Background: In daily life tasks of the upper limb, we must make quick corrections with our hands in unstable postural situations. Postural and reaching control mechanisms are involved in the accurate execution of upper-limb tasks.
Research Question: This research aimed to determine the effect of different postural stability conditions on the motor performance of the upper limb in a reaching task with non-static targets.
Methodology: 19 young participants performed a reaching task toward targets that exhibited a change in position (at 200 or 600 ms) in different postural conditions (bipedal-firm, bipedal-foam, and unipedal-foam surface). Performance on the screen (motion time and spatial error), balance (center of pressure displacements, CoP), and index finger movements were recorded during the reaching task.
Results: The instability affects the finger kinematic (displacements) and CoP kinematic (displacements, speed, and smoothness) without affecting the performance on the screen (precision and duration). The timing of target change affects the performance on the screen, finger kinematic (speed and smoothness), and CoP kinematic (displacements, speed, and smoothness).
Significance: Postural and reaching control systems enable accurate hand motions in less stable situations, even in reaching tasks with non-static targets. The postural and reaching control systems can protect the end-effector performance during unstable conditions but not during trials with less time to correct the motion.
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http://dx.doi.org/10.1016/j.gaitpost.2024.05.018 | DOI Listing |
J Imaging
December 2024
Technology Department, CERN, 1211 Geneva, Switzerland.
Detection and segmentation of brain abnormalities using Magnetic Resonance Imaging (MRI) is an important task that, nowadays, the role of AI algorithms as supporting tools is well established both at the research and clinical-production level. While the performance of the state-of-the-art models is increasing, reaching radiologists and other experts' accuracy levels in many cases, there is still a lot of research needed on the direction of in-depth and transparent evaluation of the correct results and failures, especially in relation to important aspects of the radiological practice: abnormality position, intensity level, and volume. In this work, we focus on the analysis of the segmentation results of a pre-trained U-net model trained and validated on brain MRI examinations containing four different pathologies: Tumors, Strokes, Multiple Sclerosis (MS), and White Matter Hyperintensities (WMH).
View Article and Find Full Text PDFEntropy (Basel)
December 2024
School of Mathematical and Physical Sciences, Macquarie University, Sydney, NSW 2109, Australia.
The density classification (DC) task, a computation which maps global density information to local density, is studied using one-dimensional non-unitary quantum cellular automata (QCAs). Two approaches are considered: one that preserves the number density and one that performs majority voting. For number-preserving DC, two QCAs are introduced that reach the fixed-point solution in a time scaling quadratically with the system size.
View Article and Find Full Text PDFPurpose: This study aimed to validate the accuracy of the Active Style Pro HJA-750C (ASP) in measuring metabolic equivalents (METs) during walking and reaching tasks in individuals with subacute stroke using a respiratory gas analyzer as a reference.
Methods: Twenty-three hospitalized patients with subacute stroke participated in this study. They performed sitting and standing reaching tasks, as well as walking while wearing a VO2 Master respiratory gas analyzer and ASP devices on both the paretic and non-paretic sides.
Q J Exp Psychol (Hove)
January 2025
Recent studies have demonstrated hysteresis in studies of syntactic choice in language production (e.g., Koranda et al.
View Article and Find Full Text PDFClin Neuropsychiatry
December 2024
Consiglio Nazionale delle Ricerche, Istituto di Neuroscienze, Parma, Italy.
Objective: it is well known that during an intentional behavior, the final goal of the action shapes the entire sequence of motor acts. This chained organization has been previously demonstrated to be altered in school-age autistic children, who modulate only the final motor act according to the action goal. Here, we investigate the temporal modulation during the intentional action in three groups of preschoolers: neurotypical, autistic, and non-autistic siblings of autistic children.
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