Cognitive swarming in complex environments with attractor dynamics and oscillatory computing.
We present emergent behaviors including phase-organized rings and trajectory sequences that interact with environmental cues and geometry in large, fragmented mazes. Thus, NeuroSwarms is a model artificial spatial system that integrates autonomous control and theoretical neuroscience to potentially uncover common principles to advance both domains. PMID: 32236692 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - March 31, 2020 Category: Science Authors: Monaco JD, Hwang GM, Schultz KM, Zhang K Tags: Biol Cybern Source Type: research

EO-MTRNN: evolutionary optimization of hyperparameters for a neuro-inspired computational model of spatiotemporal learning.
Abstract For spatiotemporal learning with neural networks, hyperparameters are often set manually by a human expert. This is especially the case with multiple timescale networks that require a careful setting of the values of timescales in order to learn spatiotemporal data. However, this implies a cumbersome trial-and-error process until suitable parameters are found and it reduces the long-term autonomy of artificial agents, such as robots that are controlled by multiple timescale networks. To solve the problem, we propose the evolutionary optimized multiple timescale recurrent neural network (EO-MTRNN) that is ...
Source: Biological Cybernetics - March 17, 2020 Category: Science Authors: Wieser E, Cheng G Tags: Biol Cybern Source Type: research

Simulating Small Neural Circuits with a Discrete Computational Model.
Abstract Simulations of neural activity are commonly based on differential equations. We address the question what can be achieved with a simplified discrete model. The proposed model resembles artificial neural networks enriched with additional biologically inspired features. A neuron has several states, and the state transitions follow endogenous patterns which roughly correspond to firing behavior observed in biological neurons: oscillatory, tonic, plateauing, etc. Neural interactions consist of two components: synaptic connections and extrasynaptic emission of neurotransmitters. The dynamics is asynchronous an...
Source: Biological Cybernetics - March 13, 2020 Category: Science Authors: Bazenkov NI, Boldyshev BA, Dyakonova V, Kuznetsov OP Tags: Biol Cybern Source Type: research

Editorial Board of Biological Cybernetics: Advances in Computational Neuroscience.
PMID: 32130493 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - March 4, 2020 Category: Science Authors: Stefanie D Tags: Biol Cybern Source Type: research

The effects of within-neuron degree correlations in networks of spiking neurons.
e C Abstract We consider the effects of correlations between the in- and out-degrees of individual neurons on the dynamics of a network of neurons. By using theta neurons, we can derive a set of coupled differential equations for the expected dynamics of neurons with the same in-degree. A Gaussian copula is used to introduce correlations between a neuron's in- and out-degree, and numerical bifurcation analysis is used determine the effects of these correlations on the network's dynamics. For excitatory coupling, we find that inducing positive correlations has a similar effect to increasing the coupling strength be...
Source: Biological Cybernetics - March 2, 2020 Category: Science Authors: Laing CR, Bläsche C Tags: Biol Cybern Source Type: research

Unstructured network topology begets order-based representation by privileged neurons.
In conclusion, we offer a minimal model for the representational role of pioneer neurons, as observed experimentally in vitro. In addition, we show that broadly heterogeneous connectivity enhances the representational capacity of unstructured networks. PMID: 32107622 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - February 27, 2020 Category: Science Authors: Bauermeister C, Keren H, Braun J Tags: Biol Cybern Source Type: research

Modeling of the neural mechanism underlying the terrestrial turning of the salamander.
Abstract In order to explore the neural mechanism underlying salamander terrestrial turning, an improved biomechanical model is proposed by modifying the forelimb structure of the existing biomechanical model. Based on the proposed improved biomechanical model, a new spinal locomotor network model is constructed which contains the interneuron networks and motoneuron pool. Control methods are also developed for the new model which increase its transient response speed, control the initial swing order of the forelimbs, and generate different walking turning gait and turning on the spot (turning without moving forwar...
Source: Biological Cybernetics - February 27, 2020 Category: Science Authors: Liu Q, Zhang Y, Wang J, Yang H, Hong L Tags: Biol Cybern Source Type: research

