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

The Effect of Fearful Expressions on Multiple Face Tracking

How does the visual system realize dynamic tracking? This topic has become popular within cognitive science in recent years. The classical theory argues that multiple object tracking is accomplished via pre-attention visual indexes as part of a cognitively impenetrable low-level visual system. The present research aimed to investigate whether and how tracking processes are influenced by facial expressions that convey abundant social information about one’s mental state and situated environment. The results showed that participants tracked fearful faces more effectively than neutral faces. However, this advantage was only present under the low-attentional load condition, and distractor face emotion did not impact tracking performance. These findings imply that visual tracking is not driven entirely by low-level vision and encapsulated by high-level representations; rather, that facial expressions, a kind of social information, are able to influence dynamic tracking. Furthermore, the effect of fearful expressions on multiple face tracking is mediated by the availability of attentional resources.

Current emotion research in cultural neuroscience

Classical theories of emotion have long debated the extent to which human emotion is a universal or culturally-constructed experience. Recent advances in emotion research in cultural neuroscience highlight several aspects of emotional generation and experience that are both phylogenetically conserved as well as constructed within human cultural contexts. This review highlights theories and methods from cultural neuroscience that examine how cultural and biological processes shape emotional generation, experience and regulation across multiple time scales. Recent advances in the neurobiological basis of culture-bound syndromes, such as Hwa-Byung (fire illness), provide further novel insights into emotion and mental health across cultures. Implications of emotion research in cultural neuroscience for population health disparities in psychopathology and global mental health will be discussed.

Fear conditioning with film clips: a complex associative learning paradigm

BACKGROUND AND OBJECTIVES

We argue that the stimuli used in traditional fear conditioning paradigms are too simple to model the learning and unlearning of complex fear memories. We therefore developed and tested an adapted fear conditioning paradigm, specifically designed for the study of complex associative memories. Second, we explored whether manipulating the meaning and complexity of the CS-UCS association strengthened the learned fear association.

METHODS

In a two-day differential fear conditioning study, participants were randomly assigned to two experimental conditions. All participants were subjected to the same CSs (i.e., pictures) and UCS (i.e., 3 s film clip) during fear conditioning. However, in one of the conditions (negative-relevant context), the reinforced CS and UCS were meaningfully connected to each other by a 12 min aversive film clip presented prior to fear acquisition. Participants in the other condition (neutral context) were not able to make such meaningful connection between these stimuli, as they viewed a neutral film clip.

RESULTS

Fear learning and unlearning were observed on fear-potentiated startle data and distress ratings within the adapted paradigm. Moreover, several group differences on these measures indicated increased UCS valence and enhanced associative memory strength in the negative-relevant context condition compared to the neutral context condition.

LIMITATIONS

Due to technical equipment failure, skin conductance data could not be interpreted.

CONCLUSIONS

The fear conditioning paradigm as presented in the negative-relevant context condition holds considerable promise for the study of complex associative fear memories and therapeutic interventions for such memories.

Indirect acquisition of pain-related fear: an experimental study of observational learning using coloured cold metal bars

Background

Previous research has demonstrated that pain-related fear can be acquired through observation of another’s pain behaviour during an encounter with a painful stimulus. The results of two experimental studies were presented, each with a different pain stimulus, of which the aim was to investigate the effect of observational learning on pain expectancies, avoidance behaviour, and physiological responding. Additionally, the study investigated whether certain individuals are at heightened risk to develop pain-related fear through observation. Finally, changes in pain-related fear and pain intensity after exposure to the feared stimulus were examined.

Methods

During observational acquisition, healthy female participants watched a video showing coloured cold metal bars being placed against the neck of several models. In a differential fear conditioning paradigm, one colour was paired with painful facial expressions, and another colour was paired with neutral facial expressions of the video models. During exposure, both metal bars with equal temperatures (-25° or +8° Celsius) were placed repeatedly against participants’ own neck.

Results

Results showed that pain-related beliefs can be acquired by observing pain in others, but do not necessarily cause behavioural changes. Additionally, dispositional empathy might play a role in the acquisition of these beliefs. Furthermore, skin conductance responses were higher when exposed to the pain-associated bar, but only in one of two experiments. Differential pain-related beliefs rapidly disappeared after first-hand exposure to the stimuli.

Conclusions

This study enhances our understanding of pain-related fear acquisition and subsequent exposure to the feared stimulus, providing leads for pain prevention and management strategies.

