The effects of Tai Chi on standing balance control in older adults may be attributed to the improvement of sensory reweighting and complexity rather than reduced sway velocity or amplitude.

Introduction: Tai Chi has proved to be an effective therapy for balance performance and cognition. However, non-consistency exists in the results of the effect of Tai Chi training on standing balance control in older adults. This study aimed to use traditional and non-traditional methods to investigate the effect of Tai Chi on standing balance in older adults. Methods: Thirty-six Tai Chi practitioners (TC group) and thirty-six older adults with no Tai Chi practice (control group) were recruited in this study. A Nintendo Wii Balance Board was used to record the center of pressure (COP) during standing balance over 20 s in the condition of eyes closed with three repetitions. The wavelet analysis, multiscale entropy, recurrence quantification analysis, and traditional methods were used to evaluate the standing balance control in the anterior-posterior (AP) and mediolateral (ML) directions. Results: (1) Greater sway mean velocity in the AP direction and sway Path length were found in the TC group compared with the control group; (2) lower Very-low frequency band (0.10-0.39 Hz) and higher Moderate frequency band (1.56-6.25 Hz) in the AP and ML directions were found in the TC group compared with the control group; (3) greater complexity index (CI) and lower determinism (DET) in the AP and ML directions were observed in the TC group compared with control group; (4) greater path length linked with smaller Very-low frequency band in the AP and ML directions and higher Moderate frequency band in the AP direction in both groups; (5) greater path length linked with lower DET and higher CI in the AP direction only in the TC group. Conclusion: Long-term Tai Chi practice improved sensory reweighting (more reliance on the proprioception system and less reliance on the vestibular system) and complexity of standing balance control in older adults. In addition, greater sway velocity may be as an exploratory role in standing balance control of TC older adults, which correlated with greater complexity, but no such significant relationship in the control group. Therefore, the effects of Tai Chi practice on standing balance control in older adults may be attributed to the improvement of sensory reweighting and complexity rather than reduced sway velocity or amplitude.

Gaze Restriction and Reactivation of Place-bound Content Drive Eye Movements During Mental Imagery.

When we imagine a picture, we move our eyes even though the picture is physically not present. These eye movements provide information about the ongoing process of mental imagery. Eye movements unfold over time, and previous research has shown that the temporal gaze dynamics of eye movements in mental imagery have unique properties, which are unrelated to those in perception. In mental imagery, refixations of previously fixated locations happen more often and in a more systematic manner than in perception. The origin of these unique properties remains unclear. We tested how the temporal structure of eye movements is influenced by the complexity of the mental image. Participants briefly saw and then maintained a pattern stimulus, consisting of one (easy condition) to four black segments (most difficult condition). When maintaining a simple pattern in imagery, participants restricted their gaze to a narrow area, and for more complex stimuli, eye movements were more spread out to distant areas. At the same time, fewer refixations were made in imagery when the stimuli were complex. The results show that refixations depend on the imagined content. While fixations of stimulus-related areas reflect the so-called 'looking at nothing' effect, gaze restriction emphasizes differences between mental imagery and perception.

Chemical profiling and quantitative analysis on the aqueous extract of Pimpinella anisum fruit by liquid chromatography-tandem mass spectrometry.

Anise fruit (Aniseed) has been used for many years as a traditional medicine in various countries throughout the world; however, the chemical material basis of Aniseed water extract (AWE) has not been examined in detail, limiting our understanding of its pharmacological mechanism and methods for practical quality control. A high-efficiency and high-sensitivity LC-triple time-of-flight tandem mass spectrometry (MS/MS) analysis method using data processing method combined with product ion and neutral loss filtering for systematic screening and identification of the constituents of AWE was established. A quantitative method was established by using LC-MS/MS with multiple reaction monitoring for 10 min to determine the concentration of 17 representative constituents. A total of 89 compounds were discovered in AWE, of which 31 were confirmed by the reference standards, while 24 were found in Aniseed for the first time. The qualification analysis results showed that chlorogenic acids and luteolin derivatives were the major compounds. The linearity, sensitivity, precision, stability, repeatability, and accuracy of the method were verified, which demonstrated that the method could meet the requirements for quantification. This work contributes to a better understanding of the chemical material basis of Aniseed and assists in the development of effective analytical methods for natural medicines.

