The nucleus accumbens and medial frontal cortex (MFC) are part of a loop involved in modulating behavior according to anticipated rewards. However, the precise temporal landscape of their electrophysiological interactions in humans remains unknown because it is not possible to record neural activity from the nucleus accumbens using noninvasive techniques. ...
PubMed
Spatially separated populations of many species fluctuate synchronously. Synchrony typically decays with increasing interpopulation distance. Spatial synchrony, and its distance decay, might reflect distance decay of environmental synchrony (the Moran effect), and/or short-distance dispersal. However, short-distance dispersal can ...
Long-term meditators self-induce high-amplitude gamma synchrony during mental practice Antoine Lutz, Princeton, NJ, October 6, 2004 (received for review August 26, 2004) Practitioners understand ``meditation-amplitude gamma-band oscillations and phase-synchrony during meditation. These electroencephalogram patterns
E-print Network
Analysis of S phase events requires the ability to synchronize the cell cycle for subsequent physiological or molecular analysis. The cell cycle can be arrested at different stages, using drugs or temperature-sensitive mutations, and then released (block and release). These methods offer high levels of synchrony. Synchrony is lower in ...
We study the phenomenon of cluster synchrony that occurs in ensembles of coupled phase oscillators when higher-order modes dominate the coupling between oscillators. For the first time, we develop a complete analytic description of the dynamics in the limit of a large number of oscillators and use it to quantify the degree of cluster ...
NASA Astrophysics Data System (ADS)
We consider the nonlinear extension of the Kuramoto model of globally coupled phase oscillators where the phase shift in the coupling function depends on the order parameter. A bifurcation analysis of the transition from fully synchronous state to partial synchrony is performed. We demonstrate that for small ensembles it is typically ...
The nucleus accumbens is critical for reward-guided learning and decision-making. It is thought to "gate" the flow of a diverse range of information (e.g., rewarding, aversive, and novel events) from limbic afferents to basal ganglia outputs. Gating and information encoding may be achieved via cross-frequency coupling, in which bursts of high-frequency activity occur ...
ERIC Educational Resources Information Center
Brain development is characterized by maturational processes that span the period from childhood through adolescence to adulthood, but little is known whether and how developmental processes differ during these phases. We analyzed the development of functional networks by measuring neural synchrony in EEG recordings during a Gestalt perception task in 68 ...
PubMed Central
for their usefulness in the discrimination between non-ADHD and ADHD children. We observed that phase synchrony is higher � on average � for non-ADHD participants than for the ADHD group. Based on the relatively small electrode pairs, EEG rhythm, and task � discriminate between the EEG of non-ADHD and ADHD children
Visual working memory (VWM) is used to maintain sensory information for cognitive operations, and its deficits are associated with several neuropsychological disorders. VWM is based on sustained neuronal activity in a complex cortical network of frontal, parietal, occipital, and temporal areas. The neuronal mechanisms that coordinate this distributed processing to sustain coherent mental images ...
Coherent cognition requires activity to be brought together across diverse brain networks. Synchronous, in-phase oscillations in the high-frequency (40 Hz) Gamma range are thought to be one mechanism underlying the functional integration of brain networks. While sex differences have been observed across a range of cognitive functions, their role in normal cortical ...
Signal transmission time delays in a network of nonlinear oscillators are known to be responsible for a variety of interesting dynamic behaviors including phase-flip transitions leading to synchrony or out of synchrony. Here, we uncover that phase-flip transitions are general phenomena and can occur in a network of ...
How do animals distinguish between sensations coming from external sources and those resulting from their own actions? A corollary discharge system has evolved that involves the transmission of a copy of motor commands to sensory cortex, where the expected sensation is generated. Through this mechanism, sensations are tagged as coming from self, and responsiveness to them is minimized. The present ...
The chirp-evoked ABR has been termed a more synchronous response, referring to the fact that rising-frequency chirp stimuli theoretically compensate for temporal dispersions down the basilar membrane. This compensation is made possible by delaying the higher frequency content of the stimulus until the lower frequency traveling waves are closer to the cochlea apex. However, it is not yet clear how ...
