The separate neural control of hand movements and contact forces

To manipulate an object, we must simultaneously control the contact forces exerted on the object and the movements of our hand. Two alternative views for manipulation have been proposed: one in which motions and contact forces are represented and controlled by separate neural processes, and one in which motions and forces are controlled jointly, by a single process. To evaluate these alternatives, we designed three tasks in which subjects maintained a specified contact force while their hand was moved by a robotic manipulandum. The prescribed contact force and hand motions were selected in each task to induce the subject to attain one of three goals: (1) exerting a regulated contact force, (2) tracking the motion of the manipulandum, and (3) attaining both force and motion goals concurrently. By comparing subjects' performances in these three tasks, we found that behavior was captured by the summed actions of two independent control systems: one applying the desired force, and the other guiding the hand along the predicted path of the manipulandum. Furthermore, the application of transcranial magnetic stimulation impulses to the posterior parietal cortex selectively disrupted the control of motion but did not affect the regulation of static contact force. Together, these findings are consistent with the view that manipulation of objects is performed by independent brain control of hand motions and interaction forces

Learning Redundant Motor Tasks With and Without Overlapping Dimensions: Facilitation and Interference Effects

Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills

Sensory Motor Remapping of Space in Human-Machine Interfaces

Studies of adaptation to patterns of deterministic forces have revealed the ability of the motor control system to form and use predictive representations of the environment. These studies have also pointed out that adaptation to novel dynamics is aimed at preserving the trajectories of a controlled endpoint, either the hand of a subject or a transported object. We review some of these experiments and present more recent studies aimed at understanding how the motor system forms representations of the physical space in which actions take place. An extensive line of investigations in visual information processing has dealt with the issue of how the Euclidean properties of space are recovered from visual signals that do not appear to possess these properties. The same question is addressed here in the context of motor behavior and motor learning by observing how people remap hand gestures and body motions that control the state of an external device. We present some theoretical considerations and experimental evidence about the ability of the nervous system to create novel patterns of coordination that are consistent with the representation of extrapersonal space. We also discuss the perspective of endowing human–machine interfaces with learning algorithms that, combined with human learning, may facilitate the control of powered wheelchairs and other assistive devices

The Graham Bank: hydrographic features and safety of navigation

To ensure safety of navigation, the monitoring of high-risk seabed areas is one of the primary tasks of the hydrographic activity. Monitoring of these areas also provides insights into environmental and scientific applications. The Graham Bank (Strait of Sicily in the Mediterranean Sea) has been monitored by the Italian Hydrographic Institute (IIM) for over a century. This article describes the IIM monitoring of the Graham Bank by conducting surveys using techniques and technologies available at each time and integrating all of the data into a modern bathymetric database. Based on the outcomes of this case study, the IIM proposes ways to minimize the risk to vessels passing close to the Graham Bank.Para garantizar la seguridad de la navegación, la supervisión de las zonas de los fondos marinos de alto riesgo es una de las tareas principales de la actividad hidrográfica. La supervisión de estas áreas también proporciona percepciones relativas a las aplicaciones ambientales y científicas. El Banco Graham (Estrecho de Sicilia en el mar Mediterráneo) ha sido supervisado por el Instituto Hidrográfico Italiano (IIM) durante más de un siglo. Este artículo describe la supervisión por parte del IIM del Banco Graham mediante la realización de levantamientos, utilizando las técnicas y tecnologías dispnibles en cada momento e integrando todos los datos en una base de datos batimétricos moderna. Basándose en los resultados de este estudio de caso, el IIM propone modos de minimizar el riesgo para los buques que pasan cerca del Banco Graham.Afin d'assurer la sécurité de la navigation, la surveillance des zones de fonds marins à haut risque est l'une des tâches principales de l'activité hydrographique. Surveiller ces zones permet également d'avoir un aperçu des enjeux environnementaux et scientifiques. Le Banc de Graham (Canal de Sicile, Mer Méditerranée) est surveillé par le Service hydrographique italien (IIM) depuis plus d'un siècle. Cet article décrit la surveillance du Banc de Graham par l'IIM qui s'appuie sur des levés effectués à l'aide des différentes techniques et technologies disponibles à chaque époque et sur l'intégration de toutes les données dans une base de données bathymétriques moderne. Sur la base des résultats de cette étude de cas, l'IIM propose des solutions afin de minimiser les risques pour des navires qui croisent à proximité du Banc de Graham

