Expectancy and attention bias to spiders: Dissecting anticipation and allocation processes using ERPs

The current registered report focused on the temporal dynamics of the relationship between expectancy and attention toward threat, to better understand the mechanisms underlying the prioritization of threat detection over expectancy. In the current event-related potentials experiment, a-priori expectancy was manipulated, and attention bias was measured, using a well-validated paradigm. A visual search array was presented, with one of two targets: spiders (threatening) or birds (neutral). A verbal cue stating the likelihood of encountering a target preceded the array, creating congruent and incongruent trials. Following cue presentation, preparatory processes were examined using the contingent negative variation (CNV) component. Following target presentation, two components were measured: early posterior negativity (EPN) and late positive potential (LPP), reflecting early and late stages of natural selective attention toward emotional stimuli, respectively. Behaviorally, spiders were found faster than birds, and congruency effects emerged for both targets. For the CNV, a non-significant trend of more negative amplitudes following spider cues emerged. As expected, EPN and LPP amplitudes were larger for spider targets compared to bird targets. Data-driven, exploratory, topographical analyses revealed different patterns of activation for bird cues compared to spider cues. Furthermore, 400-500 ms post-target, a congruency effect was revealed only for bird targets. Together, these results demonstrate that while expectancy for spider appearance is evident in differential neural preparation, the actual appearance of spider target overrides this expectancy effect and only in later stages of processing does the cueing effect come again into play.

Xanthogranulomatous and Emphysematous Pyelonephritis: Two Rare Entities Occurring in One Kidney

Teaching point: Both xanthogranulomatous and emphysematous pyelonephritis are severe renal inflammatory disorders, occurring simultaneously in extremely rare cases.

Rapid withdrawal from a threatening animal is movement-specific and mediated by reflex-like neural processing

Responses to potentially dangerous stimuli are among the most basic animal behaviors. While research has shown that threats automatically capture the attention of human participants, research has failed to demonstrate automatic behavioral responses to threats in humans. Using a novel naturalistic paradigm, we show that two species of animals humans often report fearing trigger rapid withdrawal responses: participants withdrew their arm from photos of snakes and spiders faster, and with higher acceleration when compared to bird and butterfly stimuli. The behavior was specific to withdrawal as approach movements or button-press/release tasks failed to detect a similar difference. Moreover, between-participant differences in how aversive they found the stimuli predicted the participant's withdrawal speed, indicating that the paradigm was also sensitive to trait-level differences between individuals. Using electroencephalography (EEG), we show that the fast withdrawal was mediated by two attentional processes. First, fast withdrawal responses were associated with early amplification of sensory signals (40-110 ms after stimulus). Second, a later correlate of feature-based attention (early posterior negativity, EPN, 200-240 ms after stimulus) revealed the opposite pattern: Stronger EPN was associated with slower behavioral responses, suggesting that the deployment of attention towards the threatening stimulus features, or failure to "disengage" attention from the stimulus, was detrimental for withdrawal speed. Altogether, the results suggest that rapid behavioral withdrawal from a threatening animal is mediated by reflex-like attentional processing, and later, conscious attention to stimulus features may hinder escaping the treat.

BSA-Seq for the Identification of Major Genes for EPN in Rice

Improving rice yield is one of the most important food issues internationally. It is an undeniable goal of rice breeding, and the effective panicle number (EPN) is a key factor determining rice yield. Increasing the EPN in rice is a major way to increase rice yield. Currently, the main quantitative trait locus (QTL) for EPN in rice is limited, and there is also limited research on the gene for EPN in rice. Therefore, the excavation and analysis of major genes related to EPN in rice is of great significance for molecular breeding and yield improvement. This study used japonica rice varieties Dongfu 114 and Longyang 11 to construct an F5 population consisting of 309 individual plants. Two extreme phenotypic pools were constructed by identifying the EPN of the population, and QTL-seq analysis was performed to obtain three main effective QTL intervals for EPN. This analysis also helped to screen out 34 candidate genes. Then, EPN time expression pattern analysis was performed on these 34 genes to screen out six candidate genes with higher expression levels. Using a 3K database to perform haplotype analysis on these six genes, we selected haplotypes with significant differences in EPN. Finally, five candidate genes related to EPN were obtained.

Predictors of mortality and nephrectomy in emphysematous pyelonephritis: a tertiary care centre study

INTRODUCTION

Emphysematous pyelonephritis (EPN) is a deadly disease due to its associated morbidity and mortality. Attempts have been made to identify predictors of severity, mortality and need for nephrectomy in EPN with little success.

METHODS

We conducted an ambispective study of EPN patients between March 2014 and September 2019. Retrospective data were collected which included age, sex, comorbidities, symptoms, signs, laboratory investigations including imaging, need for dialysis, management and any complications. All patients were then followed prospectively for renal dynamic scan, stone surgery or nephrectomy. Univariate analysis was performed to identify factors affecting mortality and need for elective nephrectomy.

RESULTS

In total, 112 patients were included. Mean patient age was 50.01 years, 55% were female and 5% had bilateral involvement. Fever and flank pain were the most common symptoms. Diabetes was seen in 75% of cases and 30% of cases required haemodialysis at initial presentation. About 60% of patients improved with pigtail drainage. Need for nephrectomy was greater in Huang-Tseng stage 3a (14.8%). Huang-Tseng stages 3b and 4 had higher mortality rates (25%) than the other stages (2.2%). Twelve of 99 patients had non functional kidney on follow-up and underwent elective nephrectomy. Low platelet counts, high body mass index, septic shock, dialysis and higher Huang-Tseng stage were found to be predictive of mortality and renal parenchymal thickness on computed tomography scan was predictive of follow-up nephrectomy.

CONCLUSIONS

Thrombocytopaenia, high body mass index, septic shock, haemodialysis and higher Huang-Tseng stage are predictors of mortality and renal parenchymal thickness <5mm is a predictor of poor salvage of affected kidney on follow-up.

The impact of emotional facial expressions on reflexive attention depends on the aim of dynamic gaze changes: An ERP study

The emotional expression and gaze direction of a face are important cues for human social interactions. However, the interplay of these factors and their neural correlates are only partially understood. In the current study, we investigated ERP correlates of gaze and emotion processing following the initial presentation of faces with different emotional expressions (happy, neutral, angry) and an averted or direct gaze direction as well as following a subsequent change in gaze direction that occurred in half of the trials. We focused on the time course and scalp topography of the N170 and EPN components. The N170 amplitude was larger to averted than direct gaze for the initial face presentation and larger to gaze changes from direct to averted than from averted to direct in response to the gaze change. For the EPN component in response to the initial face presentation, we replicate classic effects of emotion, which did not interact with gaze direction. As a major new finding, changes from direct to averted gaze elicited an EPN-like effect when the face showed a happy expression. No such effect was seen for angry expressions. We conclude that happy faces reflexively attract attention when they look at the observer rather than away from the observer. These results for happy expressions are in line with the shared signal hypothesis that posits a better processing of expressions if their approach or avoidance tendency is consistent with gaze direction. However, the shared signal hypothesis is not supported by the present results for angry faces.