Eye movements during visual imagery and perception show spatial correspondence but have unique temporal signatures.

Eye fixation patterns during mental imagery are similar to those during perception of the same picture, suggesting that oculomotor mechanisms play a role in mental imagery (i.e., the "looking at nothing" effect). Previous research has focused on the spatial similarities of eye movements during perception and mental imagery. The primary aim of this study was to assess whether the spatial similarity translates to the temporal domain. We used recurrence quantification analysis (RQA) to assess the temporal structure of eye fixations in visual perception and mental imagery and we compared the temporal as well as the spatial characteristics in mental imagery with perception by means of Bayesian hierarchical regression models. We further investigated how person and picture-specific characteristics contribute to eye movement behavior in mental imagery. Working memory capacity and mental imagery abilities were assessed to either predict gaze dynamics in visual imagery or to moderate a possible correspondence between spatial or temporal gaze dynamics in perception and mental imagery. We were able to show the spatial similarity of fixations between visual perception and imagery and we provide first evidence for its moderation by working memory capacity. Interestingly, the temporal gaze dynamics in mental imagery were unrelated to those in perception and their variance between participants was not explained by variance in visuo-spatial working memory capacity or vividness of mental images. The semantic content of the imagined pictures was the only meaningful predictor of temporal gaze dynamics. The spatial correspondence reflects shared spatial structure of mental images and perceived pictures, while the unique temporal gaze behavior could be driven by generation, maintenance and protection processes specific to visual imagery. The unique temporal gaze dynamics offer a window to new insights into the genuine process of mental imagery independent of its similarity to perception.

Detection of Age-Related Hearing Losses (ARHL) via Transient-Evoked Otoacoustic Emissions.

PURPOSE: The objective of the study was to identify subjects presenting hearing deficits, specifically age-related hearing losses (ARHL), via objective assessment methodologies. MATERIALS AND METHODS: Initially, 259 subjects (165 men, 94 women) were enrolled in the study. After the application of inclusion criteria, the final number was reduced to 88 subjects (49.8 ± 19.1 ys) subdivided into 64 normal and 83 ARHL cases. The subjects were assessed with traditional audiometry tests and with transiently evoked otoacoustic emissions (TEOAEs). Since each ear has its own acoustic signature, the TEOAE analyses were conducted in terms of ears and not subjects. The TEOAE data were processed by traditional and recurrence quantification analyses, leading to the estimation of the WWR (whole waveform reproducibility) and the new RAD2D (2-dimensional radius) parameters. A plot of WWR vs RAD2D was used to optimize the classification of the cases presenting ARHL. RESULTS: By using a WWR value of 70% as a classifier, the sensitivity of TEOAEs was estimated as 75.9% and the specificity as 89.1%. By using the RAD2D parameter (with a cut-off value of 1.78), a sensitivity value of 80.7% and a specificity value of 71.9% were obtained. When both parameters were used, a sensitivity value of 85.5% and a specificity value of 92.2% were estimated. In the latter classification paradigm, the number of false negatives decreased from 20 to 12 out of 83 ears (14%). CONCLUSION: In adult hearing screening assessments, the proposed method optimizes the identification of subjects with a hearing impairment correlated to the presence of age-related hearing loss.

Changes in behavioural synchrony during dog-assisted therapy for children with autism spectrum disorder and children with Down syndrome.

BACKGROUND: Dog-assisted therapy (DAT) is hypothesized to help children with autism spectrum disorder (ASD) and Down syndrome (DS). METHODS: The present authors compared synchronous movement patterns of these children (n = 10) and their therapy dogs during the first and last session of a DAT programme, and their post-therapy changes in emotional and behavioural problems. RESULTS: The present authors found a significant increase in synchrony between child and therapy dog over time. Exploratory analyses suggest more synchrony between children with ASD and their therapy dogs, compared to the children with DS. CONCLUSIONS: This study is the first to test the synchrony hypothesis, shedding light upon a mechanism that may underlie the effect of DAT and how this may be different for children with ASD and DS.

Data mining based approach to study the effect of consumption of caffeinated coffee on the generation of the steady-state visual evoked potential signals.

