Group membership modulates empathic neural responses to pain in deaf individuals.

Empathy deficiencies are prevalent among deaf individuals. It has yet to be determined whether they exhibit an ingroup bias in empathic responses. This study employed explicit and implicit empathy tasks (i.e. attention-to-pain-cue [A-P] task and attention-to-nonpain-cue [A-N] task) to explore the temporal dynamics of neural activities when deaf individuals were processing painful/nonpainful stimuli from both ingroup models (deaf people) and outgroup models (hearing people), which aims to not only assist deaf individuals in gaining a deeper understanding of their intergroup empathy traits but also to aid in the advancement of inclusive education. In the A-P task, we found that (i) ingroup priming accelerated the response speed to painful/nonpainful pictures; (ii) the N2 amplitude of painful pictures was significantly more negative than that of nonpainful pictures in outgroup priming trials, whereas the N2 amplitude difference between painful and nonpainful pictures was not significant in ingroup priming trials. For N1 amplitude of the A-N task, we have similar findings. However, this pattern was reversed for P3/late positive component amplitude of the A-P task. These results suggest that the deaf individuals had difficulty in judging whether hearing individuals were in pain. However, their group identification and affective responses could shape the relatively early stage of pain empathy.

An ERP investigation of electrocortical responses in pain empathy from childhood through adolescence into adulthood.

Only a few studies investigated the neurodevelopment of pain empathy. Here, the temporal dynamics of electrocortical processes in pain empathy during individual neurodevelopment from childhood through adolescence into adulthood, along with the moderation effect of top-down attention, were investigated using the event-related potential (ERP) technique. To investigate the role of top-down attention in empathy development, both A-P task and A-N task were conducted. In the A-P and A-N task, participants are instructed to judge whether the models in pictures were painful or non-painful and count the number of limbs in pictures, respectively. We found that compared to the adolescent and adult groups, the children group responded significantly worse, along with stronger neural responses in both tasks. Compared to the adolescent and adult groups, the differential amplitudes between painful and non-painful conditions of P2, N2 and P3 were significantly larger in the children group. Moreover, this P3 differential amplitude could only be modulated by age in the A-P task. These results suggest that the capacity to empathize has not yet attained complete development in these children. Significantly more attention resources were involuntarily attracted by the nociceptive cues in these children, which could also reflect the immaturity of empathy ability in these children.

Resting-state EEG Microstate Features Can Quantitatively Predict Autistic Traits in Typically Developing Individuals.

Autism spectrum disorder (ASD) is not a discrete disorder and that symptoms of ASD (i.e., so-called "autistic traits") are found to varying degrees in the general population. Typically developing individuals with sub-clinical yet high-level autistic traits have similar abnormities both in behavioral performances and cortical activation patterns to individuals diagnosed with ASD. Thus it's crucial to develop objective and efficient tools that could be used in the assessment of autistic traits. Here, we proposed a novel machine learning-based assessment of the autistic traits using EEG microstate features derived from a brief resting-state EEG recording. The results showed that: (1) through the Least Absolute Shrinkage and Selection Operator (LASSO) algorithm and correlation analysis, the mean duration of microstate class D, the occurrence rate of microstate class A, the time coverage of microstate class D and the transition rate from microstate class B to D were selected to be crucial microstate features which could be used in autistic traits prediction; (2) in the support vector regression (SVR) model, which was constructed to predict the participants' autistic trait scores using these four microstate features, the out-of-sample predicted autistic trait scores showed a significant and good match with the self-reported scores. These results suggest that the resting-state EEG microstate analysis technique can be used to predict autistic trait to some extent.

The neurophysiological mechanism of valence-space congruency effect: evidence from spatial Stroop task and event-related EEG features.

Metaphors commonly represent mental representations of abstract concepts. One example is the valence-space metaphor (i.e., positive word-up, negative word-down), which suggests that the vertical position of positive/negative words can modulate the evaluation of word valence. Here, the spatial Stroop task and electroencephalography (EEG) techniques were used to explore the neural mechanism of the valence-space congruency effect in valence-space metaphors. This study showed that the reaction time of the congruent condition (i.e., positive words at the top and negative words at the bottom of the screen) was significantly shorter than that of the incongruent condition (i.e., positive words at the bottom and negative words at the top of the screen), while the accuracy rate of the congruent condition was significantly larger than that of the incongruent condition. The analysis of the amplitudes of event-related potential components revealed that congruency between the vertical position and valence of Chinese words could significantly modulate the amplitude of attention allocation-related P2 component and semantic violations related N400 component. Moreover, statistical tests conducted on the post-stimulus inter-trial phase coherence (ITPC) found that the ITPC value of an alpha band region of interest (8-12 Hz, 100-300 ms post-stimulus) in the time-frequency plane of the congruent condition was significantly larger than that of the incongruent condition. Above all, the current study proved the existence of the space-valence congruency effect in Chinese words and provided some interesting neurophysiological mechanisms regarding the valence-space metaphor.

