Do all threats work the same way? Divergent effects of fear and disgust on sensory perception and attention

The dissociating effects of fear and disgust on multisensory integration in autism: evidence from evoked potentials

Background

Deficits in Multisensory Integration (MSI) in ASD have been reported repeatedly and have been suggested to be caused by altered long-range connectivity. Here we investigate behavioral and ERP correlates of MSI in ASD using ecologically valid videos of emotional expressions.

Methods

In the present study, we set out to investigate the electrophysiological correlates of audiovisual MSI in young autistic and neurotypical adolescents. We employed dynamic stimuli of high ecological validity (500 ms clips produced by actors) that depicted fear or disgust in unimodal (visual and auditory), and bimodal (audiovisual) conditions.

Results

We report robust MSI effects at both the behavioral and electrophysiological levels and pronounced differences between autistic and neurotypical participants. Specifically, neurotypical controls showed robust behavioral MSI for both emotions as seen through a significant speed-up of bimodal response time (RT), confirmed by Miller's Race Model Inequality (RMI), with greater MSI effects for fear than disgust. Adolescents with ASD, by contrast, showed behavioral MSI only for fear. At the electrophysiological level, the bimodal condition as compared to the unimodal conditions reduced the amplitudes of the visual P100 and auditory P200 and increased the amplitude of the visual N170 regardless of group. Furthermore, a cluster-based analysis across all electrodes revealed that adolescents with ASD showed an overall delayed and spatially constrained MSI effect compared to controls.

Conclusion

Given that the variables we measured reflect attention, our findings suggest that MSI can be modulated by the differential effects on attention that fear and disgust produce. We also argue that the MSI deficits seen in autistic individuals can be compensated for at later processing stages by (a) the attention-orienting effects of fear, at the behavioral level, and (b) at the electrophysiological level via increased attentional effort.

Is processing superiority a universal trait for all threats? Divergent impacts of fearful, angry, and disgusted faces on attentional capture

Fearful, angry, and disgusted facial expressions are evolutionarily salient and convey different types of threat signals. However, it remains unclear whether these three expressions impact sensory perception and attention in the same way. The present ERP study investigated the temporal dynamics underlying the processing of different types of threatening faces and the impact of attentional resources employed during a perceptual load task. Participants were asked to judge the length of bars superimposed over faces presented in the center of the screen. A mass univariate statistical approach was used to analyze the EEG data. Behaviorally, task accuracy was significantly reduced following exposure to fearful faces relative to neutral distractors, independent of perceptual load. The ERP results revealed that the P1 amplitude over the right hemisphere was found to be enhanced for fearful relative to disgusted faces, reflecting the rapid and coarse detection of fearful cues. The N170 responses elicited by fearful, angry, and disgusted faces were larger than those elicited by neutral faces, suggesting the largely automatic and preferential processing of threats. Furthermore, the early posterior negativity (EPN) component yielded increased responses to fearful and angry faces, indicating prioritized attention to stimuli representing acute threats. Additionally, perceptual load exerted a pronounced influence on the EPN and late positive potential (LPP), with larger responses observed in the low perceptual load condition, indicating goal-directed cognitive processing. Overall, the early sensory processing of fearful, angry, and disgusted faces is characterized by differential sensitivity in capturing attention automatically, despite the importance of these facial signals for survival. Fearful faces produce a strong interference effect and are processed with higher priority than angry and disgusted ones.

Acceptance of AI in Health Care for Short- and Long-Term Treatments: Pilot Development Study of an Integrated Theoretical Model

BACKGROUND

As digital technologies and especially artificial intelligence (AI) become increasingly important in health care, it is essential to determine whether and why potential users intend to use related health information systems (HIS). Several theories exist, but they focus mainly on aspects of health care or information systems, in addition to general psychological theories, and hence provide a small number of variables to explain future behavior. Thus, research that provides a larger number of variables by combining several theories from health care, information systems, and psychology is necessary.

OBJECTIVE

This study aims to investigate the intention to use new HIS for decisions concerning short- and long-term medical treatments using an integrated approach with several variables to explain future behavior.

METHODS

We developed an integrated theoretical model based on theories from health care, information systems, and psychology that allowed us to analyze the duality approach of adaptive and nonadaptive appraisals and their influence on the intention to use HIS. We applied the integrated theoretical model to the short-term treatment using AI-based HIS for surgery and the long-term treatment of diabetes tracking using survey data with structured equation modeling. To differentiate between certain levels of AI involvement, we used several scenarios that include treatments by physicians only, physicians with AI support, and AI only to understand how individuals perceive the influence of AI.

RESULTS

Our results showed that for short- and long-term treatments, the variables perceived threats, fear (disease), perceived efficacy, attitude (HIS), and perceived norms are important to consider when determining the intention to use AI-based HIS. Furthermore, the results revealed that perceived efficacy and attitude (HIS) are the most important variables to determine intention to use for all treatments and scenarios. In contrast, abilities (HIS) were important for short-term treatments only. For our 9 scenarios, adaptive and nonadaptive appraisals were both important to determine intention to use, depending on whether the treatment is known. Furthermore, we determined R² values that varied between 57.9% and 81.7% for our scenarios, which showed that the explanation power of our model is medium to good.

CONCLUSIONS

We contribute to HIS literature by highlighting the importance of integrating disease- and technology-related factors and by providing an integrated theoretical model. As such, we show how adaptive and nonadaptive appraisals should be arranged to report on medical decisions in the future, especially in the short and long terms. Physicians and HIS developers can use our insights to identify promising rationale for HIS adoption concerning short- and long-term treatments and adapt and develop HIS accordingly. Specifically, HIS developers should ensure that future HIS act in terms of HIS functions, as our study shows that efficient HIS lead to a positive attitude toward the HIS and ultimately to a higher intention to use.

Facial representations of complex affective states combining pain and a negative emotion

Pain is rarely communicated alone, as it is often accompanied by emotions such as anger or sadness. Communicating these affective states involves shared representations. However, how an individual conceptually represents these combined states must first be tested. The objective of this study was to measure the interaction between pain and negative emotions on two types of facial representations of these states, namely visual (i.e., interactive virtual agents; VAs) and sensorimotor (i.e., one's production of facial configurations). Twenty-eight participants (15 women) read short written scenarios involving only pain or a combined experience of pain and a negative emotion (anger, disgust, fear, or sadness). They produced facial configurations representing these experiences on the faces of the VAs and on their face (own production or imitation of VAs). The results suggest that affective states related to a direct threat to the body (i.e., anger, disgust, and pain) share a similar facial representation, while those that present no immediate danger (i.e., fear and sadness) differ. Although visual and sensorimotor representations of these states provide congruent affective information, they are differently influenced by factors associated with the communication cycle. These findings contribute to our understanding of pain communication in different affective contexts.