Case-by-case: neural markers of emotion and task stimulus significance

The present study assessed the hypothesis that electrophysiological markers of emotional and task stimulus significance can be demonstrated in concert at the level of the individual case. Participants (n = 18, 9 females) viewed low and high-arousing pictures selected from behavior systems of sexual reproduction, disease avoidance, and predator fear. Furthermore, to concurrently manipulate task relevance, participants performed an explicit emotion categorization task with either low or high-arousing pictures alternating as target stimuli in separate experimental blocks. Pooled across behavior systems, event-related components sensitive to emotional significance reached statistical significance in 100% of the tests for the early posterior negativity and in 96% of the tests for the late positive potential. Regarding explicit task relevance, the target P3 effect was significant in 96% of the tests. These findings demonstrate that neural markers of stimulus significance driven by emotional picture content and explicit task demands can be assessed at the individual level. Replicating an effect case-after-case provides strong support for an effect common-to-all and may support individual inferences. Contributions of the case-by-case approach to reveal reproducible effects and implications for the development of neural biomarkers for specific affective and cognitive component processes are discussed.

Brain potentials related to violent video clips

The aim of the present study was to investigate whether affective video can elicit ERPs related to emotional processing. Compared with neutral video clips, violent video clips elicited delayed but amplitude-similar N1 component. The most conspicuous finding was enhanced EPN and LPP components for violent than neutral video clips. These data indicate the possibility of using affective video as stimulus to elicit ERPs and provide new evidence for processing affective stimuli, using real-life video clips with better ecological validity.

Involvement of a novel Pseudomonas protegens strain associated with entomopathogenic nematode infective juveniles in insect pathogenesis

BACKGROUND

The bioinsecticidal action of entomopathogenic nematodes (EPNs) typically relies on their symbiosis with core bacteria. However, recent studies highlighted the possible involvement of other noncore species. We have recently isolated a novel Pseudomonas protegens strain as a major agent of septicaemia in larvae of the wax moth, Galleria mellonella, infected with a soil-dwelling Steinernema feltiae strain. The actual role of this bacterium in entomopathogenesis was investigated.

RESULTS

The association of P. protegens with nematodes appeared to be robust, as supported by its direct and repeated isolation from both nematodes and insect larvae infected for several consecutive generations. The bacterium appeared to be well-adapted to the insect haemocoel, being able to proliferate rapidly after the injection of even a small amount of living cells [100 colony forming units (CFU)] to a larva, causing its fast death. The bacterium also was able to act by ingestion against G. mellonella larvae [median lethal concentration (LC₅₀ ) = 4.0 × 10⁷  CFU mL^-1 ], albeit with a slower action, which supports the involvement of specific virulence factors (e.g. chitinases, Fit toxin) to overcome the intestinal barrier to the haemocoel. Varying levels of bacterial virulence were observed on diverse target Diptera and Lepidoptera.

CONCLUSION

The soil-dwelling bacterium P. protegens appears to have evolved its own potential as a stand-alone entomopathogen, yet the establishment of an opportunistic association with entomoparasitic nematodes would represent a special competitive advantage. This finding contributes to a deeper understanding of the nematode-bacteria biocontrol agent complex and the deriving paradigm of their use as biological control agents. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Different Neural Responses for Unfinished Sentence as a Conventional Indirect Refusal Between Native and Non-native Speakers: An Event-Related Potential Study

Refusal is considered a face-threatening act (FTA), since it contradicts the inviter’s expectations. In the case of Japanese, native speakers (NS) are known to prefer to leave sentences unfinished for a conventional indirect refusal. Successful comprehension of this indirect refusal depends on whether the addressee is fully conventionalized to the preference for syntactic unfinishedness so that they can identify the true intention of the refusal. Then, non-native speakers (NNS) who are not fully accustomed to the convention may be confused by the indirect style. In the present study, we used event-related potentials (ERPs) of electroencephalography in an attempt to differentiate the neural substrates for perceiving unfinished sentences in a conventionalized indirect refusal as an FTA between NS and NNS, in terms of the unfinishedness and indirectness of the critical sentence. In addition, we examined the effects of individual differences in mentalization, or the theory of mind, which refers to the ability to infer the mental states of others. We found several different ERP effects for these refusals between NS and NNS. NNS induced stronger P600 effects for the unfinishedness of the refusal sentences, suggesting their perceived syntactic anomaly. This was not evoked in NS. NNS also revealed the effects of N400 and P300 for the indirectness of refusal sentences, which can be interpreted as their increased processing load for pragmatic processing in the inexperienced contextual flow. We further found that the NNS’s individual mentalizing ability correlates with the effect of N400 mentioned above, indicating that lower mentalizers evoke higher N400 for indirect refusal. NS, on the contrary, did not yield these effects reflecting the increased pragmatic processing load. Instead, they evoked earlier ERPs of early posterior negativity (EPN) and P200, both of which are known as indices of emotional processing, for finished sentences of refusal than for unfinished ones. We interpreted these effects as a NS’s dispreference for finished sentences to realize an FTA, given that unfinished sentences are considered more polite and more conventionalized in Japanese social encounters. Overall, these findings provide evidence that a syntactic anomaly inherent in a cultural convention as well as individual mentalizing ability plays an important role in understanding an indirect speech act of face-threatening refusal.

Acute toxicity of the insecticide EPN upon zebrafish (Danio rerio) embryos and its related adverse effects: Verification of abnormal cardiac development and seizure-like events

Toxicological studies of O-ethyl-O-(4-nitrophenyl) phenylphosphonothioate (EPN) to aquatic vertebrates have been reported, but no reports on toxic mechanism was reported. As zebrafish (Danio rerio) embryos were exposed to EPN, no changes in their survival and hatching rates were observed until 96 h post fertilization (hpf), even at the highest treated concentration of 500 μg/L. In both 250 μg/L and 500 μg/L, edemas were observed in the heart and yolk sac, and a blood pool was also found. Acridine orange staining confirmed apoptotic phynotype, which was the strongest in embryos at 48 hpf. No noticeable difference in the formation and the shape of blood vessels of Tg(fli1a:EGFP) was observed. However, the total body length and number of somite were decreased. Heart formation in Tg(cmlc2:EGFP) were not properly proceeded, and the ventricle did not beat normally at 500 μg/L level. Cardiac development-related genes, myl7 and nppa, were significantly down- and up-regulated in a concentration-dependent manner. The slowed heartbeat was confirmed using Tg(gata1:EGFP), showing stagnant blood flow and seizure-like events were observed. Altogether, EPN can be the cause for the abnormal heart development accompanied by blood stagnation in embryos, interfering normal development with their inner circulatory system.

Comparison of a Vintage and a Recently Released Nematicide for the Control of Root-Knot Nematodes and Side Effects on Two Entomopathogenic Nematodes

Root-knot nematodes can cause tremendous losses in vegetable crops. Farmers usually rely on synthetic nematicides to protect their crops. Recently, newly released nematicides are giving farmers an alternative in chemical control for nematodes. In the present study, the efficacy of vintage nematicide was compared to that of a relatively new nematicide, fluopyram. The latter was always more effective in substantially lower concentrations than oxamyl. Fluopyram paralyzed more than 80% J2s after 24 h immersion at the concentration of 0.25 μL L^-1, while the percentage was increased close to 100% after immersion for 48 and 96 h. Similar levels of dead J2s were observed after immersion of J2s in oxamyl at concentrations higher than 8 μL L^-1 (24 and 48 h) or 4 μL L^-1 (96 h). An evident decrease of egg differentiation was observed when fluopyram concentration was increased to 8 μL L^-1, while no significant decrease in egg differentiation was recorded at any concentration of oxamyl. Egg hatching was decreased at concentrations of fluopyram higher than 4 μL L^-1, while no reduction was observed even when the concentration of oxamyl was increased to 64 μL L^-1. The efficacy of fluopyram in soil was superior compared to that of oxamyl. For the first time, the systemic action of fluopyram is recorded in trials with tomato plants. On the other hand, compared to oxamyl, fluopyram seems to be more toxic to non-target organisms such as the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis bacteriophora.