Evolutionary perspectives on learning: conceptual and methodological issues in the study of adaptive specializations

Inquiry into evolutionary adaptations has flourished since the modern synthesis of evolutionary biology. Comparative methods, genetic techniques, and various experimental and modeling approaches are used to test adaptive hypotheses. In psychology, the concept of adaptation is broadly applied and is central to comparative psychology and cognition. The concept of an adaptive specialization of learning is a proposed account for exceptions to general learning processes, as seen in studies of Pavlovian conditioning of taste aversions, sexual responses, and fear. The evidence generally consists of selective associations forming between biologically relevant conditioned and unconditioned stimuli, with conditioned responses differing in magnitude, persistence, or other measures relative to non-biologically relevant stimuli. Selective associations for biologically relevant stimuli may suggest adaptive specializations of learning, but do not necessarily confirm adaptive hypotheses as conceived of in evolutionary biology. Exceptions to general learning processes do not necessarily default to an adaptive specialization explanation, even if experimental results "make biological sense". This paper examines the degree to which hypotheses of adaptive specializations of learning in sexual and fear response systems have been tested using methodologies developed in evolutionary biology (e.g., comparative methods, quantitative and molecular genetics, survival experiments). A broader aim is to offer perspectives from evolutionary biology for testing adaptive hypotheses in psychological science.

Lesions of either anterior orbitofrontal cortex or ventrolateral prefrontal cortex in marmoset monkeys heighten innate fear and attenuate active coping behaviors to predator threat

The ventral prefrontal cortex is an integral part of the neural circuitry that is dysregulated in mood and anxiety disorders. However, the contribution of its distinct sub-regions to the regulation of negative emotion are poorly understood. Recently we implicated both the ventrolateral prefrontal cortex (vlPFC) and anterior orbitofrontal cortex (antOFC) in the regulation of conditioned fear and anxiety responses to a social stimulus, i.e., human intruder, in the marmoset monkey. In the present study we extend our investigations to determine the role of these two regions in regulating innate responses and coping strategies to a predator stimulus, i.e., a model snake. Both the vlPFC and antOFC lesioned groups exhibited enhanced anxiety-related responses to the snake in comparison to controls. Both groups also showed a reduction in active coping behavior. These results indicate that the vlPFC and antOFC contribute independently to the regulation of both innate fear and, as previously reported, conditioned fear, and highlight the importance of these regions in producing stimulus-appropriate coping responses. The finding that dysregulation in two distinct prefrontal regions produces the apparently similar behavioral phenotype of heightened negative emotion provides insight into the varied etiology that may underlie this symptom across a wide variety of neuropsychiatric conditions with implications for personalized treatment strategies.

High cortisol awakening response and cortisol levels moderate exposure-based psychotherapy success

BACKGROUND

Research suggests that elevated stress hormones during exposure can facilitate fear extinction in laboratory settings. However, prospective studies on the clinical benefits of endogenous cortisol on clinical improvements in naturalistic exposures are lacking.

METHODS

Twenty-six patients with panic disorder and agoraphobia completed three weekly in-vivo exposure sessions and a fourth session 2 months following therapy completion, resulting in a total of 94 in-vivo exposure sessions. Salivary cortisol was collected at multiple times during the first exposure day (cortisol morning response, prior, -during, -after exposure) and at subsequent exposure sessions (prior, -during, -after exposure). Cortisol collection on a non-exposure comparison day followed the same time schedule as session 1.

RESULTS

Exposure day anxiety and cortisol levels were significantly higher than control day levels. Higher absolute cortisol levels during exposures moderated clinical improvement (avoidance behavior, threat appraisal, perceived control). Therapeutic gains were not just related to exposure day cortisol levels, but were also linked to non-exposure day levels. Greater morning rises in cortisol on exposure day predicted greater treatment gains, but greater rises on the control day were associated with poorer outcomes.

CONCLUSIONS

The study provides first evidence for a moderating effect of cortisol awakening response and absolute cortisol levels on fear extinction processes during naturalistic, prospective exposure-therapy. Additionally, we replicated and extended prior findings on the therapeutic benefits of high exposure cortisol levels. Together, the findings suggest that cortisol may act as a general moderator of facilitated learning during exposure therapy.

Impaired acquisition of classically conditioned fear-potentiated startle reflexes in humans with focal bilateral basolateral amygdala damage

Based on studies in rodents, the basolateral amygdala (BLA) is considered a key site for experience-dependent neural plasticity underlying the acquisition of conditioned fear responses. In humans, very few studies exist of subjects with selective amygdala lesions and those studies have only implicated the amygdala more broadly leaving the role of amygdala sub-regions underexplored. We tested a rare sample of subjects (N = 4) with unprecedented focal bilateral BLA lesions due to a genetic condition called Urbach-Wiethe disease. In a classical delay fear conditioning experiment, these subjects showed impaired acquisition of conditioned fear relative to a group of matched control subjects (N = 10) as measured by fear-potentiation of the defensive eye-blink startle reflex. After the experiment, the BLA-damaged cases showed normal declarative memory of the conditioned association. Our findings provide new evidence that the human BLA is essential to drive fast classically conditioned defensive reflexes.