The psychological costs of behavioral immunity following COVID-19 diagnosis

Prior COVID-19 infection may elevate activity of the behavioral immune system-the psychological mechanisms that foster avoidance of infection cues-to protect the individual from contracting the infection in the future. Such "adaptive behavioral immunity" may come with psychological costs, such as exacerbating the global pandemic's disruption of social and emotional processes (i.e., pandemic disruption). To investigate that idea, we tested a mediational pathway linking prior COVID infection and pandemic disruption through behavioral immunity markers, assessed with subjective emotional ratings. This was tested in a sample of 734 Mechanical Turk workers who completed study procedures online during the global pandemic (September 2021-January 2022). Behavioral immunity markers were estimated with an affective image rating paradigm. Here, participants reported experienced disgust/fear and appraisals of sickness/harm risk to images varying in emotional content. Participants self-reported on their previous COVID-19 diagnosis history and level of pandemic disruption. The findings support the proposed mediational pathway and suggest that a prior COVID-19 infection is associated with broadly elevated threat emotionality, even to neutral stimuli that do not typically elicit threat emotions. This elevated threat emotionality was in turn related to disrupted socioemotional functioning within the pandemic context. These findings inform the psychological mechanisms that might predispose COVID survivors to mental health difficulties.

The impact of pandemic-related stress on attentional bias and anxiety in alexithymia during the COVID-19 pandemic

The COVID-19 pandemic had negative consequences for mental health, yet it is unknown how and to what extent the psychological outcomes of this stressful event are moderated by individual traits. Alexithymia is a risk factor for psychopathology, and thus likely predicted individual differences in resilience or vulnerability to stressful events during the pandemic. This study explored the moderating role of alexithymia in the relationships of pandemic-related stress with anxiety levels and attentional bias. The participants were 103 Taiwanese individuals who completed a survey during the outbreak of the Omicron wave. Additionally, an emotional Stroop task including pandemic-related or neutral stimuli was used to measure attentional bias. Our results demonstrate that pandemic-related stress had a lesser impact on anxiety in individuals with a higher level of alexithymia. Moreover, we found that in individuals with higher exposure to pandemic-related stressors, a higher level of alexithymia indicated less attentional bias toward COVID-19-related information. Thus, it is plausible that individuals with alexithymia tended to avoid pandemic-related information, which could temporarily relieve stressors during the pandemic.

Sensing fear: fast and precise threat evaluation in human sensory cortex

Animal models of threat processing have evolved beyond the amygdala to incorporate a distributed neural network. In human research, evidence has intensified in recent years to challenge the canonical threat circuitry centered on the amygdala, urging revision of threat conceptualization. A strong surge of research into threat processing in the sensory cortex in the past decade has generated particularly useful insights to inform the reconceptualization. Here, synthesizing findings from both animal and human research, we highlight sensitive, specific, and adaptable threat representations in the sensory cortex, arising from experience-based sculpting of sensory coding networks. We thus propose that the human sensory cortex can drive smart (fast and precise) threat evaluation, producing threat-imbued sensory afferents to elicit network-wide threat responses.

Automatic and controlled attentional orienting toward emotional faces in patients with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative motor disorder that can associate with deficits in cognitive and emotional processing. In particular, PD has been reported to be mainly associated with defects in executive control and orienting attentional systems. The deficit in emotional processing mainly emerged in facial expression recognition. It is possible that the defects in emotional processing in PD may be secondary to other cognitive impairments, such as attentional deficits. This study was designed to systematically investigate the different weight of automatic and controlled attentional orienting mechanisms implied in emotional selective attention in PD. To address our purpose, we assessed drug-naïve PD patients and age-matched healthy controls with two dot-probe tasks that differed for stimuli duration. Automatic and controlled attentions were evaluated with stimuli lasting 100 ms and 500 ms, respectively. Furthermore, we introduced an emotion recognition task to investigate the performance in explicit emotion classification. The stimuli used in both the tasks dot-probe and emotion recognition were expressive faces displaying neutral, disgusted, fearful, and happy expressions.Our results showed that in PD patients, compared with healthy controls, there was 1) an alteration of automatic and controlled attentional orienting toward emotional faces in both the dot-probe tasks (with short and long durations), and 2) no difference in the emotion recognition task. These findings suggest that, from the early stages of the disease, PD can yield specific deficits in implicit emotion processing task (i.e., dot-probe task) despite a normal performance in explicit tasks that demand overt emotion recognition.

The role of self-reported fear and disgust in the activation of behavioral harm avoidance related to medical settings

INTRODUCTION

Although adaptive defense mechanisms are useful in helping us avoid getting injured, they are also triggered by medical interventions and procedures, when avoidance is harmful. A body of previous results showed that both fear and disgust play a pivotal role in medical avoidance. However, the underlying mechanisms are not fully understood. Thus, the aim of the current study was to examine the effects of experience, perceived control, and pain on medical avoidance with disgust and fear as mediating factors from an evolutionary perspective.

METHODS

We assessed participants' knowledge of and experience with medical procedures, former negative medical experiences, and health-related information; their life history strategy variation; pain-related fear and anxiety of medical procedures; perceived control over emotional reactions and extreme threats; disgust sensitivity; blood-injury-injection phobia and medical treatment avoidance.

RESULTS

We found that more knowledge, experience, and a slower life strategy were linked to a greater level of perceived control and attenuated emotional reactions. Further, better ability to control affective and stress reactions to negative experiences was linked to reduced disgust and fear of pain, and thus might mitigate the level of perceived threat, and diminish fear and disgust reactions.

DISCUSSION

More knowledge and experiences, better perceived control together with reduced disgust and fear of pain can decrease the probability of avoiding medical situations. Implications to treatment are discussed. Results support the importance of targeting these contextual factors in prevention to increase the likelihood of people attending regular screenings or seeking medical care when needed.

Attentional Processing of Unpleasant Stimuli in Alexithymia

Alexithymia is a multi-faceted personality trait defined by difficulties in identifying and describing emotions and is considered a risk factor for multiple psychiatric disorders. Current alexithymia research debates the type of attention bias involved in the processing of negative emotional information, especially in anxiety-evoking situations that are frequently associated with stress states. Relatedly, this study aims to examine the role of emotional influence on the attentional processing of Taiwanese alexithymic individuals. Using the Chinese version of the Toronto Alexithymia Scale-20 (TAS-20), individuals with high alexithymia (HA: TAS > 60, n = 26; Mage = 23.36) and individuals with low alexithymia (LA: TAS < 39, n = 26; Mage = 25.76) were recruited. Participants performed an emotional counting Stroop task preceded by anxiety-evoking (threatening and aversive pictures) or neutral pictures. Reaction times (RTs) of the emotional Stroop task were compared between HA and LA groups. Our results demonstrate that compared to individuals with LA, individuals with HA show early avoidance tendency (i.e., allocate less attentional resources to anxiety-evoking stimuli), and that negative affect therefore does not interfere with subsequent attention processing during the Stroop task, resulting in faster RT for unpleasant stimuli (Mthreatening = 683.87, Maversive = 685.87) than neutral stimuli (Mneutral = 695.64) (ps < .05). In addition, the attentional bias toward specific types of negative emotion was not differentiated in individuals with HA (p < .05), suggesting that alexithymic individuals' emotion schemas may be underdeveloped in terms of ability to specify exact emotions. This study provides evidence regarding early sensitization to negative stimuli during information processing, consistent with the notion that alexithymia is related to avoidant emotion regulation processes.

