Phobias and preparedness: the selective, automatic, and encapsulated nature of fear

Neurocognitive mechanisms of mental imagery-based disgust learning

Disgust imagery represents a potential pathological mechanism for disgust-related disorders. However, it remains controversial as to whether disgust can be conditioned with disgust-evoking mental imagery serving as the unconditioned stimulus (US). Therefore, we examined this using a conditioned learning paradigm in combination with event-related potential (ERP) analysis in 35 healthy college students. The results indicated that the initial neutral face (conditioned stimulus, CS+) became more disgust-evoking, unpleasant, and arousing after pairing with disgust-evoking imagery (disgust CS+), compared to pairing with neutral (neutral CS+) and no (CS-) imagery. Moreover, we observed that mental imagery-based disgust conditioning was resistant to extinction. While the disgust CS + evoked larger P3 and late positive potential amplitudes than CS- during acquisition, no significant differences were found between disgust CS+ and neutral CS+, indicating a dissociation between self-reported and neurophysiological responses. Future studies may additionally acquire facial EMG as an implicit index of conditioned disgust. This study provides the first neurobiological evidence that associative disgust learning can occur without aversive physical stimuli, with implications for understanding how disgust-related disorders may manifest or deteriorate without external perceptual aversive experiences, such as in obsessive-compulsive disorder (OCD).

Can the processing of task-irrelevant threatening stimuli be inhibited? - The role of shape and valence in the saliency of threatening objects

Numerous studies have demonstrated that attention is quickly oriented towards threatening stimuli, and that this attentional bias is difficult to inhibit. The root cause(s) of this bias may be attributable to the affective (e.g., valence) or visual features (e.g., shape) of threats. In two experiments (behavioral, eye-tracking), we tested which features play a bigger role in the salience of threats. In both experiments, participants looked for a neutral target (butterfly, lock) among other neutral objects. In half of the trials a threatening (snake, gun) or nonthreatening (but visually similar; worm, hairdryer) task-irrelevant distractor was also present at a near or far distance from the target. Behavioral results indicate that both distractor types interfered with task performance. Rejecting nonthreatening distractors as nontargets was easier when they were presented further from the target but distance had no effect when the distractor was threatening. Eye-tracking results showed that participants fixated less often (and for less time) on threatening compared to nonthreatening distractors. They also viewed targets for less time when a threatening distractor was present (compared to nonthreatening). Results suggest that visual features of threats are easier to suppress than affective features, and the latter may have a stronger role in eliciting attentional biases.

Reliability of repeated exposure to the human elevated plus-maze in virtual reality: Behavioral, emotional, and autonomic responses

Approach-avoidance conflicts are a hallmark of anxiety-related behaviors. A gold standard for assessing anxiety-related behaviors in rodents is the elevated plus-maze (EPM), which was recently translated to humans using immersive virtual reality. Repeated behavioral testing is particularly interesting for clinical and pharmacological research in humans but could be limited by habituation effects. Here, we tested whether comparable strategies that are used in rodents (different environments and inter-trial interval of 28 days) are sufficient to avoid habituation or sensitization effects on the EPM, making it possible to perform repeated measurement of anxiety-related behavior in humans. Moreover, we developed two novel virtual environments for repeated testing to explore whether a scenario resembling the real world is superior to a video game-like EPM in terms of lifelike physiological, emotional, and behavioral responses. On a behavioral level, no significant differences but a high correlation between first and repeated exposure to the human EPM independent of EPM version were found. On a psychophysiological level, salivary alpha-amylase, skin-conductance, and respiratory frequency increased at first and second exposure independent of EPM version. However, at repeated exposure, skin-conductance and heart rate showed indicators for anticipatory anxiety and a small sensitization effect, while no effect of real-world resemblance on these physiological measures was found. This was also reflected in slightly higher subjective anxiety levels at second exposure, although subjective anxiety still correlated strongly between first and second exposure. In conclusion, the human EPM can be used for longitudinal assessments of human anxiety-related behavior when strategies to avoid habituation and sensitization are considered.

Generalization of beneficial exposure effects to untreated stimuli from another fear category

Previous research has shown that fear associated with one stimulus often spreads to other stimuli with similar perceptual features as well as across different stimulus categories. Exposure is considered as the most effective intervention to attenuate exaggerated fear. The extent to which exposure treatment effects can generalize to fears not targeted during treatment remains elusive. Previous studies on possible generalization of beneficial effects of exposure used stimuli sharing the same stimulus category and/or stimuli having high perceptual similarity. The current study examined whether exposure treatment generalization can be achieved for untreated stimuli which do not share any perceptual resemblance and belong to a different fear category. An analogue sample of fifty participants with fear of spiders (animal-related fears) and heights (natural environment-related fears) was tested. Participants have been randomly assigned to either an exposure treatment (n = 24) or a control condition (n = 26). Exposure treatment was designed to only target participants' fear of spiders, leaving their fear of heights untreated. Results demonstrated that the effects of exposure treatment generalized to fear of heights, as indicated by a reduction in behavioral avoidance, as well as self-reported acrophobia symptoms. The present study confutes the assumption that generalization of exposure effects to untreated fears is based on perceptual similarity. Clearly, further research is required to determine the decisive factors, in order to expand the generalization effect permanently to any given type of fear.

