking 360,000 assessments. focused nine diagnostic groups: hip and knee...

Brain lesions may disturb hand functioning in children with cerebral palsy (CP), making it difficult or even impossible for them to perform several manual activities. Most conventional treatments dysfunction CP assume that reducing the dysfunctions will improve capacity manage activities (i.e., ability, MA). The aim of this study was investigate directional relationships (direct and indirect pathways) through which skills influence MA CP. A total 136 (mean age: 10 years; range: 6-16 35...

Background. After stroke, deregulated interhemispheric interactions influence residual paretic hand function. Anodal or cathodal transcranial direct current stimulation (tDCS) can rebalance these abnormal and improve motor Objective. We explored whether dual-hemisphere tDCS (dual-tDCS) in participants with chronic stroke fine function 2 important aspects: precision grip dexterity. Methods. In all, 19 hemiparetic individuals mild to moderate impairment participated a double-blind, randomized...

Abstract In a forced-choice task, we asked human participants to discriminate by touch alone glass plates from transparent polymethyl methacrylate (PMMA) plastic plates. While the surfaces were flat and did not exhibit geometric features beyond few tens of nanometres, materials differed their molecular structures. They produced similar coefficients friction thermal effects controlled. Most performed well above chance with dry fingers discriminated especially well. Current models tactile...

Human tactile afferents provide essential feedback for grasp stability during dexterous object manipulation. Interacting forces between an and the fingers induce slip events that are thought to information about stability. To gain insight into this phenomenon, we made a transparent surface against fixed fingerpad while monitoring skin deformation at contact. Using microneurography, simultaneously recorded activity of single innervating fingertips. This unique combination allowed us describe...

The planning and control of motor actions requires knowledge the dynamics controlled limb to generate appropriate muscular commands achieve desired goal. Such imply that CNS must be able deal with forces constraints acting on limb, such as omnipresent force gravity. present study investigates effect hypergravity induced by parabolic flights trajectory vertical pointing movements test hypothesis are optimized respect gravity limb. Subjects performed in normal hypergravity. We use a model...

When we touch an object or explore a texture, frictional strains are induced by the tactile interactions with surface of object. Little is known about how these perceived, although it becomes crucial for nascent industry interactive displays haptic feedback (e.g. smartphones and tablets) where based on friction modulation particularly relevant. To investigate human perception strains, mounted high-fidelity modulating ultrasonic device robotic platform performing controlled rubbing fingertip...

Abstract Humans and other animals adapt motor commands to predictable disturbances within tens of trials in laboratory conditions. A central question is how does the nervous system natural conditions when exactly same movements cannot be practiced several times. Because sensory feedback together carry continuous information about limb dynamics, we hypothesized that could unexpected online. We tested this hypothesis two reaching experiments during which velocity-dependent force fields (FFs)...

During object manipulation, humans adjust the grip force to friction, such that slippery objects are squeezed more firmly than sticky ones. This essential mechanism keep a stable grasp relies on feedback from tactile afferents innervating fingertips, sensitive local skin strains. To test if this originates skin-object interface, we asked participants perform grip-lift task with an instrumented able monitor strains at contact through transparent plates of different frictions. We observed...