Eye-target synchrony is critical during smooth pursuit. We apply stochastic phase synchronization to human pursuit of a moving target, in both normal and mild traumatic brain injured (TBI) subjects. Smooth pursuit utilizes the same neural networks used by attention. To test whether smooth pursuit is modulated by attention, subjects tracked a target while ...
Muscarinic acetylcholine receptors in the nucleus accumbens play an important role in mediating the reinforcing effects of cocaine. However, there is a paucity of data regarding the role of accumbal muscarinic acetylcholine receptors in the reinstatement of cocaine-seeking behavior. The goal of these experiments was to assess the role of muscarinic acetylcholine receptors in ...
The temporal behavior of segmentation clock oscillations shows phase synchrony via mean field like coupling of delta protein restricting to nearest neighbors only, in a configuration of cells arranged in a regular three dimensional array. We found the increase of amplitudes of oscillating dynamical variables of the cells as the activation rate of ...
Experiments are carried out with three locally coupled phase coherent chaotic electrochemical oscillators (A-B-C) in nickel dissolution in sulfuric acid. As the interaction strength is increased among the electrodes, an onset of synchronization is observed where the frequencies become identical and the phase differences are bounded. The precision of the ...
Background- There are ongoing efforts to optimize patient selection criteria for cardiac resynchronization therapy (CRT). In this regard, the relationship between acute change in left ventricular synchrony (LV) after CRT and patient outcome remains undefined. Methods and Results- A novel protocol was designed to evaluate acute change in left LV synchrony ...
Research on continuous fermentation has produced a novel method for exploring and exploiting microbial cells. The new development, known as continuous phased growth, produces a continuous culture having most of the cells 'in synchrony', that is, doing the...
National Technical Information Service (NTIS)
for causality. Direct causal roles can be tested by manipulating the responses of the cortical neurons. This has that they correspond physiologically to regular-spiking (RS) cells. We consider one class of inhibitory neurons). Gain Modulation Can Be Achieved by Modulating Inhibitory Synchrony and Phase The fluctuation
Synchrony among multicortical EEGs 2 Freeman, Ga�l & J�rnsten Information transfer and integration among functionally distinct areas of cerebral cortex of oscillatory activity requires some degree of phase synchrony of the trains of action potentials that carry the information prior to the integration. However, propagation ...
While oscillations of the local field potential (LFP) are commonly attributed to the synchronization of neuronal firing rate on the same time scale, their relationship to coincident spiking in the millisecond range is unknown. Here, we present experimental evidence to reconcile the notions of synchrony at the level of spiking and at the mesoscopic scale. We demonstrate that ...
Synchronous interactions arise in various animal species that rhythmically broadcast acoustic, vibratory, and visual signals. These interactions are characterized by a coincidence in both rate and phase of the rhythms of neighboring signalers. Theory predicts several ways in which synchronized rhythms may specifically benefit the interacting signalers. However, ...
Pattern formation in plants has to cope with ambient variability and therefore must integrate environmental cues such as light. Synchrony of cell divisions was previously observed in cell files of tobacco suspension cultures, which represents a simple case of pattern formation. To develop cellular approaches for light-dependent patterning, light-responsive tobacco cell lines ...
Rhythmic neural synchronization is found throughout the brain during many different tasks and even at rest. Beyond their underlying mechanisms, the question of their role is still controversial. Modeling can bring insight on this difficult question. We review here our recent modeling results concerning this issue in different situations. During rest, we show how local rhythmic ...
While previous research has demonstrated that people's movements can become coordinated during social interaction, little is known about the cognitive consequences of behavioral synchrony. Given intimate links between the systems that regulate perception and action, we hypothesized that the synchronization of movements during a dyadic interaction may prompt increased attention ...
We report on a self-emerging chimera state in a homogeneous chain of nonlocally and nonlinearly coupled oscillators. This chimera, i.e., a state with coexisting regions of complete and partial synchrony, emerges via a supercritical bifurcation from a homogeneous state. We develop a theory of chimera based on the Ott-Antonsen equations for the local complex order parameter. ...