Attentional, emotional, and behavioral response toward spiders, scorpions, crabs, and snakes provides no evidence for generalized fear between spiders and scorpions

Spiders are among the animals evoking the highest fear and disgust and such a complex response might have been formed throughout human evolution. Ironically, most spiders do not present a serious threat, so the evolutionary explanation remains questionable. We suggest that other chelicerates, such as scorpions, have been potentially important in the formation and fixation of the spider-like category. In this eye-tracking study, we focused on the attentional, behavioral, and emotional response to images of spiders, scorpions, snakes, and crabs used as task-irrelevant distractors. Results show that spider-fearful subjects were selectively distracted by images of spiders and crabs. Interestingly, these stimuli were not rated as eliciting high fear contrary to the other animals. We hypothesize that spider-fearful participants might have mistaken crabs for spiders based on their shared physical characteristics. In contrast, subjects with no fear of spiders were the most distracted by snakes and scorpions which supports the view that scorpions as well as snakes are prioritized evolutionary relevant stimuli. We also found that the reaction time increased systematically with increasing subjective fear of spiders only when using spiders (and crabs to some extent) but not snakes and scorpions as distractors. The maximal pupil response covered not only the attentional and cognitive response but was also tightly correlated with the fear ratings of the picture stimuli. However, participants' fear of spiders did not affect individual reactions to scorpions measured by the maximal pupil response. We conclude that scorpions are evolutionary fear-relevant stimuli, however, the generalization between scorpions and spiders was not supported in spider-fearful participants. This result might be important for a better understanding of the evolution of spider phobia.

The Role of Expectancy Violation in Extinction Learning: A Two-Day Online Fear Conditioning Study

Background

Exposure therapy is at the core of the treatment of pathological anxiety. While the inhibitory learning model proposes a framework for the mechanisms underlying exposure therapy, in particular expectancy violation, causal evidence for its assumptions remains elusive. Therefore, the aim of the current study was to provide evidence for the influence of expectancy violation on extinction retention by manipulating the magnitude of expectancy violation during extinction learning.

Method

In total, 101 individuals completed a web-based fear conditioning protocol, consisting of a fear acquisition and extinction phase, as well as a spontaneous recovery and fear reinstatement test 24h later. To experimentally manipulate expectancy violation, participants were presented only with states of the conditioned stimulus that either weakly or strongly predicted the aversive outcome. Consequently, the absence of any aversive outcomes in the extinction phase resulted in low or high expectancy violation, respectively.

Results

We found successful fear acquisition and manipulation of expectancy violation, which was associated with reduced threat ratings for the high compared to the low expectancy violation group directly after extinction learning. On Day 2, inhibitory CS-noUS associations could be retrieved for expectancy ratings, whereas there were no substantial group differences for threat ratings.

Conclusion

These findings indicate that the magnitude of expectancy violation is related to the retrieval of conscious threat expectancies, but it is unclear how these changes translate to affective components (i.e., threat ratings) of the fear response and to symptoms of pathological anxiety.

Startle responses in Duchenne muscular dystrophy: a novel biomarker of brain dystrophin deficiency

Duchenne muscular dystrophy (DMD) is characterized by loss of dystrophin in muscle, however patients also have variable degree of intellectual disability and neurobehavioural co-morbidities. In contrast to muscle, in which a single full-length dystrophin isoform (Dp427) is produced, multiple isoforms are produced in the brain, and their deficiency accounts for the variability of CNS manifestations, with increased risk of comorbidities in patients carrying mutations affecting the 3' end of the gene, which disrupt expression of shorter Dp140 and Dp71 isoforms. A mouse model (mdx mouse) lacks Dp427 in muscle and CNS and exhibits exaggerated startle responses to threat, linked to the deficiency of dystrophin in limbic structures such as the amygdala, which normalize with postnatal brain dystrophin-restoration therapies. A pathological startle response is not a recognized feature of DMD, and its characterization has implications for improved clinical management and translational research. To investigate startle responses in DMD, we used a novel fear-conditioning task in an observational study of 56 males aged 7-12 years (31 affected boys, mean age 9.7 ± 1.8 years; 25 controls, mean age 9.6 ± 1.4 years). Trials of two neutral visual stimuli were presented to participants: one 'safe' cue presented alone; one 'threat' cue paired with an aversive noise to enable conditioning of physiological startle responses (skin conductance response and heart rate). Retention of conditioned physiological responses was subsequently tested by presenting both cues without the aversive noise in an 'Extinction' phase. Primary outcomes were the initial unconditioned skin conductance and change in heart rate responses to the aversive 'threat' and acquisition and retention of conditioned responses after conditioning. Secondary and exploratory outcomes were neuropsychological measures and genotype associations. The mean unconditioned skin conductance response was greater in the DMD group than controls [mean difference 3.0 µS (1.0, 5.1); P = 0.004], associated with a significant threat-induced bradycardia only in the patient group [mean difference -8.7 bpm (-16.9, -0.51); P = 0.04]. Participants with DMD found the task more aversive than controls, with increased early termination rates during the Extinction phase (26% of DMD group versus 0% of controls; P = 0.007). This study provides the first evidence that boys with DMD show similar increased unconditioned startle responses to threat to the mdx mouse, which in the mouse respond to brain dystrophin restoration. Our study provides new insights into the neurobiology underlying the complex neuropsychiatric co-morbidities in DMD and defines an objective measure of this CNS phenotype, which will be valuable for future CNS-targeted dystrophin-restoration studies.

[The sovereignty of the visible: how traumatic memory becomes traumatic stress]

Since the release of the third version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), biological psychiatry has been systematically applying its classification reasoning to social phenomena of many natures. From this perspective, the discourse of trauma gained relevance and events of devastating magnitude began to receive neurobehavioral interpretations until finally being recognized less for their cultural and subjective effects than for the physiological changes they cause. By a narrative review, this study aims to analyze the transition of traumatic rationality from the 19th century, when trauma was associated with the cognitive concept of memory, to the 20th century, when this phenomenon was finally attached to neuroscientific research on stress. The plurality of conceptual models and deterministic paradigms can contribute to the fact that trauma research produces multifactorial coping protocols more appropriate to the human experience of post-traumatic suffering.

