Positive Amplitude Research Articles

Predicting atrial fibrillation from ECG characteristics

Abstract Background/Introduction Atrial fibrillation (AF) is the most common cardiac arrythmia, and demographic shifts in age continues to increase the prevalence of atrial fibrillation on a global scale. With manifestations of short and intermittent duration, identifying and diagnosing AF often proves to be a challenge. As a consequence, patients who develop AF are at risk of experiencing stroke and other cardiac diseases such as heart failure (HF) before appropriate treatment is initialized. Despite the potential benefits of early AF detection, risk profiling based on electrocardiographic (ECG) findings is currently lacking. Several smaller studies have identified ECG characteristics associated with increased risk of AF, but these characteristics have not been individually evaluated in large-scale nationwide cohorts, and no evidence exists on the additive effect of these ECG characteristics. Purpose We aimed to evaluate the risk of new-onset AF, HF, and stroke according to five ECG characteristics previously linked to AF, in order to identify potential predictors of AF. Methods We used national registers and the Danish Nationwide ECG Cohort to include patients with ECG measurements taken between 2010 and 2022. Patients were grouped according to how many of the following ECG characteristics were present in their baseline ECG: Elevated heart rate (>80), prolonged PR-interval (≥196 ms for women and ≥204 ms for men), biphasic P-waves (positive and negative amplitude within same p-wave), abnormal P terminal force (≥ 6000 mV×ms), and prolonged P-wave duration(≥120 ms). Patients were followed for 2 years to evaluate the risk of atrial fibrillation, heart failure (HF), and stroke, according to baseline ECG characteristics. Results We included 1,505,474 patients of whom 594,702 had exactly one ECG characteristic, 197,367 had two characteristics, 44,983 had three characteristics, 6,390 had four characteristics, and 451 had all five characteristics on their baseline ECG. The risk of developing AF or HF increased with the number of ECG characteristics present on the baseline ECG. Patients with two ECG characteristics had a 2-fold increased risk of AF or HF compared to patients with no ECG characteristics (HR: 2.11 95%CI: 2.05-2.16). Patients with two or more ECG characteristics present on their baseline ECG exceeded a 5% 2-year absolute risk of developing either AF or HF. Among patients with only one ECG characteristic on their baseline ECG, elevated heart rate and prolonged PR interval were the factors most associated with an increased risk of AF compared to patients with none of the ECG characteristics on their baseline ECG. Conclusions The absolute and relative risk of atrial fibrillation, heart failure, and stroke increased with the number of ECG characteristics present on the baseline ECG. We suggest that the ECG characteristics evaluated in this study could be used in screening scenarios for atrial fibrillation to identify high risk patients.Absolute and relative 2-year risksRisk acc. to specific ECG characteristic

What Is Faster than Where in Vocal Emotional Perception.

Voices carry a vast amount of information about speakers (e.g., emotional state; spatial location). Neuroimaging studies postulate that spatial ("where") and emotional ("what") cues are processed by partially independent processing streams. Although behavioral evidence reveals interactions between emotion and space, the temporal dynamics of these processes in the brain and its modulation by attention remain unknown. We investigated whether and how spatial and emotional features interact during voice processing as a function of attention focus. Spatialized nonverbal vocalizations differing in valence (neutral, amusement, anger) were presented at different locations around the head, whereas listeners discriminated either the spatial location or emotional quality of the voice. Neural activity was measured with ERPs of the EEG. Affective ratings were collected at the end of the EEG session. Emotional vocalizations elicited decreased N1 but increased P2 and late positive potential amplitudes. Interactions of space and emotion occurred at the salience detection stage: neutral vocalizations presented at right (vs. left) locations elicited increased P2 amplitudes, but no such differences were observed for emotional vocalizations. When task instructions involved emotion categorization, the P2 was increased for vocalizations presented at front (vs. back) locations. Behaviorally, only valence and arousal ratings showed emotion-space interactions. These findings suggest that emotional representations are activated earlier than spatial representations in voice processing. The perceptual prioritization of emotional cues occurred irrespective of task instructions but was not paralleled by an augmented stimulus representation in space. These findings support the differential responding to emotional information by auditory processing pathways.

