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The purpose of this study is to discriminate mild Alzheimer’s disease (AD) patients from the normal aging. The EEG coherence was applied to analyze the data from auditory oddball paradigm to discriminate the differences of corticocortical connections between mild AD patients and healthy subjects. The results showed that the lower values of coherence were performed in mild AD patients than in the normal aging subjects, especially in theta band. The implications and suggestions are shown in this study.

Recent changes in ongoing background activity are one of the most popular approaches to investigate brain activity for understanding child development. However, research using event-related responses of cortico-cortical connections to explore changes during childhood is rare. This study investigates mature changes in brain connectivity in associative reorganization patterns and hypothesizes that age-related changes affect oscillatory connections. The sample included children aged 7 years, 11 years, and adults. The 3 groups were studied in the time-frequency domain to analyze event-related cross phase coherence (ERPCOH) between different parts of the brain as they performed an auditory oddball task. Compared to the adult participants, the 11-year-old participants were found to have increased connectivity in theta (4-7 Hz), beta-2 (20-30 Hz), and gamma bands (30-50 Hz) in the early component (N1, 80-140 ms), although ERPCOH value decreased in the alpha-1 (7-10 Hz) and alpha-2 bands (10-13 Hz). Compared to the 11-year-old participants, 7-year-old participants had greater connectivity decreases in all frequency bands, most significantly in theta, beta-2, and gamma bands.

Brain dynamics is an important issue in understanding child development. However, very little research of the event-related responses has been used to explore changes during childhood. The aim of this study was to investigate mature changes in spatiotemporal organization of brain dynamics. We hypothesized that oscillatory event-related brain activity were affected by age-related changes. The sample include three age groups, namely 7 years (N = 18), 11 years (N = 18), and adults (N = 18). The event-related spectral power (ERPSP), and inter-trial phase locking (ITPL) of the event-related potentials (ERPs) were obtained from the time-frequency analysis of the auditory oddball task. Results revealed that: (a) decreased theta power, but alpha power increased with age; (b) the values of ITPL in the theta and alpha bands increased with age. These suggest that ERPSP, and ITPL provide useful indicators of cognitive maturation processes in children aged 7 and 11 years.

Auditory phase-synchronization near 40Hz is reportedly related to sensory stimulation. This study applied the phase synchrony analysis and Bi-coherence analyses to analyze the electroencephalographic measurements. Four experimental stages were conducted with 34 healthy high school students to collect the data: (A) resting with eyes closed, (B) listening to the classical music, (C) resting with eyes closed, and (D) listening to popular music. The result shows that the whole brain phase-synchronization occurs at 40Hz and lasts about 400 ms, which is quite different from the estimated 40Hz phase-coupling lasting about 20–25 ms in previous studies and seems to play an important role in inducing auditory attention loss. Additionally, the result also shows that hypersynchronous states may affect perceptual processing. This study develops an original nonlinear time serial analytical approach and suggests that 40Hz phase-synchronization might be an important indicator in perceptual process.

Mental rotation is an important psychological process for identifying rotated or misoriented objects. In this study, ERPs were recorded while 18 participants responded to two types of two-dimensional (2D) pictures. The participants matched the pictures of a blank Task without using mental rotation, but used mental rotation to match the pictures of Task A. The ERPs data were analyzed using spatial complexity analysis. The results showed: a) the rotation-related negativity of the ERPs data was shown when mental rotation was performed; b) the EEG data showed a significantly greater synchronization in the fast frequency bands (> 20 Hz) when the participants used their mental rotation ability.

The aim of this study was to apply frequency bands to explore how mental rotation strategies affect the identification of 2D figures. Eighteen adults were recruited for this study. In the ERP experiments, the participants were required to identify 2D figures with mental rotation. The results showed the differences between the high-achieving (HA) and low-achieving (LA) spatial ability participants in their use of mental rotation for identifying 2D figures. At 300-380 ms, the HA participants showed higher brain activity in the right hemisphere than in other brain areas, whereas the LA participants showed activity in the whole brain. At 520 to 620 ms, the areas of brain activity were in the opposite hemisphere for the HA and LA participants. The highest brain activity was shown in the left hemisphere of the HA participants and in the right hemisphere for the LA participants at 520 to 620 ms. The implication of this study is that right hemisphere specialization for mental rotation might appear in early cognitive processing, but in late cognitive processing, the left hemisphere specialization form of mental rotation might show an advantage.

Different from the previous studies, observing the various chaotic behaviors via modifying the resistance in Chua's Circuit, we perturb the plant capacitance which is imposed on Chua's Circuit and analyze the phenomenon by human body. In this work, We used plants to experienced outside stimulation, the phenomenon of chaotic suppression is found as a result when plants are slightly perturbed, namely, the capacitance of the plants would vary due to the effect of capacitive coupling from the outside world, ranging from 0∼100pF. Additionally, the results would potentially lead to further developments of measuring technology of micro-signals.