Propranolol, post-traumatic stress disorder, and intensive care: incorporating new advances in psychiatry into the ICU

Post-traumatic stress disorder (PTSD) is a common complication of an ICU admission. Rarely is there a continuation of care, which is aimed at screening for and treating this debilitating disease. Current treatment options for PTSD are held back by inconsistent efficacy, poor evidence, and a lack of understanding of its psychopathology. Without 'gold standard' assessment techniques to diagnose PTSD after an ICU admission, the development of care pathways is hindered. This paper advocates for two interwoven advances in psychiatric care (specifically for PTSD) after ICU: (1) incorporate the monitoring and treating of psychiatric co-morbidities during extended patient follow-up, and (2) rapidly adopting the latest research to maximize its benefit. The discovery that memories were not fixed, but malleable to change, set off a sequence of experiments that have revolutionized the approach to treating PTSD. It is hoped that the phenomenon of reconsolidation can be exploited therapeutically. In the act of remembering and re-storing traumatic memories, propranolol can act to dissociate the state of sympathetic arousal from their recollection. Often, ICU patients have multiple physical co-morbidities that may be exacerbated, or their treatment disrupted, by such a pervasive psychological condition. The rapid uptake of new techniques, aimed at reducing PTSD after ICU admission, is necessary to maximize the quality of care given to patients. Increasingly, the realization that the role of intensive care specialists may extend beyond the ICU is changing clinical practice. As this field advances, intensivists and psychiatrists alike must collaborate by using the latest psychopharmacology to treat their patients and combat the psychological consequences of experiencing the extremes of physiological existence.

Cognitive evolutionary therapy for depression: a case study

KEY CLINICAL MESSAGE

We present an evolutionary-driven cognitive-behavioral intervention for a moderately depressed patient. Standard cognitive and behavioral therapy techniques focused on the patient's perfectionistic and self-downing beliefs, while novel, evolutionary-informed techniques were used to guide behavioral activation and conceptualize secondary emotional problems related to anger. The treatment reduced depressive symptomatology and increased evolutionary fitness.

Prereactivation propranolol fails to reduce skin conductance reactivity to prepared fear-conditioned stimuli

Pharmacologic blockade of memory reconsolidation has been demonstrated in fear-conditioned rodents and humans and may provide a means to reduce fearfulness in anxiety disorders and posttraumatic stress disorder. Studying the efficacy of potential interventions in clinical populations is challenging, creating a need for paradigms within which candidate reconsolidation-blocking interventions can be readily tested. We used videos of biologically prepared conditioned stimuli (tarantulas) to test the efficacy of propranolol in blocking reconsolidation of conditioned fear in healthy young adults. Strong differential conditioning, measured by skin conductance, was observed among a screened subset of participants during acquisition. However, subsequent propranolol failed to reduce reactivity to the reactivated conditioned stimulus. These results are consistent with other recent findings and point to a need for testing other candidate drugs.

The concepts of representation and information in explanatory theories of human behavior

Focusing in experimental study of human behavior, this article discusses the concepts of information and mental representation aiming the integration of their biological, computational, and semantic aspects. Assuming that the objective of any communication process is ultimately to modify the receiver's state, the term correlational information is proposed as a measure of how changes occurring in external world correlate with changes occurring inside an individual. Mental representations are conceptualized as a special case of information processing in which correlational information is received, recorded, but also modified by a complex emergent process of associating new elements. In humans, the acquisition of information and creation of mental representations occurs in a two-step process. First, a sufficiently complex brain structure is necessary to establishing internal states capable to co-vary with external events. Second, the validity or meaning of these representations must be gradually achieved by confronting them with the environment. This contextualization can be considered as part of the process of ascribing meaning to information and representations. The hypothesis introduced here is that the sophisticated psychological constructs classically associated with the concept of mental representation are essentially of the same nature of simple interactive behaviors. The capacity of generating elaborated mental phenomena like beliefs and desires emerges gradually during evolution and, in a given individual, by learning and social interaction.