Neural correlates of prospective memory in college students with anxiety.

Prospective memory (PM) is the ability to create and execute future tasks. It is comprised of two components: cue detection and intention retrieval. PM is essential for performing high-level goals, a proficiency extremely important in college populations. Anxiety is a prevalent psychological experience in college populations that may be associated with impairments in PM. The present study examined PM performance and anxiety in college students, using neurophysiology to measure the mechanism of impairment. After self-reporting anxiety levels, 80 participants completed an event-based, focal PM task while two event-related potentials were recorded from an electroencephalogram: the N300 to assess cue detection, and the prospective positivity to assess intention retrieval. The results demonstrated that, when controlling for age and gender, higher state anxiety was significantly associated with lower PM accuracy (β = -0.27, p = 0.020) and lower prospective positivity amplitude (β = -0.04, p = 0.021). Lower prospective positivity amplitude was significantly associated with lower PM accuracy (β = 0.27, p = 0.015). Higher state anxiety was significantly indirectly associated with lower PM accuracy mediated by lower prospective positivity amplitude (ab = -0.11, p = 0.047). These findings suggest intention retrieval could be a key component in supporting PM for college students with high state anxiety.

Influence of presentation duration on filtering of irrelevant stimuli in visual working memory

In environments teeming with distractions, the ability to selectively focus on relevant information is crucial for advanced cognitive processing. Existing research using event-related potential (ERP) technology has shown active suppression of irrelevant stimuli during the consolidation phase of visual working memory (VWM). In previous studies, participants have always been given sufficient time to consolidate VWM, while suppressing distracting information. However, it remains unclear whether the suppression of irrelevant distractors requires continuous effort throughout their presence or whether this suppression is only necessary after the consolidation of task-relevant information. To address this question, our study examines whether distractor suppression is necessary in scenarios where consolidation time is limited. This research investigates the effect of varying presentation durations on the filtering of distractors in VWM. We tasked participants with memorizing two color stimuli and ignoring four distractors, presented for either 50 ms or 200 ms. Using ERP technology, we discovered that the distractor-induced distractor positivity (PD) amplitude is larger during longer presentation durations compared to shorter ones. These findings underscore the significant impact of presentation duration on the efficacy of distractor suppression in VWM, as prolonged exposure results in a stronger suppression effect on distractors. This study sheds light on the temporal dynamics of attention and memory, emphasizing the critical role of stimulus timing in cognitive tasks. These findings provide valuable insights into the mechanisms underlying VWM and have significant implications for models of attention and memory.

On the stability of fully nonlinear hydraulic-fall solutions to the forced water wave problem

Two-dimensional free-surface flow over localised topography is examined, with the emphasis on the stability of hydraulic-fall solutions. A Gaussian topography profile is assumed with a positive or negative amplitude modelling a bump or a dip, respectively. Steady hydraulic-fall solutions to the full incompressible, irrotational Euler equations are computed, and their linear and nonlinear stability is analysed by computing eigenspectra of the pertinent linearised operator and by solving an initial value problem. The computations are carried out numerically using a specially developed computational framework based on the finite-element method. The Hamiltonian structure of the problem is demonstrated, and stability is determined by computing eigenspectra of the pertinent linearised operator. It is found that a hydraulic-fall flow over a bump is spectrally stable. The corresponding flow over a dip is found to be linearly unstable. In the latter case, time-dependent simulations show that ultimately, the flow settles into a time-periodic motion that corresponds to an invariant solution in an appropriately defined phase space. Physically, the solution consists of a localised large-amplitude wave that pulsates above the dip while simultaneously emitting nonlinear cnoidal waves in the upstream direction and multi-harmonic linear waves in the downstream direction.