The steady-state visual evoked potentials (SSVEP), are elicited at the parieto-occipital region of the cortex when a light source (3.5-75 Hz), flickering at a constant frequency, stimulates the retinal cells. In the last few decades, researchers have reported that caffeine enhances the vigilance and the executive control of visual attention. However, no study has investigated the effect of caffeinated coffee on the SSVEP response, which is used for controlling the brain-computer interface (BCI) devices for rehabilitative applications. The current work proposes a data mining-based approach to gain insight into the alterations in the SSVEP signals after the consumption of caffeinated coffee. Recurrence quantification analysis (RQA) of the electroencephalogram (EEG) signals was employed for this purpose. The EEG signals were acquired at seven frequencies of photic stimuli. The stimuli frequencies were chosen such that they were distributed throughout the EEG frequency bands. The prominent SSVEP signals were identified using the Canonical Correlation Analysis (CCA) method. Several statistical features were extracted from the recurrence plot of the SSVEP signals. Statistical analyses using the t-test and decision tree-based methods helped to select the most relevant features, which were then classified using Automated Neural Network (ANN). The relevant features could be classified with a maximum accuracy of 97%. This supports our hypothesis that the consumption of caffeinated coffee can alter the SSVEP response. In conclusion, utmost care should be taken in selecting the features for designing BCI devices.

Application of nonlinear methods to discriminate fractionated electrograms in paroxysmal versus persistent atrial fibrillation.

BACKGROUND AND OBJECTIVE: Complex fractionated atrial electrograms (CFAE) may contain information concerning the electrophysiological substrate of atrial fibrillation (AF); therefore they are of interest to guide catheter ablation treatment of AF. Electrogram signals are shaped by activation events, which are dynamical in nature. This makes it difficult to establish those signal properties that can provide insight into the ablation site location. Nonlinear measures may improve information. To test this hypothesis, we used nonlinear measures to analyze CFAE. METHODS: CFAE from several atrial sites, recorded for a duration of 16 s, were acquired from 10 patients with persistent and 9 patients with paroxysmal AF. These signals were appraised using non-overlapping windows of 1-, 2- and 4-s durations. The resulting data sets were analyzed with Recurrence Plots (RP) and Recurrence Quantification Analysis (RQA). The data was also quantified via entropy measures. RESULTS: RQA exhibited unique plots for persistent versus paroxysmal AF. Similar patterns were observed to be repeated throughout the RPs. Trends were consistent for signal segments of 1 and 2 s as well as 4 s in duration. This was suggestive that the underlying signal generation process is also repetitive, and that repetitiveness can be detected even in 1-s sequences. The results also showed that most entropy metrics exhibited higher measurement values (closer to equilibrium) for persistent AF data. It was also found that Determinism (DET), Trapping Time (TT), and Modified Multiscale Entropy (MMSE), extracted from signals that were acquired from locations at the posterior atrial free wall, are highly discriminative of persistent versus paroxysmal AF data. CONCLUSIONS: Short data sequences are sufficient to provide information to discern persistent versus paroxysmal AF data with a significant difference, and can be useful to detect repeating patterns of atrial activation.

Nonlinear Analysis of Eye-Tracking Information for Motor Imagery Assessments.

This study investigates the assessment of motor imagery (MI) ability in humans. Commonly, MI ability is measured through two methodologies: a self-administered questionnaire (MIQ-3) and the mental chronometry (MC), which measures the temporal discrepancy between the actual and the imagined motor tasks. However, both measures rely on subjects' self-assessment and do not use physiological measures. In this study, we propose a novel set of features extracted from the nonlinear dynamics of the eye gaze signal to discriminate between good and bad imagers. To this aim, we designed an experiment where twenty volunteers, categorized as good or bad imagers according to MC, performed three tasks: a motor task (MT), a visual Imagery task (VI), and a kinaesthetic Imagery task (KI). Throughout the experiment, the subjects' eye gaze was continuously monitored using an eye-tracking system. Eye gaze time series were analyzed through recurrence quantification analysis of the reconstructed phase space and compared between the two groups. Statistical results have shown how nonlinear eye behavior can express an inner dynamics of imagery mental process and may be used as a more objective and physiological-based measure of MI ability.

Classification and quantification of palm oil adulteration via portable NIR spectroscopy.