Testing the snake-detection hypothesis: larger early posterior negativity in humans to pictures of snakes than to pictures of other reptiles, spiders and slugs

According to the snake detection hypothesis (Isbell, 2006), fear specifically of snakes may have pushed evolutionary changes in the primate visual system allowing pre-attentional visual detection of fearful stimuli. A previous study demonstrated that snake pictures, when compared to spiders or bird pictures, draw more early attention as reflected by larger early posterior negativity (EPN). Here we report two studies that further tested the snake detection hypothesis. In Study 1, we tested whether the enlarged EPN is specific for snakes or also generalizes to other reptiles. Twenty-four healthy, non-phobic women watched the random rapid serial presentation of snake, crocodile, and turtle pictures. The EPN was scored as the mean activity at occipital electrodes (PO3, O1, Oz, PO4, O2) in the 225-300 ms time window after picture onset. The EPN was significantly larger for snake pictures than for pictures of the other reptiles. In Study 2, we tested whether disgust plays a role in the modulation of the EPN and whether preferential processing of snakes also can be found in men. 12 men and 12 women watched snake, spider, and slug pictures. Both men and women exhibited the largest EPN amplitudes to snake pictures, intermediate amplitudes to spider pictures and the smallest amplitudes to slug pictures. Disgust ratings were not associated with EPN amplitudes. The results replicate previous findings and suggest that ancestral priorities modulate the early capture of visual attention.

Experimental evolution of prepared learning

Animals learn some things more easily than others. To explain this so-called prepared learning, investigators commonly appeal to the evolutionary history of stimulus-consequence relationships experienced by a population or species. We offer a simple model that formalizes this long-standing hypothesis. The key variable in our model is the statistical reliability of the association between stimulus, action, and consequence. We use experimental evolution to test this hypothesis in populations of Drosophila. We systematically manipulated the reliability of two types of experience (the pairing of the aversive chemical quinine with color or with odor). Following 40 generations of evolution, data from learning assays support our basic prediction: Changes in learning abilities track the reliability of associations during a population's selective history. In populations where, for example, quinine-color pairings were unreliable but quinine-odor pairings were reliable, we find increased sensitivity to learning the quinine-odor experience and reduced sensitivity to learning quinine-color. To the best of our knowledge this is the first experimental demonstration of the evolution of prepared learning.

Being "in" or "out" of the game: subjective and acoustic reactions to exclusion and popularity in social anxiety

Social Anxiety (SA) has been shown to be associated with compensatory deficits in pro-social behavior following exclusion and with failure to capitalize on social success. We assessed the subjective and expressive responses of high (n = 48) and low (n = 56) socially anxious individuals to exclusion, acceptance, and popularity induced by a participation in an online ball-tossing game. Before the manipulation, participants read aloud neutral and command utterances. Following the manipulation, participants rated their mood and cognitions and re-read the utterances. Acoustic properties (fundamental frequency-mF0, vocal intensity) of these utterances were analyzed. We found greater differences in self-esteem between high and low socially anxious individuals following the exclusion condition, as compared to the acceptance condition. Among low socially anxious individuals, exclusion promoted increased vocal confidence, as indicated by decreased mF0 and increased vocal intensity in uttering commands; High socially anxious individuals exhibited an opposite reaction, responding to exclusion by decreased vocal confidence. Following popularity, high SA was associated with decreased enhancement in mood and self-esteem in women but not in men. Consistent with evolutionary and interpersonal accounts of SA, we highlight the importance of examining the effects of SA and gender on events indicating unambiguous and unanimous social acceptance. Examining reactivity to changes in belongingness may have important implications for understanding the core mechanisms of SA.

Enhanced avoidance behavior in social anxiety: evidence from a probabilistic learning task

BACKGROUND AND OBJECTIVES

Social phobia is characterized by avoidance of feared social situations. Although avoidance is a central feature of social anxiety, few studies have examined avoidance learning.

METHODS

We used a probabilistic instrumental learning paradigm where participants had to learn by trial and error which response led to the disappearance of a neutral or angry face. 20 high socially anxious and 20 non-socially anxious individuals with an average level of social anxiety learned to avoid an angry or a neutral face by choosing one of two cues. Each of the cues led to the disappearance of the face either with high or low reinforcement probability.

RESULTS

Groups learned to choose the more effective cue across trials and did not differ with regard to self-report valence, arousal for the faces or the a posteriori estimated reinforcement probability for both cues. High socially anxious individuals as compared to the controls chose the high probability cue significantly more often and were slower particularly when the neutral face could be avoided. Notably, HSA engaged in more avoidance responding to the neutral as compared to the angry face early on during the experiment.

LIMITATIONS

Due to the experimental design, the observed avoidance behavior most likely reflects the motivation for avoidance rather than contingency learning per se.

CONCLUSIONS

In social anxiety, neutral faces might be processed as ambiguous social cues and strongly motivate avoidance behavior.

Coming to terms with fear

The brain mechanisms of fear have been studied extensively using Pavlovian fear conditioning, a procedure that allows exploration of how the brain learns about and later detects and responds to threats. However, mechanisms that detect and respond to threats are not the same as those that give rise to conscious fear. This is an important distinction because symptoms based on conscious and nonconscious processes may be vulnerable to different predisposing factors and may also be treatable with different approaches in people who suffer from uncontrolled fear or anxiety. A conception of so-called fear conditioning in terms of circuits that operate nonconsciously, but that indirectly contribute to conscious fear, is proposed as way forward.

