Editorial: How Do Motivational States Influence Motor Resonance?

status: publishe

Using an inverse modelling approach to evaluate the water retention in a simple water harvesting technique

In arid and semi-arid zones, runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Nevertheless, few efforts were observed to quantify the water harvesting processes of these techniques and to evaluate their efficiency. In this study, a combination of detailed field measurements and modelling with the HYDRUS-2D software package was used to visualize the effect of an infiltration trench on the soil water content of a bare slope in northern Chile. Rainfall simulations were combined with high spatial and temporal resolution water content monitoring in order to construct a useful dataset for inverse modelling purposes. Initial estimates of model parameters were provided by detailed infiltration and soil water retention measurements. Four different measurement techniques were used to determine the saturated hydraulic conductivity (<I>K</I><sub>sat</sub>) independently. The tension infiltrometer measurements proved a good estimator of the <I>K</I><sub>sat</sub> value and a proxy for those measured under simulated rainfall, whereas the pressure and constant head well infiltrometer measurements showed larger variability. Six different parameter optimization functions were tested as a combination of soil-water content, water retention and cumulative infiltration data. Infiltration data alone proved insufficient to obtain high model accuracy, due to large scatter on the data set, and water content data were needed to obtain optimized effective parameter sets with small confidence intervals. Correlation between the observed soil water content and the simulated values was as high as <I>R</I><sup>2</sup>=0.93 for ten selected observation points used in the model calibration phase, with overall correlation for the 22 observation points equal to 0.85. The model results indicate that the infiltration trench has a significant effect on soil-water storage, especially at the base of the trench

EEG alpha–theta dynamics during mind wandering in the context of breath focus meditation: An experience sampling approach with novice meditation practitioners

Peer Review: The peer review history for this article is available at https://publons.com/publon/10.1111/ejn.15073.Supporting Information is avaiable online at: https://onlinelibrary.wiley.com/doi/full/10.1111/ejn.15073?saml_referrer#support-information-section .Meditation practice entails moments of distraction dominated by self‐generated thoughts (i.e. mind wandering). Initial studies assessing the neural correlates of mind wandering in the context of meditation practice have identified an important role of theta (4–8 Hz) and alpha (8–14 Hz) neural oscillations. In this study, we use a probe‐caught experience sampling paradigm to assess spectral changes in the theta‐alpha frequency range during mind wandering in the context of breath focus meditation. Electroencephalography (EEG) was measured in 25 novice meditation practitioners during a breath focus task in which they were repeatedly probed to report whether they were focusing on their breath or thinking about something else. Mind wandering episodes were associated with an increase in the amplitude and a decrease in the frequency of theta (4–8 Hz) oscillations. Conversely, alpha oscillations (8–14 Hz) were shown to decrease in amplitude and increase in frequency during mind wandering relative to breath focus. In addition, mind wandering episodes were shown to be accompanied by increased harmonicity and phase synchrony between alpha and theta rhythms. Because similar spectral changes in the theta‐alpha frequency range have been reported during controlled cognitive processes involving memory and executive control, we speculate that mind wandering and controlled processes could share some neurocognitive mechanisms. From a translational perspective, this study indicates that oscillatory activity in the theta‐alpha frequency range could form adequate parameters for developing EEG‐neurofeedback protocols aimed at facilitating the detection of mind wandering during meditation practice.Fonds Wetenschappelijk Onderzoek. Grant Numbers: 1506716N, G079017N; Mind & Life Europe; The Branco Weiss Fellowship - Society in Science

Tracking Transient Changes in the Neural Frequency Architecture: Harmonic Relationships between Theta and Alpha Peaks Facilitate Cognitive Performance