Spatial Attention to Emotional Images and Psychopathic Personality Traits

Psychopathy has often been thought to be associated with a deficit in processing of the affective content of stimuli. This hypothesis was tested by examining if stimuli that depicted a threat to the viewer, or stimuli that depicted distressing scenes, would produce an automatic shift in spatial attention, and whether this effect would be modified by individual differences in trait psychopathy as conceptualised by the triarchic model of psychopathy. Using a large mixed gender community sample (N = 286) it was found that spatial attention was averted away from threat stimuli for both short (200 ms) and long (500 ms) periods from cue to target, while the distress cues did not produce any spatial attention shifts. The trait of Meanness was found to be associated with a reduction in the effect of threat stimuli, while the trait of Disinhibition was found to be associated with an increase in this threat effect. However, the dot-probe task showed poor reliability. We conclude that the callous unemotional aspects of psychopathy, as captured by the Meanness scale, are underpinned by a lack of response to affective information, whereas impulsive/irresponsible traits of psychopathy, as captured by the Disinhibition scale, are underpinned by an exaggerated response to such affective information.

Common and separable behavioral and neural mechanisms underlie the generalization of fear and disgust

Generalization represents the transfer of a conditioned responses to stimuli that resemble the conditioned stimulus (CS). Previous studies on generalization of defensive avoidance responses have primarily focused on fear and have neglected disgust generalization, which represents a key pathological mechanism in some anxiety disorders. In the present study we examined common and distinct mechanisms of fear and disgust generalization by means of a fear or disgust multi-CS conditioning and generalization paradigm with concomitant event-related potential (ERPs) acquisition in n = 62 subjects. We demonstrate that compared to fear, disgust-relevant generalized stimuli (GS) elicited larger expectancy ratings and longer reaction times (RTs) reflecting stronger ratings of 'risk'. On the electrophysiological level, increased P2 amplitudes were found in response to conditioned CS+ versus CS- across both domains, possibly reflecting higher motivational and attentional salience of aversive conditioned stimuli per se. Contingent negative variation (CNV) amplitude was significantly larger for disgust-CS+ than disgust-CS-, reflecting a stronger preparation of the disgust US. Additionally, we found that the contingent negative variation (CNV) fear generalization gradient, and CNV amplitude were increased with similarity to CS+. In contrast the CNV to disgust-GS did not differ and did not reflect disgust generalization. Together this may indicate that the CNV represents a highly fear-specific index for generalization learning. This study provides the first neurobiological evidence for common and distinct generalization learning in fear versus disgust suggesting that dysregulations in separable defensive avoidance mechanisms may underly different anxiety disorder subtypes.

Saccadic eye movements are deployed faster for salient facial stimuli, but are relatively indifferent to their emotional content

The present study explores the threat bias for fearful facial expressions using saccadic latency, with a particular focus on the role of low-level facial information, including spatial frequency and contrast. In a simple localisation task, participants were presented with spatially-filtered versions of neutral, fearful, angry and happy faces. Together, our findings show that saccadic responses are not biased toward fearful expressions compared to neutral, angry or happy counterparts, regardless of their spatial frequency content. Saccadic response times are, however, significantly influenced by the spatial frequency and contrast of facial stimuli. We discuss the implications of these findings for the threat bias literature, and the extent to which image processing can be expected to influence behavioural responses to socially-relevant facial stimuli.

Emotion schema effects on associative memory differ across emotion categories at the behavioural, physiological and neural level: Emotion schema effects on associative memory differs for disgust and fear

Previous behavioural and neuroimaging studies have consistently reported that memory is enhanced for associations congruent or incongruent with the structure of prior knowledge, termed as schemas. However, it remains unclear if similar effects arise with emotion-related associations, and whether they depend on the type of emotions. Here, we addressed this question using a novel face-word pair association paradigm combined with fMRI and eye-tracking techniques. In two independent studies, we demonstrated and replicated that both congruency with emotion schemas and emotion category interact to affect associative memory. Overall, memory retrieval was higher for faces from pairs congruent vs. incongruent with emotion schemas, paralleled by a greater recruitment of left inferior frontal gyrus (IFG) during successful encoding. However, emotion schema effects differed across two negative emotion categories. Disgust was remembered better than fear, and only disgust activated left IFG stronger during encoding of congruent vs. incongruent pairs, suggestive of deeper semantic processing for the associations. On the contrary, encoding of congruent fear vs. disgust-related pairs was accompanied with greater activity in right fusiform gyrus (FG), suggesting a stronger sensory processing of faces. In addition, successful memory formation for congruent disgust pairs was associated with a higher pupil dilation index related to sympathetic activation, longer gaze time on words compared to faces, and more gaze switches between paired words and faces. This was reversed for fear-related congruent pairs where the faces attracted longer gaze time (compared to words). Overall, our results provide converging evidence from behavioural, physiological, and neural measures to suggest that congruency with available emotion schemas influence memory associations in a similar manner to semantic schemas. However, these effects vary across distinct emotion categories, pointing to a differential role of semantic processing and visual attention processes in the modulation of memory by disgust and fear, respectively.

Pattern differentiation and tuning shift in human sensory cortex underlie long-term threat memory

The amygdala-prefrontal-cortex circuit has long occupied the center of the threat system,¹ but new evidence has rapidly amassed to implicate threat processing outside this canonical circuit.^2-4 Through nonhuman research, the sensory cortex has emerged as a critical substrate for long-term threat memory,^5-9 underpinned by sensory cortical pattern separation/completion^10,11 and tuning shift.^12,13 In humans, research has begun to associate the human sensory cortex with long-term threat memory,^14,15 but the lack of mechanistic insights obscures a direct linkage. Toward that end, we assessed human olfactory threat conditioning and long-term (9 days) threat memory, combining affective appraisal, olfactory psychophysics, and functional magnetic resonance imaging (fMRI) over a linear odor-morphing continuum (five levels of binary mixtures of the conditioned stimuli/CS+ and CS- odors). Affective ratings and olfactory perceptual discrimination confirmed (explicit) affective and perceptual learning and memory via conditioning. fMRI representational similarity analysis (RSA) and voxel-based tuning analysis further revealed associative plasticity in the human olfactory (piriform) cortex, including immediate and lasting pattern differentiation between CS and neighboring non-CS and a late onset, lasting tuning shift toward the CS. The two plastic processes were especially salient and lasting in anxious individuals, among whom they were further correlated. These findings thus support an evolutionarily conserved sensory cortical system of long-term threat representation, which can underpin threat perception and memory. Importantly, hyperfunctioning of this sensory mnemonic system of threat in anxiety further implicates a hitherto underappreciated sensory mechanism of anxiety.