Real-time sensory-motor integration of hippocampal place cell replay and prefrontal sequence learning in simulated and physical rat robots for novel path optimization.
Abstract An open problem in the cognitive dimensions of navigation concerns how previous exploratory experience is reorganized in order to allow the creation of novel efficient navigation trajectories. This behavior is revealed in the "traveling salesrat problem" (TSP) when rats discover the shortest path linking baited food wells after a few exploratory traversals. We have recently published a model of navigation sequence learning, where sharp wave ripple replay of hippocampal place cells transmit "snippets" of the recent trajectories that the animal has explored to the prefrontal cortex (PFC)...
Source: Biological Cybernetics - February 24, 2020 Category: Science Authors: Cazin N, Scleidorovich P, Weitzenfeld A, Dominey PF Tags: Biol Cybern Source Type: research

Modeling awake hippocampal reactivations with model-based bidirectional search.
Abstract Hippocampal offline reactivations during reward-based learning, usually categorized as replay events, have been found to be important for performance improvement over time and for memory consolidation. Recent computational work has linked these phenomena to the need to transform reward information into state-action values for decision making and to propagate it to all relevant states of the environment. Nevertheless, it is still unclear whether an integrated reinforcement learning mechanism could account for the variety of awake hippocampal reactivations, including variety in order (forward and reverse re...
Source: Biological Cybernetics - February 17, 2020 Category: Science Authors: Khamassi M, Girard B Tags: Biol Cybern Source Type: research

Cortical stimulation in aphasia following ischemic stroke: toward model-guided electrical neuromodulation.
Abstract The aim of this paper is to integrate different bodies of research including brain traveling waves, brain neuromodulation, neural field modeling and post-stroke language disorders in order to explore the opportunity of implementing model-guided, cortical neuromodulation for the treatment of post-stroke aphasia. Worldwide according to WHO, strokes are the second leading cause of death and the third leading cause of disability. In ischemic stroke, there is not enough blood supply to provide enough oxygen and nutrients to parts of the brain, while in hemorrhagic stroke, there is bleeding within the enclosed ...
Source: Biological Cybernetics - February 4, 2020 Category: Science Authors: Beuter A, Balossier A, Vassal F, Hemm S, Volpert V Tags: Biol Cybern Source Type: research

Phase resetting and intermittent control at the edge of stability in a simple biped model generates 1/f-like gait cycle variability.
Abstract The 1/f-like gait cycle variability, characterized by temporal changes in stride-time intervals during steady-state human walking, is a well-documented gait characteristic. Such gait fractality is apparent in healthy young adults, but tends to disappear in the elderly and patients with neurological diseases. However, mechanisms that give rise to gait fractality have yet to be fully clarified. We aimed to provide novel insights into neuro-mechanical mechanisms of gait fractality, based on a numerical simulation model of biped walking. A previously developed heel-toe footed, seven-rigid-link biped model wit...
Source: Biological Cybernetics - January 20, 2020 Category: Science Authors: Fu C, Suzuki Y, Morasso P, Nomura T Tags: Biol Cybern Source Type: research

Establishing metrics and control laws for the learning process: ball and beam balancing.
This study provides an example of how mathematical analysis together with careful experimental observations can shed light onto the early stages of skill acquisition. Since the difficulty of this task depends on the length of the beam, ball and beam balancing tasks may be useful for the rehabilitation of children with dyspraxia and those recovering from a stroke. PMID: 31955261 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - January 18, 2020 Category: Science Authors: Buza G, Milton J, Bencsik L, Insperger T Tags: Biol Cybern Source Type: research

A computational model for spatial cognition combining dorsal and ventral hippocampal place field maps: multiscale navigation.
Abstract Classic studies have shown that place cells are organized along the dorsoventral axis of the hippocampus according to their field size, with dorsal hippocampal place cells having smaller field sizes than ventral place cells. Studies have also suggested that dorsal place cells are primarily involved in spatial navigation, while ventral place cells are primarily involved in context and emotional encoding. Additionally, recent work has shown that the entire longitudinal axis of the hippocampus may be involved in navigation. Based on the latter, in this paper we present a spatial cognition reinforcement learn...
Source: Biological Cybernetics - January 9, 2020 Category: Science Authors: Scleidorovich P, Llofriu M, Fellous JM, Weitzenfeld A Tags: Biol Cybern Source Type: research

