86,571 research outputs found
FUNCTIONAL COUPLING OF PARIETAL ALPHA RHYTHMS IS ENHANCED IN ATHLETES BEFORE VISUOMOTOR PERFORMANCE: A COHERENCE ELECTROENCEPHALOGRAPHIC STUDY
No full textIt has been shown that elite pistol shooters are characterized by a power increase of wide cortical electroencephalographic (EEG) alpha (about 8-12 Hz) and beta (about 14-35 Hz) rhythms during the preparation of air pistol shots, possibly related to selective attentional and "neural efficiency" processes [Del Percio C, Babiloni C, Bertollo M, Marzano N, lacoboni M, Infarinato F, Lizio R, Stocchi M, Robazza C, Cibelli G, Comani S, Eusebi F (2009a) Hum Brain Mapp 30(11):3527-3540; Del Percio C, Babiloni C, Marzano N, lacoboni M, Infarinato F, Vecchio F, Lizio R, Aschieri P, Fiore A, Toran G, Gallamini M, Baratto M, Eusebi F (2009b) Brain Res Bull 79(3-4):193-200]. Here, we tested the hypothesis that such processes are associated with an enhanced functional coupling of posterior cortical regions involved in task-relevant attentional processes and visuo-motor transformations. To this aim, between-electrodes spectral coherence was computed from spatially enhanced EEG data collected during a previous study (i.e. right handed 18 elite air pistol shooters and 10 matched non-athletes; augmented 10-20 system; surface Laplacian estimation). Theta (about 4-6 Hz), low-frequency alpha (about 8-10 Hz), high-frequency alpha (about 10-12 Hz), low-frequency beta (14-22 Hz), high-frequency beta (23-35 Hz), and gamma (36-44 Hz) bands were considered. Statistical results showed that intra-hemispheric low-frequency alpha (parietal-temporal and parietal-occipital regions), high-frequency alpha (parietal-temporal and parietal-occipital regions), high-frequency beta, and gamma (parietal-temporal regions) coherence values were stable in amplitude in the elite athletes but not in the non-athletes during the preparation of pistol shots. The same applies to interhemispheric low-frequency alpha (parietal regions), high-frequency alpha (parietal regions), high-frequency beta and gamma coherence values. These findings suggest that under the present experimental conditions, elite athletes are characterized by the stabilization of functional coupling of preparatory EEG rhythms between "visuo-spatial" parietal area and other posterior cortical areas. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved
FUNCTIONAL COUPLING OF PARIETAL ALPHA RHYTHMS IS ENHANCED IN ATHLETES BEFORE VISUOMOTOR PERFORMANCE: A COHERENCE ELECTROENCEPHALOGRAPHIC STUDY
No full textIt has been shown that elite pistol shooters are characterized by a power increase of wide cortical electroencephalographic (EEG) alpha (about 8-12 Hz) and beta (about 14-35 Hz) rhythms during the preparation of air pistol shots, possibly related to selective attentional and "neural efficiency" processes [Del Percio C, Babiloni C, Bertollo M, Marzano N, lacoboni M, Infarinato F, Lizio R, Stocchi M, Robazza C, Cibelli G, Comani S, Eusebi F (2009a) Hum Brain Mapp 30(11):3527-3540; Del Percio C, Babiloni C, Marzano N, lacoboni M, Infarinato F, Vecchio F, Lizio R, Aschieri P, Fiore A, Toran G, Gallamini M, Baratto M, Eusebi F (2009b) Brain Res Bull 79(3-4):193-200]. Here, we tested the hypothesis that such processes are associated with an enhanced functional coupling of posterior cortical regions involved in task-relevant attentional processes and visuo-motor transformations. To this aim, between-electrodes spectral coherence was computed from spatially enhanced EEG data collected during a previous study (i.e. right handed 18 elite air pistol shooters and 10 matched non-athletes; augmented 10-20 system; surface Laplacian estimation). Theta (about 4-6 Hz), low-frequency alpha (about 8-10 Hz), high-frequency alpha (about 10-12 Hz), low-frequency beta (14-22 Hz), high-frequency beta (23-35 Hz), and gamma (36-44 Hz) bands were considered. Statistical results showed that intra-hemispheric low-frequency alpha (parietal-temporal and parietal-occipital regions), high-frequency alpha (parietal-temporal and parietal-occipital regions), high-frequency beta, and gamma (parietal-temporal regions) coherence values were stable in amplitude in the elite athletes but not in the non-athletes during the preparation of pistol shots. The same applies to interhemispheric low-frequency alpha (parietal regions), high-frequency alpha (parietal regions), high-frequency beta and gamma coherence values. These findings suggest that under the present experimental conditions, elite athletes are characterized by the stabilization of functional coupling of preparatory EEG rhythms between "visuo-spatial" parietal area and other posterior cortical areas. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved
Neuroimaging biomarkers toward an optimized and personalized AOT