Distinct medial-tempora lobe mechanisms of encoding and amygdala-mediated memory reinstatement for disgust and fear

Current models of episodic memory posit that retrieval involves the reenactment of encoding processes. Recent evidence has shown that this reinstatement process - indexed by subsequent encoding-retrieval similarity of brain activity patterns - is related to the activity in the hippocampus during encoding. However, we tend to re-experience emotional events in memory more richly than dull events. The role of amygdala - a critical hub of emotion processing - in reinstatement of emotional events was poorly understood. To investigate it, we leveraged a previously overlooked divergence in the role of amygdala in memory modulation by distinct emotions - disgust and fear. Here we used a novel paradigm in which participants encoded complex events (word pairs) and their memory was tested after 3 weeks, both phases during fMRI scanning. Using representational similarity analysis and univariate analyses, we show that the strength of amygdala activation during encoding was correlated with memory reinstatement of individual event representations in emotion-specific regions. Critically, amygdala modulated reinstatement more for disgust than fear. This was in line with other differences observed at the level of memory performance and neural mechanisms of encoding. Specifically, amygdala and perirhinal cortex were more involved during encoding of disgust-related events, whereas hippocampus and parahippocampal gyrus during encoding of fear-related events. Together, these findings shed a new light on the role of the amygdala and medial temporal lobe regions in encoding and reinstatement of specific emotional memories.

Exploration of Exogenous Attention to Disgust and Fear Pictures with Different Spatial Frequencies Through Event-related Potentials

The study of the effects of fear and disgust on the capture of automatic attention is gaining interest. Most findings reveal a more efficient capture of exogenous attention by disgust than by fear stimuli, although the underlying mechanisms are not completely understood. The manipulation of their spatial frequency may provide new insight that may contribute to clarify this issue. The present study aimed to explore differential processing of disgust and fear scenes containing only low spatial frequencies (LSF) or all spatial frequencies (intact) presented as distractors in an exogenous attention task. Event-related potentials (ERPs) and behavioral responses were recorded as dependent variables from forty participants (29 women). The results showed that disgust and fear distractors captured exogenous attention equally early, as indicated by the augmented amplitude of the N2p, and later disgust distractors are the ones eliciting the highest amplitude of the LPP component. While in an initial stage, both stimuli seem to have similar preferential access to further processing allowing fast responding in both cases, disgust is more deeply processed at a later stage probably facilitating its examination. These findings suggest that exploring the temporal course of processing is relevant for the understanding of the differential capture of exogenous attention by disgust and fear distractors.

Do facially disfiguring features influence attention and perception of faces? Evidence from an antisaccade task

Facial disfigurements can influence how observers attend to and interact with the person, leading to disease-avoidance behaviour and emotions (disgust, threat, fear for contagion). However, it is unclear whether this behaviour is reflected in the effect of the facial stigma on attention and perceptual encoding of facial information. We addressed this question by measuring, in a mixed antisaccade task, observers' speed and accuracy of orienting of visual attention towards or away from peripherally presented upright and inverted unfamiliar faces that had either a realistic looking disease-signalling feature (a skin discolouration), a non-disease-signalling control feature, or no added feature. The presence of a disfiguring or control feature did not influence the orienting of attention (in terms of saccadic latency) towards upright faces, suggesting that avoidance responses towards facial stigma do not occur during covert attention. However, disfiguring and control features significantly reduced the effect of face inversion on saccadic latency, thus suggesting an impact on the holistic processing of facial information. The implications of these findings for the encoding and appraisal of facial disfigurements are discussed.

The Effects of Angry Expressions and Fearful Expressions on Duration Perception: An ERP Study

Little is known about the electrophysiological basis of the effect of threat-related emotional stimuli with different motivational direction on duration perception. Thus, event-related potentials were employed to examine the effects of angry expressions and fearful expressions on perception of different duration (490-910 ms). Behavioral results showed there was a greater underestimation of the duration of angry expressions (approach-motivated negative stimuli) than fearful expressions (withdrawal-motivated negative stimuli), compared with neutral expressions. Event-related potentials results showed that, the area of Contingent Negative Variation (CNV) evoked by angry expression, fearful expression and neutral expression gradually increased. These results indicated that specific electrophysiological mechanisms may underlie the attention effects of angry and fearful expressions on timing. Specifically, compared with neutral expressions, fearful expressions and angry expressions both are likely to distract more attentional resources from timer, in particular, angry expressions attract more attention resources than fearful expressions from timer. The major contribution of the current study is to provide electrophysiological evidences of fear vs. anger divergence in the aspect of time perception and to demonstrate beyond the behavioral level that the categorization of threat-related emotions should be refined so to highlight the adaptability of the human defense system.

In exogenous attention, time is the clue: Brain and heart interactions to survive threatening stimuli

The capture of exogenous attention by negative stimuli has been interpreted as adaptive for survival in a diverse and changing environment. In the present paper, we investigate the neural responses towards two discrete negative emotions with different biological meanings, disgust and fear, and its potential relationships with heart rate variability (HRV) as an index of emotional regulation. With that aim, 30 participants performed a digit categorization task while fear, disgust and neutral distractor pictures were presented. Resting HRV at baseline, behavioral responses, and event-related potentials were recorded. Whereas P1 amplitudes were highest to fear distractors, the disgust stimulation led to augmented P2 amplitudes compared to the rest of distractors. Interestingly, increased N2 amplitudes were also found to disgust distractors, but only in high HRV participants. Neural source estimation data point to the involvement of the insula in this exogenous attentional response to disgust. Additionally, disgust distractors provoked longer reaction times than fear and neutral distractors in the high HRV group. Present findings are interpreted in evolutionary terms suggesting that exogenous attention is captured by negative stimuli following a different time course for fear and disgust. Possible HRV influences on neural mechanisms underlying exogenous attention are discussed considering the potential important role of this variable in emotional regulation processes.