Instructions and experiential learning have similar impacts on pain and pain-related brain responses but produce dissociations in value-based reversal learning

Recent data suggest that interactions between systems involved in higher order knowledge and associative learning drive responses during value-based learning. However, it is unknown how these systems impact subjective responses, such as pain. We tested how instructions and reversal learning influence pain and pain-evoked brain activation. Healthy volunteers (n=40) were either instructed about contingencies between cues and aversive outcomes or learned through experience in a paradigm where contingencies reversed three times. We measured predictive cue effects on pain and heat-evoked brain responses using functional magnetic resonance imaging. Predictive cues dynamically modulated pain perception as contingencies changed, regardless of whether participants received contingency instructions. Heat-evoked responses in the insula, anterior cingulate, and other regions updated as contingencies changed, and responses in the prefrontal cortex mediated dynamic cue effects on pain, whereas responses in the brainstem's rostroventral medulla (RVM) were shaped by initial contingencies throughout the task. Quantitative modeling revealed that expected value was shaped purely by instructions in the Instructed Group, whereas expected value updated dynamically in the Uninstructed Group as a function of error-based learning. These differences were accompanied by dissociations in the neural correlates of value-based learning in the rostral anterior cingulate, thalamus, and posterior insula, among other regions. These results show how predictions dynamically impact subjective pain. Moreover, imaging data delineate three types of networks involved in pain generation and value-based learning: those that respond to initial contingencies, those that update dynamically during feedback-driven learning as contingencies change, and those that are sensitive to instruction. Together, these findings provide multiple points of entry for therapies designs to impact pain.

Propranolol versus Other Selected Drugs in the Treatment of Various Types of Anxiety or Stress, with Particular Reference to Stage Fright and Post-Traumatic Stress Disorder

Propranolol, a non-cardioselective β1,2 blocker, is most commonly recognised for its application in the therapy of various cardiovascular conditions, such as hypertension, coronary artery disease, and tachyarrhythmias. However, due to its ability to cross the blood-brain barrier and affinity towards multiple macromolecules, not only adrenoreceptors, it has also found application in other fields. For example, it is one of the very few medications successfully applied in the treatment of stage fright. This review focuses on the application of propranolol in the treatment of various types of anxiety and stress, with particular reference to stage fright and post-traumatic stress disorder (PTSD). Both mechanisms of action as well as comparison with other therapies are presented. As those indications for propranolol are, in most countries, considered off-label, this review aims to gather information that can be useful while making a decision about the choice of propranolol as a drug in the treatment of those mental conditions.

The relationship between meat disgust and meat avoidance-A chicken-and-egg problem

Feelings of disgust toward meat have been researched for at least 30 years, but so far the causal relationship that may link meat disgust and meat consumption has remained elusive. Two possible pathways have been proposed in previous literature: the more common pathway seems to be that meat disgust is developed after a transition to vegetarianism, potentially via the process of moralization and recruitment of (moral) disgust. Other accounts suggest the existence of a second pathway in which disgust initiates the avoidance of meat and this can be explained by existing theories of disgust functioning as a pathogen avoidance mechanism and meat serving as a pathogen cue. However, the evidence base for either relationship remains thin and to our knowledge no research has examined whether temporary meat abstention can lead to increases in meat disgust, as the first pathway suggests. We measured meat disgust and meat intake in n = 40 meat eaters before and after attempting a meat-free diet for 1 month (while taking part in the annual vegan campaign Veganuary). Although most participants lapsed to eating meat during this period, we found that reductions in meat intake during the month were predictive of increases in meat disgust afterwards. This supports the view that meat disgust is expressed as a result of meat avoidance in meat eaters. Implications for theoretical understanding of the relationship between meat disgust and meat avoidance, as well as the development of disgust based interventions are discussed.

Development of a novel startle response task in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD), an X-linked childhood-onset muscular dystrophy caused by loss of the protein dystrophin, can be associated with neurodevelopmental, emotional and behavioural problems. A DMD mouse model also displays a neuropsychiatric phenotype, including increased startle responses to threat which normalise when dystrophin is restored in the brain. We hypothesised that startle responses may also be increased in humans with DMD, which would have potential translational therapeutic implications. To investigate this, we first designed a novel discrimination fear-conditioning task and tested it in six healthy volunteers, followed by male DMD (n = 11) and Control (n = 9) participants aged 7–12 years. The aims of this methodological task development study were to: i) confirm the task efficacy; ii) optimise data processing procedures; iii) determine the most appropriate outcome measures. In the task, two neutral visual stimuli were presented: one ‘safe’ cue presented alone; one ‘threat’ cue paired with a threat stimulus (aversive noise) to enable conditioning of physiological startle responses (skin conductance response, SCR, and heart rate). Outcomes were the unconditioned physiological startle responses to the initial threat, and retention of conditioned responses in the absence of the threat stimulus. We present the protocol development and optimisation of data processing methods based on empirical data. We found that the task was effective in producing significantly higher physiological startle SCR in reinforced ‘threat’ trials compared to ‘safe’ trials (P < .001). Different data extraction methods were compared and optimised, and the optimal sampling window was derived empirically. SCR amplitude was the most effective physiological outcome measure when compared to SCR area and change in heart rate, with the best profile on data processing, the least variance, successful conditioned response retention (P = .01) and reliability assessment in test-retest analysis (rho = .86). The definition of this novel outcome will allow us to study this response in a DMD population.

Unpleasant Odors Affect Alerting Attention in Young Men: An Event-Related Potential Study Using the Attention Network Test

Attention to unpleasant odors is crucial for human safety because they may signal danger; however, whether odor concentration also plays a role remains debated. Here, we explored the effects of two concentrations of pleasant and unpleasant odors on the attention network, comprising the alerting, orienting, and executive control networks. Behavioral responses were examined using the Attention Network Test, while electrophysiological responses were examined by assessing N1 and N2 amplitudes in 30 young men. We found that irrespective of odor concentration, an unpleasant odor induced larger cue-related N1 and N2 amplitudes in the alerting and executive control networks at occipital and frontal electrode sites and that was only paralleled by a reduced behavioral response time of cue-related trails in the alerting network. Thus, our results do not provide supporting evidence for a concentration-dependent effect, but they do suggest that more attentional resources are allocated to alerting-relevant stimuli to improve behavioral response times to a potential threat in young men.