Spatiotemporal Dynamics of Covert Versus Overt Processing of Happy, Fearful and Sad Facial Expressions

Behavioral and electrophysiological correlates of the influence of task demands on the processing of happy, sad, and fearful expressions were investigated in a within-subjects study that compared a perceptual distraction condition with task-irrelevant faces (e.g., covert emotion task) to an emotion task-relevant categorization condition (e.g., overt emotion task). A state-of-the-art non-parametric mass univariate analysis method was used to address the limitations of previous studies. Behaviorally, participants responded faster to overtly categorized happy faces and were slower and less accurate to categorize sad and fearful faces; there were no behavioral differences in the covert task. Event-related potential (ERP) responses to the emotional expressions included the N170 (140-180 ms), which was enhanced by emotion irrespective of task, with happy and sad expressions eliciting greater amplitudes than neutral expressions. EPN (200-400 ms) amplitude was modulated by task, with greater voltages in the overt condition, and by emotion, however, there was no interaction of emotion and task. ERP activity was modulated by emotion as a function of task only at a late processing stage, which included the LPP (500-800 ms), with fearful and sad faces showing greater amplitude enhancements than happy faces. This study reveals that affective content does not necessarily require attention in the early stages of face processing, supporting recent evidence that the core and extended parts of the face processing system act in parallel, rather than serially. The role of voluntary attention starts at an intermediate stage, and fully modulates the response to emotional content in the final stage of processing.

Increased early and late neuronal responses to aversively conditioned faces across different attentional conditions

Faces with emotional information-by virtue of their expression or their history of affective learning-are prioritized during neuronal processing as compared to neutral faces. Classical conditioning studies have shown that aversively conditioned (CS+) faces potentiate different face processing stages as evidenced by increased early and late event-related potential (ERPs) components. However, it is unknown whether and how ERP modulations depend on certain attentional conditions. To examine this question, this preregistered study investigated ERPs to faces paired with aversive screams or neutral sounds under three tasks with increasing attention to CS + relevant features of the face: Participants (N = 40) had to discriminate either the orientation of superimposed lines, perceived gender, or the CS association. We found potentiation of the N170, the Early Posterior Negativity (EPN), and, most remarkably, the Late Positive Potential (LPP) to CS + faces regardless of task condition. This finding suggests that, in contrast to other types of emotional information and learning, classical conditioning boosts early and late processing stages, even if no explicit attention to the face information or the CS association is required.

Reduced early fearful face processing during perceptual distraction in high trait anxious participants

Fearful facial expressions are prioritized across different stages of information processing as reflected by early, mid-latency, and late components of event-related brain potentials (ERP). Trait anxiety has been proposed to modulate these responses, but it is yet unclear how such modulations depend on feature-based attention. In this preregistered study (N = 80), we investigated the effects of trait anxiety on ERP differences between fearful and neutral faces across three different tasks. Participants had to discriminate either the orientation of lines overlaid onto the faces, the gender of the face, or the emotional expression, thus increasing attention to emotionally relevant facial features across the tasks. Fearful versus neutral faces elicited increased P1 and N170 amplitudes across tasks and potentiated amplitudes when attention was directed to faces (early posterior negativity [EPN]) or the expression (EPN and late positive potential). Higher trait anxiety was related to smaller EPN differences between fearful and neutral faces during the perceptual discrimination task. This early relationship suggests reduced instead of amplified processing of fearful faces for high trait anxious participants under perceptual distraction.

Molecular Characterization and Functional Analysis of the Hb-hsp90-1 Gene in Relation to Temperature Changes in Heterorhabditis bacteriophora

Understanding how entomopathogenic nematodes respond to temperature changes and have adapted to the local environment is crucial to improve their potential as biocontrol agents. In order to improve understanding of Heterorhabditis bacteriophora's potential adaptability to future climate changes, full-length cDNA and the corresponding gene of heat shock protein 90 (Hsp90) were isolated and fully characterized. The reproductive potential of the Apulian strain of H. bacteriophora increased when the temperature rose from 23 to 30°C, but no reproduction was found at 12°C. Expression analyses revealed that Hb-hsp90-1 was differentially expressed in Infective Juveniles (IJs) and adults (hermaphrodites, females and males). Up-regulation of Hb-hsp90-1 was higher during the recovery process in Galleria mellonella larvae than adults, thus confirming the protective role of Hb-hsp90-1 in coping with the host environment. Silencing of Hb-hsp90-1 resulted in a significant reduction (76%) in the expression level. Silenced IJs took longer than untreated nematodes to infect G. mellonella, showing that Hb-hsp90-1 could be also involved in chemosensation. Furthermore, the number of adults and IJs recovered from G. mellonella infected with silenced nematodes and incubated at 30°C was higher than that obtained from G. mellonella infected with untreated nematodes. These data confirm the crucial role of Hb-hsp90-1 allowing acclimation to increased temperatures and modulation of the recovery process.

Early posterior negativity indicates time dilation by arousal

We investigated whether Early Posterior Negativity (EPN) indicated the subjective dilation of time when judging the duration of arousing stimuli. Participants performed a visual temporal bisection task along with high-level and low-level arousing auditory stimuli, while we simultaneously recorded EEG. In accordance with previous studies, arousing stimuli were temporally overestimated and led to higher EPN amplitude. Yet, we observed that time dilation and EPN amplitude were significantly correlated and this effect cannot be explained by confounds from stimulus valence. We interpret our findings in terms of the pacemaker–accumulator model of human timing, and suggest that EPN indicates an arousal-based increasing of the speed of our mental clock.

Single-Cell RNA-Seq Reveals Cellular Hierarchies and Impaired Developmental Trajectories in Pediatric Ependymoma

Ependymoma is a heterogeneous entity of central nervous system tumors with well-established molecular groups. Here, we apply single-cell RNA sequencing to analyze ependymomas across molecular groups and anatomic locations to investigate their intratumoral heterogeneity and developmental origins. Ependymomas are composed of a cellular hierarchy initiating from undifferentiated populations, which undergo impaired differentiation toward three lineages of neuronal-glial fate specification. While prognostically favorable groups of ependymoma predominantly harbor differentiated cells, aggressive groups are enriched for undifferentiated cell populations. The delineated transcriptomic signatures correlate with patient survival and define molecular dependencies for targeted treatment approaches. Taken together, our analyses reveal a developmental hierarchy underlying ependymomas relevant to biological and clinical behavior.