Exploring the Influence of Object, Subject, and Context on Aesthetic Evaluation through Computational Aesthetics and Neuroaesthetics

Background: In recent years, computational aesthetics and neuroaesthetics have provided novel insights into understanding beauty. Building upon the findings of traditional aesthetics, this study aims to combine these two research methods to explore an interdisciplinary approach to studying aesthetics. Method: Abstract artworks were used as experimental materials. Based on traditional aesthetics and in combination, features of composition, tone, and texture were selected. Computational aesthetic methods were then employed to correspond these features to physical quantities: blank space, gray histogram, Gray Level Co-occurrence Matrix (GLCM), Local Binary Pattern (LBP), and Gabor filters. An electroencephalogram (EEG) experiment was carried out, in which participants conducted aesthetic evaluations of the experimental materials in different contexts (genuine, fake), and their EEG data were recorded to analyze the impact of various feature classes in the aesthetic evaluation process. Finally, a Support Vector Machines (SVMs) was utilized to model the feature data, Event-Related Potentials (ERPs), context data, and subjective aesthetic evaluation data. Result: Behavioral data revealed higher aesthetic ratings in the genuine context. ERP data indicated that genuine contexts elicited more negative deflections in the prefrontal lobes between 200 and 1000 ms. Class II compositions demonstrated more positive deflections in the parietal lobes at 50–120 ms, while Class I tones evoked more positive amplitudes in the occipital lobes at 200–300 ms. Gabor features showed significant variations in the parieto-occipital area at an early stage. Class II LBP elicited a prefrontal negative wave with a larger amplitude. The results of the SVM models indicated that the model incorporating aesthetic subject and context data (ACC = 0.76866) outperforms the model using only parameters of the aesthetic object (ACC = 0.68657). Conclusion: A positive context tends to provide participants with a more positive aesthetic experience, but abstract artworks may not respond to this positivity. During aesthetic evaluation, the ERP data activated by different features show a trend from global to local. The SVM model based on multimodal data fusion effectively predicts aesthetics, further demonstrating the feasibility of the combined research approach of computational aesthetics and neuroaesthetics.

Attentional resource consumption of verbal-humor processing: An ERP study

As a high-demanding mental activity with both cognitive and emotional factors, verbal-humor processing consumes more attentional resources than non-humor processing, which has been demonstrated by behavioral studies, but little has been examined at a real-time scale. Based on the three-stage model (incongruity detection, incongruity resolution, and mirth), the current study used event-related potential (ERP) and event-related oscillation (ERO) to explore the attentional resource consumption of verbal-humor processing by employing a dual-task paradigm in which sentence comprehension (humorous, positive, neutral) was the primary task and arithmetical calculation (simple, difficult) was the secondary task.Participants’ (N=38) behavioral performance and ERP/ERO measures in two tasks were analyzed. ERP results of verbal-humor processing revealed significantly larger LAN, LLAN, and LPP activation, which indexed three stages. ERO results showed significant beta power changes in the detection stage and theta changes in the resolution and mirth stages. The behavioral data indicated that the Reaction Times (RTs) of the arithmetical task following verbal-humor processing were longer than those following non-humorous positive and neutral ones. The ERP results of arithmetical calculation found that the calculations following verbal-humor processing elicited significantly greater P2, P3b, and positive slow wave amplitudes than those following the other two processings, which reflected more resource allocation in the calculation to compensate for the resource preemption of verbal-humor processing. In addition, the calculation following positive sentence exhibited a greater ERP amplitude in the relatively early P2 time intervals than that following the neutral sentences. Collectively, the behavioral, ERP, and ERO results concurrently confirmed that verbal-humor processing consumed more attentional resources compared with non-humorous counterparts, and moreover, the comparison of ERP following humorous and positive sentences suggested that the processing of the cognitive factor consumes more attentional resources than the emotional factor although both factors play a role in the process.

The impact of safety attitude on hazard identification and risk analysis: evidence from event-related potentials

ABSTRACT A questionnaire survey and an event-related potential (ERP) experiment were used to reveal the impact of safety attitudes on risk perception. The results revealed that during hazard identification, the N130 amplitude of subjects with negative safety attitude was significantly higher, which implied that subjects with negative safety attitude were more likely to feel confused. During risk analysis, subjects with positive safety attitude were more inclined to overestimate the probability and damage degree of risks; subjects with positive safety attitudes displayed higher P150 and late positive potential amplitudes, which indicated that subjects with positive safety attitudes devoted more attention to risks in the early stage of risk analysis and had a more intense affective response in the later period. The risk judgment ability of subjects with positive safety attitude was affected by time pressure, and they exhibited higher risk judgment accuracy only under no time pressure.