An inverse optimization approach to understand human acquisition of kinematic coordination in bimanual fine manipulation tasks.
Abstract Tasks that require the cooperation of both hands and arms are common in human everyday life. Coordination helps to synchronize in space and temporally motion of the upper limbs. In fine bimanual tasks, coordination enables also to achieve higher degrees of precision that could be obtained from a single hand. We studied the acquisition of bimanual fine manipulation skills in watchmaking tasks, which require assembly of pieces at millimeter scale. It demands years of training. We contrasted motion kinematics performed by novice apprentices to those of professionals. Fifteen subjects, ten novices and five ex...
Source: Biological Cybernetics - January 6, 2020 Category: Science Authors: Yao K, Billard A Tags: Biol Cybern Source Type: research

Spiking time-dependent plasticity leads to efficient coding of predictions.
Abstract Latency reduction in postsynaptic spikes is a well-known effect of spiking time-dependent plasticity. We expand this notion for long postsynaptic spike trains on single neurons, showing that, for a fixed input spike train, STDP reduces the number of postsynaptic spikes and concentrates the remaining ones. Then, we study the consequences of this phenomena in terms of coding, finding that this mechanism improves the neural code by increasing the signal-to-noise ratio and lowering the metabolic costs of frequent stimuli. Finally, we illustrate that the reduction in postsynaptic latencies can lead to the emer...
Source: Biological Cybernetics - December 24, 2019 Category: Science Authors: Vilimelis Aceituno P, Ehsani M, Jost J Tags: Biol Cybern Source Type: research

A neuromechanical model exploring the role of the common inhibitor motor neuron in insect locomotion.
Abstract In this work, we analyze a simplified, dynamical, closed-loop, neuromechanical simulation of insect joint control. We are specifically interested in two elements: (1) how slow muscle fibers may serve as temporal integrators of sensory feedback and (2) the role of common inhibitory (CI) motor neurons in resetting this integration when the commanded position changes, particularly during steady-state walking. Despite the simplicity of the model, we show that slow muscle fibers increase the accuracy of limb positioning, even for motions much shorter than the relaxation time of the fiber; this increase in accu...
Source: Biological Cybernetics - December 2, 2019 Category: Science Authors: Naris M, Szczecinski NS, Quinn RD Tags: Biol Cybern Source Type: research

The case for emulating insect brains using anatomical "wiring diagrams" equipped with biophysical models of neuronal activity.
The case for emulating insect brains using anatomical "wiring diagrams" equipped with biophysical models of neuronal activity. Biol Cybern. 2019 Nov 06;: Authors: Collins LT Abstract Developing whole-brain emulation (WBE) technology would provide immense benefits across neuroscience, biomedicine, artificial intelligence, and robotics. At this time, constructing a simulated human brain lacks feasibility due to limited experimental data and limited computational resources. However, I suggest that progress toward this goal might be accelerated by working toward an intermediate objective, namely...
Source: Biological Cybernetics - November 6, 2019 Category: Science Authors: Collins LT Tags: Biol Cybern Source Type: research

Investigating the role of gap junctions in seizure wave propagation.
R, Mauro AJ Abstract The effect of gap junctions as well as the biological mechanisms behind seizure wave propagation is not completely understood. In this work, we use a simple neural field model to study the possible influence of gap junctions specifically on cortical wave propagation that has been observed in vivo preceding seizure termination. We consider a voltage-based neural field model consisting of an excitatory and an inhibitory population as well as both chemical and gap junction-like synapses. We are able to approximate important properties of cortical wave propagation previously observed in vivo befor...
Source: Biological Cybernetics - November 6, 2019 Category: Science Authors: González-Ramírez LR, Mauro AJ Tags: Biol Cybern Source Type: research

A neural model of schemas and memory encoding.
Abstract The ability to rapidly assimilate new information is essential for survival in a dynamic environment. This requires experiences to be encoded alongside the contextual schemas in which they occur. Tse et al. (Science 316(5821):76-82, 2007) showed that new information matching a preexisting schema is learned rapidly. To better understand the neurobiological mechanisms for creating and maintaining schemas, we constructed a biologically plausible neural network to learn context in a spatial memory task. Our model suggests that this occurs through two processing streams of indexing and representation, in which...
Source: Biological Cybernetics - November 4, 2019 Category: Science Authors: Hwu T, Krichmar JL Tags: Biol Cybern Source Type: research