SIGNIFICANCE STATEMENT Neural activity is known to oscillate within discrete frequency bands and the interplay between these brain rhythms is hypothesized to underlie cognitive functions. A recent theory posits that shifts in the peak frequencies of oscillatory rhythms form the principal mechanism by which cross-frequency coupling and decoupling is implemented in the brain. In line with this notion, we show that the occurrence of a cross-frequency arrangement that mathematically enables coupling between alpha and theta rhythms is more prominent during active cognitive processing (compared with rest and non-cognitively demanding tasks) and is associated with improved cognitive performance. Together, our results open new vistas for future research on cross-frequency dynamics in the brain and their functional role in cognitive processing.The synchronization between neural oscillations at different frequencies has been proposed as a core mechanism for the coordination and integration of neural systems at different spatiotemporal scales. Because neural oscillations of different frequencies can only fully synchronize when their “peak” frequencies form harmonic relationships (e.g., f2 = f1/2), the present study explored whether the transient occurrence of harmonic cross-frequency relationship between task-relevant rhythms underlies efficient cognitive processing. Continuous EEG recordings (51 human participants; 14 males) were obtained during an arithmetic task, rest and breath focus. In two separate experiments, we consistently show that the proportion of epochs displaying a 2:1 harmonic relationship between alpha (8–14 Hz) and theta (4–8 Hz) peak frequencies (i.e., alphapeak ≈ 10.6 Hz; thetapeak ≈ 5.3 Hz), was significantly higher when cognitive demands increased. In addition, a higher incidence of 2:1 harmonic cross-frequency relationships was significantly associated with increased alpha–theta phase synchrony and improved arithmetic task performance, thereby underlining the functional relevance of this cross-frequency configuration. Notably, opposite dynamics were identified for a specific range of “nonharmonic” alpha–theta cross-frequency relationships (i.e., alphapeak/thetapeak = 1.1–1.6), which showed a higher incidence during rest compared with the arithmetic task. The observation that alpha and theta rhythms shifted into harmonic versus nonharmonic cross-frequency relationships depending on (cognitive) task demands is in line with the notion that the neural frequency architecture entails optimal frequency arrangements to facilitate cross-frequency “coupling” and “decoupling”.Branco Weiss fellowship of the Society in Science–ETH Zurich and by Grants from the Flanders Fund for Scientific Research (FWO projects KAN 1506716N and G079017N)

Results of transmission measurements for 40Ca at GELINA

Transmission measurements have been performed at a 50 transmission station of the neutron time-of-flight facility GELINA to determine the total cross section for neutron induced reactions on 40Ca. These measurements are part of a collaboration of the Joint Research Centre and the Oak Ridge National Laboratory (US) to improve nuclear data for nuclear criticality safety applications. They have been supported by the EUFRAT project. This report provides the experimental details required to submit the data to the EXFOR data library which is maintained by the Nuclear Data Section of the IAEA and the Nuclear Energy Agency of the OECD. The experimental details, i.e. measurement conditions, sample characteristics, measurement procedures and experimental uncertainty components, together with the data reduction procedures are described. The experimental results including the full covariance information, based on the AGS-formalism, are reported following the latest recommendations of the International Nuclear Data Committee. This includes the information that is required to derive nuclear reaction model parameters together with their covariances by a least squares adjustment to experimental data.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Mindfulness Training is Associated with Changes in Alpha-Theta Cross-Frequency Dynamics During Meditation

Data Availability: All data are available at the Open Science Framework: https://osf.io/y23k8/?view_only=74193001fd39435b853b6a0b641d1e72Objectives: Previous literature suggests that cross-frequency phase synchronization is a mechanism by which information is transmitted and coordinated in the brain. Since cross-frequency phase synchronization is only strictly possible when two oscillators form a harmonic frequency ratio (e.g., 2:1, 3:1), a recent theory posited that interactions between brain oscillations at different frequencies are facilitated/hindered by the transient occurrence of harmonic/non-harmonic cross-frequency arrangements. In this line, recent evidence has shown that 2:1 harmonic relationships between alpha (8–14 Hz) and theta (4–8 Hz) rhythms are reduced during meditative states in experienced practitioners. In the present study, we investigated whether mindfulness training in novices is associated with longitudinal changes in alpha-theta cross-frequency dynamics during meditation practice. Methods: Thirty-six participants (mean age = 30.3; 2 men) underwent an 8-week mindfulness training program based on the mindfulness-based stress reduction (MBSR) syllabus and electroencephalography (EEG) recordings (64 electrodes) were performed during a guided meditation before and after the training. Results: Mindfulness training compliance (quantified by minutes of attendance and practice at home) was significantly correlated to decreased 3:1 harmonicity and cross-frequency phase synchrony between alpha and theta rhythms during meditation. Conclusions: Mindfulness training in novices was shown to be associated with a reduction in alpha-theta cross-frequency coupling during meditation. EEG parameters based on alpha-theta cross-frequency dynamics may be adequate for quantifying and/or facilitating mindfulness meditation training.Branco Weiss fellowship of the Society in Science–ETH Zurich, by Grants from the Flanders Fund for Scientific Research (FWO projects KAN 1506716N and G079017N); the Far East Organization

