The acquisition of novel muscle activity patterns is a key aspect of motor skill learning, which can be seen, for example, when beginner musicians learn new guitar or piano chords. To study this process, we introduce here a new paradigm that requires learning new patterns of flexion and extension of multiple fingers. First, participants practiced all the 242 possible combinations of isometric finger flexion and extension around the metacarpophalangeal joint (i.
View Article and Find Full Text PDFA primary goal of systems neuroscience is to discover how ensembles of neurons transform inputs into goal-directed behavior, a process known as neural computation. A powerful framework for understanding neural computation uses neural dynamics - the rules that describe the temporal evolution of neural activity - to explain how goal-directed input-output transformations occur. As dynamical rules are not directly observable, we need computational models that can infer neural dynamics from recorded neural activity.
View Article and Find Full Text PDFRecent advances in neural recording technology allow simultaneously recording action potentials from hundreds to thousands of neurons in awake, behaving animals. However, characterizing spike patterns in the resulting data, and linking these patterns to behaviour, remains a challenging task. The lack of a rigorous mathematical language for variable numbers of events (spikes) emitted by multiple agents (neurons) is an important limiting factor.
View Article and Find Full Text PDFBrain-computer interfaces (BCIs) have the potential to restore hand movement for people with paralysis, but current devices still lack the fine control required to interact with objects of daily living. Following our understanding of cortical activity during arm reaches, hand BCI studies have focused primarily on velocity control. However, mounting evidence suggests that posture, and not velocity, dominates in hand-related areas.
View Article and Find Full Text PDFArtificial neural networks (ANNs) are a powerful class of computational models for unravelling neural mechanisms of brain function. However, for neural control of movement, they currently must be integrated with software simulating biomechanical effectors, leading to limiting impracticalities: (1) researchers must rely on two different platforms and (2) biomechanical effectors are not generally differentiable, constraining researchers to reinforcement learning algorithms despite the existence and potential biological relevance of faster training methods. To address these limitations, we developed MotorNet, an open-source Python toolbox for creating arbitrarily complex, differentiable, and biomechanically realistic effectors that can be trained on user-defined motor tasks using ANNs.
View Article and Find Full Text PDFNeurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups.
View Article and Find Full Text PDFIn recent years many countries have created national bodies that provide evidence-based guidance and policy relating to the commissioning and provision of healthcare services. However, such guidance often fails to be consistently implemented. The differing perspectives from which guidance is developed is suggested as a significant contributor to these failures.
View Article and Find Full Text PDFNeurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups.
View Article and Find Full Text PDFBackground: Varicose vein (VV) treatments have changed significantly in recent years leading to potential disparities in service provision. The aim of this study was to examine the trends in VV treatment in England and to identify disparities in the provision of day-case and inpatient treatments related to deprivation, ethnicity, and other demographic, and geographical factors.
Method: A population-based study using linked hospital episode statistics for England categorized VV procedures and compared population rates and procedure characteristics by ethnicity, deprivation quintile, and geographical area.
Many healthcare agencies are producing evidence-based guidance and policy that may determine the availability of particular healthcare products and procedures, effectively rationing aspects of healthcare. They claim legitimacy for their decisions through reference to evidence-based scientific method and the implementation of just decision-making procedures, often citing the criteria of 'accountability for reasonableness'; publicity, relevance, challenge and revision, and regulation. Central to most decision methods are estimates of gains in quality-adjusted life-years (QALY), a measure that combines the length and quality of survival.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2020
One of the primary ways we interact with the world is using our hands. In macaques, the circuit spanning the anterior intraparietal area, the hand area of the ventral premotor cortex, and the primary motor cortex is necessary for transforming visual information into grasping movements. However, no comprehensive model exists that links all steps of processing from vision to action.