Comparative study of forced oscillators for the adaptive generation of rhythmic movements in robot controllers.
aff P Abstract The interest of central pattern generators in robot motor coordination is universally recognized so much so that a lot of possibilities on different scales of modeling are nowadays available. While each method obviously has its advantages and drawbacks, some could be more suitable for human-robot interactions. In this paper, we compare three oscillator models: Matsuoka, Hopf and Rowat-Selverston models. These models are integrated to a control architecture for a robotic arm and evaluated in simulation during a simplified handshaking interaction which involves constrained rhythmic movements. Furtherm...
Source: Biological Cybernetics - October 1, 2019 Category: Science Authors: Jouaiti M, Hénaff P Tags: Biol Cybern Source Type: research

NeuroSLAM: a brain-inspired SLAM system for 3D environments.
Abstract Roboticists have long drawn inspiration from nature to develop navigation and simultaneous localization and mapping (SLAM) systems such as RatSLAM. Animals such as birds and bats possess superlative navigation capabilities, robustly navigating over large, three-dimensional environments, leveraging an internal neural representation of space combined with external sensory cues and self-motion cues. This paper presents a novel neuro-inspired 4DoF (degrees of freedom) SLAM system named NeuroSLAM, based upon computational models of 3D grid cells and multilayered head direction cells, integrated with a vision s...
Source: Biological Cybernetics - September 30, 2019 Category: Science Authors: Yu F, Shang J, Hu Y, Milford M Tags: Biol Cybern Source Type: research

Generalised free energy and active inference.
Abstract Active inference is an approach to understanding behaviour that rests upon the idea that the brain uses an internal generative model to predict incoming sensory data. The fit between this model and data may be improved in two ways. The brain could optimise probabilistic beliefs about the variables in the generative model (i.e. perceptual inference). Alternatively, by acting on the world, it could change the sensory data, such that they are more consistent with the model. This implies a common objective function (variational free energy) for action and perception that scores the fit between an internal mod...
Source: Biological Cybernetics - September 27, 2019 Category: Science Authors: Parr T, Friston KJ Tags: Biol Cybern Source Type: research

A generic deviance detection principle for cortical On/Off responses, omission response, and mismatch negativity.
TR Abstract Neural responses to sudden changes can be observed in many parts of the sensory pathways at different organizational levels. For example, deviants that violate regularity at various levels of abstraction can be observed as simple On/Off responses of individual neurons or as cumulative responses of neural populations. The cortical deviance-related responses supporting different functionalities (e.g., gap detection, chunking, etc.) seem unlikely to arise from different function-specific neural circuits, given the relatively uniform and self-similar wiring patterns across cortical areas and spatial scale...
Source: Biological Cybernetics - August 19, 2019 Category: Science Authors: Chien VSC, Maess B, Knösche TR Tags: Biol Cybern Source Type: research

A theory of consciousness: computation, algorithm, and neurobiological realization.
Abstract The most enigmatic aspect of consciousness is the fact that it is felt, as a subjective sensation. The theory proposed here aims to explain this particular aspect. The theory encompasses both the computation that is presumably involved and the way in which that computation may be realized in the brain's neurobiology. It is assumed that the brain makes an internal estimate of an individual's own evolutionary fitness, which can be shown to produce a special, distinct form of causation. Communicating components of the fitness estimate (either for external or for internal use) requires inverting them. Such in...
Source: Biological Cybernetics - July 9, 2019 Category: Science Authors: van Hateren JH Tags: Biol Cybern Source Type: research

Frequency-dependent responses of neuronal models to oscillatory inputs in current versus voltage clamp.
Abstract Action potential generation in neurons depends on a membrane potential threshold and therefore on how subthreshold inputs influence this voltage. In oscillatory networks, for example, many neuron types have been shown to produce membrane potential ([Formula: see text]) resonance: a maximum subthreshold response to oscillatory inputs at a nonzero frequency. Resonance is usually measured by recording [Formula: see text] in response to a sinusoidal current ([Formula: see text]), applied at different frequencies (f), an experimental setting known as current clamp (I-clamp). Several recent studies, however, us...
Source: Biological Cybernetics - July 8, 2019 Category: Science Authors: Rotstein HG, Nadim F Tags: Biol Cybern Source Type: research