In this paper, we fulfill an idea, output will be equal to input, derived from zero-dispersion nonlinear resonance (ZDNR), and achieve the complete synchronization without modulating the coupling strength. Additionally, phase locking is also observed via inputting partial signal calculated on the basis of ZDNR. Besides, a section of fixed phase is used to observe the phase locking phenomenon resulting from the chaotic driver. The effectiveness and feasibility of our proposed scheme are demonstrated by Lorenz system.

The researches relevant to age-related changes have been the significant subject causing more and more attraction. This study is to investigate age-related changes of event-related potentials with detrended partial cross-correlation analysis (DPCCA) [11,12] to explore the discrimination between the young and the older. We hypothesized that the DPCCA coefficients were affected by age-related changes which could be reflected in the ERP indices, and differed with different neural communication. An oddball task was conducted in two experimental groups, the young (N=15) and the older (N=15), to analyze long-time coherence. The results show the difference of DPCCA coefficients from the young and the older. Moreover, this study provides some explanation and suggestion for these findings.

In this work we present experimental observation of self-mixing laser Doppler velocimetry (LDV) with laser-diode-pumped single-mode microchip Nd:YAG laser. The temporal waveforms are detected by oscilloscope, and proceed with Fourier transform spectrum analysis and local maximum analysis. The result displays the period transformation of intensity fluctuation which is observed via spectrum analysis and local maximum analysis.

Typically, the circuit realization of synchronization is to impose an external signal which is periodic on the response system. Herein we propose a novel study which is different from the previous methods using feedback to achieve synchronization. Our work is to make the individual inductance of two Chua's circuit systems produce mutual inductance effect, and achieve bidirectional coupling of two Chua's circuit systems. The synchronization phenomenon is observed successfully, and we demonstrate the analysis of phase synchronization further.

The aim of this study was to investigate changes in task-related brain oscillations and corticocortical connections in patients with mild cognitive impairment (MCI) and those with normal aging using cross-mutual information (CMI) analysis. We hypothesized that task-related brain oscillations and corticocortical connections were affected by age- and disease-related changes, which could be reflected in the CMI analysis. Electroencephalogram (EEG) recordings were measured in 16 MCI patients, 15 healthy age-matched controls, and 16 healthy younger individuals. The frequencies and interhemispheric CMI data were estimated in all groups. The specific EEG rhythms measured were delta (δ), theta (θ), alpha (α), beta (β), and gamma (γ) bands. Significant differences in δ, θ, α, and β bands were observed between the younger and elderly groups. However, only the θ band was significantly different between the elderly and MCI groups. Moreover, this study used EEG recordings to investigate age- and disease-related changes in the corticocortical connections of the brain. This study proves that the θ-band frequency of the connection between the parietal and occipital lobes for the age- and disease-related changes can be depicted using the CMI analysis.

In this Letter we demonstrate the experimental observation of chaotic phase synchronization (CPS) in a periodically pump-modulated multimode microchip Nd:YVO 4 laser. PS transition is displayed via the stroboscopic technique. We apply the recurrence probability and correlation probability of recurrence to estimate the degree of PS. The degree of PS is studied taking into account the modulation amplitude and modulation frequency. We also propose an experimental compatible numerical simulation to reflect the fact that the Arnold tongues are experimentally and numerically exhibited in the periodically pump-modulated multimode microchip Nd:YVO 4 laser.

During the past few years, many researchers have demonstrated the importance of the age-related changes in spontaneous electroencephalography. However, very little research on of the event-related responses of oscillations connections has been used to examine the changes during normal aging. The aim of the present study was to investigate age-related changes of task-related brain oscillations, which include spectral power and omega-complexity. We hypothesized that the power and omega-complexity of the brain are affected by age-related changes, which could be observed in this study. The samples included young and healthy elderly groups. Compared to young participants, elderly participants were found to have increased power in anterior area and decreased power in posterior area, and have shown a decreased power in the alpha-1 (7 - 10 Hz) and alpha-2 (10 - 13 Hz) bands and an increased power in the delta (1 - 4 Hz) band. Elderly participants were found to have increased omega-complexity in the anterior and posterior brain areas, and have shown an increased omega-complexity in the alpha-2, beta-1 (13 - 18 Hz), and beta-2 (18 - 30 Hz) bands. The findings in this study suggest that power and omega-complexity changes in task-specific neural activity may potentially be used to assess age-related decline in the brain.