Synchronous oscillatory dynamics is frequently observed in the human brain. We analyze the fine temporal structure of phase-locking in a realistic network model and match it with the experimental data from Parkinsonian patients. We show that the experimentally observed intermittent synchrony can be generated just by moderately increased coupling strength ...
Synchronous oscillatory dynamics is frequently observed in the human brain. We analyze the fine temporal structure of phase-locking in a realistic network model and match it with the experimental data from parkinsonian patients. We show that the experimentally observed intermittent synchrony can be generated just by moderately increased coupling strength ...
Individual wind turbine electrical output typically includes significant periodic content at multiples of the rotor rotational frequency. Qualitative field observations indicate groups of vertical or horizontal axis turbines in wind farms may assume frequency and phase synchrony of output fluctuation, with the result that individual turbine output ...
Energy Citations Database
Pairs of discharges of single motor units recorded in the same or different muscles often show synchronisation above chance levels. If large numbers of units are synchronous within and between muscles then the synchrony will be measurable in population recordings such as surface EMG. Measuring synchrony between surface EMG recordings has a number of ...
We propose a novel method of reconstructing the topology and interaction functions for a general oscillator network. An ensemble of initial phases and the corresponding instantaneous frequencies is constructed by repeating random phase resets of the system dynamics. The desired details of network structure are then revealed by appropriately averaging over ...
It has been proven that there are synchrony (or phase-locking) phenomena present in multiple oscillating systems such as electrical circuits, lasers, chemical reactions, and human neurons. If the measurements of these systems cannot detect the individual oscillators but rather a superposition of them, as in brain electrophysiological signals (electo{-} and ...
In this study, we proposed and evaluated the use of the empirical mode decomposition (EMD) technique combined with phase synchronization analysis to investigate the human brain synchrony of the supplementary motor area (SMA) and primary motor area (M1) during complex motor imagination of combined body and limb action. We separated the EEG data of the SMA ...
Computing phase-locking values between EEG signals is a popular method for quantifying functional connectivity. However, this method involves large-scale, high-resolution datasets, which impose a serious multiple testing problem. Standard multiple testing methods fail to exploit the information from the complex dependence structure that varies across hypotheses in spectral, ...
Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, the role of neural synchrony in cortical networks has been expanded to provide a general mechanism for the coordination of distributed neural activity patterns. In the current paper, we present an update of the status of this hypothesis through summarizing ...
The temporal coordination of interpersonal behavior is a foundation for effective joint action with synchronized movement moderating core components of person perception and social exchange. Questions remain, however, regarding the precise conditions under which interpersonal synchrony emerges. In particular, with whom do people reliably synchronize their movements? The ...
Recent experiments have shown that GABAA receptor mediated inhibition in adult hippocampus is shunting rather than hyperpolarizing. Simulation studies of realistic interneuron networks with strong shunting inhibition have been demonstrated to exhibit robust gamma band (20�80 Hz) synchrony in the presence of heterogeneity in the intrinsic firing rates ...
Systems theoretic tools (i.e. mathematical modelling, control, and feedback design) advance the understanding of robust performance in complex biological networks. We highlight phase entrainment as a key performance measure used to investigate dynamics of a single deterministic circadian oscillator for the purpose of generating insight into the behaviour of a population of ...
We apply an information-theoretic measure for phase synchrony to local field potentials recorded with a multi-electrode array implanted in area V4 of the monkey visual cortex during a reinforcement pairing experiment. We show for the first time that (1) the phase synchrony is significantly higher for the rewarded ...
The authors studied the interaction between rider and horse by measuring their ensemble motions in a trot sequence, comparing 1 expert and 1 novice rider. Whereas the novice�s movements displayed transient departures from phase synchrony, the expert�s motions were continuously phase-matched with those of the horse. The tight ...
Spatially synchronized fluctuations in system state are common in physical and biological systems ranging from individual atoms to species as diverse as viruses, insects and mammals. Although the causal factors are well known for many synchronized phenomena, several processes concurrently have an impact on spatial synchrony of species, making their separate effects and ...