No full textStroke is the second leading cause of death in industrialized countries. In recent years, some scientific studies have focused on the search for new non-invasive strategies which contribute to the functional recovery of stroke patients. Action Observation Therapy (AOT) is one of them. This rehabilitative approach is aimed at facilitating neural plasticity toward the reconstruction of impaired motor functions through the stimulation of motor cortex via visual stimuli containing actions. This study was carried out fitting into this research context, proposing an analysis of the electroencephalographic signals acquired during an action observation protocol. The aim of the work is to identify, through the study of the desynchronization and synchronization index (ERD/ERS), the categories of gestures that cause greater cortical activation to optimize intervention based on AOT protocol. The results showed that the behavior of motor cortex during the visualization of motor gestures is statistically different respect to control videos (not human actions) with a p-value < 0.03 for mu band (8-13 Hz) and p-value < 0.0001 for beta band (15-20 Hz). Another key result based on time course of signals power showed that the control stimuli cause less desynchronization in the motor area compared to visual motor stimuli
Kinematic parameters for tracking patient progress during upper limb robot-assisted rehabilitation: an observational study on subacute stroke subjects
No full textBackground. Upper limb robot-assisted therapy (RT) provides intensive, repetitive, and task-specific treatment, and its efficacy for stroke survivors is well established in literature. Biomechanical data from robotic devices has been widely employed for patient’s assessment, but rarely it has been analysed for tracking patient progress during RT. The goal of this retrospective study is to analyse built-in kinematic data registered by a planar end-effector robot for assessing the time course of motor recovery and patient’s workspace exploration skills. A comparison of subjects having mild and severe motor impairment has been also conducted. For that purpose, kinematic data recorded by a planar end-effector robot have been processed for investigating how motor performance in executing point-to-point trajectories with different directions changes during RT. Methods. Observational retrospective study of 68 subacute stroke patients who conducted 20 daily sessions of upper limb RT with the InMotion 2.0 (Bionik Laboratories, USA): planar point-to-point reaching tasks with an “assist as needed” strategy. The following kinematic parameters (KPs) were computed for each subject and for each point-to-point trajectory executed during RT: movement accuracy, movement speed, number of peak speed, and task completion time. The Wilcoxon signed-rank tests were used with clinical outcomes. the Friedman test and post hoc Conover’s test (Bonferroni’s correction) were applied to KPs. A secondary data analysis has been conducted by comparing patients having different severities of motor impairment. The level of significance was set at p value < 0.05. Results. At the RT onset, the movements were less accurate and smoothed, and showed higher times of execution than those executed at the end of treatment. The analysis of the time course of KPs highlighted that RT seems to improve the motor function mainly in the first sessions of treatment: most KPs show significant intersession differences during the first 5/10 sessions. Afterwards, no further significant variations occurred. The ability to perform movements away from the body and from the hemiparetic side remains more challenging. The results obtained from the data stratification show significant differences between subjects with mild and severe motor impairment. Conclusion. Significant improvements in motor performance were registered during the time course of upper limb RT in subacute stroke patients. The outcomes depend on movement direction and motor impairment and pave the way to optimize healthcare resources and to design patient-tailored rehabilitative protocols
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Directional information flows between brain hemispheres across waking, non-REM and REM sleep states: an EEG study
No full text
Sensor network for analyzing upper body strategies in parkinson’s disease versus normative kinematic patterns
No full textIn rehabilitation, the upper limb function is generally assessed using clinical scales and functional motor tests. Although the Box and Block Test (BBT) is commonly used for its simplicity and ease of execution, it does not provide a quantitative measure of movement quality. This study proposes the integration of an ecological Inertial Measurement Units (IMUs) system for analysis of the upper body kinematics during the execution of a targeted version of BBT, by able-bodied persons with subjects with Parkinson’s disease (PD). Joint angle parameters (mean angle and range of execution) and hand trajectory kinematic indices (mean velocity, mean acceleration, and dimensionless jerk) were calculated from the data acquired by a network of seven IMUs. The sensors were applied on the trunk, head, and upper limb in order to characterize the motor strategy used during the execution of BBT. Statistics revealed significant differences (p < 0.05) between the two groups, showing compensatory strategies in subjects with PD. The proposed IMU-based targeted BBT protocol allows to assess the upper limb function during manual dexterity tasks and could be used in the future for assessing the efficacy of rehabilitative treatments
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