The paradox of social avoidance and the yearning for understanding: Elevated interbrain synchrony among socially avoidant individuals during expression of negative emotions

Social avoidance refers to the tendency to be alone and non-participating to social interactions, which is considered to hamper health interpersonal relationship. However, the neural underpinnings of social and emotional interactions among social avoidant individuals have not been fully studied. In the present study, we used EEG hyperscanning technology to investigate the brain activity and its synchronization of 25 socially avoidant dyads and 28 comparison dyads during an emotional communication task. The emotional communication task consisted of the emotional processing stage and emotional interaction stage. Event-related potentials (ERPs) of the senders during the emotional processing stage and the interbrain synchrony (IBS) of the dyads during the emotional interaction stage were analyzed. Results showed that (1) socially avoidant group showed higher beta, theta and gamma IBS in the negative condition than in the positive and neutral condition; (2) in positive condition, the N1 and LPP amplitudes during the emotional processing stage of socially avoidant individuals were negatively correlated with the IBS within dyads during the emotional communication stage. The findings suggest that the dysfunctional emotional interaction of social avoidant individuals may be attributed to the negative impact of emotional stimuli processing during emotional communication.

Electrical brain activations in preadolescents during a probabilistic reward-learning task reflect cognitive processes and behavioral strategy.

Both adults and children learn through feedback which environmental events and choices are associated with higher probability of reward, an ability thought to be supported by the development of fronto-striatal reward circuits. Recent developmental studies have applied computational models of reward learning to investigate such learning in children. However, tasks and measures effective for assaying the cascade of reward-learning neural processes in children have been limited. Using a child-version of a probabilistic reward-learning task while recording event-related-potential (ERP) measures of electrical brain activity, this study examined key processes of reward learning in preadolescents (8-12 years old; n=30), namely: (1) reward-feedback sensitivity, as measured by the early-latency, reward-related, frontal ERP positivity, (2) rapid attentional shifting of processing toward favored visual stimuli, as measured by the N2pc component, and (3) longer-latency attention-related responses to reward feedback as a function of behavioral strategies (i.e., Win-Stay-Lose-Shift), as measured by the central-parietal P300. Consistent with our prior work in adults, the behavioral findings indicate preadolescents can learn stimulus-reward outcome associations, but at varying levels of performance. Neurally, poor preadolescent learners (those with slower learning rates) showed greater reward-related positivity amplitudes relative to good learners, suggesting greater reward-feedback sensitivity. We also found attention shifting towards to-be-chosen stimuli, as evidenced by the N2pc, but not to more highly rewarded stimuli as we have observed in adults. Lastly, we found the behavioral learning strategy (i.e., Win-Stay-Lose-Shift) reflected by the feedback-elicited parietal P300. These findings provide novel insights into the key neural processes underlying reinforcement learning in preadolescents.

A simplified model for predicting ventricular hypertrophy than traditional methods

Ventricular hypertrophy is the thickening of the muscles in the ventricular chambers of the heart which stiffens and thickens the cardiac walls giving rise to many complications like arrhythmia, high blood pressure, or even heart failure. One of the ways to diagnose ventricular hypertrophy is through an Echocardiogram which can be predicted by the positive large amplitude of Chest Leads [V4–V6] of an Electrocardiogram (ECG). But chest lead application is one of the complicated more parts of the ECG than limb lead. Here we have tried to predict ventricular hypertrophy with bipolar limb lead electrocardiogram [L-I, L-II & L-III] without any chest leads which can be easily designed to make an ECG prototype instead of any sophisticated instruments to increase its global accessibility even in remote areas for the prediction of ventricular hypertrophy even may be for other diagnosis in future. We acquired electrocardiogram data sets from the physio-net database, specifically collected data from both normal and hypertrophic patients in an institute. These data sets were obtained using the same recording device. The Lead-I of the RVH and normal patients were not satisfactorily distinguishable. However, in this work, it has been established that Lead-I can be used to predict for identification of LVH patients.

