Seeing the world through non rose-colored glasses: anxiety and the amygdala response to blended expressions

Ganoderma lucidum polysaccharide peptides GL-PPSQ2 alleviate intestinal ischemia-reperfusion injury via inhibiting cytotoxic neutrophil extracellular traps

Ganoderma lucidum polysaccharides peptides (GLPP) are the main effective ingredients from G. lucidum (Leyss. ex Fr.) Karst with anti-inflammatory, antioxidant, and immunoregulatory activities. We extracted and characterized a novel GLPP, named GL-PPSQ₂, which were found to have 18 amino acids and 48 proteins, connected by O-glycosidic bonds. The monosaccharide composition of GL-PPSQ₂ was determined to be composed of fucose, mannose, galactose and glucose with a molar ratio of 1: 1.45:2.37:16.46. By using asymmetric field-flow separation technique, GL-PPSQ₂ were found to have a highly branched structure. Moreover, in an intestinal ischemia-reperfusion (I/R) mouse model, GL-PPSQ₂ significantly increased the survival rate and alleviated intestinal mucosal hemorrhage, pulmonary permeability, and pulmonary edema. Meanwhile, GL-PPSQ₂ significantly promoted intestinal tight junction, decreased inflammation, oxidative stress and cellular apoptosis in the ileum and lung. Analysis with Gene Expression Omnibus series indicates that neutrophil extracellular trap (NET) formation plays an important role in intestinal I/R injury. GL-PPSQ₂ remarkedly inhibited NETs-related protein myeloperoxidase (MPO) and citrulline-Histone H3 (citH3) expression. GL-PPSQ₂ could alleviate intestinal I/R and its induced lung injury via inhibiting oxidative stress, inflammation, cellular apoptosis, and cytotoxic NETs formation. This study proves that GL-PPSQ₂ is a novel drug candidate for preventing and treating intestinal I/R injury.

Cumulative lifetime stressor exposure assessed by the STRAIN predicts economic ambiguity aversion

Uncertainty is inherent in most decisions humans make. Economists distinguish between two types of decision-making under non-certain conditions: those involving risk (i.e., known outcome probabilities) and those that involve ambiguity (i.e., unknown outcome probabilities). Prior research has identified individual differences that explain risk preferences, but little is known about factors associated with ambiguity aversion. Here, we hypothesized that cumulative exposure to major psychosocial stressors over the lifespan might be one factor that predicts individuals’ ambiguity aversion. Across two studies (Study 1: n = 58, M_age = 25.7; Study 2: n = 188, M_age = 39.81), we used a comprehensive lifetime stressor exposure inventory (i.e., the Stress and Adversity Inventory for Adults, or STRAIN) and a standard economic approach to quantify risk and ambiguity preferences. Greater lifetime stressor exposure as measured by the STRAIN, particularly in early life, was associated with higher aversion to ambiguity but not risk preferences.

Uncertainty is a factor in most decisions. Here the authors quantify tolerance for two forms of economic uncertainty—risk and ambiguity—and show that greater lifetime stressor exposure (as assessed by a comprehensive lifetime stressor exposure inventory) was associated with higher aversion to decisions involving ambiguity, but not risk.

Reappraisal-but not Suppression-Tendencies Determine Negativity Bias After Laboratory and Real-World Stress Exposure

Higher reactivity to stress exposure is associated with an increased tendency to appraise ambiguous stimuli as negative. However, it remains unknown whether tendencies to use emotion regulation strategies—such as cognitive reappraisal, which involves altering the meaning or relevance of affective stimuli—can shape individual differences regarding how stress affects perceptions of ambiguity. Here, we examined whether increased reappraisal use is one factor that can determine whether stress exposure induces increased negativity bias. In Study 1, healthy participants (n = 43) rated the valence of emotionally ambiguous (surprised) faces before and after an acute stress or control manipulation and reported reappraisal habits. Increased negativity ratings were milder for stressed individuals that reported more habitual reappraisal use. In Study 2 (n = 97), we extended this investigation to real-world perceived stress before and during the COVID-19 pandemic. We found that reappraisal tendency moderates the relationship between perceived stress and increased negativity bias. Collectively, these findings suggest that the propensity to reappraise determines negativity bias when evaluating ambiguity under stress.