Short wave near infrared spectroscopy (NIR) method was used to detect the presence of lard adulteration in palm oil. MicroNIR was set up in two different scan modes to study the effect of path length to the performance of spectral measurement. Pure and adulterated palm oil sample were classified using soft independent modeling class analogy (SIMCA) algorithm with model accuracy more than 0.95 reported for both transflectance and transmission modes. Additionally, by employing partial least square (PLS) regression, the coefficient of determination (R2) of transflectance and transmission were 0.9987 and 0.9994 with root mean square error of calibration (RMSEC) of 0.5931 and 0.6703 respectively. In order to remove the uninformative variables, variable selection using cumulative adaptive reweighted sampling (CARS) has been performed. The result of R2 and RMSEC after variable selection for transflectance and transmission were improved significantly. Based on the result of classification and quantification analysis, the transmission mode has yield better prediction model compared to the transflectance mode to distinguish the pure and adulterated palm oil.

Chaos-chaos transition of left hemisphere EEGs during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility.

A recent study, recurrence quantification analysis of EEG signals during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility investigated recurrence quantifiers (RQs) of hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility to distinguish subjects of different hypnotizability levels. Following the same analysis, the current study determines the capability of different RQs to distinguish subjects of low, medium and high hypnotizability level and studies the influence of hypnotizability level on underlying dynamic of tasks. Besides, EEG channels were sorted according to the number of their RQs, which differed significantly among subjects of different hypnotizability levels. Another valuable result was determination of major brain regions in observing significant differences in various task types (ideomotors, hallucination, challenge and memory).

Recurrence quantification analysis of electroencephalograph signals during standard tasks of Waterloo-Stanford group scale of hypnotic susceptibility.

The purpose of this study was to apply RQA (recurrence quantification analysis) on hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of the Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility. Then recurrence quantifiers were used to analyse the influence of hypnotic depth on EEGs. By the application of this method, the capability of tasks to distinguish subjects of different hypnotizability levels was determined. Besides, medium hypnotizable subjects showed the highest disposition to be inducted by hypnotizer. Similarities between brain governing dynamics during tasks of the same type were also observed. The present study demonstrated two remarkable innovations; investigating the EEGs of the hypnotized as doing mental tasks of Waterloo-Stanford Group Scale (WSGS) and applying RQA on hypnotic EEGs.

Hypnotic assessment based on the recurrence quantification analysis of EEG recorded in the ordinary state of consciousness.

The cerebral cortical correlates of the susceptibility to hypnosis in the ordinary states of consciousness have not been clarified. Aim of the study was to characterize the EEG dynamics of subjects with high (highs) and low hypnotisability (lows) through the non-linear method of Recurrence Quantification Analysis (RQA). The EEG of 16 males--8 highs and 8 lows--was monitored for 1min without instructions other than keeping the eyes closed, being silent and avoiding movements (short resting), and during 15 min of simple relaxation, that is with the instruction to relax at their best. Highs and lows were compared on the RQA measures of Determinism (DET) and Entropy (ENT), which are related to the signal determinism and complexity. In the short resting condition discriminant analysis could classify highs and lows on the basis of DET and ENT values at temporo-parietal sites. Many differences in DET and all differences in ENT disappeared during simple relaxation, although DET still separated the two groups in the earliest 6min of relaxation at temporo-parietal sites. Our RQA based approach allows to develop computer-based methods of hypnotic assessment using short-lasting, single channel EEG recordings analyzed through standard mathematical methods.

Effects of Plant Extracts on Microbial Population, Methane Emission and Ruminal Fermentation Characteristics in In vitro.

This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle) were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2%) in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively) filled with O2-free N2 gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at 39°C for 24 h. Total gas production in all plant extracts was higher (p<0.05) than that of the control, and total gas production of ginger extract was highest (p<0.05). The methane emission was highest (p<0.05) at control, but lowest (p<0.05) at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM). Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%). Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53) than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens community in added wormwood, garlic, mandarin orange and honeysuckle extracts increased more than that of the others. The addition of onion extract increased R. albus diversity, while other extracts did not influence the R. albus community. The R. flavefaciens population in added wormwood and garlic extracts decreased, while other extracts increased its abundance compared to the control. In conclusion, the results indicated that the plant extracts used in the experiment could be promising feed additives to decrease methane gas emission from ruminant animals while improving ruminal fermentation.