Information processing in the LGN: a comparison of neural codes and cell types.
Abstract To understand how anatomy and physiology allow an organism to perform its function, it is important to know how information that is transmitted by spikes in the brain is received and encoded. A natural question is whether the spike rate alone encodes the information about a stimulus (rate code), or additional information is contained in the temporal pattern of the spikes (temporal code). Here we address this question using data from the cat Lateral Geniculate Nucleus (LGN), which is the visual portion of the thalamus, through which visual information from the retina is communicated to the visual cortex. W...
Source: Biological Cybernetics - June 26, 2019 Category: Science Authors: Pregowska A, Casti A, Kaplan E, Wajnryb E, Szczepanski J Tags: Biol Cybern Source Type: research

An insect-inspired model for acquiring views for homing.
l W Abstract Wasps and bees perform learning flights when leaving their nest or food locations for the first time during which they acquire visual information that enables them to return successfully. Here we present and test a set of simple control rules underlying the execution of learning flights that closely mimic those performed by ground-nesting wasps. In the simplest model, we assume that the angle between flight direction and the nest direction as seen from the position of the insect is constant and only flips sign when pivoting direction around the nest is changed, resulting in a concatenation of piecewis...
Source: Biological Cybernetics - May 10, 2019 Category: Science Authors: Schulte P, Zeil J, Stürzl W Tags: Biol Cybern Source Type: research

Modeling of spike trains in auditory nerves with self-exciting point processes of the von Mises type.
This article presents the modeling of spike trains in auditory nerve fiber (ANF) models with a one-memory self-exciting point process (SEPP) of the von Mises type. The ANF models were acoustically stimulated by a synaptic current of inner hair cells, or electrically stimulated by sinusoidally amplitude-modulated pulsatile waveforms. It has been shown that the parameters of one-memory SEPP of the von Mises type could be estimated by numerically maximizing the likelihood function from sample realizations of the spike trains in response to acoustic or electric stimulus. Furthermore, it was found that period histograms of the ...
Source: Biological Cybernetics - April 19, 2019 Category: Science Authors: Mino H Tags: Biol Cybern Source Type: research

Tutorial and simulations with ADAM: an adaptation and anticipation model of sensorimotor synchronization.
Abstract Interpersonal coordination of movements often involves precise synchronization of action timing, particularly in expert domains such as ensemble music performance. According to the adaptation and anticipation model (ADAM) of sensorimotor synchronization, precise yet flexible interpersonal coordination is supported by reactive error correction mechanisms and anticipatory mechanisms that exploit systematic patterns in stimulus timing to plan future actions. Here, we provide a tutorial introduction to the computational architecture of ADAM and present a series of single- and dual-virtual agent simulations th...
Source: Biological Cybernetics - April 8, 2019 Category: Science Authors: Harry B, Keller PE Tags: Biol Cybern Source Type: research

An unsupervised neuromorphic clustering algorithm.
Abstract Brains perform complex tasks using a fraction of the power that would be required to do the same on a conventional computer. New neuromorphic hardware systems are now becoming widely available that are intended to emulate the more power efficient, highly parallel operation of brains. However, to use these systems in applications, we need "neuromorphic algorithms" that can run on them. Here we develop a spiking neural network model for neuromorphic hardware that uses spike timing-dependent plasticity and lateral inhibition to perform unsupervised clustering. With this model, time-invariant, rate-...
Source: Biological Cybernetics - April 3, 2019 Category: Science Authors: Diamond A, Schmuker M, Nowotny T Tags: Biol Cybern Source Type: research

Explaining event-related fields by a mechanistic model encapsulating the anatomical structure of auditory cortex.
We present predictions for testing to what degree subject-specificity is due to cross-subject variations in dynamical parameters rather than in the cortical surface morphology. PMID: 30820663 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - February 28, 2019 Category: Science Authors: Hajizadeh A, Matysiak A, May PJC, König R Tags: Biol Cybern Source Type: research