Questioning the role of amygdala and insula in an attentional capture by emotional stimuli task

Our senses are constantly monitoring the environment for emotionally salient stimuli that are potentially relevant for survival. Because of our limited cognitive resources, emotionally salient distractors prolong reaction times (RTs) as compared to neutral distractors. In addition, many studies have reported fMRI blood oxygen level-dependent (BOLD) activation of both the amygdala and the anterior insula for similar valence contrasts. However, a direct correlation of trail-by-trial BOLD activity with RTs has not been shown, yet, which would be a crucial piece of evidence to relate the two observations. To investigate the role of the above two regions in the context of emotional distractor effects, we study here the correlation between BOLD activity and RTs for a simple attentional capture by emotional stimuli (ACES) choice reaction time task using a general linear subject-level model with a parametric RT regressor. We found significant regression coefficients in the anterior insula, supplementary motor cortex, medial precentral regions, sensory-motor areas and others, but not in the amygdala, despite activation of both insula and amygdala in the traditional valence contrast across trials (i.e., negative vs. neutral pictures). In addition, we found that subjects that exhibit a stronger RT distractor effect across trials also show a stronger BOLD valence contrast in the right anterior insula but not in the amygdala. Our results indicate that the current neuroimaging-based evidence for the involvement of the amygdala in RT slowing is limited. We advocate that models of emotional capture should incorporate both the amygdala and the anterior insula as separate entities.

Social connectedness and negative affect uniquely explain individual differences in response to emotional ambiguity

Negativity bias is not only central to mood and anxiety disorders, but can powerfully impact our decision-making across domains (e.g., financial, medical, social). This project builds on previous work examining negativity bias using dual-valence ambiguity. Specifically, although some facial expressions have a relatively clear negative (angry) or positive valence (happy), surprised expressions are interpreted negatively by some and positively by others, providing insight into one's valence bias. Here, we examine putative sources of variability that distinguish individuals with a more negative versus positive valence bias using structural equation modeling. Our model reveals that one's propensity toward negativity (operationalized as temperamental negative affect and internalizing symptomology) predicts valence bias particularly in older adulthood when a more positive bias is generally expected. Further, variability in social connectedness (a propensity to seek out social connections, use those connections to regulate one's own emotions, and be empathic) emerges as a notable and unique predictor of valence bias, likely because these traits help to override an initial, default negativity. We argue that this task represents an important approach to examining variability in affective bias, and can be specifically useful across the lifespan and in populations with internalizing disorders or even subclinical symptomology.

Posterior Fusiform and Midfusiform Contribute to Distinct Stages of Facial Expression Processing

Though the fusiform is well-established as a key node in the face perception network, its role in facial expression processing remains unclear, due to competing models and discrepant findings. To help resolve this debate, we recorded from 17 subjects with intracranial electrodes implanted in face sensitive patches of the fusiform. Multivariate classification analysis showed that facial expression information is represented in fusiform activity and in the same regions that represent identity, though with a smaller effect size. Examination of the spatiotemporal dynamics revealed a functional distinction between posterior fusiform and midfusiform expression coding, with posterior fusiform showing an early peak of facial expression sensitivity at around 180 ms after subjects viewed a face and midfusiform showing a later and extended peak between 230 and 460 ms. These results support the hypothesis that the fusiform plays a role in facial expression perception and highlight a qualitative functional distinction between processing in posterior fusiform and midfusiform, with each contributing to temporally segregated stages of expression perception.