Human Sensory Cortex Contributes to the Long-Term Storage of Aversive Conditioning

Growing animal data evince a critical role of the sensory cortex in the long-term storage of aversive conditioning, following acquisition and consolidation in the amygdala. Whether and how this function is conserved in the human sensory cortex is nonetheless unclear. We interrogated this question in a human aversive conditioning study using multidimensional assessments of conditioning and long-term (15 d) retention. Conditioned stimuli (CSs; Gabor patches) were calibrated to differentially activate the parvocellular (P) and magnocellular (M) visual pathways, further elucidating cortical versus subcortical mechanisms. Full-blown conditioning and long-term retention emerged for M-biased CS (vs limited effects for P-biased CS), especially among anxious individuals, in all four dimensions assessed: threat appraisal (threat ratings), physiological arousal (skin conductance response), perceptual learning [discrimination sensitivity (d') and response speed], and cortical plasticity [visual evoked potentials (VEPs) and cortical current density]. Interestingly, while behavioral, physiological, and VEP effects were comparable at immediate and delayed assessments, the cortical substrates evolved markedly over time, transferring from high-order cortices [inferotemporal/fusiform cortex and orbitofrontal cortex (OFC)] immediately to the primary and secondary visual cortex after the delay. In sum, the contrast between P- and M-biased conditioning confirms privileged conditioning acquisition via the subcortical pathway while the immediate cortical plasticity lends credence to the triadic amygdala-OFC-fusiform network thought to underlie threat processing. Importantly, long-term retention of conditioning in the basic sensory cortices supports the conserved role of the human sensory cortex in the long-term storage of aversive conditioning.SIGNIFICANCE STATEMENT A growing network of neural substrates has been identified in threat learning and memory. The sensory cortex plays a key role in long-term threat memory in animals, but such a function in humans remains unclear. To explore this problem, we conducted multidimensional assessments of immediate and delayed (15 d) effects of human aversive conditioning. Behavioral, physiological, and scalp electrophysiological data demonstrated conditioning effects and long-term retention. High-density EEG intracranial source analysis further revealed the cortical underpinnings, implicating high-order cortices immediately and primary and secondary visual cortices after the long delay. Therefore, while high-order cortices support aversive conditioning acquisition (i.e., threat learning), the human sensory cortex (akin to the animal homolog) underpins long-term storage of conditioning (i.e., long-term threat memory).

Understanding the capture of exogenous attention by disgusting and fearful stimuli: The role of interoceptive accuracy

The aim of the study was to explore the role of interoceptive accuracy (IA) on exogenous attention to disgusting and fearful distractors of a main concurrent task. Participants were thirty university students previously identified as high (N = 16) or normal IA according their performance in a heartbeat detection task. Event-related potentials and behavioural responses were recorded. The results showed that disgusting stimuli capture exogenous attention in a first stage as reflected by the augmented amplitude of the P100 component of the ERPs in high IA participants. Fearful distractors may capture attention in a later moment in all participants as revealed by a marginally significant effect on the amplitude of N200. At behavioural level, disgusting distractors provoked a higher number of errors than neutral in normal IA participants. The time course of the effect of disgust and fearful eliciting distractors on exogenous attention appeared to depend on the individual characteristic of participants.

Investigating the replicability and boundary conditions of the mnemonic advantage for disgust

Research has demonstrated that people remember emotional information better than neutral information. However, such research has almost exclusively defined emotion in terms of valence and arousal. Discrete emotions may affect memory above and beyond such dimensions, with recent research indicating that disgusting information is better remembered than frightening information. We initially sought to determine whether participants are sensitive to the effects of discrete emotions when predicting their future memory performance. Participants in Experiment 1 were more confident in their memory for emotional (both frightening and disgusting) images relative to neutral images, but confidence did not differ between frightening and disgusting images. However, because we did not replicate the mnemonic advantage of disgust, subsequent experiments were concerned with testing the replicability of this effect. Because metamemorial judgments sometimes eliminate memory effects, participants in Experiment 2 did not make such judgments. Even so, the effect did not replicate. The disgust advantage was ultimately replicated in Experiment 3, where participants completed a secondary task at encoding. The disgust advantage is replicable but appears less robust than previously recognised. A single-paper meta-analysis indicated that the effect is more likely under divided attention, perhaps because the mechanisms which mediate disgust-memory are relatively automatic.

The Influence of Discrete Negative and Positive Stimuli on Recognition Memory of Younger vs. Older Adults

Background: The effects of emotional stimuli on memory in older adults are often addressed in terms of socio-emotional selectivity theory and the valence dimension. Older adults usually remember positive stimuli better than negative stimuli. However, studies examining the effects of discrete emotions on the elderly are still limited. The present study examined the effects of negative and positive discrete emotions (fear, disgust, and happiness) on recognition memory of older and younger adults. Method: In the encoding phase, participants studied happiness-, disgust-, fear-, and neutral- related photos while doing a line discrimination task that assessed their attention. After 45 minutes, they completed an old/new recognition memory test on a confidence rating scale and also rated self-relevance of photos. Results: Younger participants showed a more liberal response bias for disgust- and fear-related stimuli, and were also more accurate in recognizing disgust-related photos compared to others. Older adults showed a more liberal bias only for disgust-related stimuli, however, their recognition accuracy did not differ across emotion categories. Conclusion: These results suggested that the effect of disgust-related stimuli on recognition memory may decrease with age and emotion effects cannot solely be accounted for by the valence/arousal dimensions.

Visually-induced dizziness is associated with sensitivity and avoidance across all senses

BACKGROUND

Persistent postural perceptual dizziness (PPPD) is a common chronic condition presenting in neurology and neuro-otology clinics. Symptoms lie on a spectrum in the general population. The cause is unknown and thought to involve interactions between visual and vestibular systems, but symptoms also correlate with anxiety and migraine.

OBJECTIVE

To test whether PDDD symptoms are associated with reported differences in other senses (touch, hearing, smell and taste); to investigate possible mediation via anxiety or migraine; to discover the proportion of variance accountable to these non-vestibular factors.

METHODS

We measured self-report multisensory sensitivity, anxiety, visual difficulties, visual discomfort and migraine in patients with PPPD (N = 29) and a large general population cohort (N > 1100). We used structural equation modelling to examine relationships between the factors using a step-wise approach.

RESULTS

We found increased self-reported over-sensitivity in sensory domains beyond vision and balance in both patients with PPPD and non-clinical participants with more PPPD symptoms. SEM analysis revealed that anxiety partly, but not wholly, mediated this relationship. Adding visual difficulties and visual discomfort to the model allowed it to explain 50% of PPPD symptom variance. Most of the path coefficients and mediation effects in our model were unchanged between participants with and without migraine.

CONCLUSIONS

Our findings support the idea that PPPD is a complex neurological condition that includes broad perceptual factors, and may suggest that some brains are predisposed to generalised cross-modal sensory-overload. This may give rise to vulnerability to severe PPPD should a vestibular insult occur.