Evaluation of connectivity estimates using spiking neuronal network models.
Abstract The flow of information between different regions of the cortex is fundamental for brain function. Researchers use causality detection techniques, such as Granger causality, to infer connectivity among brain areas from time series. Generalized partial directed coherence (GPDC) is a frequency domain linear method based on vector autoregressive model, which has been applied in electroencephalography, local field potential, and blood oxygenation level-dependent signals. Despite its widespread usage, previous attempts to validate GPDC use oversimplified simulated data, which do not reflect the nonlinearities ...
Source: Biological Cybernetics - February 19, 2019 Category: Science Authors: Nunes RV, Reyes MB, de Camargo RY Tags: Biol Cybern Source Type: research

A process account of the uncontrolled manifold structure of joint space variance in pointing movements.
r G Abstract In many situations, the human movement system has more degrees of freedom than needed to achieve a given movement task. Martin et al. (Neural Comput 21(5):1371-1414, 2009) accounted for signatures of such redundancy like self-motion and motor equivalence in a process model in which a neural oscillator generated timed end-effector virtual trajectories that a neural dynamics transformed into joint virtual trajectories while decoupling task-relevant and task-irrelevant combinations of joint angles. Neural control of muscle activation and the biomechanical dynamics of the arm were taken into account. The ...
Source: Biological Cybernetics - February 15, 2019 Category: Science Authors: Martin V, Reimann H, Schöner G Tags: Biol Cybern Source Type: research

Emergence of cognitive priming and structure building from the hierarchical interaction of canonical microcircuit models.
In this study, we establish minimal canonical microcircuit models as elements of hierarchical processing networks. Based on a combination of descriptive time simulations and explanatory state-space mappings, we show that minimal canonical microcircuits effectively segregate feedforward and feedback information flows and that feedback information conditions basic processing operations in minimal canonical microcircuits. Further, we derive and examine two prototypical meta-circuits of cooperating minimal canonical microcircuits for the neurocognitive problems of priming and structure building. Through the application of thes...
Source: Biological Cybernetics - February 14, 2019 Category: Science Authors: Kunze T, Haueisen J, Knösche TR Tags: Biol Cybern Source Type: research

Extracellular GABA assisting in organizing dynamic cell assemblies to shorten reaction time to sensory stimulation.
Abstract Until recently, glia, which exceeds the number of neurons, was considered to only have supportive roles in the central nervous system, providing homeostatic controls and metabolic supports. However, recent studies suggest that glia interacts with neurons and plays active roles in information processing within neuronal circuits. To elucidate how glia contributes to neuronal information processing, we simulated a sensory neuron-glia (neuron-astrocyte) network model. It was investigated in association with ambient (extracellular) GABA level, because the astrocyte has a major role in removing extracellular GA...
Source: Biological Cybernetics - February 12, 2019 Category: Science Authors: Sakamoto R, Kameno R, Kobayashi T, Ishiyama A, Watanabe K, Hoshino O Tags: Biol Cybern Source Type: research

Control theory in biology and medicine : Introduction to the special issue.
Abstract From September-December 2017, the Mathematical Biosciences Institute at Ohio State University hosted a series of workshops on control theory in biology and medicine, including workshops on control and modulation of neuronal and motor systems, control of cellular and molecular systems, control of disease / personalized medicine across heterogeneous populations, and sensorimotor control of animals and robots. This special issue presents tutorials and research articles by several of the participants in the MBI workshops. PMID: 30701314 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - January 30, 2019 Category: Science Authors: Thomas PJ, Olufsen M, Sepulchre R, Iglesias PA, Ijspeert A, Srinivasan M Tags: Biol Cybern Source Type: research

Editorial Board of Biological Cybernetics: Advances in Computational Neuroscience.
Abstract PMID: 30659361 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - January 19, 2019 Category: Science Authors: Stefanie D Tags: Biol Cybern Source Type: research

Representation of object's shape by multiple electric images in electrolocation.
Abstract Weakly electric fish generate an electric field by discharging an electric organ located on the tail region. An object near the fish modulates the self-generated electric field. The modulated field enables the fish to perceive objects even in complete darkness. The ability to perceive objects is provided by the electrosensory system of the fish. Electroreceptors distributed on the fish's skin surface can sense the modulated field, on the basis of transdermal voltage across the skin surface, called electric images. The fish can extract object's features such as lateral distance, size, shape, and electric p...
Source: Biological Cybernetics - January 10, 2019 Category: Science Authors: Fujita K, Kashimori Y Tags: Biol Cybern Source Type: research