In this paper, we present an optical stimulation based approach to induce 1:1 in-phase synchrony in a network of coupled interneurons wherein each interneuron expresses the light sensitive protein channelrhodopsin-2 (ChR2). We begin with a transition rate model for the channel kinetics of ChR2 in response to light stimulation. We then define "functional ...
The degree of synchronization in electroencephalography (EEG) signals is commonly characterized by the time-series measures, namely, correlation, phase synchrony, and magnitude squared coherence (MSC). However, it is now well established that the interpretation of the results from these measures are confounded by the recording reference signal and that ...
connected to screws set in the posterior skull to stabilize the dental acrylic mounting for attaching the 64. Buprenorphine and Baytril antibiotic were given for 5 days postoperatively. Placements were verified by dorsal transient episodes of phase stabilization or convergence to zero phase differences between the sensory areas
The phase-synchronization of Gamma-band oscillations has been postulated as a mechanism of "network binding" and implicated in various aspects of perception, memory, and cognition. The current study investigates a possible link between Gamma synchrony and individual differences in intelligence within the theory of fluid and crystallized intelligence, with ...
Climatically driven Moran effects have often been invoked as the most likely cause of regionally synchronized outbreaks of insect herbivores without identifying the exact mechanism. However, the degree of match between host plant and larval phenology is crucial for the growth and survival of many spring-feeding pest insects, suggesting that a phenological match/mismatch-driven Moran effect may act ...
Glutamate Transmission in the Nucleus Accumbens Mediates Relapse in Cocaine Addiction Jennifer L Carolina, Charleston, South Carolina 29425 Elevated dopamine transmission in the nucleus accumbens in the nucleus accumbens, is a primary mediator of cocaine- induced reinstatement of drug-seeking behavior
Pulse coupled oscillators (PCOs) represent an ubiquitous model for a number of physical and biological systems. Phase response curves (PRCs) provide a general mathematical framework to analyze patterns of synchrony generated within these models. A general theoretical approach to account for the nonlinear contributions from higher-order PRCs in the ...
Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible ...
The mechanism of phase synchronization between uncoupled limit-cycle oscillators induced by common random impulsive forcing is analyzed. By reducing the dynamics of the oscillator to a random phase map, it is shown that phase synchronization generally occurs when the oscillator is driven by weak random impulsive forcing in the limit of ...
... GLU projections from the neo- or allocortex have been found to terminate in nucleus accumbens and other forebrain and hypothalamic nuclei. ...
DTIC Science & Technology
Combined activation of dopamine D1- and NMDA-glutamate receptors in the nucleus accumbens has been strongly implicated in instrumental learning, the process in which an individual learns that a specific action has a wanted outcome. To assess dopaminergic activity, we presented rats with two sessions (30 trials each) of a one-lever appetitive instrumental task and ...
Synchronization analysis of multitrial EEG or (magneto encephalogram) MEG signals is an excellent approach to detect functional connectivity between different neuronal oscillators. In our current research, the n:m phase synchronization index (n:m PSI ) is of special interest. We prove the existence of stable and unstable synchronies dependent upon the ...
Objects are more easily recognized in their typical context. However, is contextual information activated early enough to facilitate the perception of individual objects, or is contextual facilitation caused by postperceptual mechanisms? To elucidate this issue, we first need to study the temporal dynamics and neural interactions associated with contextual processing. Studies have shown that the ...
OBJECTIVE: To investigate abnormal phase on susceptibility-weighted imaging (SWI)-filtered phase images indicative of iron content, in subcortical deep-gray matter (SDGM) of multiple sclerosis (MS) patients and healthy controls (HC), and to explore its relationship with MRI outcomes. METHODS: 169 relapsing-remitting (RR) and 64 secondary-progressive (SP) ...
This study investigated the influence of individual differences in attentional impulsivity (Att-Imp), learning ability, and learning practice on oscillatory activity and phase synchrony responses to monetary gain and loss signals during an instrumental-learning task in healthy women. We used a trial-by-trial wavelet-based time-frequency analysis of the ...
During slow-wave sleep, the brain shows slow oscillatory activity with remarkable long-range synchrony. Intracellular recordings show that the slow oscillation consists of two phases: an textit{up} state and a textit{down} state. Deriving the phase-response function of simplified neuronal systems, we examine the synchronization ...