Not All Emotions Are Equal: Fear Chemosignals Lower Awareness Thresholds Only for Fearful Faces

Exposure to body odors (chemosignals) collected under different emotional states (i.e., emotional chemosignals) can modulate our visual system, biasing visual perception. Recent research has suggested that exposure to fear body odors, results in a generalized faster access to visual awareness of different emotional facial expressions (i.e., fear, happy, and neutral). In the present study, we aimed at replicating and extending these findings by exploring if these effects are limited to fear odor, by introducing a second negative body odor—that is, disgust. We compared the time that 3 different emotional facial expressions (i.e., fear, disgust, and neutral) took to reach visual awareness, during a breaking continuous flash suppression paradigm, across 3 body odor conditions (i.e., fear, disgust, and neutral). We found that fear body odors do not trigger an overall faster access to visual awareness, but instead sped-up access to awareness specifically for facial expressions of fear. Disgust odor, on the other hand, had no effects on awareness thresholds of facial expressions. These findings contrast with prior results, suggesting that the potential of fear body odors to induce visual processing adjustments is specific to fear cues. Furthermore, our results support a unique ability of fear body odors in inducing such visual processing changes, compared with other negative emotional chemosignals (i.e., disgust). These conclusions raise interesting questions as to how fear odor might interact with the visual processing stream, whilst simultaneously giving rise to future avenues of research.

Time course of attentional bias in social anxiety: The effects of spatial frequencies and individual threats

Hypervigilance and attentional bias to threat faces with low-spatial-frequency (LSF) information have been found in individuals with social anxiety. The vigilance-avoidance hypothesis posits that socially anxious individuals exhibit initial vigilance and later avoidance to threatening cues. However, the temporal dynamics of these two processes in response to various LSF threats in social anxiety remain unclear. In the current study, we presented faces containing anger, disgust, and fear in high and low spatial frequencies and compared the neural correlates with sensory perception and attention in individuals with high versus low social anxiety (HSA/LSA, n = 24). A visual search task was used to investigate the attentional effects of threats and spatial frequencies, and event-related potentials, particularly, the visual components of P1 and P250, were measured to index visual perceptual and attentional processes, respectively. We found that HSA individuals showed pronounced P1 and reduced P250 to LSF (vs. HSF) faces, regardless of emotion type, suggesting a general pattern of initial vigilance and later avoidance to LSF faces in social anxiety. Furthermore, while LSA individuals showed enhanced P250 to both fear and disgust (vs. neutral) faces, HSA individuals showed pronounced P250 to disgust faces alone. Our results, thus, elucidate the temporal profile of early vigilance and later avoidance in social anxiety, highlighting its broad implication for all faces and predominance in the low spatial frequency. Considering individual threats, our results demonstrate specific attentional avoidance of fear faces in social anxiety.

Review: Exteroceptive Sensory Abnormalities in Childhood and Adolescent Anxiety and Obsessive-Compulsive Disorder: A Critical Review

OBJECTIVE

Childhood anxiety and obsessive-compulsive disorder (OCD) are defined by fear, worry, and uncertainty, but there is also evidence that affected children possess exteroceptive sensory abnormalities. These sensory features may often instigate symptoms and cause significant distress and functional impairment. In addition, a purported class of conditions known as "sensory processing disorders" may significantly overlap with childhood anxiety and OCD, which provides further support for a connection between abnormal sensation and fear-based psychopathology.

METHOD

The current review was conducted to synthesize and to critically evaluate the existing research on exteroceptive sensory abnormalities in childhood anxiety and OCD. Because of the paucity of research in this area, studies with adult populations were also briefly reviewed.

RESULTS

The review found significant support for the notion that sensory abnormalities are common in children with anxiety disorders and OCD, but there are significant limitations to research in this area that prevent firm conclusions.

CONCLUSION

Potential avenues for future research on sensory features of pediatric anxiety and OCD are discussed.

Impaired early visual categorization of fear in social anxiety

Social anxiety is associated with biased social perception, especially of ambiguous cues. While aberrations in high-level processes (e.g., cognitive appraisal and interpretation) have been implicated in such biases, contributions of early, low-level stimulus processing remain unclear. Categorical perception represents an efficient process to resolve signal ambiguity, and categorical emotion perception can swiftly classify sensory input, "tagging" biologically important stimuli at early stages of processing to facilitate ecological response. However, early threat categorization could be disrupted by exaggerated (or disinhibited) threat processing in anxiety, resulting in biased perception of ambiguous signals. We tested this hypothesis among individuals with low and high trait social anxiety (LSA/HSA; defined relative to the current sample), who performed a two-alternative forced-choice (fear or neutral) task on facial expressions parametrically varied along a neutral-fear continuum. The groups diverged in the reaction time (RT) profile along the neutral-fear continuum, which was characteristic of categorical perception in the LSA (vs. HSA) group with drastically increased RT from neutral to intermediate (boundary) fear intensities, contrasting monotonic, nonsignificant RT changes in the HSA group. Neurometric analysis along the continuum identified an early neutral-fear categorization operation (arising in the P1, an early visual ERP at 100 ms), which was nonetheless impaired in the HSA group (due to disinhibited response at the neutral-fear boundary). Absent group differences in higher-level cognitive operations (identified by later ERPs), current findings highlight a dispositional cognitive vulnerability in early visual categorization of social threat, which could precipitate further cognitive aberrations and, eventually, the onset of social anxiety disorder.

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.

(Why) Do You Like Scary Movies? A Review of the Empirical Research on Psychological Responses to Horror Films

Why do we watch and like horror films? Despite a century of horror film making and entertainment, little research has examined the human motivation to watch fictional horror and how horror film influences individuals’ behavioral, cognitive, and emotional responses. This review provides the first synthesis of the empirical literature on the psychology of horror film using multi-disciplinary research from psychology, psychotherapy, communication studies, development studies, clinical psychology, and media studies. The paper considers the motivations for people’s decision to watch horror, why people enjoy horror, how individual differences influence responses to, and preference for, horror film, how exposure to horror film changes behavior, how horror film is designed to achieve its effects, why we fear and why we fear specific classes of stimuli, and how liking for horror develops during childhood and adolescence. The literature suggests that (1) low empathy and fearfulness are associated with more enjoyment and desire to watch horror film but that specific dimensions of empathy are better predictors of people’s responses than are others; (2) there is a positive relationship between sensation-seeking and horror enjoyment/preference, but this relationship is not consistent; (3) men and boys prefer to watch, enjoy, and seek our horror more than do women and girls; (4) women are more prone to disgust sensitivity or anxiety than are men, and this may mediate the sex difference in the enjoyment of horror; (5) younger children are afraid of symbolic stimuli, whereas older children become afraid of concrete or realistic stimuli; and (6) in terms of coping with horror, physical coping strategies are more successful in younger children; priming with information about the feared object reduces fear and increases children’s enjoyment of frightening television and film. A number of limitations in the literature is identified, including the multifarious range of horror stimuli used in studies, disparities in methods, small sample sizes, and a lack of research on cross-cultural differences and similarities. Ideas for future research are explored.