Rating expectations can slow aversive reversal learning

The process of learning allows organisms to develop predictions about outcomes in the environment, and learning is sensitive to both simple associations and higher order knowledge. However, it is unknown whether consciously attending to expectations shapes the learning process itself. Here, we directly tested whether rating expectations shapes arousal during classical conditioning. Participants performed an aversive learning paradigm wherein one image (CS+) was paired with shock on 50% of trials, while a second image (CS-) was never paired with shock. Halfway through the task, contingencies reversed. One group of participants rated the probability of upcoming shock on each trial, while the other group made no online ratings. We measured skin conductance response (SCR) evoked in response to the CS and used traditional analyses as well as quantitative models of reinforcement learning to test whether rating expectations influenced arousal and aversive reversal learning. Participants who provided online expectancy ratings displayed slower learning based on a hybrid model of adaptive learning and reduced reversal of SCR relative to those who did not rate expectations. Mediation analysis revealed that the effect of associative learning on SCR could be fully explained through its effects on subjective expectancy within the group who provided ratings. This suggests that the act of rating expectations reduces the speed of learning, likely through changes in attention, and that expectations directly influence arousal. Our findings indicate that higher order expectancy judgments can alter associative learning.

Specificity of spiders among fear- and disgust-eliciting arthropods: Spiders are special, but phobics not so much

To investigate a specificity of spiders as a prototypical fear- and disgust-eliciting stimuli, we conducted an online experiment. The respondents rated images of 25 spiders, 12 non-spider chelicerates, and 10 other arthropods on a fear and disgust 7-point scale. The evaluation of 968 Central European respondents confirmed the specificity of spiders among fear- and disgust-eliciting arthropods and supported the notion of spiders as a cognitive category. We delineated this category as covering extant spider species as well as some other chelicerates bearing a physical resemblance to spiders, mainly whip spiders and camel spiders. We suggested calling this category the spider-like cognitive category. We discussed evolutionary roots of the spider-like category and concluded that its roots should be sought in fear, with disgust being secondary of the two emotions. We suggested other chelicerates, e.g., scorpions, might have been important in formation and fixation of the spider-like category. Further, we investigated an effect of respondent's sensitivity to a specific fear of spiders on evaluation of the stimuli. We found that suspected phobic respondents were in their rating nearly identical to those with only high fear of spiders and similar to those with only moderate fear of spiders. We concluded that results based on healthy respondents with elevated fear should also be considered relevant for arachnophobia research.

An exploration of the nomological network of trypophobia

BACKGROUND

Trypophobia is characterised by an aversion to or even revulsion for patterns of holes or visual stimuli featuring such patterns. Past research has shown that trypophobic stimuli trigger emotional and physiological reactions, but relatively little is known about the antecedents, prodromes, or simply covariates of trypophobia.

AIM

The goals of this study were (a) to draw the contours of the nomological network of trypophobia by assessing the associations of symptoms of trypophobia with several constructs that were deemed relevant from past research on anxiety disorders and specific phobias, (b) to compare such associations with those found for symptoms of spider phobia and blood and injection phobia (alternative dependent variables), and (c) to investigate the main effect of gender on symptoms of trypophobia and replicate the association of gender with symptoms of spider phobia and blood and injection phobia (higher scores for women).

METHODS

Participants (N = 1,134, 53% men) in this cross-sectional study completed an online questionnaire assessing the constructs of interest.

RESULTS

Most assessed constructs typically associated with anxiety disorders (neuroticism, conscientiousness, anxiety sensitivity, trait anxiety, disgust sensitivity, and disgust propensity) were also associated with trypophobia in the predicted direction. All of these constructs were also associated with spider phobia and blood and injection phobia. Behavioral inhibition was negatively associated with trypophobia and spider phobia-contrary to what was expected, but positively with blood and injection phobia. We found no gender difference in trypophobia, whereas women scored higher on spider phobia and blood and injection phobia.

DISCUSSION

Although some differences were observed, the nomological network of trypophobia was largely similar to that of spider phobia and blood and injection phobia. Further studies are needed to clarify similarities and dissimilarities between trypophobia and specific phobia.

Observation of others' threat reactions recovers memories previously shaped by firsthand experiences

Information about dangers can spread effectively by observation of others' threat responses. Yet, it is unclear if such observational threat information interacts with associative memories that are shaped by the individual's direct, firsthand experiences. Here, we show in humans and rats that the mere observation of a conspecific's threat reactions reinstates previously learned and extinguished threat responses in the observer. In two experiments, human participants displayed elevated physiological responses to threat-conditioned cues after observational reinstatement in a context-specific manner. The elevation of physiological responses (arousal) was further specific to the context that was observed as dangerous. An analogous experiment in rats provided converging results by demonstrating reinstatement of defensive behavior after observing another rat's threat reactions. Taken together, our findings provide cross-species evidence that observation of others' threat reactions can recover associations previously shaped by direct, firsthand aversive experiences. Our study offers a perspective on how retrieval of threat memories draws from associative mechanisms that might underlie both observations of others' and firsthand experiences.