An important question in healthcare for older patients is whether age-related changes in cortical reorganization can be measured with advancing age. This study investigated the factors behind such age-related changes, using time-frequency analysis of event-related potentials (ERPs). We hypothesized that brain rhythms was affected by age-related changes, which could be reflected in the ERP indices. An oddball task was conducted in two experimental groups, namely young participants ( N = 15; mean age 23.7 ± 2.8 years) and older participants ( N = 15; mean age 70.1 ± 7.9 years). Two types of stimuli were used: the target (1 kHz frequency) and standard (2 kHz frequency). We scrutinized three ERP indices: event-related spectral power (ERPSP), inter-trial phase-locking (ITPL), and event-related cross-phase coherence (ERPCOH). Both groups performed equally well for correct response rate. However, the results revealed a statistically significant age difference for inter-trial comparison. Compared with the young, the older participants showed the following age-related changes: (a) power activity decreased; however, an increase was found only in the late (P3, 280–450 ms) theta (4–7 Hz) component over the bilateral frontal and temporo-frontal areas; (b) low phase-locking in the early (N1, 80–140 ms) theta band over the parietal/frontal (right) regions appeared; (c) the functional connections decreased in the alpha (7–13 Hz) and beta (13–30 Hz) bands, but no difference emerged in the theta band between the two groups. These results indicate that age-related changes in task-specific brain activity for a normal aging population can be depicted using the three ERP indices.

When a nonlinear oscillator is driven by an external force which is calculated on the basis of the zero-dispersion nonlinear resonance (ZDNR) theory, it can be transparent, i.e., the output of the response system is the same as the magnitude of driving force without any dispersion or distortion. In fact, this is a unique phenomenon, called zero-dispersion nonlinear resonance (ZDNR). Herein, we used the generic input–output analysis to realize the ZDNR circuit experiment of two unidirectional coupling self-excited oscillators. The experimental observations also show good agreement with numerical simulations.

The study focuses on the average energy of a monolayer of granular particles confined in a rectangular container. The container is shaken sinusoidally in a horizontal plane. The motion of every particle is recorded by a CCD camera so that the kinetic energy of the system can be analyzed by tracking the trajectory of each particle. It is found that the average energy changes abruptly at a certain critical filling fraction while the configuration of the particles makes a transition from a disordered to a solid-like state. We determine the critical value of the filling fraction and the energy of the solid-like state using a resonant condition.

This paper presents the synchronization between uncertain hyperchaotic and chaotic systems. Based on Lyapunov stability theory, an adaptive controller is derived to achieve synchronization of hyperchaotic and chaotic systems, including the case of unknown parameters in these two systems. The T.N.Č. hyperchaotic oscillator is used as the master system, and the Rössler system is used as the slave system. Numerical simulations verify these results. Additionally, the effect of noise is investigated by measuring the mean squared error (MSE) of two systems.

Disordered cellular automata (DCA) represent an intermediate class between elementary cellular automata and the Kauffman network. Recently, Rule 126 of DCA has been explicated: the system can be accurately described by a discrete probability function. However, a means of extending to other rules has not been developed. In this investigation, a density map of the dynamical behavior of DCA is formulated based on Rule 22 and other totalistic rules. The numerical results reveal excellent agreement between the model and original automata. Furthermore, the inhomogeneous situation is also discussed.

In this article, we investigate the synchronization of uncertain chaotic systems. Based upon the parameters identification technique and a simple but efficient control method, we control the response system to be the drive system with parameters unknown. The techniques are successfully applied to Lorenz system and Chen system. Furthermore, the effect of external noise is under our discussion.

We investigate the interplay between phase synchronization and amplitude synchronization in nonlinear dynamical systems. It is numerically found that phase synchronization intends to be established earlier than amplitude synchronization. Nevertheless, amplitude synchronization (or the state with large correlation between the amplitudes) is crucial for the maintenance of a high correlation between two time series. A breakdown of high correlation in amplitudes will lead to a desynchronization of two time series. It is shown that these unique features are caused essentially by the Hilbert transform. This leads to a deep concern and criticism on the current usage of phase synchronization.

Color preferences in engineering are very important, and there exists relationship between color preference and visual comfort. In this study, there are thirty university students who participated in the experiment, supplemented by pre- and posttest questionnaires, which lasted about an hour. The main purpose of this study is to explore the visual effects of different color assignment with subjective color preferences via eye tracking technology. Eye-movement data through a nonlinear analysis detect slight differences in color preferences and visual comfort, suggesting effective physiological indicators as extensive future research discussed. Results found that the average pupil size of eye-movement indicators can effectively reflect the differences of color preferences and visual comfort. This study more confirmed that the subjective feeling will make people have misjudgment.

In this Letter, we study the chaos synchronization of two stochastically coupled random Boolean networks (RBNs). Instead of using the “site-by-site and all-to-all” coupling, the coupling mechanism we consider here is that: the n th cell in a network is linked by an arbitrarily chosen cell in the other network with probability ρ , and it possesses no links with probability 1 − ρ . The mechanism is useful to investigate the coevolution of biological species via horizontal genetic exchange. We show that the density evolution of networks can be described by two deterministic coupled polynomial maps. The complete synchronization occurs when the coupling parameter exceeds a critical value. Moreover, the reverse bifurcations in inhomogeneous condition are observed and under our discussion.