Lasting connectivity increase and anxiety reduction via transcranial alternating current stimulation

Growing evidence of transcranial alternating current stimulation (tACS) modulating intrinsic neural oscillations has spawned interest in applying tACS to treat psychiatric disorders associated with aberrant neural oscillations. The alpha rhythmic activity is known to dominate neural oscillations at the awake, restful state, while attenuated resting-state alpha activity has been implicated in anxious mood. Administering repeated alpha-frequency tACS (α-tACS; at individual peak alpha frequency; 8–12 Hz) over four consecutive days (in the experiment group, sham stimulation in the control group), we demonstrated immediate and lasting (>24 h) increases in resting-state posterior ➔frontal connectivity in the alpha frequency, quantified by Granger causality. Critically, this connectivity enhancement was accompanied by sustained reductions in both anxious arousal and negative perception of sensory stimuli. Resting-state alpha power also increased, albeit only transiently, reversing to the baseline level within 24 h after tACS. Therefore, the lasting enhancement of long-range alpha connectivity due to α-tACS differs from local alpha activity that is nonetheless conserved, highlighting the adaptability of alpha oscillatory networks. In light of increasing recognition of large-scale network dysfunctions as a transdiagnostic pathophysiology of psychiatric disorders, this enduring connectivity plasticity, along with the behavioral improvements, paves the way for tACS applications in clinical interventions of psychiatric ‘oscillopathies’.

Uncertainty Modulates the Effect of Transcranial Stimulation Over the Right Dorsolateral Prefrontal Cortex on Decision-Making Under Threat

Threat is a strategy that can be used to impact decision-making processes in bargaining. Abundant evidence suggests that credible threat and incredible threat both influence the obeisance of others. However, it is not clear whether the decision-making processes under credible threat and incredible threat during bargaining involve differential neurocognitive mechanisms. Here, we employed cathodal transcranial direct current stimulation (tDCS) to deactivate the right dorsolateral prefrontal cortex (rDLPFC) to address this question while subjects allocated and reported the subjective probability of future rejection under incredible threat and credible threat. We found that application of cathodal tDCS over the rDLPFC decreased the proposer's subjective inference of probability of rejection and the offer to the responder under incredible threat. Conversely, the same stimulation did not lead to a significant difference compared to the sham group in subjective probability and offer under credible threat. These results suggested that decision-making processes under the two types of threat during bargaining were associated with different neurocognitive substrates, because the punishment for non-compliance was uncertain under incredible threat, whereas it was certain under credible threat. We decreased activity in the rDLPFC, which is involved in decision-making processes related to bargaining under incredible threats, and observed significantly impacted behavior. The differential neurocognitive bases of subjective probability of rejection under incredible threat and credible threat resulted in different tDCS effects.

Empathy in Facial Mimicry of Fear and Disgust: Simultaneous EMG-fMRI Recordings During Observation of Static and Dynamic Facial Expressions

Real-life faces are dynamic by nature, particularly when expressing emotion. Increasing evidence suggests that the perception of dynamic displays enhances facial mimicry and induces activation in widespread brain structures considered to be part of the mirror neuron system, a neuronal network linked to empathy. The present study is the first to investigate the relations among facial muscle responses, brain activity, and empathy traits while participants observed static and dynamic (videos) facial expressions of fear and disgust. During display presentation, blood-oxygen level-dependent (BOLD) signal as well as muscle reactions of the corrugator supercilii and levator labii were recorded simultaneously from 46 healthy individuals (21 females). It was shown that both fear and disgust faces caused activity in the corrugator supercilii muscle, while perception of disgust produced facial activity additionally in the levator labii muscle, supporting a specific pattern of facial mimicry for these emotions. Moreover, individuals with higher, compared to individuals with lower, empathy traits showed greater activity in the corrugator supercilii and levator labii muscles; however, these responses were not differentiable between static and dynamic mode. Conversely, neuroimaging data revealed motion and emotional-related brain structures in response to dynamic rather than static stimuli among high empathy individuals. In line with this, there was a correlation between electromyography (EMG) responses and brain activity suggesting that the Mirror Neuron System, the anterior insula and the amygdala might constitute the neural correlates of automatic facial mimicry for fear and disgust. These results revealed that the dynamic property of (emotional) stimuli facilitates the emotional-related processing of facial expressions, especially among whose with high trait empathy.

Electro-cortical correlates of multisensory integration using ecologically valid emotional stimuli: Differential effects for fear and disgust

Multisensory integration (MSI) is crucial for human communication and social interaction and has been investigated in healthy populations and neurodevelopmental disorders. However, the use of stimuli with high ecological validity is sparse, especially in event-related potential (ERP) studies. The present study examined the ERP correlates of MSI in healthy adults using short (500 ms) ecologically valid professional actor-produced emotions of fear or disgust as vocal exclamation or facial expression (unimodal conditions) or both (bimodal condition). Behaviourally, our results show a general visual dominance effect (similarly fast responses following bimodal and visual stimuli) and an MSI-related speedup of responses only for fear. Electrophysiologically, both P100 and N170 showed MSI-related amplitude increases only following fear, but not disgust stimuli. Our results show for the first time that the known differential neural processing of fear and disgust also holds for the integration of dynamic auditory and visual information.

Human chemosignals of disgust facilitate food judgment

Choosing food is not a trivial decision that people need to make daily, which is often subject to social influences. Here, we studied a human homolog of social transmission of food preference (STFP) as observed in rodents and other animals via chemosignals of body secretions. Human social chemosignals (sweat) produced during a disgust or neutral state among a group of donors were presented to participants undergoing a 2-alternative-forced-choice food healthiness judgment task during functional magnetic resonance imaging (fMRI). Response speed and two key signal detection indices—d’ (discrimination sensitivity) and β (response bias)—converged to indicate that social chemosignals of disgust facilitated food healthiness decisions, in contrast to primary disgust elicitors (disgust odors) that impaired the judgment. fMRI analyses (disgust vs. neutral sweat) revealed that the fusiform face area (FFA), amygdala, and orbitofrontal cortex (OFC) were engaged in processing social chemosignals of disgust during food judgment. Importantly, a double contrast of social signaling across modalities (olfactory vs. visual—facial expressions) indicated that the FFA and OFC exhibited preferential response to social chemosignals of disgust. Together, our findings provide initial evidence for human STFP, where social chemosignals are incorporated into food decisions by engaging social and emotional areas of the brain.

