Central Pattern Generator - Science topic

Herpes zoster commonly occurs in older adults, whose renal function often declines, necessitating careful dosing of antivirals such as acyclovir, valacyclovir, and famciclovir. Insufficient dose adjustment can increase central nervous system (CNS) disturbance risk. Although previous reports show varying neurotoxic risk among these drugs, the safety...

We demonstrate the consistency of character expansion for the Itzykson-Zuber (IZ) model in terms of Schur polynomials with the old formulas for pair correlators with the IZ measure. An essential new feature of the correlators is that they are not symmetric in eigenvalues – and thus can not be expressed through Schur polynomials only. Instead, we de...

There is great potential for legged robots in unstructured environments. However, model‐based approaches benefit from precise model analysis, which can be cumbersome and demand substantial domain expertise, while learning‐based methods, though promising, often necessitate prolonged training periods and may result in complex and opaque controllers....

In this work, we propose the integration of a mechanism to enable smooth transitions between different locomotion patterns in a hexapod robot. Specifically, we utilize a spiking neural network (SNN) functioning as a Central Pattern Generator (CPG) to generate three distinct locomotion patterns, or gaits: walk, jog, and run. This network produces co...

We present a model of a crawler consisting of several suckers distributed along a straight line and connected by springs. Both proprioception and control are binary: the system responds to the elongation vs compression of its springs and the suckers can either adhere or remain idle. A central pattern generator delivers a traveling wave of compressi...

The relationship between morphology and locomotion performance in amphibious fish remains poorly understood, particularly in axial-appendage-based and appendage-based movements. To address this, we introduce Polymander, a reconfigurable robot capable of mimicking Polypterus-like walking and mudskipper-like crutching, enabling systematic investigati...

Panoptic Scene Graph Generation (PSG) aims to segment objects and predict the relation triplets <subject, relation, object> within an image. Despite the impressive achievements in PSG, current methods still struggle to capture fine-grained visual context, eschewing spatial and situational information in favor of visual features related to object id...

Background: Bilateral movement training (BMT) and interlimb coupling have emerged as promising neurophysiologically-based rehabilitation approaches for stroke survivors. However, the underlying mechanisms and optimal implementation strategies remain incompletely understood. This systematic review explored the neurophysiological principles underlyin...

Addressing the dynamic stability issue of quadruped robots with a relatively high proportion of leg mass in various structured terrains, this paper proposes a hybrid control strategy. Initially, the gait scheduling framework is constructed using Hopf oscillators within the Central Pattern Generator (CPG) to emulate the bio-inspired characteristics...

Airway defensive reflexes, such as pharyngeal swallowing, coughing, and sneezing, play a pivotal role in maintaining airway homeostasis. These reflexes are controlled by complex mechanisms primarily governed by specific neuronal circuitry in the brainstem, referred to as central pattern generators. These behaviors also require optimal conditions fo...

Age-related skeletal muscle deterioration, referred to as sarcopenia, poses significant risks to astronaut health and mission success during spaceflight, yet its multisystem drivers remain poorly understood. While terrestrial sarcopenia manifests gradually through aging, spaceflight induces analogous musculoskeletal decline within weeks, providing...

It has been suggested that during locomotion, the nervous system controls movement by activating groups of muscles, or muscle synergies. Analysis of muscle synergies can reveal the organization of spinal locomotor networks and how it depends on the state of the nervous system, such as before and after spinal cord injury, and on different locomotor...

We present a novel framework for central pattern generator design that leverages the intrinsic rebound excitability of neurons in combination with winner-takes-all computation. Our approach unifies decision-making and rhythmic pattern generation within a simple yet powerful network architecture that employs all-to-all inhibitory connections enhance...

We propose a hybrid numerical model for the collective motion of fish groups, which integrates an agent-based model with a CFD-based model. In the agent-based model, the fish group is represented by self-propelled particles (SPPs), incorporating social forces with local interactive rules. The CFD-based model treats the fish body with an undulated f...

Stick insect stepping patterns have been studied for insights about locomotor rhythm generation and control, because the underlying neural system is relatively accessible experimentally and produces a variety of rhythmic outputs. Harnessing the experimental identification of effective interactions among neuronal units involved in stick insect stepp...

Investigations into animal locomotion across diverse environments have highlighted the universal applicability of adjustable reciprocal motion, offering insights into simplifying actuation systems for multi-modal robots. However, achieving unified and efficient reciprocal motion with environmental adaptability in miniature robotic systems is challe...

Wall-climbing robots can stably ascend vertical walls and even ceilings, making them suitable for specialized tasks in high-risk, confined, and harsh conditions. Therefore, they have excellent application prospects and substantial market demand. However, several challenges remain, including limited load-carrying capacity, short operational duration...