Growing pains and pleasures: how emotional learning guides development

The nervous system promotes adaptive responding to myriad environmental stimuli by ascribing emotion to specific stimulus domains. This affects the salience of different stimuli, facilitates learning, and likely involves the amygdala. Recent studies suggest a strong homology between adaptive responses that result from learning and those that emerge during development. As in motivated learning, developmental studies have found the salience of different classes of stimulus (e.g., peers) undergoes marked fluctuation across maturation and may involve differential amygdala engagement. In this review, by highlighting the importance of particular stimulus categories during sensitive periods of development, we suggest that variability in amygdala response to different stimulus domains has an active and functional role in shaping emerging cortical circuits across development.

Exposure to bisphenol-A affects fear memory and histone acetylation of the hippocampus in adult mice

Bisphenol-A (BPA), an environmental endocrine disruptor, has been reported to possess weak estrogenic, anti-estrogenic, and anti-androgen properties. Previous evidence indicates that perinatal exposure to low levels of BPA affects anxiety-like and cognitive behaviors in adult rodents. The present study aims to investigate the effect of BPA on emotional memory using the contextual fear conditioning of male mice in adulthood exposed to BPA for 90days. The results indicated that exposure to BPA increased the freezing time 1h and 24h after fear conditioning training. Furthermore, western blot analyses showed that BPA exposure decreased the level of N-methyl-d-aspartic acid (NMDA) receptor subunit NR1 and increased the expression of histone deacetylase 2 (HDAC2) before fear conditioning training in the hippocampus of male mice. One and twenty-four hours after fear conditioning training, BPA enhanced the changes of the expressions of NR1, phosphorylated extracellular regulated protein kinases (ERK1/2), and histone acetylation induced by contextual fear conditioning in the hippocampus. These results suggest that long term exposure to BPA enhanced fear memory by the concomitant increased level of NMDA receptor and/or the enhanced histone acetylation in the hippocampus, which may be associated with activation of ERK1/2 signaling pathway.

Recognition and Approach Responses Toward Threatening Objects

Previous research suggests that positive stimuli are often approached as well as recognized faster than negative stimuli. We argue that this effect does not hold if negative stimuli are associated with threat. Based on fear module theory ( Öhman & Mineka, 2001 , 2003 ), we argue that individuals recognize threatening stimuli faster than positive stimuli because of a constant monitoring of the environment for threatening objects. Moreover, based on the assumption of a motivational account underlying approach-avoidance responses ( Krieglmeyer & Deutsch, 2010 ), we assume the recognition then directly evokes a careful and slow approach of threatening objects. Applying a response time task that measures approach movement and recognition times within the same task, we found that individuals recognize threatening pictures faster than positive pictures, but approach the threatening pictures slower than the positive pictures.

Fear acquisition and extinction in offspring of mothers with anxiety and depressive disorders

Maternal anxiety and depression are significant risk factors for the development of these disorders in offspring. The pathways through which risk is conferred remain unclear. This study examined fear acquisition and extinction in 26 children at high risk for emotional disorders by virtue of maternal psychopathology (n=14 with a mother with a principal anxiety disorder and n=12 with a mother with a principal unipolar depressive disorder) and 31 low risk controls using a discriminative Pavlovian conditioning procedure. Participants, aged between 7 and 14 years, completed 16 trials of discriminative conditioning of two geometric figures, with (CS+) and without (CS-) an aversive tone (US), followed by 8 extinction trials (4×CS+, 4×CS-). In the context of comparable discriminative conditioning, children of anxious mothers showed larger skin conductance responses during extinction to the CS+ compared to the CS-, and to both CSs from the first to the second block of extinction trials, in comparison with low risk controls. Compared to low risk controls, children of depressed mothers showed smaller skin conductance responses to the CS+ than the CS- during acquisition. These findings suggest distinct psychophysiological premorbid risk markers in offspring of anxious and depressed mothers.

Animal models of fear relapse

Whereas fear memories are rapidly acquired and enduring over time, extinction memories are slow to form and are susceptible to disruption. Consequently, behavioral therapies that involve extinction learning (e.g., exposure therapy) often produce only temporary suppression of fear and anxiety. This review focuses on the factors that are known to influence the relapse of extinguished fear. Several phenomena associated with the return of fear after extinction are discussed, including renewal, spontaneous recovery, reacquisition, and reinstatement. Additionally, this review describes recent work, which has focused on the role of psychological stress in the relapse of extinguished fear. Recent developments in behavioral and pharmacological research are examined in light of treatment of pathological fear in humans.