A Spoof Surface Plasmon Polaritons Filter with Controllable Negative Slope Equalization Based on Surface Resistance

This paper presents a novel spoof surface plasmon polariton (SSPP) filter integrated with controllable negative slope equalization. Different from traditional microwave filters, two microwave functions - amplitude compensation and interference suppression - are integrated into one device by depositing a lossy indium tin oxide (ITO) film on the rectangular corrugated stub of the SSPP unit. The key point of negative slope equalization benefits from the surface resistance of the ITO film, and the circuit model and behavior are analyzed in detail. Based on the principle, a prototype of a SSPP filter operating from S to C band is designed and fabricated. The measurement results show that the attenuation in the passband increases almost linearly from 3.5 GHz (−4.8 dB) to 6.9 GHz (−15.4 dB), indicating that −10.6 dB equalization is achieved. The improved S21 is attributed to the good impedance matching by sputtering the ITO film on the rectangular metal strip rather than the central strip. Due to the natural low-pass property of SSPPs, the high-order parasitic band is suppressed above the cut-off frequency of 8.5 GHz. The analyses, simulations and measurements show that the proposed SSPP filter is provided with an additional ability to compensate for positive amplitude fluctuation in wideband antennas.

Simulation of large plausible tsunami scenarios associated with the 2019 Durres (Albania) earthquake source and adjacent seismogenic zones

We present an analysis of the hazards of potential earthquake-generated tsunamis along the Albanian–Adriatic coast. The study adopts a case study approach to model plausible tsunamigenic events associated with the 2019 Mw 6.4 Durres (Albania) earthquake source zone. The approach combines current findings on regional tectonics and scenario-based calculations of potential tsunami impacts. The study’s goal is to analyse the propagation of tsunami waves generated by identified seismogenic sources (namely ALCS002 [Lushnje] and ALCS018 [Shijak]) and determine the tsunami risk assessment for Durres City on the Albanian–Adriatic coast. The sources can generate earthquakes with maximum moment magnitudes of Mw 7.5 and Mw 6.8, which are likely to trigger tsunamis that could cause significant impacts in the region. The modelling is performed deterministically with the NAMI DANCE numerical code, including scenarios associated with the largest plausible earthquake. The model integrates bathymetry and topography datasets of large and medium resolutions. Each tsunami scenario simulation is based on the solution of the non-linear shallow water equations used to generate maximum positive wave amplitudes (water elevation), travel time, and tsunami inundation maps. In Durres City, modelling indicates that medium-sized waves could reach up to 2.5 m inland, posing a significant danger to the city’s low-lying areas. The most substantial tsunami waves are expected to impact the area within the first 10 to 20 min. Combining inundation maps and information on exposed assets allows for identifying areas where damages can be expected. In terms of human impact, a preliminary analysis shows that the study area is prone to tsunami threat, with more than 138,000 inhabitants living in vulnerable urban areas of Durres City by 2036. The model’s capacity to capture details related to the presence of buildings is limited due to constraints posed by the resolution of bathymetry and topography datasets available during this study. If refined with high-resolution bathymetry and topography datasets, our results can be considered a backbone for exposure and resilience assessment features to be integrated into preparedness or new urban development plans.

How Socially Avoidant Emerging Adults Process Social Feedback during Human-to-Human Interaction after Social Rejection: An Event-Related Potential Study.