Hexapod robots have been applied often due to their high flexibility, stability, and reliability. However, the control of hexapod robots is more complicated due to their highly redundant structures and intricate degrees of freedom. Inspired by the praying mantis, this paper presents the design of a hexapod mantis-like robot equipped with passive el...

Background The ability to start and stop locomotion in response to different situations is an essential survival strategy in mammals. Mammalian locomotion is controlled by central pattern generators in the spinal cord, which are modulated by higher centers, particularly by the stimulation of the midbrain locomotor region. The midbrain locomotor reg...

We present a data-driven deep reinforcement learning (DRL) method for the optimization of a hierarchically structured control policy that includes the central pattern generator. This method, which is as a whole referred to as the hierarchical reinforcement learning with the central pattern generator (HRL-CPG), is then evaluated with the expectation...

In neuroscience, delayed synaptic activity plays a pivotal and pervasive role in influencing synchronization, oscillation, and information-processing properties of neural networks. In small rhythm-generating networks, such as central pattern generators (CPGs), time-delays may regulate and determine the stability and variability of rhythmic activity...

Purpose: Here, we discuss the neurophysiology of controlling the pharyngeal phase of swallowing (PPS) and explore how it can adapt to different tasks and contexts. Method: In a review study, we explored extant and recently emerging literature. Results: Findings indicated that the brainstem, traditionally considered the central pattern generator...

Biological neural circuits, central pattern generators (CPGs), located at the spinal cord are the underlying mechanisms that play a crucial role in generating rhythmic locomotion patterns. In this paper, we propose a novel approach that leverages the inherent rhythmicity of CPGs to enhance the locomotion capabilities of quadruped robots. Our propos...

The reference trajectory, serving as the sole kinematic guidance, is crucial for exoskeleton robot systems. This study introduces a method for generating an optimal trajectory for lower-limb exoskeletons, aiming at reducing human power during walking. Initially, the human joint angles were computed from measured data by a neighborhood field optimiz...

Background/Objectives: The GO-TRYKE® Kid (GTK®) is an arm- and leg-powered tricycle which, in addition to promoting strength, endurance, and coordination, aims to reactivate the central pattern generators of the spine for locomotion through cyclical movements. The present study investigated the effects of GTK® training on walking ability, GTK® ridi...

Modular robotics enables the development of versatile and adaptive robotic systems with autonomous reconfiguration. This paper presents a modular robotic system in which each module has independent actuation, battery power, and control, allowing both individual mobility and coordinated locomotion. A hierarchical Central Pattern Generator (CPG) fram...

The dynamic interaction between central respiratory chemoreceptors and the respiratory central pattern generator constitutes a critical homeostatic axis for stabilizing breathing rhythm and pattern, yet its circuit‐level organization remains poorly characterized. Here, the functional connectivity between two key medullary hubs: the nucleus tractus...

In neuroscience, delayed synaptic activity plays a pivotal and pervasive role in influencing synchronization, oscillation , and information-processing properties of neural networks. In small rhythm-generating networks, such as central pattern generators (CPGs), time-delays may regulate and determine the stability and variability of rhythmic activit...

On-robot Reinforcement Learning is a promising approach to train embodiment-aware policies for legged robots. However, the computational constraints of real-time learning on robots pose a significant challenge. We present a framework for efficiently learning quadruped locomotion in just 8 minutes of raw real-time training utilizing the sample effic...

Neural circuits in the brain perform a variety of essential functions, including input classification, pattern completion, and the generation of rhythms and oscillations that support functions such as breathing and locomotion. There is also substantial evidence that the brain encodes memories and processes information via sequences of neural activi...

Introduction: Implanted spinal cord epidural stimulation (SCES) is an emerging neuromodulation approach that increases the excitability of the central pattern generator [CPG] and enhances tonic and rhythmic motor patterns after spinal cord injury (SCI). We determine the effects of exoskeleton-assisted walking [EAW] + epidural stimulation [ES] + res...

The swallowing reflex is a critical component of the digestive process, triggered when food or liquids pass from the oral cavity to the oesophagus. Although adenosine triphosphate (ATP) is involved in various physiological processes, its potential to trigger the swallowing reflex has not been fully explored. This study investigated the ability of A...

Molluscan brains are composed of morphologically consistent and functionally interrogable neurons, offering rich opportunities for understanding how neural circuits drive behavior. Nonetheless, detailed component-level CNS maps are often lacking, total neuron numbers are unknown, and organizational principles remain poorly defined, limiting a full...