When gut feelings teach the brain to fear pain: Context-dependent activation of the central fear network in a novel interoceptive conditioning paradigm

The relevance of contextual factors in shaping neural mechanisms underlying visceral pain-related fear learning remains elusive. However, benign interoceptive sensations, which shape patients' clinical reality, may context-dependently become conditioned predictors of impending visceral pain. In a novel context-dependent interoceptive conditioning paradigm, we elucidated the putative role of the central fear network in the acquisition and extinction of pain-related fear induced by interoceptive cues and pain-predictive contexts. In this fMRI study involving rectal distensions as a clinically-relevant model of visceroception, N = 27 healthy men and women underwent differential conditioning. During acquisition training, visceral sensations of low intensity as conditioned stimuli (CS) predicted visceral pain as unconditioned stimulus (US) in one context (Con⁺), or safety from pain in another context (Con^-). During extinction training, interoceptive CS remained unpaired in both contexts, which were operationalized as images of different rooms presented in the MRI scanner. Successful contextual conditioning was supported by increased negative valence of Con⁺ compared to Con^- after acquisition training, which resolved after extinction training. Although interoceptive CS were perceived as comparatively pleasant, they induced significantly greater neural activation of the amygdala, ventromedial PFC, and hippocampus when presented in Con⁺, while contexts alone did not elicit differential responses. During extinction training, a shift from CS to context differentiation was observed, with enhanced responses in the amygdala, ventromedial, and ventrolateral PFC to Con⁺ relative to Con^-, whereas no CS-induced differential activation emerged. Context-dependent interoceptive conditioning can turn benign interoceptive cues into predictors of visceral pain that recruit key regions of the fear network. This first evidence expands knowledge about learning and memory mechanisms underlying interoceptive hypervigilance and maladaptive avoidance behavior, with implications for disorders of the gut-brain axis.

Biobehavioral Aspects of the COVID-19 Pandemic: A Review

OBJECTIVE

This review highlights the scope and significance of the coronavirus disease 2019 (COVID-19) pandemic with a focus on biobehavioral aspects and critical avenues for research.

METHODS

A narrative review of the published research literature was undertaken, highlighting major empirical findings emerging during the first and second waves of the COVID-19 pandemic.

RESULTS

Interactions among biological, behavioral, and societal processes were prominent across all regions of the globe during the first year of the COVID-19 emergency. Affective, cognitive, behavioral, socioeconomic, and technological factors all played a significant role in the spread of infection, response precautions, and outcomes of mitigation efforts. Affective symptoms, suicidality, and cognitive dysfunction have been widely described consequences of the infection, the economic fallout, and the necessary public health mitigation measures themselves. The impact of COVID-19 may be especially serious for those living with severe mental illness and/or chronic medical diseases, given the confluence of several adverse factors in a manner that appears to have syndemic potential.

CONCLUSIONS

The COVID-19 pandemic has made clear that biological and behavioral factors interact with societal processes in the infectious disease context. Empirical research examining mechanistic pathways from infection and recovery to immunological, behavioral, and emotional outcomes is critical. Examination of how emotional and behavioral factors relate to the pandemic-both as causes and as effects-can provide valuable insights that can improve management of the current pandemic and future pandemics to come.

Efectos de algunas señales visuales y olfativas sobre el consumo de cigarrillo y el ansia para fumar

Las señales inductoras para el consumo (SIC) son uno de los factores que inciden en que un fumador encienda, o no, el próximo cigarrillo. Las SIC impactan más a los fumadores no dependientes de la nicotina (FND) que a los fumadores dependientes (FD). Los FND no son dependientes de la nicotina y sus niveles de monóxido de carbono tienden a ser más bajos. Los FD muestran niveles de nicotina y monóxido de carbono más altos (dependientes). Este estudio evaluó el nivel de ansia de los individuos frente a imágenes relacionadas con el producto (cigarrillos y cajetilla de cigarrillos) y si existen diferencias entre inductores visuales y olfativos en relación con el consumo de cigarrillo. Los FD muestran niveles de nicotina y monóxido de carbono más altos. Los participantes mostraron mayor ansia ante las imágenes que presentaban cigarrillos saliendo de la cajetilla. No se hallaron diferencias entre inductores visuales y olfativos en relación con el consumo de cigarrillo. No obstante, la ocurrencia de fumar fue mayor en FD que en FND. Por eso, es importante clasificar el tipo de fumador en futuras investigaciones que pretendan evaluar esta población. 

Social dominance and multiple dimensions of psychopathology: An experimental test of reactivity to leadership and subordinate roles

Background

Theory and research suggest that social dominance is important for multiple forms of psychopathology, and yet few studies have considered multiple dimensions of psychopathology simultaneously, and relatively few have used well-validated behavioral indices.

Method

Among 81 undergraduates, we used a well-validated experimental approach of assigning participants to a leadership or subordinate position, and we examined how self-rated severity of depression, social anxiety, manic tendencies, and psychopathy relate to psychophysiological and affective reactivity to this role.

Results

Consistent with hypotheses, manic symptoms related to more discomfort in the subordinate role compared to the leadership role, as evidenced by more decline in positive affect, more discomfort, and a larger RSA decline, while depression symptoms related to a more positive response to the subordinate role than the leadership role, including more positive affect and more comfort in the assigned role. Social anxiety was related to discomfort regardless of the assigned role, and those with higher psychopathy symptoms did not show differential response to assigned roles.

Limitations

Findings are limited by the mild symptom levels and absence of hormonal data.

Conclusions

Findings provide novel transdiagnostic evidence for the importance of social dominance to differentiate diverse forms of psychopathology.

Interfering with fear memories by eye movement desensitization and reprocessing

OBJECTIVE

Pharmacologic and behavioral interventions that block reconsolidation of reactivated fear memory have demonstrated only limited success in modifying stronger and long-standing fear memories. Given the efficacy of Eye Movement Desensitization and Reprocessing (EMDR) in treating PTSD, pursuit eye movements are a promising and novel intervention for studies of human memory reconsolidation. Here, we examined the efficacy of pursuit eye movements in interfering with reconsolidation of conditioned fear memories.

METHODS

We conducted a 3-day differential Pavlovian fear conditioning procedure in healthy adults, using videos of biologically prepared stimuli (tarantulas), partly reinforced with electrical shocks while recording skin conductance response (SCR) as a measure of autonomic conditioned responses. Fear conditioning was performed on Day 1. On Day 2, 38 participants were randomized into groups performing pursuit eye movements either immediately after fear memory reactivation, when the fear memory was stable, or 10 min later, when the fear memory was assumed to be more labile. On Day 3, fear memory strength was assessed by SCR to both reactivated and nonreactivated fear memories.