A review on animal-robot interaction: from bio-hybrid organisms to mixed societies.
Abstract Living organisms are far superior to state-of-the-art robots as they have evolved a wide number of capabilities that far encompass our most advanced technologies. The merging of biological and artificial world, both physically and cognitively, represents a new trend in robotics that provides promising prospects to revolutionize the paradigms of conventional bio-inspired design as well as biological research. In this review, a comprehensive definition of animal-robot interactive technologies is given. They can be at animal level, by augmenting physical or mental capabilities through an integrated technolog...
Source: Biological Cybernetics - November 14, 2018 Category: Science Authors: Romano D, Donati E, Benelli G, Stefanini C Tags: Biol Cybern Source Type: research

Parameter subset selection techniques for problems in mathematical biology.
This study demonstrates that methods based on local sensitivities are preferable in terms of computational cost and model fit when good initial parameter values are available, but that global methods should be considered when initial parameter value is not known or poorly understood. For global sensitivity analysis, Morris screening provides results in terms of parameter sensitivity ranking at a much lower computational cost. PMID: 30377765 [PubMed - as supplied by publisher] (Source: Biological Cybernetics)
Source: Biological Cybernetics - October 30, 2018 Category: Science Authors: Olsen CH, Ottesen JT, Smith RC, Olufsen MS Tags: Biol Cybern Source Type: research

An optimal control approach for blood pressure regulation during head-up tilt.
Abstract This paper presents an optimal control approach to modeling effects of cardiovascular regulation during head-up tilt (HUT). Many patients who suffer from dizziness or light-headedness are administered a head-up tilt test to explore potential deficits within the autonomic control system, which maintains the cardiovascular system at homeostasis. This system is complex and difficult to study in vivo, and thus we propose to use mathematical modeling to achieve a better understanding of cardiovascular regulation during HUT. In particular, we show the feasibility of using optimal control theory to compute physi...
Source: Biological Cybernetics - October 30, 2018 Category: Science Authors: Williams ND, Mehlsen J, Tran HT, Olufsen MS Tags: Biol Cybern Source Type: research

Human-like hopping in machines : Feedback- versus feed-forward-controlled motions.
Abstract Template models of legged locomotion are powerful tools for gait analysis, but can also inspire robot design and control. In this paper, a spring-loaded inverted pendulum (SLIP) model is employed to control vertical hopping of a 2-segmented legged robot. Feed-forward and bio-inspired virtual model control using the SLIP model are compared. In the latter approach, the feedback control emulates a virtual spring between hip and foot. The results demonstrate similarity of human and robot hopping. Moreover, the feedback control proves to simplify and improve hopping control. It yields better perturbation recov...
Source: Biological Cybernetics - October 28, 2018 Category: Science Authors: Oehlke J, Beckerle P, Seyfarth A, Sharbafi MA Tags: Biol Cybern Source Type: research

Deep active inference.
r K Abstract This work combines the free energy principle and the ensuing active inference dynamics with recent advances in variational inference in deep generative models, and evolution strategies to introduce the "deep active inference" agent. This agent minimises a variational free energy bound on the average surprise of its sensations, which is motivated by a homeostatic argument. It does so by optimising the parameters of a generative latent variable model of its sensory inputs, together with a variational density approximating the posterior distribution over the latent variables, given its observat...
Source: Biological Cybernetics - October 22, 2018 Category: Science Authors: Ueltzhöffer K Tags: Biol Cybern Source Type: research

Auditory gap detection: psychometric functions and insights into the underlying neural activity.
Abstract The detection of a silent interval or gap provides important insight into temporal processing by the auditory system. Previous research has uncovered a multitude of empirical findings leaving the mechanism of gap detection poorly understood and key issues unresolved. Here, we expand the findings by measuring psychometric functions for a number of conditions including both across-frequency and across-intensity gap detection as a first study of its kind. A model is presented which not only accounts for our findings in a quantitative manner, but also helps frame the body of work on auditory gap research. The...
Source: Biological Cybernetics - October 20, 2018 Category: Science Authors: Mori S, Kikuchi Y, Hirose N, Lepage H, Wong W Tags: Biol Cybern Source Type: research