Behavioral and electrophysiological evidence for valence-space congruency effect of emotional pictures in a spatial Stroop task.

Previous studies have shown that people implicitly associate the emotional valence of abstract words with vertical position (i.e., positive words up, negative words down), resulting in the so-called valence-space congruency effect. Research has demonstrated that there is a valence-space congruency effect when it comes to emotional words. It's interesting to see that whether the emotional pictures with different levels of valence are mapped to distinct vertical space positions. Here, the event-related potential (ERP) and time-frequency techniques were employed to investigate the neural basis of the valence-space congruency effect of emotional pictures in a spatial Stroop task. Firstly, this study showed that the reaction time of the congruent condition (i.e., positive pictures in the top and negative pictures in the bottom of the screen) was significantly shorter than that of the incongruent condition (i.e., positive pictures in the bottom and negative pictures in the top of the screen), suggesting that exposure to stimuli with positive or negative valence, regardless of whether these stimuli were comprised of words or pictures, would be enough to invoke the vertical metaphor. Moreover, we found that the congruency between the vertical position and the valence of emotional pictures could significantly modulate the amplitude of the P2 component and the Late Positive Component (LPC) in ERP waveforms, as well as the post-stimulus alpha-ERD in the time-frequency plane. This study has conclusively demonstrated the presence of a space-valence congruency effect in emotional pictures and has elucidated the underlying neurophysiological mechanisms associated with the valence-space metaphor.

Preparation and Properties of Bio-Based Attapulgite Copolymer (BAC) Sand-Fixing Material.

Desertification, one of the world's most pressing serious environmental problems, poses a serious threat to human survival as well as to social, economic, and political development. Nevertheless, the development of environmentally friendly sand-fixing materials is still a tremendous challenge for preventing desertification. This study developed a bio-based attapulgite copolymer (BAC) by grafting copolymerization of attapulgite, starch, sulfomethyl lignin, and biological mycelia. Water retention, anti-water erosion, and anti-wind erosion tests were conducted to assess the application performance of the BAC. Scanning electron microscopy (SEM) was then employed to determine the morphology of the attapulgite and attapulgite graft copolymer sand-fixing material (CSF). The intermolecular interactions in CSF were revealed using Fourier transform infrared spectrum (FT-IR). The role of sand-fixing materials on soil physicochemical properties and seed germination was then discussed based on the germination rate experiments, and 16S rDNA sequencing technology was used to analyze the differences in microbial communities in each sample group. The results demonstrated that the BAC not only has superior application properties and significantly increased seed germination (95%), but also promotes soil development by regulating the structure of the soil microbial community. This work provides novel insights into the design of sand-fixing material for preventing desertification while improving soil fertility.

Just world beliefs and altruistic behaviors of college students during the COVID-19 pandemic: The mediating role of empathy.

Altruistic behavior is of great significance for individual happiness and social development. The study has focused on the influence of two factors at the individual level on college students' altruistic behavior. The self-report questionnaires of 2,272 college students on belief in a just world, empathy and altruistic behavior were investigated. The results of the study found that: 1) Just-world belief and empathy both positively predicted altruistic behavior; 2) Empathy influenced altruistic behavior through just-world belief. And from the perspective of motivation theory, it explains that individuals affirm that altruistic behavior will bring spiritual pleasure, so individuals will maintain the consistency of their own internal factors to promote altruistic behavior.This study enriches the research value of altruistic behavior at the individual level and provides an empirical basis for the cultivation of altruistic behavior at the individual level.

Scale-Free Dynamics in Instantaneous Alpha Frequency Fluctuations: Validation, Test-Retest Reliability and Its Relationship with Task Manipulations.