RESULTS

Strong differential conditioning to the spider stimuli were observed during both fear acquisition and fear memory reactivation. Reactivated fear memory conditioned responses of participants performing pursuit eye movements after a 10-min delay were significantly smaller in the reinstatement phase (0.16 μS; 95% CI [0.02, 0.31]).

CONCLUSIONS

Pursuit eye movements were effective in reducing fear-conditioned SCR in reinstatement. This result supports the theoretical proposition that EMDR can interfere with reactivated fear memory reconsolidation.

Preferential Neuronal Responses to Snakes in the Monkey Medial Prefrontal Cortex Support an Evolutionary Origin for Ophidiophobia

Ophidiophobia (snake phobia) is one of the most common specific phobias. It has been proposed that specific phobia may have an evolutionary origin, and that attentional bias to specific items may promote the onset of phobia. Noninvasive imaging studies of patients with specific phobia reported that the medial prefrontal cortex (mPFC), especially the rostral part of the anterior cingulate cortex (rACC), and amygdala are activated during the presentation of phobogenic stimuli. We propose that the mPFC-amygdala circuit may be involved in the pathogenesis of phobia. The mPFC receives inputs from the phylogenically old subcortical visual pathway including the superior colliculus, pulvinar, and amygdala, while mPFC neurons are highly sensitive to snakes that are the first modern predator of primates, and discriminate snakes with striking postures from those with non-striking postures. Furthermore, the mPFC has been implicated in the attentional allocation and promotes amygdala-dependent aversive conditioning. These findings suggest that the rACC focuses attention on snakes, and promotes aversive conditioning to snakes, which may lead to anxiety and ophidiophobia.

Reappraising fear: is up-regulation more efficient than down-regulation?

Catastrophizing thoughts may contribute to the development of anxiety, but functional emotion regulation may help to improve treatment. No study so far directly compared up- and down-regulation of fear by cognitive reappraisal. Here, healthy individuals took part in a cued fear experiment, in which multiple pictures of faces were paired twice with an unpleasant scream or presented as safety stimuli. Participants (N = 47) were asked (within-subjects) to down-regulate, to up-regulate and to maintain their natural emotional response. Valence and arousal ratings indicated successful up- and down-regulation of the emotional experience, while heart rate and pupil dilation increased during up-regulation, but showed no reduction in down-regulation. State and trait anxiety correlated with evaluations of safety but not threat stimuli, which supports the role of deficient safety learning in anxiety. Reappraisal did not modulate this effect. In conclusion, this study reveals evidence for up-regulation effects in fear, which might be even more efficient than down-regulation on a physiological level and highlights the importance of catastrophizing thoughts for the maintenance of fear and anxiety.

Early posterior negativity in humans to pictures of snakes and spiders: effects of proximity

Snakes have proven to drive early attentional capture due to their evolutionary importance, as reflected by the early posterior negativity (EPN). The EPN snake effect might be partly driven by the proximity of the animal. In this study, by employing full-body (medium shot) and head-focused (close-up) pictures, we investigated whether the relative nearness (proximity) of the animal on the picture affects the snake EPN effect. We presented thirty participants with medium shot and close-up snake, spider and bird pictures in a rapid serial presentation paradigm at a presentation rate of three frames per second. We extracted the mean EPN activity from the 225–330 ms time frame after stimulus onset at the parietal–occipital cluster (PO3, O1, Oz, O2, PO4). The results indicate enhanced EPN for snake pictures as compared to spider and bird pictures. In addition, medium-shot snake pictures elicited higher EPN amplitudes than close-up snake pictures, suggesting that the EPN is higher when local, high spatial frequency attributes are visible. Spatial frequency analysis of the stimuli indicated that medium-shot snake pictures possess more power in the high spatial frequency bands, compared to medium-shot spider and bird pictures.

A learning theory of attachment: Unraveling the black box of attachment development

Attachment is an inborn behavioral system that is biologically driven and essential for survival. During child development, individual differences in (in)secure attachment emerge. The development of different attachment behaviors has been traditionally explained as a process during which experiences with (lack of) responsive and supportive care are internalized into working models of attachment. However, this idea has been criticized for being vague and even untestable. With the aim of unraveling this black box, we propose to integrate evidence from conditioning research with attachment theory to formulate a Learning Theory of Attachment. In this review, we explain how the development of individual differences in attachment security at least partly follows the principles of classical and operant conditioning. We combine observed associations between attachment and neurocognitive and endocrinological (cortisol, oxytocin, and dopamine) processes with insights in conditioning dynamics to explain the development of attachment. This may contribute to the explanation of empirical observations in attachment research that are insufficiently accounted for by traditional attachment theory.

Fear and Anxiety Pathways Associated with Root Canal Treatments Amongst a Population of East Asian Origin

Objective

This study aimed to identify and compare the pathways of endodontic fear and anxiety amongst East Asian origin patients attending Griffith University's Dental Clinics, Gold Coast, Australia.

Methods

East Asian patients who attended the Griffith University dental clinics were included in this study. The "My Endodontic Fear" survey was used. The pathways involved in self-perception of dental fear and anxiety were assessed through 5 different questions. Chi-square test was for statistical analysis and the level of significance was set at P<0.05.

Results

One hundred and forty six participants (n=146) (ages 18-62 years) of East Asian descent met the criteria to participate. 58.2% were females, and 41.8% males. The ethnicities were split into Chinese origin and non-Chinese origin (Korean, Phillipino, Japanese, Vietnamese). Results indicate multiple pathways affect the origin of fear, regardless of ethnicity. The Cognitive Conditioning pathway was the primary pathway selected by the Chinese and non-Chinese sub groups (51.4%, 43.6%) followed by the Informative (38.3%, 38.5%), then Vicarious (27.1%, 33.3%) and Parental (18.7%, 33.3%) pathways respectively.The Verbal Threat pathway was the least selected pathway for both groups, however the non- Chinese group selected this pathway significantly more often than the Chinese group (P<0.001).