Non-monotonic accumulation of spike time variance during membrane potential oscillations.
Abstract A spike-phase neural code has been proposed as a mechanism to encode stimuli based on the precise timing of spikes relative to the phase of membrane potential oscillations. This form of coding has been reported in both in vivo and in vitro experiments across several regions of the brain, yet there are concerns that such precise timing may be compromised by an effect referred to as variance accumulation, wherein spike timing variance increases over the phase of an oscillation. Here, we provide a straightforward explanation of this effect based on the theoretical spike time variance. The proposed theory is ...
Source: Biological Cybernetics - October 5, 2018 Category: Science Authors: Kuebler ES, Calderini M, Longtin A, Bent N, Vincent-Lamarre P, Thivierge JP Tags: Biol Cybern Source Type: research

Cardiovascular regulation in response to multiple hemorrhages: analysis and parameter estimation.
Abstract Mathematical models can provide useful insights explaining behavior observed in experimental data; however, rigorous analysis is needed to select a subset of model parameters that can be informed by available data. Here we present a method to estimate an identifiable set of parameters based on baseline left ventricular pressure and volume time series data. From this identifiable subset, we then select, based on current understanding of cardiovascular control, parameters that vary in time in response to blood withdrawal, and estimate these parameters over a series of blood withdrawals. These time-varying p...
Source: Biological Cybernetics - September 12, 2018 Category: Science Authors: Ciocanel MV, Docken SS, Gasper RE, Dean C, Carlson BE, Olufsen MS Tags: Biol Cybern Source Type: research

Phase reduction and phase-based optimal control for biological systems: a tutorial.
Abstract A powerful technique for the analysis of nonlinear oscillators is the rigorous reduction to phase models, with a single variable describing the phase of the oscillation with respect to some reference state. An analog to phase reduction has recently been proposed for systems with a stable fixed point, and phase reduction for periodic orbits has recently been extended to take into account transverse directions and higher-order terms. This tutorial gives a unified treatment of such phase reduction techniques and illustrates their use through mathematical and biological examples. It also covers the use of pha...
Source: Biological Cybernetics - September 10, 2018 Category: Science Authors: Monga B, Wilson D, Matchen T, Moehlis J Tags: Biol Cybern Source Type: research

Cellular switches orchestrate rhythmic circuits.
Abstract Small inhibitory neuronal circuits have long been identified as key neuronal motifs to generate and modulate the coexisting rhythms of various motor functions. Our paper highlights the role of a cellular switching mechanism to orchestrate such circuits. The cellular switch makes the circuits reconfigurable, robust, adaptable, and externally controllable. Without this cellular mechanism, the circuit rhythms entirely rely on specific tunings of the synaptic connectivity, which makes them rigid, fragile, and difficult to control externally. We illustrate those properties on the much studied architecture of a...
Source: Biological Cybernetics - September 3, 2018 Category: Science Authors: Drion G, Franci A, Sepulchre R Tags: Biol Cybern Source Type: research

A normative approach to neuromotor control.
Abstract While we can readily observe and model the dynamics of our limbs, analyzing the neurons that drive movement is not nearly as straightforward. As a result, their role in motor behavior (e.g., forward models, state estimators, controllers, etc.) remains elusive. Computational explanations of electrophysiological data often rely on firing rate models or deterministic spiking models. Yet neither can accurately describe the interactions of neurons that issue spikes, probabilistically. Here we take a normative approach by designing a probabilistic spiking network to implement LQR control for a limb model. We fi...
Source: Biological Cybernetics - September 3, 2018 Category: Science Authors: Berniker M, Penny S Tags: Biol Cybern Source Type: research

Improved lower bound for the mutual information between signal and neural spike count.
Abstract The mutual information between a stimulus signal and the spike count of a stochastic neuron is in many cases difficult to determine. Therefore, it is often approximated by a lower bound formula that involves linear correlations between input and output only. Here, we improve the linear lower bound for the mutual information by incorporating nonlinear correlations. For the special case of a Gaussian output variable with nonlinear signal dependencies of mean and variance we also derive an exact integral formula for the full mutual information. In our numerical analysis, we first compare the linear and nonli...
Source: Biological Cybernetics - August 28, 2018 Category: Science Authors: Voronenko SO, Lindner B Tags: Biol Cybern Source Type: research