Previous studies showed that scale-free structures and long-range temporal correlations are ubiquitous in physiological signals (e.g., electroencephalography). This is supposed to be associated with optimized information processing in human brain. The instantaneous alpha frequency (IAF) (i.e., the instantaneous frequency of alpha band of human EEG signals) may dictate the resolution at which information is sampled and/or processed by cortical neurons. To the best of our knowledge, no research has examined the scale-free dynamics and potential functional significance of IAF. Here, through three studies (Study 1: 25 participants; Study 2: 82 participants; Study 3: 26 participants), we investigated the possibility that time series of IAF exhibit scale-free property through maximum likelihood based detrended fluctuation analysis (ML-DFA). This technique could provide the scaling exponent (i.e., DFA exponent) on the basis of presence of scale-freeness being validated. Then the test-retest reliability (Study 1) and potential influencing factors (Study 2 and Study 3) of DFA exponent of IAF fluctuations were investigated. Firstly, the scale-free property was found to be inherent in IAF fluctuations with fairly high test-retest reliability over the parietal-occipital region. Moreover, the task manipulations could potentially modulate the DFA exponent of IAF fluctuations. Specifically, in Study 2, we found that the DFA exponent of IAF fluctuations in eye-closed resting-state condition was significantly larger than that in eye-open resting-state condition. In Study 3, we found that the DFA exponent of IAF fluctuations in eye-open resting-state condition was significantly larger than that in visual n-back tasks. The DFA exponent of IAF fluctuations in the 0-back task was significantly larger than in the 2-back and 3-back tasks. The results in studies 2 and 3 indicated that: (1) a smaller DFA exponent of IAF fluctuations should signify more efficient online visual information processing; (2) the scaling property of IAF fluctuations could reflect the physiological arousal level of participants.

Aberrant dynamic minimal spanning tree parameters within default mode network in patients with autism spectrum disorder.

The altered functional connectivity (FC) level and its temporal characteristics within certain cortical networks, such as the default mode network (DMN), could provide a possible explanatory framework for Autism spectrum disorder (ASD). In the current study, we hypothesized that the topographical organization along with its temporal dynamics of the autistic brain measured by temporal mean and variance of complex network measures, respectively, were significantly altered, which may further explain the autistic symptom severity in patients with ASD. To validate these hypotheses, the precise FCs between DMN regions at each time point were calculated using the resting-state functional magnetic resonance imaging (fMRI) datasets from the Autism Brain Imaging Data Exchange (ABIDE) project. Then, the minimal spanning tree (MST) technique was applied to construct a time-varying complex network of DMN. By analyzing the temporal mean and variance of MST parameters and their relationship with autistic symptom severity, we found that in persons with ASD, the information exchange efficiencies between cortical regions within DMN were significantly lower and more volatile compared with those in typical developing participants. Moreover, these alterations within DMN were closely associated with the autistic symptom severity of the ASD group.

Impact of Graphene Oxide on Properties and Structure of Thin-Film Composite Forward Osmosis Membranes.

Forward osmosis (FO) membranes have the advantages of low energy consumption, high water recovery rate, and low membrane pollution trend, and they have been widely studied in many fields. However, the internal concentration polarization (ICP) caused by the accumulation of solutes in the porous support layer will reduce permeation efficiency, which is currently unavoidable. In this paper, we doped Graphene oxide (GO) nanoparticles (50~150 nm) to a polyamide (PA) active layer and/or polysulfone (PSF) support layer, investigating the influence of GO on the morphology and properties of thin-film composite forward osmosis (TFC-FO) membranes. The results show that under the optimal doping amount, doping GO to the PA active layer and PSF support layer, respectively, is conducive to the formation of dense and uniform nano-scale water channels perpendicular to the membrane surface possessing a high salt rejection rate and low reverse solute flux without sacrificing high water flux. Moreover, the water channels formed by doping GO to the active layer possess preferable properties, which significantly improves the salt rejection and water permeability of the membrane, with a salt rejection rate higher than 99% and a water flux of 54.85 L·m-2·h-1 while the pure PSF-PA membrane water flux is 12.94 L·m-2·h-1. GO-doping modification is promising for improving the performance and structure of TFC-FO membranes.

Aberrant dynamic functional connectivity features within default mode network in patients with autism spectrum disorder: evidence from dynamical conditional correlation.