The EEG spectral properties of meditation and mind wandering differ between experienced meditators and novices

Data and code availability statement: Raw EEG data and MATLAB code will be publicly available in the Open Science Framework webpage (see https://osf.io/3uszv/?view_only=d41ddd2200e642cf9992a016cb739b90).Supplementary materials are available online at: https://www.sciencedirect.com/science/article/pii/S1053811921009423?via%3Dihub#sec0018 .Copyright © 2021 The Authors. Previous literature suggests that individuals with meditation training become less distracted during meditation practice. In this study, we assess whether putative differences in the subjective experience of meditation between meditators and non-meditators are reflected in EEG spectral modulations. For this purpose, we recorded electroencephalography (EEG) during rest and two breath focus meditations (with and without experience sampling) in a group of 29 adult participants with more than 3 years of meditation experience and a control group of 29 participants without any meditation experience. Experience sampling in one of the meditation conditions allowed us to disentangle periods of breath focus from mind wandering (i.e. moments of distraction driven by task-irrelevant thoughts) during meditation practice. Overall, meditators reported a greater level of focus and reduced mind wandering during meditation practice than controls. In line with these reports, EEG spectral modulations associated with meditation and mind wandering also differed significantly between meditators and controls. While meditators (but not controls) showed a significant decrease in individual alpha frequency / amplitude and a steeper 1/f slope during meditation relative to rest, controls (but not meditators) showed a relative increase in individual alpha amplitude during mind wandering relative to breath focus periods. Together, our results show that the subjective experience of meditation and mind wandering differs between meditators and novices and that this is reflected in oscillatory and non-oscillatory properties of EEG.Branco Weiss fellowship of the Society in Science–ETH Zurich; Grants from the Flanders Fund for Scientific Research (FWO G079017N and G046321N); European Varela Awards (Mind & Life Europe)

Combining oxytocin and cognitive bias modification training in a randomized controlled trial:Effects on trust in maternal support

Background and objectives: Research on the social effects of intranasal oxytocin in children is scarce. Oxytocin has been proposed to have clearer beneficial effects when added to social learning paradigms. The current study tested this proposition in middle childhood by assessing effects of cognitive bias modification (CBM) training and oxytocin on trust in maternal support. Methods: Children (N = 100, 8–12 years) were randomly assigned to one of two training conditions: CBM training aimed at increasing trust or neutral placebo training. Within each training condition, half the participants received oxytocin and half a placebo. Main and interaction effects were assessed on measures of trust-related interpretation bias and trust. We explored whether child characteristics moderated intervention effects. Results: Children in the CBM training were faster to interpret maternal behaviour securely versus insecurely. Effects did not generalize to interpretation bias measures or trust. There were no main or interaction effects of oxytocin. Exploratory moderation analyses indicated that combining CBM training with oxytocin had less positive effects on trust for children with more internalizing problems. Limitations: As this was the first study combining CBM and oxytocin, replication of the results is needed. Conclusions: This study combined a social learning paradigm with oxytocin in children. CBM training was effective at an automatic level of processing. Oxytocin did not enhance CBM effects or independently exert effects. Research in larger samples specifying when oxytocin might have beneficial effects is necessary before oxytocin can be used as intervention option in children