Perceiving facial affective ambiguity: A behavioral and neural comparison of adolescents and adults

The current study examined perceptual differences between adults and youth in perceiving ambiguous facial expressions. We estimated individuals' internal representation for facial expressions and compared it between age groups (adolescents: N = 108, Mage = 13.04 years, 43.52% female; adults: N = 81, Mage = 31.54, 65.43% female). We found that adolescents' perceptual representation for facial emotion is broader than that of adults', such that adolescents experience more difficulty in identifying subtle configurational differences of facial expressions. At the neural level, perceptual uncertainty in face-selective regions (e.g., fusiform face area, occipital face area) were significantly higher for adolescents than for adults, suggesting that adolescents' brains more similarly represent lower intensity emotional faces than do adults'. Our results provide evidence for age-related differences concerning psychophysical differences in perceptual representation of emotional faces at the neural and behavioral level. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Individual differences in valence bias: fMRI evidence of the initial negativity hypothesis

Facial expressions offer an ecologically valid model for examining individual differences in affective decision-making. They convey an emotional signal from a social agent and provide important predictive information about one's environment (presence of potential rewards or threats). Although some expressions provide clear predictive information (angry, happy), others (surprised) are ambiguous in that they predict both positive and negative outcomes. Thus, surprised faces can delineate an individual's valence bias, or the tendency to interpret ambiguity as positive or negative. Our initial negativity hypothesis suggests that the initial response to ambiguity is negative, and that positivity relies on emotion regulation. We tested this hypothesis by comparing brain activity during explicit emotion regulation (reappraisal) and while freely viewing facial expressions, and measuring the relationship between brain activity and valence bias. Brain regions recruited during reappraisal showed greater activity for surprise in individuals with an increasingly positive valence bias. Additionally, we linked amygdala activity with an initial negativity, revealing a pattern similarity in individuals with negative bias between viewing surprised faces and maintaining negativity. Finally, these individuals failed to show normal habituation to clear negativity. These results support the initial negativity hypothesis, and are consistent with emotion research in both children and adult populations.

Cortisol responses enhance negative valence perception for ambiguous facial expressions

Stress exposure elicits a prolonged neuroendocrine response, marked by cortisol release, which can influence important forms of affective decision-making. Identifying how stress reactivity shapes subjective biases in decisions about emotional ambiguity (i.e., valence bias) provides insight into the role stress plays in basic affective processing for healthy and clinical populations alike. Here, we sought to examine how stress reactivity affects valence decisions about emotional ambiguity. Given that stress prioritizes automatic emotional processing which, in the context of valence bias, is associated with increased negativity, we tested how individual differences in acute stress responses influence valence bias and how this decision process evolves over time. Participants provided baseline ratings of clear (happy, angry) and ambiguous (surprised) facial expressions, then re-rated similar stimuli after undergoing an acute stress or control manipulation a week later; salivary cortisol was measured throughout to assay stress reactivity. Elevations in cortisol were associated with more negative ratings of surprised faces, and with more direct response trajectories toward negative ratings (i.e., less response competition). These effects were selectively driven by the stress group, evidencing that increased stress reactivity is associated with a stronger negativity bias during ambiguous affective decision-making.

Sex-Related Differences in Emotion Recognition in Multi-concussed Athletes

OBJECTIVES

Concussion is defined as a complex pathophysiological process affecting the brain. Although the cumulative and long-term effects of multiple concussions are now well documented on cognitive and motor function, little is known about their effects on emotion recognition. Recent studies have suggested that concussion can result in emotional sequelae, particularly in females and multi-concussed athletes. The objective of this study was to investigate sex-related differences in emotion recognition in asymptomatic male and female multi-concussed athletes.

METHODS

We tested 28 control athletes (15 males) and 22 multi-concussed athletes (10 males) more than a year since the last concussion. Participants completed the Post-Concussion Symptom Scale, the Beck Depression Inventory-II, the Beck Anxiety Inventory, a neuropsychological test battery and a morphed emotion recognition task. Pictures of a male face expressing basic emotions (anger, disgust, fear, happiness, sadness, surprise) morphed with another emotion were randomly presented. After each face presentation, participants were asked to indicate the emotion expressed by the face.