Individual Differences in Attentional Capture by Pictures of Fear and Disgust as Indexed by Cardiac Responses

Abstract. Emotional stimuli automatically capture attention in ways that are relevant to the survival value of the stimuli. We have previously shown that individual differences in resting heart rate variability (HRV) were related to attentional capture by negative (fearful) and neutral distractors. However, different negative emotions such as fear and disgust may differentially capture attention. In the present study we investigated the effect of automatic attention capture by disgust and fear stimuli on behavioral and phasic heart rate responses as well as its relationship with resting heart rate variability (HRV). Twenty-eight participants (14 men) were divided into two groups based on their resting HRV. Phasic cardiac responses as well as reaction times and errors on a digit categorization task were assessed with disgust, fear, and neutral pictures as distractors. In the high HRV group disgusting distractors produced the strongest interference on the ongoing cognitive task indicated by more errors and longer reaction times as well as a deeper cardiac deceleration compared to fearful or neutral distractors. In contrast, the low HRV group showed faster reaction times to fear evoking pictures, whereas their heart rate responses and number of errors did not distinguish between the three emotional categories. Our results suggest that high HRV participants showed the emotional context appropriate responses while low HRV participants seem to be hypervigilant to fear.

Dopamine neurons projecting to the posterior striatum reinforce avoidance of threatening stimuli

Midbrain dopamine neurons are well known for their role in reward-based reinforcement learning. We found that the activity of dopamine axons in the posterior tail of the striatum (TS) scaled with the novelty and intensity of external stimuli, but did not encode reward value. We demonstrated that the ablation of TS-projecting dopamine neurons specifically inhibited avoidance of novel or high-intensity stimuli without affecting animals' initial avoidance responses, suggesting a role in reinforcement rather than simply in avoidance itself. Furthermore, we found that animals avoided optogenetic activation of dopamine axons in TS during a choice task and that this stimulation could partially reinstate avoidance of a familiar object. These results suggest that TS-projecting dopamine neurons reinforce avoidance of threatening stimuli. More generally, our results indicate that there are at least two axes of reinforcement learning using dopamine in the striatum: one based on value and one based on external threat.

Cognitive mechanisms of disgust in the development and maintenance of psychopathology: A qualitative review and synthesis

A growing body of research has implicated disgust in various psychopathologies, especially anxiety-related disorders. Although the observed role of disgust in many disorders is robust, the mechanisms that may explain this role are unclear. Cutting-edge research in cognitive science has the potential to elucidate such mechanisms and consequently improve our understanding of how disgust contributes to the etiology and maintenance of psychopathology. In this qualitative review, we systematically assess cognitive bias mechanisms that have been linked to disgust and its disorders. This review suggests that disgust-related biases may be observed in memory, interpretation, judgment of expectancies, and attention, as well as at implicit levels. Of these cognitive domains, the most robust bias appears to be observed at the level of attention. However, reliable moderators of attentional biases for disgust have not yet been identified, and this bias has not been systematically linked to other levels of analysis. Despite these limitations, the available research indicates that attentional avoidance rather than orienting or maintenance may be the most characteristic of disgust. Attentional avoidance of disgust may have important implications for etiological and treatment models of disorders characterized by excessive disgust reactions. The implications for advancing such models are discussed in the context of a combined cognitive bias hypothesis.

Ecological and Evolutionary Consequences of Parasite Avoidance

Predators often cause prey to adopt defensive strategies that reduce predation risk. The 'ecology of fear' examines these trait changes and their consequences. Similarly, parasites can cause hosts to adopt defensive strategies that reduce infection risk. However the ecological and evolutionary consequences of these behaviors (the 'ecology of disgust') are seldom considered. Here we identify direct and indirect effects of parasite avoidance on hosts and parasites, and examine differences between predators and parasites in terms of cost, detectability, and aggregation. We suggest that the nonconsumptive effects of parasites might overshadow their consumptive effects, as has been shown for predators. We emphasize the value of uniting predator-prey and parasite-host theory under a general consumer-resource framework.

Dysfunctional Early Processing of Facial Expressions in Hazardous Drinkers: Evidence from an ERP Study

Chronic alcohol intoxication impairs multiple cognitive functions. According to the dual system model (DSM), the development of alcohol dependence (AD) involves the imbalance between the automatic-affective system and the reflective system. However, the cognitive functions of non-AD hazardous drinkers (HDs) remain unclear. The present study aimed to explore how the HDs process facial expressions differently from the healthy subjects. Sixteen HDs and seventeen control subjects (CSs) completed an emotional working memory (WM) task while the electroencephalogram (EEG) was recorded. We found that there was no significant group difference in behavioral performance between the two groups. In the ERP data, relative to the CSs, the HDs showed delayed latencies of P1 and N170. Moreover, the CSs showed significant differences between the amplitudes of neural/fear and disgust expressions while these differences were insignificant in the HDs. The current results suggest that the main deficits in the processing of facial expression in HDs existed in the early automatic-affective system instead of in the reflective system.

Here Comes Trouble: Prestimulus Brain Activity Predicts Enhanced Perception of Threat

Research on the perceptual prioritization of threatening stimuli has focused primarily on the physical characteristics and evolutionary salience of these stimuli. However, perceptual decision-making is strongly influenced by prestimulus factors such as goals, expectations, and prior knowledge. Using both event-related potentials and functional magnetic resonance imaging, we test the hypothesis that prior threat-related information and related increases in prestimulus brain activity play a key role in subsequent threat-related perceptual decision-making. After viewing threatening and neutral cues, participants detected perceptually degraded threatening and neutral faces presented at individually predetermined perceptual thresholds in a perceptual decision-making task. Compared with neutral cues, threat cues resulted in (1) improved perceptual sensitivity and faster detection of target stimuli; (2) increased late positive potential (LPP) and superior temporal sulcus (STS) activity, both of which are measures of emotional face processing; and (3) increased amygdala activity for subsequently presented threatening versus and neutral faces. Importantly, threat cue-related LPP and STS activity predicted subsequent improvement in the speed and precision of perceptual decisions specifically for threatening faces. Present findings establish the importance of top-down factors and prestimulus neural processing in understanding how the perceptual system prioritizes threatening information.

Emotional responses to disfigured faces and Disgust Sensitivity: An eye-tracking study

Facial disfigurement attracts attention and evokes negative emotion, but evidence is lacking for a link between these two reactions. The present experiment ( n = 29) investigated emotional and attentional reactions to photographs of people with disfigured faces. An eye-tracker was used to measure fixation on internal expressive features and on the forehead. Disfigurement to the internal expressive features invoked a stronger emotional reaction than disfigurement to the forehead. Attention in the area of disfigurement was associated with negative emotion (embarrassment, sympathy, disgust, repulsion) as well as surprise. Attention to the disfigurement, and negative emotion, was related to the trait of Disgust Sensitivity.