Three-body interactions have been found in physics, biology, and sociology. To investigate their effect on dynamical systems, as a first step, we study numerically and theoretically a system of phase oscillators with a three-body interaction. As a result, an infinite number of multistable synchronized states appear above a critical coupling strength, while a stable incoherent ...
. We pre- viously reported that intensive mental training in a style of meditation aimed at reducing that 3 months of in- tensive training in a style of meditation, which allegedly reduces elaborate object., 2007). This common style of open monitoring (OM) meditation, also known as Vipassana meditation
. We pre- viously reported that intensive mental training in a style of meditation aimed at reducing found that 3 months of in- tensive training in a style of meditation, which allegedly reduces elaborate (Slagter et al., 2007). This common style of open monitoring (OM) meditation, also known as Vipassana
We show that for pulse-coupled oscillators a class of phase response curves with both excitation and inhibition exhibit robust convergence to synchrony on arbitrary aperiodic connected graphs with delays. We describe the basins of convergence and give explicit bounds on the convergence times. These results provide new and more robust methods for ...
attention through phase relationship of excitatory and inhibitory input synchrony in a model cortical neuron representation of the excitatory and inhibitory synaptic inputs projecting onto the multicompartmental V 4 neuron 2). The V 4 neuron also received continuous uncorrelated background excitatory and inhibitory
within the framework of the Hodgkin- Huxley formalism CVi = F Vi,hi,mi - gs Vi - Es Vj - syn , hhi = G Vi. 5. Color online Stability islands for in-phase synchroni- zation in the syn, gs -parameter diagram. Level curves of the Lyapunov exponent Lmax show two large islands of stable syn- chrony, where Lmax 0
Patients with hypertrophic cardiomyopathy (HCM) may have delayed septal activation and left ventricular (LV) mechanical dyssynchrony, and may improve after alcohol septal ablation (ASA). This study used phase analysis of gated SPECT myocardial perfusion imaging (MPI) to evaluate septal activation and LV dyssynchrony in HCM patients pre- and post-ASA. Phase ...
of this disorder in adulthood [16]. It has also been shown that, undiagnosed in childhood, ADHD may be successfully shows that the average PS is higher � for a number of electrode pairs � for non-ADHD than for ADHD. The Euclidean classifier with electrode masking yields 66 % correct classification on average for ADHD and non-ADHD
on the basis of his data that the ground beat changes from phrase to phrase. Leaving aside for the moment what it means for, say, 19 ground beats to occur in a phrase containing 24 nominal beats. Surely representations), the phrase boundary occurs after 24 beats, not 19. Even though Epstein discusses metrical
The abundance of Canadian lynx follows 10-year density fluctuations across the Canadian subcontinent. These cyclic fluctuations have earlier been shown to be geographically structured into three climatic regions: the Atlantic, Continental, and Pacific zones. Recent genetic evidence revealed an essentially similar spatial structuring. Introducing a new population model, the �climate forcing of ...
Recent studies have shown that audiovisual synchrony is recalibrated after exposure to asynchronous auditory and visual signals. This temporal recalibration has been shown only under a dual-task situation for speech signals. Here we examined whether the temporal recalibration occurs for audiovisual speech in a single-task situation using an offline adaptation method. In the ...
This protocol defines conditions under which the germination of spores can be used to synchronize Bacillus subtilis cells, utilizing the time-ordered sequence of events taking place during the transition from spore to vegetative cells. The transition stages involve: phase change, swelling, emergence, initial division, and elongation. By using this method we have obtained two ...
We study directional relationships�in the driver-responder sense�in networks of coupled nonlinear oscillators using a phase modeling approach. Specifically, we focus on the identification of drivers in clusters with varying levels of synchrony, mimicking dynamical interactions between the seizure generating region (epileptic focus) and other brain ...
... dispersal was likely underlying within-lake synchrony but climate was more likely underlying between-lake synchrony. The broad scale of synchrony in Great Lakes bloater populations increases their probabil...
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