RESULTS

Results revealed significant sex by group interactions in accuracy and intensity threshold for negative emotions, together with significant main effects of emotion and group.

CONCLUSIONS

Male concussed athletes were significantly impaired in recognizing negative emotions and needed more emotional intensity to correctly identify these emotions, compared to same-sex controls. In contrast, female concussed athletes performed similarly to same-sex controls. These findings suggest that sex significantly modulates concussion effects on emotional facial expression recognition. (JINS, 2017, 23, 65-77).

Depression or anxiety: which is best able to predict patterns of lateralisation for the processing of emotional faces?

Previous research has shown that both anxiety and depression are associated with strength of lateralisation for the processing of emotive faces, although these clinical measures have always been considered in separate studies. In the present study, we measure depression and anxiety, within the same non-clinical sample, and consider whether these variables can predict strength of lateralisation, measured using the chimeric faces test. There are two key findings from this study. First, for females only, anxiety is negatively associated with right hemispheric superiority for processing of negative emotional expressions. Second, there was only one finding for depression, showing a relationship with strength of lateralisation for the processing of fearful faces that differed according to sex.

First Steps in Using Multi-Voxel Pattern Analysis to Disentangle Neural Processes Underlying Generalization of Spider Fear

A core symptom of anxiety disorders is the tendency to interpret ambiguous information as threatening. Using electroencephalography and blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), several studies have begun to elucidate brain processes involved in fear-related perceptual biases, but thus far mainly found evidence for general hypervigilance in high fearful individuals. Recently, multi-voxel pattern analysis (MVPA) has become popular for decoding cognitive states from distributed patterns of neural activation. Here, we used this technique to assess whether biased fear generalization, characteristic of clinical fear, is already present during the initial perception and categorization of a stimulus, or emerges during the subsequent interpretation of a stimulus. Individuals with low spider fear (n = 20) and high spider fear (n = 18) underwent functional MRI scanning while viewing series of schematic flowers morphing to spiders. In line with previous studies, individuals with high fear of spiders were behaviorally more likely to classify ambiguous morphs as spiders than individuals with low fear of spiders. Univariate analyses of BOLD-MRI data revealed stronger activation toward spider pictures in high fearful individuals compared to low fearful individuals in numerous areas. Yet, neither average activation, nor support vector machine classification (i.e., a form of MVPA) matched the behavioral results – i.e., a biased response toward ambiguous stimuli – in any of the regions of interest. This may point to limitations of the current design, and to challenges associated with classifying emotional and neutral stimuli in groups that differ in their judgment of emotionality. Improvements for future research are suggested.

Distinct frontal and amygdala correlates of change detection for facial identity and expression

Recruitment of 'top-down' frontal attentional mechanisms is held to support detection of changes in task-relevant stimuli. Fluctuations in intrinsic frontal activity have been shown to impact task performance more generally. Meanwhile, the amygdala has been implicated in 'bottom-up' attentional capture by threat. Here, 22 adult human participants took part in a functional magnetic resonance change detection study aimed at investigating the correlates of successful (vs failed) detection of changes in facial identity vs expression. For identity changes, we expected prefrontal recruitment to differentiate 'hit' from 'miss' trials, in line with previous reports. Meanwhile, we postulated that a different mechanism would support detection of emotionally salient changes. Specifically, elevated amygdala activation was predicted to be associated with successful detection of threat-related changes in expression, over-riding the influence of fluctuations in top-down attention. Our findings revealed that fusiform activity tracked change detection across conditions. Ventrolateral prefrontal cortical activity was uniquely linked to detection of changes in identity not expression, and amygdala activity to detection of changes from neutral to fearful expressions. These results are consistent with distinct mechanisms supporting detection of changes in face identity vs expression, the former potentially reflecting top-down attention, the latter bottom-up attentional capture by stimulus emotional salience.