Social avoidance refers to active non-participation in social activities, which is detrimental to healthy interpersonal interaction for emerging adults. Social rejection is a kind of negative social evaluation from others making people feel social pain. However, how socially avoidant emerging adults process social feedback information after experiencing social rejection has received less attention. The current study aimed to explore the differences in social interaction feedback processing after social rejection between a socially avoidant group (n = 16) and a comparison group (n = 16) in a human-to-human interaction context. Computer game tasks with two types of interaction (cooperation and competition) were used to record the event-related potentials when receiving social interaction feedback in two conditions (social rejection and control condition). The results showed that (1) the socially avoidant group had lower reward positivity amplitudes than the comparison group when receiving social feedback; (2) the socially avoidant group presented larger P300 amplitudes in the social rejection condition than in the control condition, but the comparison group did not; and (3) social rejection evoked more negative N1 amplitudes in the socially avoidant and comparison groups. The findings suggest that socially avoidant emerging adults may have flaws in reward sensitivity during interpersonal interaction, and they might also exert more attentional and emotional resources to social feedback after social rejection.

The priming effect of emotional words on body expressions: Two ERP studies

The impact of emotional words on the recognition of body expression and the underlying neurodynamic mechanisms remain poorly understood. This study used a classic supraliminal priming paradigm and event related potential (ERP) to investigate the effect of emotion-label words (experiment 1) and emotional verbs (experiment 2) on the recognition of body expressions. The behavioral results revealed that individuals exhibited a higher accuracy in recognizing happy expressions when presented with a happy-label word condition, in contrast to neutral expressions. Furthermore, it was observed that the accuracy of recognizing happy body expressions was reduced when preceded by angry verb priming, compared to happy and neutral priming conditions. Conversely, the accuracy of recognizing angry body expressions was higher in response to angry verb priming than happy and neutral primings. The ERP results showed that, in the recognition of happy body expressions, the P300 amplitude elicited by angry-label words was more positive, while a congruent verb-expression condition elicited more positive P300 amplitude than an incongruent condition in the left hemisphere and midline. However, in the recognition of angry body expressions, the N400 amplitude elicited by a congruent verb-expression condition was smaller than that elicited by an incongruent condition. These results suggest that both abstract emotion-label words and specific emotional verbs influence the recognition of body expressions. In addition, integrating happy semantic context and body expression might occur at the P300 stage, whereas integrating angry semantic context and body expression might occur at the N400 stage. These findings present novel evidence regarding the criticality of emotional context in the recognition of emotions.

Altered Error Monitoring and Decreased Flanker Task Accuracy in Pediatric Obsessive-Compulsive Disorder.

The error-related negativity (ERN) and error positivity (Pe) are components of the event-related potential following an error that are potential mechanistic biomarkers of obsessive-compulsive disorder (OCD). The study examined the ERN, Pe, flanker task accuracy, and clinical measures in 105 OCD cases and 105 matched healthy controls (HC) ages 8-18years. Higher flanker task accuracy in all participants was associated with an increased ERN amplitude and increased difference between Pe and correct positivity amplitudes (ΔPe). Compared to HC, OCD cases had an increased ERN but decreased ΔPe and flanker task accuracy. Those differences were also significant in tic-related and non-tic-related OCD cases compared to HC. A lower ΔPe was associated in cases with an earlier age at OCD symptom onset. The results support the hypothesis that OCD involves defects in an error monitoring system and suggest a reduced ΔPe may compromise error signaling and cause uncertainty about the correctness of a response.

Distinct neural markers of evidence accumulation index metacognitive processing before and after simple visual decisions.

Perceptual decision-making is affected by uncertainty arising from the reliability of incoming sensory evidence (perceptual uncertainty) and the categorization of that evidence relative to a choice boundary (categorical uncertainty). Here, we investigated how these factors impact the temporal dynamics of evidence processing during decision-making and subsequent metacognitive judgments. Participants performed a motion discrimination task while electroencephalography was recorded. We manipulated perceptual uncertainty by varying motion coherence, and categorical uncertainty by varying the angular offset of motion signals relative to a criterion. After each trial, participants rated their desire to change their mind. High uncertainty impaired perceptual and metacognitive judgments and reduced the amplitude of the centro-parietal positivity, a neural marker of evidence accumulation. Coherence and offset affected the centro-parietal positivity at different time points, suggesting that perceptual and categorical uncertainty affect decision-making in sequential stages. Moreover, the centro-parietal positivity predicted participants' metacognitive judgments: larger predecisional centro-parietal positivity amplitude was associated with less desire to change one's mind, whereas larger postdecisional centro-parietal positivity amplitude was associated with greater desire to change one's mind, but only following errors. These findings reveal a dissociation between predecisional and postdecisional evidence processing, suggesting that the CPP tracks potentially distinct cognitive processes before and after a decision.