Conclusion

This study demonstrates that the Cognitive Conditioning pathway was the primary fear and anxiety pathway utilized by both East Asian sub-groups. Understanding how patients develop fear and anxiety can help treating dentists discuss triggering factors for patients and alleviate undue anxiety prior to treatment.

Making translation work: Harmonizing cross-species methodology in the behavioural neuroscience of Pavlovian fear conditioning

Translational neuroscience bridges insights from specific mechanisms in rodents to complex functions in humans and is key to advance our general understanding of central nervous function. A prime example of translational research is the study of cross-species mechanisms that underlie responding to learned threats, by employing Pavlovian fear conditioning protocols in rodents and humans. Hitherto, evidence for (and critique of) these cross-species comparisons in fear conditioning research was based on theoretical viewpoints. Here, we provide a perspective to substantiate these theoretical concepts with empirical considerations of cross-species methodology. This meta-research perspective is expected to foster cross-species comparability and reproducibility to ultimately facilitate successful transfer of results from basic science into clinical applications.

Disentangling the facilitating and hindering effects of threat-related stimuli - A visual search study

Although large body of research has demonstrated the attention-grabbing nature of threat-related stimuli, threat could also facilitate attentional processes. Previous studies suggest a linear relationship between the facilitating effect of the arousal level conveyed by threat and performance on visual search tasks. Due to the temporal competition bias favouring stimuli with higher arousal level, this could be more pronounced for shorter onset times. Here, through two experiments we aimed to disentangle the two effects by using a visual search paradigm that allowed us to separate the emotional stimuli and the cognitive task. We manipulated stimulus onset time and threat intensity. Participants saw neutral and threatening pictures as priming stimuli, and then, they had to find numbers in ascending order in a matrix array. We measured the reaction time for finding the first number, and search time for finding all the numbers. Our results showed that when the priming stimulus is presented, longer threatening pictures produced longer reaction times compared to neutral ones, which was reversed with increase in arousal. We did not find any significant effects for the shorter onset time. Further theoretical and methodological implications are discussed.

White matter correlates of contextual pavlovian fear extinction and the role of anxiety in healthy humans

Pavlovian contextual fear extinction is viewed as an important mechanism for behavioral adaptation in everyday life, including challenging situations of stress and anxiety. It has frequently been shown to relate to the function of brain areas like the hippocampus and medial prefrontal cortex (mPFC), while the role of structural properties, like white matter tracts in these regions, has been less studied. We employed diffusion tensor imaging to determine structural white matter connectivity (cingulum and uncinate fasciculus) correlates of contextual pavlovian fear extinction indicators measured through functional magnetic resonance imaging, skin conductance responses (SCRs) and self-reports of valence, arousal and contingency in 93 healthy individuals. Higher fractional anisotropy values in the hippocampal cingulum were significantly related to higher SCRs during extinction of contextual conditioned responses (explained variance: 11.2%) as an indicator of extinction deficits on the level of physiological arousal. However, FA was neither related to any of the other fear extinction measures, nor did we find associations with functional extinction responses in the hippocampus or mPFC. Trait anxiety was a significant moderator of the SCR-hippocampal cingulum association (explained variance: 32.09%). The data add evidence for a critical role of the hippocampal formation in contextual pavlovian extinction, and, together with the strong effect of trait anxiety, may have implications for the development of anxiety disorders where contextual extinction learning deficits are observed.

(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.

Effect of d-cycloserine on fear extinction training in adults with social anxiety disorder

Preclinical and clinical data have shown that D-cycloserine (DCS), a partial agonist at the N-methyl-d-aspartate receptor complex, augments the retention of fear extinction in animals and the therapeutic learning from exposure therapy in humans. However, studies with non-clinical human samples in de novo fear conditioning paradigms have demonstrated minimal to no benefit of DCS. The aim of this study was to evaluate the effects of DCS on the retention of extinction learning following de novo fear conditioning in a clinical sample. Eighty-one patients with social anxiety disorder were recruited and underwent a previously validated de novo fear conditioning and extinction paradigm over the course of three days. Of those, only 43 (53%) provided analyzable data. During conditioning on Day 1, participants viewed images of differently colored lamps, two of which were followed by with electric shock (CS+) and a third which was not (CS-). On Day 2, participants were randomly assigned to receive either 50 mg DCS or placebo, administered in a double-blind manner 1 hour prior to extinction training with a single CS+ in a distinct context. Day 3 consisted of tests of extinction recall and renewal. The primary outcome was skin conductance response to conditioned stimuli, and shock expectancy ratings were examined as a secondary outcome. Results showed greater skin conductance and expectancy ratings in response to the CS+ compared to CS- at the end of conditioning. As expected, this difference was no longer present at the end of extinction training, but returned at early recall and renewal phases on Day 3, showing evidence of return of fear. In contrast to hypotheses, DCS had no moderating influence on skin conductance response or expectancy of shock during recall or renewal phases. We did not find evidence of an effect of DCS on the retention of extinction learning in humans in this fear conditioning and extinction paradigm.

Does Threat Have an Advantage After All? - Proposing a Novel Experimental Design to Investigate the Advantages of Threat-Relevant Cues in Visual Processing

The automatic visual attentional procession of threatening stimuli over non-threatening cues has long been a question. The so-called classical visual search task (VST) has quickly become the go-to paradigm to investigate this. However, the latest results showed that the confounding results could originate from the shortcomings of the VST. Thus, here we propose a novel approach to the behavioral testing of the threat superiority effect. We conducted two experiments using evolutionary relevant and modern real-life scenes (e.g., forest or street, respectively) as a background to improve ecological validity. Participants had to find different targets in different spatial positions (close to fovea or periphery) using a touch-screen monitor. In Experiment 1 participants had to find the two most often used exemplar of the evolutionary and modern threatening categories (snake and gun, respectively), or neutral objects of the same category. In Experiment 2 we used more exemplars of each category. All images used were controlled for possible confounding low-level visual features such as contrast, frequency, brightness, and image complexity. In Experiment 1, threatening targets were found faster compared to neutral cues irrespective of the evolutionary relevance. However, in Experiment 2, we did not find an advantage for threatening targets over neutral ones. In contrast, the type of background, and spatial position of the target only affected the detection of neutral targets. Our results might indicate that some stimuli indeed have an advantage in visual processing, however, they are not highlighted based on evolutionary relevance of negative valence alone, but rather through different associational mechanisms.