Deconstructing threat: Rethinking the interplay between biological and social relevance in the emotional salience of unpleasant images

The type of threat shown in an image influences the emotional salience of unpleasant images. Seventy-four participants (21 male) rated high threat, moderate threat, and neutral images featuring reptiles, firearms, or humans as electroencephalographic activity was recorded. The magnitude of P3b amplitudes coincided with the threat level of firearm and human images, whereas scenes of attacking snakes and aimed handguns evoked more positive late positive component (LPC) activity than non-attacking or neutral versions of these same stimuli. The lateralised early posterior negativity (EPN) in temporal occipital regions was most negative for firearms, followed by reptiles, and then humans, while the midline EPN in occipital regions was most negative for reptiles, followed by firearms, and then humans. These findings imply late event-related potential positivity is influenced by social relevance (the P3b) or the level of aggression displayed by the stimulus (the LPC), whereas stimulus type may be indexed by EPN modulation.

Pattern matters: Snakes exhibiting triangular and diamond-shaped skin patterns modulate electrophysiological activity in human visual cortex

The neural and perceptual mechanisms that support the efficient visual detection of snakes in humans are still not fully understood. According to the Snake Detection Theory, selection pressures posed by snakes on early primates have shaped the development of the visual system. Previous studies in humans have investigated early visual electrophysiological activity in response to snake images vs. various alternative dangerous or non-dangerous stimuli. These studies have shown that the Early Posterior Negativity (EPN) component is selectively elicited by snake or snake-like images. Recent findings yielded the complementary/alternative hypothesis that early humans (and possibly other primates) evolved an aversion especially for potentially harmful triangular shapes, such as teeth, claws or spikes. In the present study we investigated the effect of triangular and diamond-shaped patterns in snake skins on the ERP correlates of visual processing in humans. In the first experiment, we employed pictures of snakes displaying either triangular/diamond-shaped patterns or no particular pattern on their skins, and pictures of frogs as control. Participants observed a random visual presentation of these pictures. Consistent with previous studies, snakes elicited an enhanced negativity between 225 and 300 ms (EPN) compared to frogs. However, snakes featuring triangular/diamond-shaped patterns on their skin produced an enhanced EPN compared to the snakes that did not display such patterns. In a second experiment we used pictures displaying only skin patterns of snakes and frogs. Results from the second experiment confirmed the results of the first experiment, suggesting that triangular snake-skin patterns modulate the activity in human visual cortex. Taken together, our results constitute an important contribution to the snake detection theory.

Joint Modulation of Facial Expression Processing by Contextual Congruency and Task Demands

Faces showing expressions of happiness or anger were presented together with sentences that described happiness-inducing or anger-inducing situations. Two main variables were manipulated: (i) congruency between contexts and expressions (congruent/incongruent) and (ii) the task assigned to the participant, discriminating the emotion shown by the target face (emotion task) or judging whether the expression shown by the face was congruent or not with the context (congruency task). Behavioral and electrophysiological results (event-related potentials (ERP)) showed that processing facial expressions was jointly influenced by congruency and task demands. ERP results revealed task effects at frontal sites, with larger positive amplitudes between 250–450 ms in the congruency task, reflecting the higher cognitive effort required by this task. Effects of congruency appeared at latencies and locations corresponding to the early posterior negativity (EPN) and late positive potential (LPP) components that have previously been found to be sensitive to emotion and affective congruency. The magnitude and spatial distribution of the congruency effects varied depending on the task and the target expression. These results are discussed in terms of the modulatory role of context on facial expression processing and the different mechanisms underlying the processing of expressions of positive and negative emotions.

First Screening of Entomopathogenic Nematodes and Fungus as Biocontrol Agents against an Emerging Pest of Sugarcane, Cacosceles newmannii (Coleoptera: Cerambycidae)

Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus were investigated as potential biological control agents to be used in an integrated pest management system. The nematodes Steinernema yirgalemense, S. jeffreyense, Heterorhabditis indica, and different concentrations of the fungus Metarhiziumpinghaense were screened for efficacy (i.e., mortality rate) against larvae of C. newmannii. The different biocontrol agents used, revealed a low level of pathogenicity to C. newmannii larvae, when compared to control treatments.

Rapid brain responses to affective pictures indicate dimensions of trauma-related psychopathology in adolescents

A variety of mental disorders are related to deviant brain activity, but these neural alterations do not validate psychiatric diagnostic categories. High symptom overlap and variable symptom patterns encourage a dimensional approach. Following the logic of the Research Domain Criteria (RDoC), we investigated trauma survivors for symptom clusters that might be associated with characteristics of ERPs, in particular with the early posterior negativity (EPN) elicited during affective picture processing. In rapid serial visual presentation, 90 adolescents (40 male/50 female, age M = 15.0 ± 2.5 years) who had been exposed to varying amounts of traumatic stress passively viewed a stream of high‐arousing positive and low‐arousing neutral pictures taken from the International Affective Picture System (IAPS). Using standardized interviews, symptoms of trauma‐related mental disorders were assessed (including those for PTSD, depression, borderline personality disorder, and behavioral problems). A principal component analysis was performed to derive potential dimensions of psychopathology. Multiple regression analysis confirmed a factor comprising problems concentrating, sleeping difficulties, and mistrust as a predictor of a larger EPN difference between high‐arousing positive and low‐arousing neutral IAPS pictures (β = 0.19, p < 0.05). Sex predicted the magnitude of the EPN (β = 0.45, p < 0.001). Male adolescents displayed a stronger EPN suppression than female adolescents. The result suggests that problems concentrating, sleeping difficulties, and mistrust seem to be trans‐diagnostic elements related to diminished early emotional discrimination represented by the EPN. Furthermore, our findings indicate that the EPN in response to emotional processing is modulated by sex.

Based on the RDoC heuristic, symptom clusters that may be associated with the early posterior negativity (EPN) elicited during affective picture processing were investigated in youth trauma survivors. Analysis confirmed a factor comprising problems concentrating, sleeping difficulties, and mistrust as a predictor of a larger EPN difference between high arousing positive and low arousing neutral IAPS pictures using rapid serial visual presentation (RSVP). The EPN component was also modulated by sex. The findings also extend those of prior research on emotional processing confirming that EPN suppression can also be found in adolescents.

Implicit Emotion Regulation Deficits in Trait Anxiety: An ERP Study

According to the framework of emotion regulation (ER), both explicit and implicit forms are essential to our well-being. It is the interaction between these two processes that ensures adaptive emotional responses. Although many studies have focused on explicit ER deficits in anxiety, there is still a lack of awareness about the implicit form and its role in anxiety. To address this issue, we explored the time course of implicit ER processes in individuals with high and low trait anxiety (LTA). To do this, we employed the newly developed Priming-Identify (PI) paradigm, which includes a word-matching task (externally-generated implicit goals) and a facial expression identification task (emotion processing). We aimed to modulate the implicit ER goals of individuals through the application of different priming conditions (ER-related and -unrelated words). In addition to their behavioral effects, we recorded the influence of these priming conditions through event-related potentials (ERPs) during the facial expression identification task. Three ERP components were chosen as indexes of three stages of implicit ER processing: N170, early posterior negativity (EPN) and late positive potential (LPP). In individuals with LTA, the early N170 and the middle EPN were enlarged under the ER-related priming condition, while the LPP was not influenced. However, in individuals with high trait anxiety (HTA), we observed an absence of any significant differences between the ER-related and -unrelated priming conditions across all three ERP components. Furthermore, enlargements of N170 and EPN amplitudes were significantly correlated with a decrease in negative emotion experience scores. Our results suggest that HTA individuals experience implicit ER deficits during the early and middle stages of ER.