Data Science in Neuroscience: A Review of The EEG Analytical Workflow

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The dynamics of motor learning through the formation of internal models

A medical student learning to perform a laparoscopic procedure or a recently paralyzed user of a powered wheelchair must learn to operate machinery via interfaces that translate their actions into commands for an external device. Since the user\u2019s actions are selected from a number of alternatives that would result in the same effect in the control space of the external device, learning to use such interfaces involves dealing with redundancy. Subjects need to learn an externally chosen many-to-one map that transforms their actions into device commands. Mathematically, we describe this type of learning as a deterministic dynamical process, whose state is the evolving forward and inverse internal models of the interface. The forward model predicts the outcomes of actions, while the inverse model generates actions designed to attain desired outcomes. Both the mathematical analysis of the proposed model of learning dynamics and the learning performance observed in a group of subjects demonstrate a first-order exponential convergence of the learning process toward a particular state that depends only on the initial state of the inverse and forward models and on the sequence of targets supplied to the users. Noise is not only present but necessary for the convergence of learning through the minimization of the difference between actual and predicted outcomes

A Case of RhabdomyoSarcoma Following a Metal Surgical Implant

Patient. We report a 51-year-old male presenting with Grade III rhabdomyosarcoma

Conventional and algorithmic music listening before radiotherapy treatment: A randomized controlled pilot study

Music listening is a widespread approach in the field of music therapy. In this study, the effects of music listening on anxiety and stress in patients undergoing radiotherapy are investigated. Sixty patients with breast cancer who were candidates for postoperative curative radiotherapy were recruited and randomly assigned to three groups: Melomics-Health (MH) group (music listening algorithmically created, n = 20); individualized music listening (IML) group (playlist of preferred music, n = 20); no music group (n = 20). Music listening was administered for 15 min immediately before simulation and during the first five radiotherapy sessions. The State-Trait Anxiety Inventory (STAI) and the Psychological Distress Inventory (PDI) were administered before/after treatment. Cochran’s Q test and McNemar test for paired proportions were performed to evaluate if the proportion of subjects having an outcome score below the critical value by treatment and over time was different, and if there was a change in that proportion. The MH group improved in STAI and PDI. The IML group worsened in STAI at T1 and improved STAI-Trait at T2. The IML group worsened in PDI at T2. The No music group generally improved in STAI and PDI. Clinical and music listening-related implications are discussed defining possible research perspectives in this field

Caratterizzazione dell’ambiente marino dei Campi Flegrei. Risultati preliminari della campagna oceanografica RICAMAR 2013

The caldera of the Phlegraean Fields (also known as Campi Flegrei) is one of the most dangerous and populated volcanic area in the world, covering an area that comprises the western part of Naples and the Gulf of Pozzuoli. The main peculiarity of current volcanic activity is the gradual and periodic lift (positive or negative) of part of the Earth\u27s surface (bradyseism) combined, only during the positive phase, with a strong sismicity and surficial hydrotermal activity. Deformative models, calibrated using land-based measurements, highlighted the Gulf of Pozzuoli as the area with the largest deformation. Although the network of monitoring sensors on land is well developed and structured, there is a lack of sensing systems for the marine deformation. The activities of RIlievi per la Caratterizzazione dell’Ambiente MARino nel Golfo di Pozzuoli 2013 (RICAMAR2013) project - sinergically conducted by the Italian Navy\u27s Survey Vessel Ammiraglio Magnaghi , the Italian Hydrographic Office (IIM) and the Istituto Nazionale di Geofisica e Vulcanologia (INGV)- were targeted to fulfill this gap. In fact, the creation of marine observatories about the caldera\u27s phenomena will be based on the data collected during these bathymetric, magnetometric, stratigrafic and hydrologic surveys