Looming animate and inanimate threats: the response of the amygdala and periaqueductal gray

Looming stimuli are processed as threatening and activate basic neural defense systems. However, it is unclear how animacy information modulates this response. Participants (N = 25) viewed threatening or neutral images that were either animate (animals) or inanimate (objects) and which either approached (loomed) or receded from the participant. The amygdala was responsive to emotional, animacy, and looming information (particularly to looming threats and looming animate stimuli). Periaqueductal gray was also sensitive to emotional information and particularly responsive to looming threats. The data are interpreted within category-specific models of the amygdala and temporal cortex.

Are we afraid of different categories of stimuli in identical ways? Evidence from skin conductance responses

Studies have shown that emotional pictures attract more attention than neutral pictures, and pictures of living stimuli have similar advantage in driving attention (vs. nonliving). However, factors of emotion, category and picture context are usually mixed so that whether living and nonliving categories elicit different skin conductance (SC) responses, in both conscious and unconscious conditions, remains to be clarified. In this study, participants were presented with negative and neutral pictures denoting different living and nonliving concepts in conscious (Experiments 1 and 2) and unconscious conditions (40ms, Experiment 3) when their SC responses were measured. The picture context was manipulated in Experiments 2 and 3 as half including human-related information. In three experiments, the emotional levels of different categories were matched in different and identical cohorts of participants. The results showed that living pictures in a negative, high-arousing dimension elicited stronger SC responses than nonliving pictures. When nonhuman animals and inanimate objects were compared, the increased SC responses to animals was obtained only for negative pictures without human contexts in the conscious condition, but regardless of human context in the unconscious condition. These results suggested that contextual information and level of conscious awareness are important to modulate the animate advantage in emotional processing.

The Common Fears and Their Origins Among Turkish Children and Adolescents

The present study aimed to investigate the common fears and their origins among children and adolescents from different age, gender, and socioeconomic levels (SES). The sample was comprised of 642 females (48.8%) and 673 males (51.2%) with a total of 1,315 participants aged between 8 and 18 (M = 13.15; SD = 3.18). The Fear interview was utilised to examine the common fears and the role of conditioning, modelling and negative information in the development of children's fears. The result showed that the most common fear in Turkey was ‘God’, followed by ‘losing my friends’ and ‘going to Hell’. In addition, the findings revealed that Turkish students are more likely to learn fears by modelling rather than negative information transmission and conditioning. The results also indicated that negative information transmission had a more intensifying effect on the children and adolescents’ existing fear rather than modelling and conditioning. Furthermore, multinomial logistic regression was conducted to examine the effects of age, gender and SES on the origins of fear. Results showed that age and gender were significant predictors of origins of fear.

Witchcraft beliefs and witch hunts: an interdisciplinary explanation

This paper proposes an interdisciplinary explanation of the cross-cultural similarities and evolutionary patterns of witchcraft beliefs. It argues that human social dilemmas have led to the evolution of a fear system that is sensitive to signs of deceit and envy. This was adapted in the evolutionary environment of small foraging bands but became overstimulated by the consequences of the Agricultural Revolution, leading to witch paranoia. State formation, civilization, and economic development abated the fear of witches and replaced it in part with more collectivist forms of social paranoia. However, demographic-economic crises could rekindle fear of witches-resulting, for example, in the witch craze of early modern Europe. The Industrial Revolution broke the Malthusian shackles, but modern economic growth requires agricultural development as a starting point. In sub-Saharan Africa, witch paranoia has resurged because the conditions for agricultural development are lacking, leading to fighting for opportunities and an erosion of intergenerational reciprocity.

Contextual fear conditioning in virtual reality is affected by 5HTTLPR and NPSR1 polymorphisms: effects on fear-potentiated startle

The serotonin (5-HT) and neuropeptide S (NPS) systems are discussed as important genetic modulators of fear and sustained anxiety contributing to the etiology of anxiety disorders. Sustained anxiety is a crucial characteristic of most anxiety disorders which likely develops through contextual fear conditioning. This study investigated if and how genetic alterations of the 5-HT and the NPS systems as well as their interaction modulate contextual fear conditioning; specifically, function polymorphic variants in the genes coding for the 5-HT transporter (5HTT) and the NPS receptor (NPSR1) were studied. A large group of healthy volunteers was therefore stratified for 5HTTLPR (S+ vs. LL carriers) and NPSR1 rs324981 (T+ vs. AA carriers) polymorphisms resulting in four genotype groups (S+/T+, S+/AA, LL/T+, LL/AA) of 20 participants each. All participants underwent contextual fear conditioning and extinction using a virtual reality (VR) paradigm. During acquisition, one virtual office room (anxiety context, CXT+) was paired with an unpredictable electric stimulus (unconditioned stimulus, US), whereas another virtual office room was not paired with any US (safety context, CXT−). During extinction no US was administered. Anxiety responses were quantified by fear-potentiated startle and ratings. Most importantly, we found a gene × gene interaction on fear-potentiated startle. Only carriers of both risk alleles (S+/T+) exhibited higher startle responses in CXT+ compared to CXT−. In contrast, anxiety ratings were only influenced by the NPSR1 polymorphism with AA carriers showing higher anxiety ratings in CXT+ as compared to CXT−. Our results speak in favor of a two level account of fear conditioning with diverging effects on implicit vs. explicit fear responses. Enhanced contextual fear conditioning as reflected in potentiated startle responses may be an endophenotype for anxiety disorders.