From Extinction Learning to Anxiety Treatment: Mind the Gap

Laboratory models of extinction learning in animals and humans have the potential to illuminate methods for improving clinical treatment of fear-based clinical disorders. However, such translational research often neglects important differences between threat responses in animals and fear learning in humans, particularly as it relates to the treatment of clinical disorders. Specifically, the conscious experience of fear and anxiety, along with the capacity to deliberately engage top-down cognitive processes to modulate that experience, involves distinct brain circuitry and is measured and manipulated using different methods than typically used in laboratory research. This paper will identify how translational research that investigates methods of enhancing extinction learning can more effectively model such elements of human fear learning, and how doing so will enhance the relevance of this research to the treatment of fear-based psychological disorders.

Automatic and controlled attentional capture by threatening stimuli

The rapid orienting of attention to potential threats would seem to proceed outside of top-down control. However, there is no convincing empirical finding that threatening stimuli only capture attention in a bottom-up way. The present study was designed to investigate the role of top-down and bottom-up processes in attentional bias to threats. We report a dot-probe experiment examining spatial cuing (valid and invalid) using threatening (spiders or snakes) or neutral (clownfish) stimuli in two conditions (predictable and unpredictable task). Forty-two students between the ages of 20 and 35 years participated in the study. They performed the probe detection task. Results suggested that threatening stimuli can capture attention, but this attentional effect cannot be regarded as totally bottom-up or automatic. We argue that attentional capture by threatening stimuli could be the result of a mechanism of attention shifting between bottom-up and top-down systems.

What drives prioritized visual processing? A motivational relevance account

Emotion is fundamental to our being, and an essential aspect guiding behavior when rapid responding is required. This includes whether we approach or avoid a stimulus, and the accompanying physiological responses. A common tenet is that threat-related content drives stimulus processing and biases visual attention, so that rapid responding can be initiated. In this paper, it will be argued instead that prioritization of threatening stimuli should be encompassed within a motivational relevance framework. To more fully understand what is, or is not, prioritized for visual processing one must, however, additionally consider: (i) stimulus ambiguity and perceptual saliency; (ii) task demands, including both perceptual load and cognitive load; and (iii) endogenous/affective states of the individual. Combined with motivational relevance, this then leads to a multifactorial approach to understanding the drivers of prioritized visual processing. This accords with current recognition that the brain basis allowing for visual prioritization is also multifactorial, including transient, dynamic and overlapping networks. Taken together, the paper provides a reconceptualization of how "emotional" information prioritizes visual processing.

Do Emotional Faces Affect Inhibition of Return? An ERP Study

Inhibition of Return (IOR) refers to an individual's slowed localization or discrimination performance for targets that appear in previously cued versus uncued location after a relatively long delay after cue (∼300-500 ms). The current study adopted a cue-target paradigm and used behavioral and event-related potential (ERP) measures to investigate whether IOR would be modulated by emotional faces during an emotion recognition task. For reaction time measure, we found IOR effect and the magnitude of IOR effect were comparable for fearful face target and neutral face target. For ERP measures, valid cues were associated with smaller P1 and larger N1 waveform than that for invalid cues. Fearful faces were associated with a larger N170 than neutral faces. The onset latency of the stimulus-locked lateralised readiness potential (LRP) in the valid cue condition was longer than that in the invalid cue condition, while there was no significant difference on the onset latency of the response-locked LRP between the valid cue and invalid cue condition. These results support the notion that, regardless the emotion component of the stimulus, the inhibitory bias of attention to previous visited location before response contributes to the IOR.

A review of boundary conditions and variables involved in the prevention of return of fear after post-retrieval extinction

Experimental evidence suggests that the return of fear may be prevented by post-retrieval extinction (PRE), a procedure consisting of extinction training after the presentation of a retrieval cue. However, attempts to replicate these findings have yielded mixed results, with some studies showing diminished fear responses after PRE, whereas others show no effect on the return of fear following this procedure. The discrepancies across studies have been interpreted as evidence that there might be conditions under which PRE is not effective (boundary conditions), but these variables have yet to be fully described. We aimed to provide an overview of PRE in humans. We briefly present the theory and research that originated post-retrieval procedures with a focus on the experimental setup used in human studies. We continue with a compilation of possible experimental boundary conditions along with some questions for future research.

Beauty Is in the Eye of the Beholder: The Appraisal of Facial Attractiveness and Its Relation to Conscious Awareness

Previous research suggests that facial attractiveness relies on features such as symmetry, averageness and above-average sexual dimorphic characteristics. Due to the evolutionary and sociobiological value of these characteristics, it has been suggested that attractiveness can be processed in the absence of conscious awareness. This raises the possibility that attractiveness can also be appraised without conscious awareness. In this study, we addressed this hypothesis. We presented neutral and emotional faces that were rated high, medium and low for attractiveness during a pilot experimental stage. We presented these faces for 33.33 ms with backwards masking to a black and white pattern for 116.67 ms and measured face-detection and emotion-discrimination performance, and attractiveness ratings. We found that high-attractiveness faces were detected and discriminated more accurately and rated higher for attractiveness compared with other appearance types. A Bayesian analysis of signal detection performance indicated that faces were not processed significantly at-chance. Further assessment revealed that correct detection (hits) of a presented face was a necessary condition for reporting higher ratings for high-attractiveness faces. These findings suggest that the appraisal of attractiveness requires conscious awareness.