The behaviour of the nematode, Steinernema feltiae (Nematoda: Steinernematidae) in sand contaminated with the industrial pollutant chromium VI

This study set out to determine the suitability of the nematode Steinernema feltiae as a bioindicator for heavy metal pollution, specifically chromium VI. Nematodes were introduced into sand contaminated with concentrations of Cr VI⁺, in a range between 10 and 100 ppm, in increments of 10. Reproductive potential, development times and infectivity vs exposure times to Cr VI were employed as endpoints. It was observed that infective juveniles (IJ) from this nematode can survive and successfully infect host insects in the presence of Cr VI for as much as 13 days, and that the nematode increases its reproductive potential at concentrations up to 100 ppm Cr VI⁺. Conversely, development times (time in days taken for progeny to emerge after larval host death) and IJ infectivity rates were observed to reduce with increasing concentrations of Cr VI. The ability of this nematode to survive in the presence of high concentrations of Cr VI, and its ability to increase progeny numbers at the early stages of Cr VI exposure may provide a survival advantage for this nematode at contaminated sites. It may also demonstrate potential for development as a model species for toxicological assessment in in-situ field sampling.

Berberine nanoparticles with enhanced in vitro bioavailability: characterization and antimicrobial activity

BACKGROUND

Berberine is an isoquinoline alkaloid widely used in Ayurveda and traditional Chinese medicine to treat illnesses such as hypertension and inflammatory conditions, and as an anticancer and hepato-protective agent. Berberine has low oral bioavailability due to poor aqueous solubility and insufficient dissolution rate, which can reduce the efficacy of drugs taken orally. In this study, evaporative precipitation of nanosuspension (EPN) and anti-solvent precipitation with a syringe pump (APSP) were used to address the problems of solubility, dissolution rate and bioavailability of berberine.

METHODS

Semi-crystalline nanoparticles (NPs) of 90-110 nm diameter for APSP and 65-75 nm diameter for EPN were prepared and then characterized using differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). Thereafter, drug content solubility and dissolution studies were undertaken. Berberine and its NPs were evaluated for their antibacterial activity.

RESULTS

The results indicate that the NPs have significantly increased solubility and dissolution rate due to conversion of the crystalline structure to a semi-crystalline form.

CONCLUSION

Berberine NPs produced by both APSP and EPN methods have shown promising activities against Gram-positive and Gram-negative bacteria, and yeasts, with NPs prepared through the EPN method showing superior results compared to those made with the APSP method and the unprocessed drug.

Event-related brain potential correlates of words' emotional valence irrespective of arousal and type of task

Many Event-Related brain Potential (ERP) experiments have explored how the two main dimensions of emotion, arousal and valence, affect linguistic processing. However, the heterogeneity of experimental paradigms and materials has led to mixed results. In the present study, we aim to clarify words' emotional valence effects on ERP when arousal is controlled, and determine whether these effects may vary as a function of the type of task performed. For these purposes, we designed an ERP experiment with the valence of words manipulated, and arousal equated across valences. The participants performed two types of task: in one, they had to read aloud each word, written in black on a white background; in the other, they had to name the color of the ink in which each word was written. The results showed the main effects of valence irrespective of task, and no interaction between valence and task. The most marked effects of valence were in response to negative words, which elicited an Early Posterior Negativity (EPN) and a Late Positive Complex (LPC). Our results suggest that, when arousal is controlled, the cognitive information in negative words triggers a 'negativity bias', these being the only words able to elicit emotion-related ERP modulations. Moreover, these modulations are largely unaffected by the types of task explored here.

Neurophysiological Markers of Emotion Processing in Burnout Syndrome

The substantial body of research employing subjective measures indicates that burnout syndrome is associated with cognitive and emotional dysfunctions. The growing amount of neurophysiological and neuroimaging research helps in broadening existing knowledge of the neural mechanisms underlying core burnout components (emotional exhaustion and depersonalization/cynicism) that are inextricably associated with emotional processing. In the presented EEG study, a group of 93 participants (55 women; mean age = 35.8) were selected for the burnout group or the demographically matched control group on the basis of the results of the Maslach Burnout Inventory – General Survey (MBI-GS) and the Areas of Worklife Survey (AWS). Subjects then participated in an EEG experiment using two experimental procedures: a facial recognition task and viewing of passive pictures. The study focuses on analyzing event-related potentials (ERPs): N170, VPP, EPN, and LPP, as indicators of emotional information processing. Our results show that burnout subjects, as compared to the control group, demonstrate significantly weaker response to affect-evoking stimuli, indexed by a decline in VPP amplitude to emotional faces and decreased EPN amplitude in processing emotional scenes. The analysis of N170 and LPP showed no significant between-group difference. The correlation analyses revealed that VPP and EPN, which are ERP components related to emotional processing, are associated with two core burnout symptoms: emotional exhaustion and cynicism. To our knowledge, we are one of the first research groups to use ERPs to demonstrate such a relationship between neurophysiological activity and burnout syndrome in the context of emotional processing. Thus, in conclusion we emphasized that the decreased amplitude of VPP and EPN components in the burnout group may be a neurophysiological manifestation of emotional blunting and may be considered as neurophysiological markers of emotional exhaustion and cynicism. Additionally, we did not observe a decrease in LPP, which may be considered as a marker that significantly differentiates burnout from depression.

Empathy, Pain and Attention: Cues that Predict Pain Stimulation to the Partner and the Self Capture Visual Attention

Empathy motivates helping and cooperative behaviors and plays an important role in social interactions and personal communication. The present research examined the hypothesis that a state of empathy guides attention towards stimuli significant to others in a similar way as to stimuli relevant to the self. Sixteen couples in romantic partnerships were examined in a pain-related empathy paradigm including an anticipation phase and a stimulation phase. Abstract visual symbols (i.e., arrows and flashes) signaled the delivery of a Pain or Nopain stimulus to the partner or the self while dense sensor event-related potentials (ERPs) were simultaneously recorded from both persons. During the anticipation phase, stimuli predicting Pain compared to Nopain stimuli to the partner elicited a larger early posterior negativity (EPN) and late positive potential (LPP), which were similar in topography and latency to the EPN and LPP modulations elicited by stimuli signaling pain for the self. Noteworthy, using abstract cue symbols to cue Pain and Nopain stimuli suggests that these effects are not driven by perceptual features. The findings demonstrate that symbolic stimuli relevant for the partner capture attention, which implies a state of empathy to the pain of the partner. From a broader perspective, states of empathy appear to regulate attention processing according to the perceived needs and goals of the partner.

Effects of task demands on the early neural processing of fearful and happy facial expressions

Task demands shape how we process environmental stimuli but their impact on the early neural processing of facial expressions remains unclear. In a within-subject design, ERPs were recorded to the same fearful, happy and neutral facial expressions presented during a gender discrimination, an explicit emotion discrimination and an oddball detection tasks, the most studied tasks in the field. Using an eye tracker, fixation on the face nose was enforced using a gaze-contingent presentation. Task demands modulated amplitudes from 200 to 350ms at occipito-temporal sites spanning the EPN component. Amplitudes were more negative for fearful than neutral expressions starting on N170 from 150 to 350ms, with a temporo-occipital distribution, whereas no clear effect of happy expressions was seen. Task and emotion effects never interacted in any time window or for the ERP components analyzed (P1, N170, EPN). Thus, whether emotion is explicitly discriminated or irrelevant for the task at hand, neural correlates of fearful and happy facial expressions seem immune to these task demands during the first 350ms of visual processing.