Post-retrieval extinction as reconsolidation interference: methodological issues or boundary conditions?

Memories that are emotionally arousing generally promote the survival of species; however, the systems that modulate emotional learning can go awry, resulting in pathological conditions such as post-traumatic stress disorders, phobias, and addiction. Understanding the conditions under which emotional memories can be targeted is a major research focus as the potential to translate these methods into clinical populations carries important implications. It has been demonstrated that both fear and drug-related memories can be destabilised at their retrieval and require reconsolidation to be maintained. Therefore, memory reconsolidation offers a potential target period during which the aberrant memories underlying psychiatric disorders can be disrupted. Monfils et al. (Science 324:951-955, 2009) have shown for the first time that safe information provided through an extinction session after retrieval (during the reconsolidation window) may update the original memory trace and prevent the return of fear in rats. In recent years, several authors have then tested the effect of post-retrieval extinction on reconsolidation of either fear or drug-related memories in both laboratory animals and humans. In this article, we review the literature on post-reactivation extinction, discuss the differences across studies on the methodological ground, and review the potential boundary conditions that may explain existing discrepancies and limit the potential application of post-reactivation extinction approaches.

Autobiographical memories of vomiting in people with a specific phobia of vomiting (emetophobia)

BACKGROUND

Vomiting is an almost universal phenomenon, but little is known about the aetiology of a specific phobia of vomiting (SPOV). The associations with vomiting during childhood and autobiographical memories may have relevance for our understanding of the development of SPOV and its treatment.

METHOD

Two groups: (a) a group with SPOV (n = 94) and (b) a control group (n = 90) completed a self-report questionnaire assessing their lifetime memories of both their own vomiting and others vomiting.

RESULTS

People with SPOV recalled the memories of their own and others vomiting experiences from an earlier age and rated them as significantly more distressing than the control group. There was no difference between the groups in the number of memories of their own vomiting recalled before the age at which vomiting became a problem. However, the SPOV group recalled more memories of others vomiting before the onset of the problem. After the age at which the phobia became a problem they recalled less memories of their own vomiting and more memories of others vomiting than the control group. They recalled significantly more memories of vomiting associated with inter-personal events, health or emotional or unrelated life events.

CONCLUSIONS

Avoidance and hyper-vigilance for others vomiting after the onset of the phobia may have slightly reduced the risk of vomiting. There is some evidence for associative learning in SPOV with aversive consequences of vomiting and an unrelated life event. It suggests a model of autobiographical memories of vomiting that have lost a time perspective and context, which are being reactivated with cues for vomiting. The limitations of the study are those of memory biases in both groups.

Enhanced discrimination between threatening and safe contexts in high-anxious individuals

Trait anxiety, a stable personality trait associated with increased fear responses to threat, is regarded as a risk factor for the development and maintenance of anxiety disorders. Although the effect of trait anxiety has been examined with regard to explicit threat cues, little is known about the effect of trait anxiety on contextual threat learning. To assess this issue, extreme groups of low and high trait anxiety underwent a contextual fear conditioning protocol using virtual reality. Two virtual office rooms served as the conditioned contexts. One virtual office room (CXT+) was paired with unpredictable electrical stimuli. In the other virtual office room, no electrical stimuli were delivered (CXT-). High-anxious participants tended to show faster acquisition of startle potentiation in the CXT+ versus the CXT- than low-anxious participants. This enhanced contextual fear learning might function as a risk factor for anxiety disorders that are characterized by sustained anxiety.

Toxoplasma gondii infection induces dendritic retraction in basolateral amygdala accompanied by reduced corticosterone secretion

Pathological anxiety is thought to reflect a maladaptive state characterized by exaggerated fear. Naturally occurring perturbations that reduce fear can be crucial in the search for new treatments. The protozoan parasite Toxoplasma gondii invades rat brain and removes the fear that rats have of cat odors, a change believed to be parasitic manipulation of host behavior aimed at increasing parasite transmission. It is likely that mechanisms employed by T. gondii can be used as a heuristic tool to understand possible means of fear reduction in clinical settings. Male Long-Evans rats were infected with T. gondii and compared with sham-infected animals 8 weeks after infection. The amount of circulating plasma corticosterone and dendritic arborization of basolateral amygdala principal neurons were quantified. Previous studies have shown that corticosterone, acting within the basolateral amygdala, enhances the fear response to environmental stimuli. Here we show that T. gondii infection causes a dendritic retraction in basolateral amygdala neurons. Such dendritic retraction is accompanied by lower amounts of circulating corticosterone, both at baseline and when induced by an aversive cat odor. The concerted effects of parasitism on two pivotal physiological nodes of the fear response provide an animal model relevant to interactions between stress hormones and amygdalar plasticity.