Autism spectrum disorder (ASD) is characterized by aberrant functional connectivity (FC) within/between certain large-scale brain networks. Although relatively lower level of FC between default mode network (DMN) regions (i.e., DMN-FC) has been detected in many previous studies, they failed to capture the temporal dynamic features of DMN-FC and were limited by small sample size. Here, the dynamical conditional correlation, which could assess precise FC at each time point and has been proved to be a technique with high test-retest reliability, was applied to investigate the DMN-FC pattern of patients with ASD from the Autism Brain Imaging Data Exchange, which included functional and structural brain imaging data of more than 1000 participants. The data analysis here showed that compared to typical developing (TD) participants, patients with ASD exhibited significantly lower mean DMN-FC level across recording time, but significantly higher variance of DMN-FC level across recording time. Moreover, these alterations were significantly associated with symptom severity of patients, especially their impaired communication skills and repetitive behaviors. These results support the view that aberrant temporal dynamic of FC within DMN is an important neuropathological feature of ASD and is a potential biomarker for ASD diagnosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s11571-021-09723-9.

Attenuation of temporal correlations of neuronal oscillations in patients with mild spastic diplegia.

The aim of this study was to investigate the temporal correlations of neuronal oscillations in patients with mild spastic diplegia (MSD). Resting-state electroencephalography (EEG) was recorded from 15 male adolescent and young adult patients with MSD and 15 healthy controls. We characterized the temporal correlations of neuronal oscillations, both on long temporal scale (i.e., >1 second) and short-to-intermediate temporal scale (i.e., <≈1 second) using detrended fluctuation analysis (DFA) and an analysis of the life- and waiting-time statistics of oscillation bursts respectively. The DFA exponents at alpha and beta bands, the life-time biomarker of alpha oscillation, and the life- and waiting-time biomarkers of beta oscillation were significantly attenuated in the patients compared with controls. Moreover, altered scalp distributions of some temporal correlation measures were found at alpha and beta bands in these patients. All these findings suggest that MSD is associated with highly volatile neuronal states of alpha and beta oscillations on short-to-intermediate and much longer time scales, which may be related to cognitive dysfunction in patients with MSD.

Altered Resting-State EEG Microstate Parameters and Enhanced Spatial Complexity in Male Adolescent Patients with Mild Spastic Diplegia.

The aim of this study was to investigate the resting-state EEG microstate parameters and spatial complexity in male adolescent patients with mild spastic diplegia (MSD). Resting-state EEG data were collected from male adolescent patients with MSD and healthy controls with eyes closed. EEG microstate and omega complexity analysis were performed. Microstate analysis revealed that the occurrence rate of microstate class A and D were significantly higher and the duration of microstate class B was significantly lower in the patients compared to healthy controls, which indicated that the temporal complexity may be higher and certain cognitive functions may be impaired in these patients. Omega complexity analysis showed that the global omega complexity of alpha-2 band was significantly higher in the patients than the controls. Besides, compared to the anterior regional omega complexities, the posterior regional omega complexities were significantly lower in the delta, theta, alpha-1 and alpha-2 bands, but significantly higher in the beta-2 and gamma-1 bands. And the regional omega complexities in the delta, theta and alpha-1 bands were significantly higher in the patients than controls. The present study reveals that in male adolescent patients with MSD, the temporal and spatial complexities of EEG signal are enhanced, which may be closely associated with the altered brain functions in these patients.

Vertical position of Chinese power words influences power judgments: Evidence from spatial compatibility task and event-related Potentials.

The present study used event-related potentials (ERPs) to explore the influence of vertical position on power judgments. Participants were asked to identify whether a Chinese word represented a powerful or powerless group (e.g., "king" or "servant"), which was presented in the top or bottom of the screen. The behavioral analysis showed that judging the power of powerful words were significantly faster when they were presented at the top position, compared with when they were presented at the bottom position. The ERP analysis showed enhanced N1 amplitude for congruent trials (i.e., the powerful words in the top and the powerless words in the bottom of the screen) and larger P300 and LPC amplitude for incongruent trials (i.e., the powerful words in the bottom and the powerless words in the top of the screen). The present findings provide further electrophysiological evidence that thinking about power can automatically activate the underlying spatial up-down (verticality) image schema and that the influence of vertical position on the power judgments not only occurs at the early perceptual stage of power word processing, but also at the higher cognitive stage (i.e., allocation of attention resources, conflict solving and response selection). This study revealed the neural underpinnings of metaphor congruent effect which have great significance to our understanding of the abstract concept power.