Efficacy of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) on developmental stages of house fly, Musca domestica

The housefly, Musca domestica is a major domestic, medical and veterinary pest. The management of these flies reliance on insecticide, causes environmental constraints, insecticide resistance and residues in the meat, skin. Therefore one of the eco-friendly alternate methods is by using biological agents such as entomopathogenic nematodes (EPN). In the present study evaluated the survival of EPN species Steinernema feltiae, Heterorhabditis indica, S. carpocapsae, S. glaseri and S. abbasi in poultry manure and also their efficacy against different developmental stages of house fly. After exposing to poultry manure, S. feltiae showed more survival as followed by H. indica, S. carpocapsae, S. glaseri and S. abbasi in all exposition period. When the exposition period extended to 96 h, all nematode species survivability was drastically reduced. After exposing these nematodes to poultry manure at 24 h their virulence capacity against wax moth, Galleria mellonella showed all the nematode species were able cause 100% mortality. However their progeny production was significantly reduced. Fly eggs and pupae were refractory to these nematode infection. Petri dish without artificial diet assay showed that, second and 3rd-instar larvae were highly susceptible to EPNs as compared to larvae provided with artificial diet. H. indica showed high virulence capacity compared to other nematodes tested. Poultry manure assay revealed that, H. indica and S. carpocapsae caused minimal mortality where as S. feltiae, S. glaseri and S. abbasi did not cause any mortality. This may be because of poor survival and limited movement of nematodes in poultry manure which may be due to ammonia, other toxic substances in poultry manure. The decrease in larval mortality in manure suggests that biocontrol of housefly by using EPNs is unlikely.

Using ERPs to investigate valence processing in the affect misattribution procedure

The construct validity of the affect misattribution procedure (AMP) has been challenged by theories proposing that the task does not actually measure affect misattribution. The current study tested the validity of the AMP as a measure of affect misattribution by examining three components of the ERP known to be associated with the allocation of motivated attention. Results revealed that ERP amplitudes varied in response to affectively ambiguous targets as a function of the valence of preceding primes. Furthermore, differences in ERP responses to the targets were largely similar to differences in ERPs elicited by the primes. The existence of valence differentiation in both the prime-locked and the target-locked ERPs, along with the similarity in this differentiation, provides evidence that the affective content of the primes is psychologically registered, and that this content influences the processing of the subsequent, evaluatively ambiguous targets, both of which are required if the priming effects found in the AMP are the result of affect misattribution. However, the behavioral priming effect was uncorrelated with ERP amplitudes, leaving some question as to the locus of this effect in the information-processing system. Findings are discussed in light of the strengths and weaknesses of using ERPs to understand the priming effects in the AMP.

Contextual Valence and Sociality Jointly Influence the Early and Later Stages of Neutral Face Processing

Recent studies have demonstrated that face perception is influenced by emotional contextual information. However, because facial expressions are routinely decoded and understood during social communication, sociality should also be considered-that is, it seems necessary to explore whether emotional contextual effects are influenced by the sociality of contextual information. Furthermore, although one behavioral study has explored the effects of context on selective attention to faces, the exact underlying mechanisms remain unknown. Therefore, the current study investigated how valence and sociality of contextual information influenced the early and later stages of neutral face processing. We first employed an established affective learning procedure, wherein neutral faces were paired with verbal information that differed in valence (negative, neutral) and sociality (social, non-social), to manipulate contextual information. Then, to explore the effects of context on face perception, participants performed a face perception task, while the N170, early posterior negativity (EPN), and late positive potential (LPP) components were measured. Finally, to explore the effects of context on selective attention, participants performed a dot probe task while the N2pc was recorded. The results showed that, in the face perception task, faces paired with negative social information elicited greater EPN and LPP than did faces paired with neutral social information; no differences existed between faces paired with negative and neutral non-social information. In the dot probe task, faces paired with negative social information elicited a more negative N2pc amplitude (indicating attentional bias) than did faces paired with neutral social information; the N2pc did not differ between faces paired with negative and neutral non-social information. Together, these results suggest that contextual information influenced both face perception and selective attention, and these context effects were governed by the interaction between valence and sociality of contextual information.

Neural processing of fearful and happy facial expressions during emotion-relevant and emotion-irrelevant tasks: A fixation-to-feature approach

Research suggests an important role of the eyes and mouth for discriminating facial expressions of emotion. A gaze-contingent procedure was used to test the impact of fixation to facial features on the neural response to fearful, happy and neutral facial expressions in an emotion discrimination (Exp.1) and an oddball detection (Exp.2) task. The N170 was the only eye-sensitive ERP component, and this sensitivity did not vary across facial expressions. In both tasks, compared to neutral faces, responses to happy expressions were seen as early as 100-120ms occipitally, while responses to fearful expressions started around 150ms, on or after the N170, at both occipital and lateral-posterior sites. Analyses of scalp topographies revealed different distributions of these two emotion effects across most of the epoch. Emotion processing interacted with fixation location at different times between tasks. Results suggest a role of both the eyes and mouth in the neural processing of fearful expressions and of the mouth in the processing of happy expressions, before 350ms.

Electrophysiological Correlates of Emotional Content and Volume Level in Spoken Word Processing

For visual stimuli of emotional content as pictures and written words, stimulus size has been shown to increase emotion effects in the early posterior negativity (EPN), a component of event-related potentials (ERPs) indexing attention allocation during visual sensory encoding. In the present study, we addressed the question whether this enhanced relevance of larger (visual) stimuli might generalize to the auditory domain and whether auditory emotion effects are modulated by volume. Therefore, subjects were listening to spoken words with emotional or neutral content, played at two different volume levels, while ERPs were recorded. Negative emotional content led to an increased frontal positivity and parieto-occipital negativity-a scalp distribution similar to the EPN-between ~370 and 530 ms. Importantly, this emotion-related ERP component was not modulated by differences in volume level, which impacted early auditory processing, as reflected in increased amplitudes of the N1 (80-130 ms) and P2 (130-265 ms) components as hypothesized. However, contrary to effects of stimulus size in the visual domain, volume level did not influence later ERP components. These findings indicate modality-specific and functionally independent processing triggered by emotional content of spoken words and volume level.

Fixation to features and neural processing of facial expressions in a gender discrimination task

Early face encoding, as reflected by the N170 ERP component, is sensitive to fixation to the eyes. Whether this sensitivity varies with facial expressions of emotion and can also be seen on other ERP components such as P1 and EPN, was investigated. Using eye-tracking to manipulate fixation on facial features, we found the N170 to be the only eye-sensitive component and this was true for fearful, happy and neutral faces. A different effect of fixation to features was seen for the earlier P1 that likely reflected general sensitivity to face position. An early effect of emotion (∼120 ms) for happy faces was seen at occipital sites and was sustained until ∼350 ms post-stimulus. For fearful faces, an early effect was seen around 80 ms followed by a later effect appearing at ∼150 ms until ∼300 ms at lateral posterior sites. Results suggests that in this emotion-irrelevant gender discrimination task, processing of fearful and happy expressions occurred early and largely independently of the eye-sensitivity indexed by the N170. Processing of the two emotions involved different underlying brain networks active at different times.