Miniature robots are useful during disaster response and accessing remote or unsafe areas. They need to navigate uneven terrains without supervision and under severe resource constraints such as limited compute, storage and power budget. Event-based sensorimotor control in edge robotics has potential to enable fully autonomous and adaptive robot na...

Earthworm-like robots have excellent locomotion capability in confined environments. Central pattern generator (CPG) based controllers utilize the dynamics of coupled nonlinear oscillators to spontaneously generate actuation signals for all segments, which offer significant merits over conventional locomotion control strategies. There are a number...

Contact-awareness poses a significant challenge in the locomotion control of soft snake robots. This paper is to develop bio-inspired contact-aware locomotion controllers, grounded in a novel theory pertaining to the feedback mechanism of the Matsuoka oscillator. This mechanism enables the Matsuoka central pattern generator (CPG) system to function...

Animals and robots employ central pattern generators, networks that invoke rhythmic patterns from constant inputs, to orchestrate limb movements during locomotion. Artificial central pattern generators (CPGs) can be either implemented in software or constructed in a physical domain. The former lacks embodiment, inhibiting direct interactions with t...

Inspired by the dynamic coupling of moto-neurons and physical elasticity in animals, this work explores the possibility of generating locomotion gaits by utilizing physical oscillations in a soft snake by means of a low-level spiking neural mechanism. To achieve this goal, we introduce the Double Threshold Spiking neuron model with adjustable thres...

Rhythmic orofacial movements, such as eating, drinking, or vocalization, are controlled by distinct premotor oscillator networks in the brainstem. Orofacial movements must be coordinated with rhythmic breathing to avoid aspiration and because they share muscles. Understanding how brainstem circuits coordinate rhythmic motor programs requires neurop...

The efficiency of helical locomotion in snake-like robots along high-voltage transmission lines is often hindered by low motion efficiency, high joint signal noise, and challenges in traversing obstacles. This study aims to address these issues by proposing a gait generation method that leverages a standardized Central Pattern Generator (CPG). We m...

We present a model of the central pattern generator (CPG) network that can control gait transitions in hexapod robots in a simple manner based on phase reduction theory. Our CPG network consists of six weakly coupled limit-cycle oscillators as the CPG units, where arbitrary smooth limit-cycle oscillators can be employed as the CPG unit. The synchro...

This study introduces a novel neuromechanical model employing a detailed spiking neural network to explore the role of axial proprioceptive sensory feedback, namely stretch feedback, in salamander locomotion. Unlike previous studies that often oversimplified the dynamics of the locomotor networks, our model includes detailed simulations of the clas...

Robots, as a form of technology with various designs, have infinite potential to serve in multiple areas. Hexapod robots are a design that mimics the six-legged structure of many insects. The six-legged structure offers significant advantages in stability, adaptability to diverse environments, and fault tolerance compared to other widely used robot...

Among control methods for robotic exoskeletons, biologically inspired control based on central pattern generators (CPGs) offer a promising approach to generate natural and robust walking patterns. Compared to other approaches, like model-based and machine learning-based control, the biologically inspired control provides robustness to perturbations...

Rhythmic motor behaviors are generated by neural networks termed central pattern generators (CPGs). Although locomotor CPGs have been extensively characterized, it remains unknown how the neuronal populations composing them interact to generate adaptive rhythms. We explored the non-linear cooperation dynamics among the three main populations of ips...

Walking ability is essential for human survival and health. Its basic rhythm is mainly generated by the central pattern generator of the spinal cord. The rhythmic stimulation of music to the auditory center affects the cerebral cortex and other higher nerve centers, and acts on the central pattern generator. By means of rhythm entrainment, the cent...

In this study, an ergodic sequential logic central pattern generator model was developed to demonstrate the capability of producing various gait patterns. A simple parameter search method enabled the model to acquire typical hexapod gaits such as tripod, tetrapod, and wave gaits. The model was then implemented in a field-programmable gate array (FP...

Locomotion control for quadruped robots has been extensively studied through various methodologies, including model-based, learning-based, and bio-inspired approaches. The integration of these methods is increasingly recognized as a powerful strategy for enhancing locomotion performance. Among them, the Central Pattern Generator-Reinforcement Learn...

Neurological injuries and disorders such as spinal cord injury, stroke, and cerebral palsy often result in persistent motor function deficits, severely impairing patients’ independence, mobility, and overall quality of life. Over the past few years, spinal cord stimulation (SCS), including epidural spinal cord stimulation (eSCS) and transcutaneous...