View Article and Find Full Text PDFThe rapid development in healthcare technologies in recent years has resulted in the need for health services, whether publicly funded or insurance based, to identify means to maximise the benefits and provide equitable distribution of limited resources. This has resulted in the need for rationing decisions, and there has been considerable debate regarding the substantive and procedural ethical principles that promote distributive justice when making such decisions. In this paper, I argue that while the scientifically rigorous approaches of evidence-based healthcare are claimed as aspects of procedural justice that legitimise such guidance, there are biases and distortions in all aspects of the process that may lead to epistemic injustices.
View Article and Find Full Text PDFConsiderable 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).
View Article and Find Full Text PDFAim: To identify the symptoms and quality of life impacts that are important from the perspective of patients with varicose veins and to compare identified themes to items in varicose vein patient-reported outcome measures (PROMs).
Background: Varicose veins are common worldwide and are considered a chronic condition with implications for quality of life. Treatment is predominantly conservative; therefore, understanding patients' experiences of living with varicose veins is important to inform the provision of clinical care.
Background: Abdominal aortic aneurysm (AAA) screening programmes have been established for men in the UK to reduce deaths from AAA rupture. Whether or not screening should be extended to women is uncertain.
Objective: To evaluate the cost-effectiveness of population screening for AAAs in women and compare a range of screening options.
Background: A third of deaths in the UK from ruptured abdominal aortic aneurysm (AAA) are in women. In men, national screening programmes reduce deaths from AAA and are cost-effective. The benefits, harms, and cost-effectiveness in offering a similar programme to women have not been formally assessed, and this was the aim of this study.
View Article and Find Full Text PDFDespite exercise being included in the recommended advice for patients with venous leg ulcers, there is a fear shared by clinicians and patients that exercise may be either inappropriate or harmful and actually delay rather than promote healing. Therefore, before implementing a larger-scale study exploring the effects of a supervised exercise programme in patients with venous ulcers being treated with compression therapy, it is important to assess exercise safety as well as fidelity and progression in a feasibility study. Eighteen participants randomised in the exercise group were asked to undertake 36 (3 times/week for 12 weeks) 60-min exercise sessions, each comprising moderate-intensity aerobic, resistance, and flexibility exercise components.
View Article and Find Full Text PDFOur voluntary grasping actions lie on a continuum between immediate action and waiting for the right moment, depending on the context. Therefore, studying grasping requires an investigation into how preparation time affects this process. Two macaque monkeys (; one male, one female) performed a grasping task with a short instruction followed by an immediate or delayed go cue (0-1300 ms) while we recorded in parallel from neurons in the grasp preparation relevant area F5 that is part of the ventral premotor cortex, and the anterior intraparietal area (AIP).
View Article and Find Full Text PDFPreparing and executing grasping movements demands the coordination of sensory information across multiple scales. The position of an object, required hand shape, and which of our hands to extend must all be coordinated in parallel. The network formed by the macaque anterior intraparietal area (AIP) and hand area (F5) of the ventral premotor cortex is essential in the generation of grasping movements.
View Article and Find Full Text PDFEur J Appl Physiol
February 2018
Purpose: To investigate the effects of a 12-week supervised exercise programme on lower-limb cutaneous microvascular reactivity in adults with venous leg ulceration.
Methods: Thirty-eight adults with unilateral venous ulceration who were being treated with lower-limb compression therapy (58% male; mean age 65 years; median ulcer size 5 cm) were randomly allocated to exercise or control groups. Exercise participants (n = 18) were invited to attend thrice weekly sessions of lower-limb aerobic and resistance exercise for 12 weeks.
Recent models of movement generation in motor cortex have sought to explain neural activity not as a function of movement parameters, known as representational models, but as a dynamical system acting at the level of the population. Despite evidence supporting this framework, the evaluation of representational models and their integration with dynamical systems is incomplete in the literature. Using a representational velocity-tuning based simulation of center-out reaching, we show that incorporating variable latency offsets between neural activity and kinematics is sufficient to generate rotational dynamics at the level of neural populations, a phenomenon observed in motor cortex.
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