Attentional bias to affective faces and complex IAPS images in early visual cortex follows emotional cue extraction

Emotionally arousing stimuli are known to rapidly draw the brain's processing resources, even when they are task-irrelevant. The steady-state visual evoked potential (SSVEP) response, a neural response to a flickering stimulus which effectively allows measurement of the processing resources devoted to that stimulus, has been used to examine this process of attentional shifting. Previous studies have used a task in which participants detected periods of coherent motion in flickering random dot kinematograms (RDKs) which generate an SSVEP, and found that task-irrelevant emotional stimuli withdraw more attentional resources from the task-relevant RDKs than task-irrelevant neutral stimuli. However, it is not clear whether the emotion-related differences in the SSVEP response are conditional on higher-level extraction of emotional cues as indexed by well-known event-related potential (ERPs) components (N170, early posterior negativity, EPN), or if affective bias in competition for visual attention resources is a consequence of a time-invariant shifting process. In the present study, we used two different types of emotional distractors - IAPS pictures and facial expressions - for which emotional cue extraction occurs at different speeds, being typically earlier for faces (at ~170ms, as indexed by the N170) than for IAPS images (~220-280ms, EPN). We found that emotional modulation of attentional resources as measured by the SSVEP occurred earlier for faces (around 180ms) than for IAPS pictures (around 550ms), after the extraction of emotional cues as indexed by visual ERP components. This is consistent with emotion related re-allocation of attentional resources occurring after emotional cue extraction rather than being linked to a time-fixed shifting process.

Following the time course of face gender and expression processing: a task-dependent ERP study

The effects of task demands and the interaction between gender and expression in face perception were studied using event-related potentials (ERPs). Participants performed three different tasks with male and female faces that were emotionally inexpressive or that showed happy or angry expressions. In two of the tasks (gender and expression categorization) facial properties were task-relevant while in a third task (symbol discrimination) facial information was irrelevant. Effects of expression were observed on the visual P100 component under all task conditions, suggesting the operation of an automatic process that is not influenced by task demands. The earliest interaction between expression and gender was observed later in the face-sensitive N170 component. This component showed differential modulations by specific combinations of gender and expression (e.g., angry male vs. angry female faces). Main effects of expression and task were observed in a later occipito-temporal component peaking around 230 ms post-stimulus onset (EPN or early posterior negativity). Less positive amplitudes in the presence of angry faces and during performance of the gender and expression tasks were observed. Finally, task demands also modulated a positive component peaking around 400 ms (LPC, or late positive complex) that showed enhanced amplitude for the gender task. The pattern of results obtained here adds new evidence about the sequence of operations involved in face processing and the interaction of facial properties (gender and expression) in response to different task demands.

Unintentionality of affective attention across visual processing stages

Affective attention involves bottom-up perceptual selection that prioritizes motivationally significant stimuli. To clarify the extent to which this process is automatic, we investigated the dependence of affective attention on the intention to process emotional meaning. Affective attention was manipulated by presenting affective images with variable arousal and intentionality by requiring participants to make affective and non-affective evaluations. Polytomous rather than binary decisions were required from the participants in order to elicit relatively deep emotional processing. The temporal dynamics of prioritized processing were assessed using early posterior negativity (EPN, 175–300 ms) as well as P3-like (P3, 300–500 ms) and slow wave (SW, 500–1500 ms) portions of the late positive potential. All analyzed components were differentially sensitive to stimulus categories suggesting that they indeed reflect distinct stages of motivational significance encoding. The intention to perceive emotional meaning had no effect on EPN, an additive effect on P3, and an interactive effect on SW. We concluded that affective attention went from completely unintentional during the EPN to partially unintentional during P3 and SW where top-down signals, respectively, complemented and modulated bottom-up differences in stimulus prioritization. The findings were interpreted in light of two-stage models of visual perception by associating the EPN with large-capacity initial relevance detection and the P3 as well as SW with capacity-limited consolidation and elaboration of affective stimuli.

Explicit semantic stimulus categorization interferes with implicit emotion processing

Previous functional magnetic resonance imaging and event-related brain potential studies revealed that performing a cognitive task may suppress the preferential processing of emotional stimuli. However, these studies utilized simple and artificial tasks (i.e. letter, shape or orientation discrimination tasks), unfamiliar to the participants. The present event-related potential study examined the emotion-attention interaction in the context of a comparably more natural scene categorization task. Deciding whether a natural scene contains an animal or not is a familiar and meaningful task to the participants and presumed to require little attentional resources. The task images were presented centrally and were overlaid upon emotional or neutral background pictures. Thus, implicit emotion and explicit semantic categorization may compete for processing resources in neural regions implicated in object recognition. Additionally, participants passively viewed the same stimulus materials without the demand to categorize task images. Significant interactions between task condition and emotional picture valence were observed for the occipital negativity and late positive potential. In the passive viewing condition, emotional background images elicited an increased occipital negativity followed by an increased late positive potential. In contrast, during the animal-/non-animal-categorization task, emotional modulation effects were replaced by strong target categorization effects. These results suggest that explicit semantic categorization interferes with implicit emotion processing when both processes compete for shared resources.

Mediterranean diet habits in older individuals: associations with cognitive functioning and brain volumes

To examine the association between dietary habits, cognitive functioning and brain volumes in older individuals, data from 194 cognitively healthy individuals who participated in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort were used. At age 70, participants kept diaries of their food intake for 1week. These records were used to calculate a Mediterranean diet (MeDi) score (comprising dietary habits traditionally found in Mediterranean countries, e.g. high intake of fruits and low intake of meat), with higher scores indicating more pronounced MeDi-like dietary habits. Five years later, participants' cognitive capabilities were examined by the seven minute screening (7MS) (a cognitive test battery used by clinicians to screen for dementia), and their brain volumes were measured by volumetric magnetic resonance imaging. Multivariate linear regression analyses were constructed to examine the association between the total MeDi score and cognitive functioning and brain volumes. In addition, possible associations between MeDi's eight dietary features and cognitive functioning and brain volumes were investigated. From the eight dietary features included in the MeDi score, pertaining to a low consumption of meat and meat products was linked to a better performance on the 7MS test (P=0.001) and greater total brain volume (i.e. the sum of white and gray matter, P=0.03) when controlling for potential confounders (e.g. BMI) in the analysis. Integrating all dietary features into the total MeDi score explained less variance in cognitive functioning and brain volumes than its single dietary component meat intake. These observational findings suggest that keeping to a low meat intake could prove to be an impact-driven public health policy to support healthy cognitive aging, when confirmed by longitudinal studies. Further, they suggest that the MeDi score is a construct that may mask possible associations of single MeDi features with brain health domains in elderly populations.