Contextual control over expression of fear is affected by cortisol

At the core of anxiety disorders is the inability to use contextual information to modulate behavioral responses to potentially threatening events. Models of the pathogenesis of anxiety disorders incorporate stress and concomitant stress hormones as important vulnerability factors, while others emphasize sex as an important factor. However, translational basic research has not yet investigated the effects of stress hormones and sex on the ability to use contextual information to modulate responses to threat. Therefore, the purpose of the present study was threefold: first, we aimed at developing an experimental paradigm specifically capable of capturing contextual modulation of the expression of fear. Second, we tested whether cortisol would alter the contextualization of fear expression. Third, we aimed at assessing whether alterations in contextualization due to cortisol were different for men and women. Healthy participants (n = 42) received placebo or hydrocortisone (20 mg) prior to undergoing a newly developed differential contextual fear-conditioning paradigm. The results indicated that people rapidly acquire differential contextual modulation of the expression of fear, as measured by fear potentiated startle (FPS) and skin conductance responses (SCR). In addition, cortisol impaired the contextualization of fear expression leading to increased fear generalization on FPS data in women. The opposite pattern was found in men. Finally, as assessed by SCR, cortisol impaired differential conditioning in men. The results are in line with models suggesting heightened vulnerability in women for developing anxiety disorders after stressful events.

CB1 receptor activation in the nucleus accumbens core impairs contextual fear learning

Contextual fear conditioning is a behavioral model in which a subject learns that a specific context is predictive of danger occurrence. There is evidence suggesting an important role for both the nucleus accumbens (NAc) and the endocannabinoid system in contextual fear conditioning formation. The purpose of this study was to assess whether endocannabinoids within the NAc modulate fear memory formation. Pre-training anandamide (AEA) infusions into the NAc core (NAcC) of male Wistar rats decreased freezing behavior in the contextual fear-conditioning paradigm, as evaluated 24h after training. However, AEA did not induce any effect on the cued fear-conditioning paradigm. Likewise, AEA infusions into the NAc shell did not interfere with the contextual fear learning. AEA's effect was blocked when co-infused with AM251 (CB1R inverse agonist). Post-training AEA infusions failed to exert an effect on contextual conditioning. These results suggest a cannabinergic regulation in the NAcC of the acquisition of contextual fear conditioning.

Neural and cellular mechanisms of fear and extinction memory formation

Over the course of natural history, countless animal species have evolved adaptive behavioral systems to cope with dangerous situations and promote survival. Emotional memories are central to these defense systems because they are rapidly acquired and prepare organisms for future threat. Unfortunately, the persistence and intrusion of memories of fearful experiences are quite common and can lead to pathogenic conditions, such as anxiety and phobias. Over the course of the last 30 years, neuroscientists and psychologists alike have attempted to understand the mechanisms by which the brain encodes and maintains these aversive memories. Of equal interest, though, is the neurobiology of extinction memory formation as this may shape current therapeutic techniques. Here we review the extant literature on the neurobiology of fear and extinction memory formation, with a strong focus on the cellular and molecular mechanisms underlying these processes.

Threat, domain-specificity and the human amygdala

It is well documented that the human amygdala responds strongly to human faces, especially when depicting negative emotions. The extent to which the amygdala also responds to other animate entities - as well as to inanimate objects - and how that response is modulated by the object's perceived affective valence and arousal value remains unclear. To address these issues, subjects performed a repetition detection task to photographs of negative, neutral, and positive faces, animals, and manipulable objects equated for emotional valence and arousal level. Both the left and right amygdala responded more to animate entities than manipulable objects, especially for negative objects (fearful faces, threatening animals, versus weapons) and to neutral stimuli (faces with neutral expressions, neutral animals, versus tools). Thus, in the absence of contextual cues, the human amygdala responds to threat associated with some object categories (animate things) but not others (weapons). Although failing to activate the amygdala, relative to viewing other manipulable objects, viewing weapons did elicit an enhanced response in dorsal stream regions linked to object action. Thus, our findings suggest two circuits underpinning an automatic response to threatening stimuli; an amygdala-based circuit for animate entities, and a cortex-based circuit for responding to manmade, manipulable objects.