Curiosity Satisfaction Increases Event-related Potentials Sensitive to Reward.

Successful learning depends on various factors such as depth of processing, motivation, or curiosity about information. A strong drive to learn something or the expectation of receiving a reward can be crucial to enhance learning. However, the influence of curiosity on the processing of new information and its similarity with reward processing is not well understood. This study examined whether states of curiosity influence specific ERPs associated with reward processing and whether these ERPs are related with later memory benefits. In an initial screening phase, participants indicated their curiosity and confidence in prior knowledge about answers to various trivia questions. In a subsequent study phase, we targeted different time windows related to reward processing during the presentation of trivia answers containing the reward positivity (RewP; 250-350 msec), the P3 (250-500 msec), and the late-positive-potential (LPP; 600-1000 msec). In a following surprise memory test, we found that participants recalled more high- than low-curiosity answers. The RewP, P3, and LPP showed greater positive mean amplitudes for high compared with low curiosity, reflecting increased reward processing. In addition, we found that the RewP and the P3 showed more positive mean amplitudes for later recalled compared with later forgotten answers, but curiosity did not modulate this encoding-related results. These findings support the view that the satisfaction of curiosity resembles reward processing, indicated by ERPs.

D-region ionospheric disturbances due to the December 2019 solar eclipse observed using multi-station VLF radio network

We present the low-latitude D-region (60–90 km) ionospheric disturbances due to the December 2019 annular solar eclipse observed using the multi-station Very Low Frequency (VLF) radio network in West Bengal, India. VLF signals from communication transmitters were received from ten places using low-cost VLF radio receivers. The receivers were capable of recording the amplitudes of VLF signals mainly from the transmitters VTX, India at 18.2 kHz and NWC, Australia at 19.8 kHz. During the solar eclipse, the VTX signal experienced considerable positive, negative, and mixed-type amplitude variations depending on the propagation lengths between the transmitter and receivers, whereas the NWC signal displayed a relatively small amplitude response. We have also found that the highest VLF signal disturbances in each propagation path occurred after the time when the solar obscuration was maximum over the entire path. We used the observations of the VTX signal to formulate the relationship between solar obscuration and D-region electron density reduction during the solar eclipse. On the basis of this, we presented the electron density distribution of the D-region ionosphere during the solar eclipse across the Indian subcontinent. This study shows a useful method for integrating VLF observations and simulations to estimate the D-region electron density distribution over a vast area during a solar eclipse.

Effect of contextual prediction on emotional word processing: an evidence from ERPNR-D-24-00189.

This study examined the effect of context on the prediction of emotional words with varying valences. It investigated the neural mechanisms underlying the processing differences of emotion words with different valences in both predictable and unpredictable contexts. Additionally, it aimed to address the conflicting results regarding the processing time in predictive contexts reported in previous studies. Participants were instructed to carefully read the text that included the specified emotion words. Event-related potentials elicited by emotional words were measured. To ensure that the participants can read the text carefully, 33% of the texts are followed by comprehension problems. After reading the text, the comprehension questions were answered based on the text content. The study revealed that the N400 amplitude elicited by an unpredictable context was greater than that elicited by a predictable context. Additionally, the N400 amplitude triggered by positive emotion words was larger than that triggered by negative emotion words. However, there was no significant difference in late positive component amplitude observed between contextual prediction and emotional word valence. The present study suggests that predictive processing takes place at an intermediate stage of speech processing, approximately 400 ms after stimulus onset. Furthermore, the presence of a predictive context enhances the processing of emotional information. Notably, brain activity is more pronounced during the processing of positive emotional stimuli compared to negative emotional stimuli. Additionally, the facilitative effect of a predictable context diminishes in the advanced phase of Chinese speech comprehension.