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Considerable progress has been made over the last decades in characterizing the neural coding of hand shape, but grasp force has been largely ignored. We trained two macaque monkeys (Macaca mulatta) on a delayed grasping task where grip type and grip force were instructed. Neural population activity was recorded from areas relevant for grasp planning and execution: the anterior intraparietal area (AIP), F5 of the ventral premotor cortex, and the hand area of the primary motor cortex (M1). Grasp force was strongly encoded by neural populations of all three areas, thereby demonstrating for the first time the coding of grasp force in single- and multi-units of AIP. Neural coding of intended grasp force was most strongly represented in area F5. In addition to tuning analysis, a dimensionality reduction method revealed low-dimensional responses to grip type and grip force. Additionally, this method revealed a high correlation between latent variables of the neural population representing grasp force and the corresponding latent variables of electromyographic forearm muscle activity. Our results therefore suggest an important role of the cortical areas AIP, F5, and M1 in coding grasp force during movement execution as well as of F5 for coding intended grasp force.
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http://dx.doi.org/10.1038/s41598-018-35488-z | DOI Listing |
Eur J Neurol
September 2025
Department of Neurology and Center for Translational and Behavioral Neurosciences, University Medicine Essen, University of Duisburg-Essen, Essen, Germany.
Background: Changes in handgrip strength have recently been adapted as clinical biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) under the assumption of a disease-specific peripheral neuromuscular dysfunction. However, some have proposed that strength impairments in ME/CFS are better explained by alterations in higher-order motor control. In serial measurements, exertion can been assessed through analysis of variation, since maximal voluntary contractions exhibit lower coefficients of variation (CV) than submaximal contractions.
View Article and Find Full Text PDFThis study aimed to evaluate the resistance of anastomoses to mechanical traction in an ex vivo biomechanical experiment, to determine the most resistant manual suture for restoring digestive tract continuity after various types of gastric resection for cancer. Materials and methods: The tensile strength of different types of anastomoses was compared ex vivo using porcine esophagus, stomach, and small intestine. The test setup included a tensile testing device, which applied a controlled force on the anastomoses until they broke, which was recorded for each type of anastomosis and was expressed in N.
View Article and Find Full Text PDFEur Biophys J
September 2025
Institute of Biophysics, National Research Council, Palermo, Italy.
The aqueous extract of Moringa oleifera leaves has been previously characterized for its polyphenolic composition, yet the behavior of its colloidal aggregates under dilution remains largely unexplored. In this study, we investigate the structural and chemical properties of these aggregates at room temperature, focusing on their stability and surface exposure upon dilution. Although the aggregates break up as dilution increases, they never fully dissolve within the conditions explored.
View Article and Find Full Text PDFIEEE Trans Neural Syst Rehabil Eng
September 2025
Limb loss affects millions globally, impairing physical function and reducing quality of life. Most traditional surface electromyographic (sEMG) and semi-autonomous methods require users to generate myoelectric signals for each control, imposing physically and mentally taxing demands. This study aims to develop a fully autonomous control system that enables a prosthetic hand to automatically grasp and release objects of various shapes using only a camera attached to the wrist.
View Article and Find Full Text PDFIEEE Trans Neural Syst Rehabil Eng
September 2025
Functional electrical stimulation (FES) is an effective technique for restoring or enhancing hand motor function in patients with neurological impairments, such as those recovering from stroke or spinal cord injuries. Although many studies have used phenomenological models to investigate the control of FES, few studies have simultaneously employed both methods to study finger output force. This study aims to accurately predict finger output force using the Hill model and a multi-joint finger model under different current conditions.
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