Quadruped robots, with their biomimetic structure, are capable of stable locomotion in complex terrains and are vital in rescue, exploration, and military applications. However, developing multi-modal robots that feature simple motion control while adapting to diverse amphibious environments remains a significant challenge. These robots need to exc...

This review discusses how the nervous system controls the complex body movements keeping animals up and running. In particular, we revisit how research in insects has shed light onto motor control principles that govern movements across the animal kingdom. Starting with the organization and evolution of the insect nervous system, we discuss insight...

Objective. Complex biological systems have evolved to control movement dynamics despite noisy and unpredictable inputs and processing delays that necessitate forward predictions. The staple example in vertebrates is the locomotor control emerging from interactions between multiple systems—from passive dynamics of inverted pendulum governing body mo...

Neurons depend on two interdependent mechanisms-homeostasis and neuromodulation-to maintain robust and adaptable functionality. Homeostasis stabilizes neuronal activity by adjusting ionic conductances, whereas neuromodulation dynamically modifies ionic properties in response to external signals. Combining these mechanisms in conductance-based model...

The proper functioning of the heart relies on the intricate interplay between the central nervous system and the local neuronal networks within the heart itself. While the central innervation of the heart has been extensively studied, the organization and functionality of the intracardiac nervous system (IcNS) remain largely unexplored. Here, we pr...

This review was inspired by a January 2024 conference held at Friday Harbor Laboratories, WA, honoring the pioneering work of A.O. Dennis Willows, who initiated research on the sea slug Tritonia diomedea (now T. exsulans). A chance discovery while he was a student at a summer course there has, over the years, led to many insights into the roles of...

In this paper, we address the critical challenge of gait transitions for legged robots, focusing on the challenges of versatile phase transitions and the generation of stable motion. We begin by investigating the deleterious phenomenon of phase locking and systematically identify the conditions under which it occurs in conventional diffusively coup...

Central pattern generators (CPGs) are biological neural circuits that allow vertebrates to control rhythmic and motor behavior by generating rhythmic output without rhythmic input. The synthetic generation of CPGs has attracted attention to control robots for locomotion tasks. The above has led to the design of CPGs using spiking neural networks (S...

INTRODUCTION: Mastication is coordinated motor skill that is most effective through synchronized crosstalk between the teeth, bone and muscles. A combination of molecular signaling and central pattern generators govern the development and physiology of mastication. As primates, humans have evolved with the changing dietary shifts for their survival...

A practical examination of the traditional robotic arm (RA) in operation revealed a significant limitation in its ability to control the position of motion. This underscores the urgent need to enhance the current RA’s position control capabilities. Therefore, this study proposes the use of nonlinear differential equations (NDEs) to establish a math...

Caenorhabditis elegans exhibits complex head exploratory behavior in natural environments. We quantified these movements and examined the motor circuits responsible for their intricate dynamics. Using variational mode decomposition, we distinguished between fast casts and slow bends. Slow bends backpropagate along the body, whereas fast casts show...

Like other brain circuits, the brainstem respiratory network is continually modulated by neurotransmitters that activate slow metabotropic receptors. In many cases, activation of these receptors only subtly modulates the respiratory motor pattern. However, activation of some receptor types evokes the arrest of the respiratory motor pattern as can o...

A central pattern generator (CPG)-based controller enhances the adaptability of quadrupedal locomotion, for example, by controlling the trunk posture. The conventional CPG-based controllers with attitude control often utilized the posture angle as feedback information. However, if the robot’s body is as soft as a musculoskeletal structure, it can d...

The mechanisms underlying the mammalian ultradian sleep rhythm—the alternation of rapid-eye-movement (REM) and slow-wave (SW) states—are not well understood but probably depend, at least in part, on circuits in the brainstem1, 2, 3, 4, 5–6. Here, we use perturbation experiments to probe this ultradian rhythm in sleeping lizards (Pogona vitticeps)7,...

The Jonah crab, Cancer borealis, is integral to marine ecosystems and supports a rapidly growing commercial fishery in the northwest Atlantic Ocean. This species also has a long history as a model for neuroscience that has expanded our understanding of central pattern generators, neuromodulation, synaptic plasticity, and the connectivity of neural...

Dung beetles impressively coordinate their six legs simultaneously to effectively roll large dung balls. They are also capable of rolling dung balls varying in the weight on different terrains. The mechanisms underlying how their motor commands are adapted to walk and simultaneously roll balls (multitasking behavior) under different conditions rema...

Relationships among membrane currents allow central pattern generator (CPG) neurons to reliably drive motor programs. We hypothesize that continually active CPG neurons utilize activity-dependent feedback to correlate expression of ion channel genes to balance essential membrane currents. However, episodically activated neurons experience absences...