In this Letter, we investigate the reduced-order synchronization of uncertain chaotic systems. Based upon the parameters modulation and the adaptive control techniques, we control the response system to be the drive system even though their orders are different and their parameters are unknown. The techniques are successfully applied to two examples: generalized Lorenz system (fourth order) and Lu system (third order); Rossler hyperchaotic system (fourth order) and Rossler system (third order). Furthermore, the effect of control modulator k is under our discussions.

The study of inhomogeneous-coupled chaotic systems has attracted a lot of attention recently. With simple definition of phase, we present the phase-locking behavior in ensembles of globally coupled non-identical maps. The inhomogeneous globally coupled maps consist of logistic map and tent map simultaneously. Average phase synchronization ratios, which are used to characterize the phase coherent phenomena, depend on different coupling coefficients and chaotic parameters. By using interdependence, the relationship between a single unit and the mean field is illustrated. Moreover, we take the effect of external noise and parameter mismatch into consideration and present the results by numerical simulation.

Using techniques from active control theory, we demonstrate that two coupled chaotic systems can be phase and anti-phase synchronized. The techniques are applied to Lorenz, Rossler, and Chen systems.  2002 Elsevier Science B.V. All rights reserved.

Cross-mutual information (CMI) can calculate to time series for thousands of sampled points from corticocortical connection among different functional states of brain in Alzheimer’s disease (AD) patients. The aim of this study was to use mutual information analysis in the multichannel EEG to predict the probability of AD disease. Considering the correlation between AD disease and ageing effect, the participants were 9 AD patients and 45 normal cases involving teenagers, young people and elders. This data revealed that both right frontal and temporo-parietal are differences between normal and AD participants. Besides, this study found the theta band is the main frequency to separate AD patients from all participants. Furthermore, this study suggested a higher distinguishable method by mutual information to predict the possibility AD patients.

When a nonlinear oscillator is driven externally, it may become transparent, i.e., the output response appears without any dispersion or distortion. Such counter-intuitive feature, in fact, is a unique zero-dispersion nonlinear resonance (ZDNR). Herein, it is examined on the base of a generic input-output analysis. The conditions for ZDNR have been clarified and a power law relation has been established to feature the interplay with noise.

The aim of this paper is applying the bispectral analysis on widespread diffuse cross-frequency interactive effects. The event-related potentials (ERPs) research method was used in this study and it could collect the widespread diffuse cross-frequency from mild cognitive impairment (MCI) patients’ brain wave. In this study, the brain wave data were collected from 12 MCI subjects, 12 healthy elderly, and 12 healthy young. The findings showed that the decreased interhemispheric coherence of 8.8 Hz for MCI compared with healthy elderly in the central-parietal cortex to respective surrounding sites and each MCI subject showed significantly widespread diffuse pattern of cross-frequency interactions in comparison with the healthy controls in the left central-parietal and right frontal. This study provides some explanation and suggestions for these findings.

We explore the possibility of creating the desired periodic output waveform in nonlinear oscillators with modulations. For a theoretic example, we show that the desired periodic output waveform can be created in a forced Duffing-Holmes oscillator. Our study may provide a way toward a goal-oriented scheme of controlling chaos based on periodic perturbations.

The detecting of phase synchronization in a forced oscillator with ill‐defined phase structure is difficult until a quantitative approach based on recurrence probability analysis is established. We study the phase synchronization diagram of a chaotic system “Chua oscillator” with dual attractor structure by analyzing the recurrence probabilities of the response system and the external periodic driving force. Numerical analysis results of the ranges and intensities of phase synchronization are described by the Arnold tongue diagram.

Cascade technique has been applied extensively to many various fields. This work applies function cascade synchronization approach to make the states of idental chaotic and hyperchaotic systems asymptotically synchronized. Although this method had been proposed, the process was illogical and the result was imperfect. We improve the defect and present a logical and rigorous scheme to achieve the function cascade synchronization with fully unknown parameters. Based on the Lyapunov stability theory, the adaptive controllers and the corresponding parameter update law are designed to achieve the function cascade synchronization for the hyperchaotic Lorenz‐Stenflo system with fully unknown parameters. Numerical simulations are performed to demonstrate the effectiveness and feasibility of our proposed control scheme.

A quantitative approach was constructed for detecting phase locking in a chaotic system with complex attractor structure via stroboscopic method. We study the route to weak phase locking by analyzing the stroboscopic points. The onset of weak phase locking detected by using this statistical approach and the critical coupling strength calculated by Lyapunov exponent are matched well. Detailed structure of phase locking intensity is described by the Arnold tongue diagram.