Danger and disease: electrocortical responses to threat- and disgust-eliciting images

Previous research suggests facilitated processing of evolutionarily significant stimuli (e.g., depictions of erotica, mutilation, threat), as reflected by augmented event-related potentials (ERPs), including the early posterior negativity (EPN) and late positive potential (LPP). Evolutionary models suggest that images that evoke disgust should be high in motivational salience, but evidence that the EPN and LPP are enhanced by disgusting images is lacking. Prior studies have employed only a small number of disgusting images that were limited in the types of content depicted. In the current study, participants viewed larger sets of disgusting, threatening, and neutral images with more varied content while electroencephalography (EEG) was recorded. Results showed that disgusting and threatening images elicited equivalent LPPs, which were both significantly increased relative to LPPs elicited by neutral images. EPN amplitudes were augmented for both disgusting and threatening relative to neutral images, though significantly more for disgust. These findings offer initial evidence that the EPN and the LPP are sensitive to disgust-eliciting pictures and that these pictures may receive processing that is at least on par with that of threatening images. Limitations of the current study and implications for future research are discussed.

Core disgust and moral disgust are related to distinct spatiotemporal patterns of neural processing: an event-related potential study

Core disgust is thought to rely more on sensory and perceptual processes, whereas moral disgust is thought to rely more on social evaluation processes. However, little is known about the neurocognitive mechanisms underlying these two types of disgust. We recorded event-related potentials (ERPs) from participants while they performed a lexical decision task in which core- and moral-disgust words were intermixed with neutral words and pseudowords. Lexical judgment was faster for coredisgust words and slower for moral-disgust words, relative to the neutral words. Core-disgust words, relative to neutral words, elicited a larger early posterior negative (EPN), a larger N320, a smaller N400, and a larger late positive component (LPC), whereas moral disgust words elicited a smaller N320 and a larger N400 than neutral words. These results suggest that the N320 and N400 components are particularly sensitive to the neurocognitive processes that overlap in processing both core and moral disgust, whereas the EPN and LPC may reflect process that are particularly sensitive to core disgust.

Gender difference in event related potentials to masked emotional stimuli in the oddball task

OBJECTIVE

We investigated gender differences in event-related potential (ERP) responses to subliminally presented threat-related stimuli.

METHODS

Twenty-four participants were presented with threat-related and neutral pictures for a very brief period of time (17 ms). To explore gender differences in ERP responses to subliminally presented stimuli, we examined six ERP components [P1, N170, N250, P300, Early Posterior Negativity (EPN) and Late Positive Potential (LPP)].

RESULTS

The result revealed that only female participants showed significant increases in the N170 and the EPN in response to subliminally presented threat-related stimuli compared to neutral stimuli.

CONCLUSION

Our results suggest that female participants exhibit greater cortical processing of subliminally presented threat-related stimuli than male participants.

Directed attention reduces processing of emotional distracters irrespective of valence and arousal level

Emotional stimuli tend to capture attention, and this so-called motivated attention is commonly measured using the early posterior negativity (EPN) and the late positive potential (LPP). We hypothesized that voluntary, directed attention reduces motivated attention more strongly for highly than moderately arousing pleasant or unpleasant pictures. Participants were instructed to direct their attention to either a picture at fixation or the letters flanking the picture. Pictures varied substantially in arousal and valence. When the pictures were attended to, EPN and LPP increased linearly with arousal. When the letters were attended to, these linear effects decreased in the EPN for pleasant and unpleasant pictures and in the LPP for pleasant pictures. Thus, directed attention decreases processing of emotional distracters more strongly for highly than moderately arousing pleasant and unpleasant pictures. These results are consistent with the view that directed attention decreases emotion effects on sensory gain.

How 'love' and 'hate' differ from 'sleep': using combined electro/magnetoencephalographic data to reveal the sources of early cortical responses to emotional words

Emotional words--as symbols for biologically relevant concepts--are preferentially processed in brain regions including the visual cortex, frontal and parietal regions, and a corticolimbic circuit including the amygdala. Some of the brain structures found in functional magnetic resonance imaging are not readily apparent in electro- and magnetoencephalographic (EEG; MEG) measures. By means of a combined EEG/MEG source localization procedure to fully exploit the available information, we sought to reduce these discrepancies and gain a better understanding of spatiotemporal brain dynamics underlying emotional-word processing. Eighteen participants read high-arousing positive and negative, and low-arousing neutral nouns, while EEG and MEG were recorded simultaneously. Combined current-density reconstructions (L2-minimum norm least squares) for two early emotion-sensitive time intervals, the P1 (80-120 ms) and the early posterior negativity (EPN, 200-300 ms), were computed using realistic individual head models with a cortical constraint. The P1 time window uncovered an emotion effect peaking in the left middle temporal gyrus. In the EPN time window, processing of emotional words was associated with enhanced activity encompassing parietal and occipital areas, and posterior limbic structures. We suggest that lexical access, being underway within 100 ms, is speeded and/or favored for emotional words, possibly on the basis of an "emotional tagging" of the word form during acquisition. This gives rise to their differential processing in the EPN time window. The EPN, as an index of natural selective attention, appears to reflect an elaborate interplay of distributed structures, related to cognitive functions, such as memory, attention, and evaluation of emotional stimuli.

The implicit nature of the anti-fat bias

The stigmatization and discrimination of obese persons is pervasive in almost any domain of living. At the explicit level, obese people are associated with a wide range of negative characteristics. Furthermore, research with the implicit association test revealed the implicit nature of the anti-fat bias. Building upon these findings, the present study used event-related brain potential recordings in order to assess key features of implicit processes. Participants viewed a series of schematic portrayals of anorexic, medium, and obese body shapes and tools. In a passive viewing condition, participants were asked to simply look at the stimuli and, in a distraction condition, participants were asked to detect a specific tool. Viewing obese body images, as compared to medium or anorexic body images, elicited a positive potential shift over fronto-central sites and a relative negative potential over occipito-temporal regions in a time window from ∼190 to 250 ms. This evaluative brain response to obese body images was similarly pronounced while participants performed a distraction task. Thus, the findings suggest that the anti-fat bias may occur spontaneously, unintentionally, and independent of explicit processing goals. A troublesome picture is emerging in Western cultures suggesting that obese-ism may appear to be as inevitable as a reflex.

A fast neural signature of motivated attention to consumer goods separates the sexes

Emotional stimuli guide selective visual attention and receive enhanced processing. Previous event-related potential studies have identified an early (>120 ms) negative potential shift over occipito-temporal regions (early posterior negativity, EPN) presumed to indicate the facilitated processing of survival-relevant stimuli. The present study investigated whether this neural signature of motivated attention is also responsive to the intrinsic significance of man-made objects and consumer goods. To address this issue, we capitalized on gender differences towards specific man-made objects, shoes and motorcycles, for which the Statistical Yearbook 2005 of Germany's Federal Statistical Office (Statistisches Bundesamt, 2005) revealed pronounced differences in consumer behavior. In a passive viewing paradigm, male and female participants viewed pictures of motorcycles and shoes, while their magnetoencephalographic brain responses were measured. Source localization of the magnetic counterpart of the EPN (EPNm) revealed pronounced gender differences in picture processing. Specifically, between 130 and 180 ms, all female participants generated stronger activity in occipito-temporal regions when viewing shoes compared to motorcycles, while all men except one showed stronger activation for motorcycles than shoes. Thus, the EPNm allowed a sex-dimorphic classification of the processing of consumer goods. Self-report data confirmed gender differences in consumer behavior, which, however, were less distinct compared to the brain based measure. Considering the latency of the EPNm, the reflected automatic emotional network activity is most likely not yet affected by higher cognitive functions such as response strategies or social expectancy. Non-invasive functional neuroimaging measures of early brain activity may thus serve as objective measure for individual preferences towards consumer goods.