Dung beetles impressively coordinate their 6 legs to effectively roll large dung balls. They can also roll dung balls varying in the weight on different terrains. The mechanisms underlying how their motor commands are adapted to walk and simultaneously roll balls (multitasking behavior) under different conditions remain unknown. This study unravels...

The central pattern generator (CPG) is widely applied in biped gait generation, and the particle swarm optimization (PSO) algorithm is commonly used to solve optimization problems for CPG network controllers. However, the canonical PSO algorithms fail to balance exploration and exploitation, resulting in reduced optimization accuracy and stability,...

Typical legged locomotion controllers are designed or trained offline. This is in contrast to many animals, which are able to locomote at birth, and rapidly improve their locomotion skills with few real-world interactions. Such motor control is possible through oscillatory neural networks located in the spinal cord of vertebrates, known as Central...

In order to improve the walking stability of a biped robot in multiple scenarios and reduce the complexity of the Central Pattern Generator (CPG) model, a new CPG walking controller based on multivariate linear mapping was proposed. At first, in order to establish a dynamics model, the lower limb mechanical structure of the biped robot was designed...

Neural circuits in the brain perform a variety of essential functions, including input classification, pattern completion, and the generation of rhythms and oscillations that support processes such as breathing and locomotion. There is also substantial evidence that the brain encodes memories and processes information via sequences of neural activi...

Neural circuits in the brain perform a variety of essential functions, including input classification, pattern completion, and the generation of rhythms and oscillations that support processes such as breathing and locomotion. There is also substantial evidence that the brain encodes memories and processes information via sequences of neural activi...

In the domain of bionic walking control for biped robots, optimizing the parameters of the central pattern generator (CPG) presents a formidable challenge due to its high-dimensional and nonlinear characteristics. The traditional particle swarm optimization (PSO) algorithm often converges to local optima, particularly when addressing CPG parameter...

Introduction In traffic rule, green/blue means go, and red means stop. It has been shown that this prior knowledge about traffic signal colors can affect reaction times (RTs). For example, RTs are longer when responding to a red “Go” signal and withholding the response to a blue “No-go” signal (Red Go/Blue No-go task) than when responding to a blue...

Spinal cord injury results in serious neurophysiological consequences that alter healthy body functions and devastate the quality of life. One of them is the loss of sensorimotor functions, including disturbance or complete loss of locomotion. Recovery of locomotor function is one of the primary goals of therapeutic interventions in the case of an...

Addressing the joint control problem of pneumatic muscle-driven robots, this study aims to design a bionic reflex mechanism to enhance the robots’ adaptive capacity to various disturbances. Based on the biological reflex mechanism, we developed a spindle reflex and deep tendon reflex control system based on CPG (central pattern generator) to mitiga...

In this study, a novel ergodic sequential logic (SL) central pattern generator (CPG) for the realization of multiple gaits of a six-legged robot is presented. First, a novel generalized ergodic SL oscillator and its theoretical analysis method are presented. Using the theoretical analysis method, it is shown that the ergodic SL oscillator can reali...

It was suggested that during locomotion, the nervous system controls movement by activating groups of muscles, or muscle synergies. Analysis of muscle synergies can reveal the organization of spinal locomotor networks and how it depends on the state of the nervous system, such as before and after spinal cord injury, and on different locomotor condi...

Neuronal activity and energy supply must maintain a fine balance for neuronal fitness. Various channels of communication between the two could impact network output in different ways. Sulfonylurea receptors (SURs) are a modification of ATP-binding cassette proteins (ABCs) that confer ATP-dependent gating on their associated ion channels. They are w...

For animals to meet environmental challenges, the activity patterns of specialized oscillatory neural circuits, central pattern generators (CPGs), controlling rhythmic movements like breathing and locomotion, are adjusted by neuromodulation. As a representative example, the leech heartbeat is controlled by a CPG driven by two pairs of mutually inhi...

This paper presents an adaptive line-of-sight (LOS) guidance method, incorporating a finite-time sideslip angle observer to achieve precise planar path tracking of a bionic robotic fish driven by LOS. First, an adaptive LOS guidance method based on real-time cross-track error is presented. To mitigate the adverse effects of the sideslip angle on tr...

Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following spinal cord injury. The thoracic lateral hemisection represents an experimental model of an incomplete spinal cord injury, where connections between the brain and spinal cord...

Although the raison d’etre of the brain is the survival of the body, there are relatively few theoretical studies of closed-loop rhythmic motor control systems. In this paper we provide a unified framework, based on variational analysis, for investigating the dual goals of performance and robustness in powerstroke–recovery systems. To demonstrate o...