Psychophysiological and subjective indicators of aversive pavlovian conditioning in generalized social phobia

Overgeneralization of conditioned fear in patients with social anxiety disorder

Introduction

While abnormal responses to threat, including overgeneralization to conditioned fear, have been postulated to play a critical role in pathological anxiety, the relevance of previous findings to social anxiety disorder (SAD) is unclear. We investigated conditioned and generalized fear responses in patients with SAD using socially relevant stimuli.

Methods

A total of 26 patients with SAD and 25 healthy controls participated in a fear conditioning and generalization paradigm consisting of two neutral faces as conditioned stimuli (CS+ or CS-) and an angry face with contemptuous comments as unconditioned stimuli. Eight morphed faces of two conditioned stimuli in each continuum were given to test generalization. Behavioral data and physiological responses were acquired.

Results

Successful conditioning was observed in the risk ratings for both groups, while only a marginal indication of conditioning was noted in physiological measures. During the generalization phase, patients rated the risk higher than CS- when the stimuli close to CS- contained a portion of CS+ features. Larger skin conductance responses to this stimulus were linked to higher fear of negative evaluation. In addition, patients spent a longer time evaluating safe and ambiguous stimuli than healthy controls and exhibited consistently high levels of subjective arousal.

Discussion

Taken together, our findings suggest that SAD patients may exhibit a tendency towards overgeneralization of fear responses and show distinct patterns in processing generalized threat stimuli compared to healthy controls. Even though overgeneralization was not evident in physiological measures, it is necessary to consider this behavioral characteristic in the clinical management of patients with SAD.

Fear conditioning and fear generalization in children and adolescents with anxiety disorders

Overgeneralization of conditioned fear is associated with anxiety disorders (AD). Most results stem from studies done in adult patients, but studies with children are rare, although the median onset of anxiety disorders lies already in childhood. Thus, the goal of the present study was to examine fear learning and generalization in youth participants, aged 10-17 years, with AD (n = 39) compared to healthy controls (HC) (n = 40). A discriminative fear conditioning and generalization paradigm was used. Ratings of arousal, valence, and US expectancy (the probability of an aversive noise following each stimulus) were measured, hypothesizing that children with AD compared to HC would show heightened ratings of arousal and US expectancy, and decreased positive valence ratings, respectively, as well as overgeneralization of fear. The results indicated that children with AD rated all stimuli as more arousing and less pleasant, and demonstrated higher US expectancy ratings to all stimuli when compared to HC. Thus, rather than displaying qualitatively different generalization patterns (e.g., a linear vs. quadratic slope of the gradient), differences between groups were more quantitative (similar, but parallel shifted gradient). Therefore, overgeneralization of conditioned fear does not seem to be a general marker of anxiety disorders in children and adolescents.

Oxytocin and social learning in socially anxious men and women

OBJECTIVE

This study extended a classic self-referential learning paradigm by investigating the effects of intranasally-administered oxytocin in high and low socially anxious participants during social learning, as a function of social anxiety levels and sex.

METHODS

In a randomized double-blinded design, 160 participants were either given intranasal oxytocin (24 I.U.) or placebo. Subsequently, while lying in an MR scanner, participants were shown neutral faces that were paired with positively, neutrally, or negatively valenced self-referential sentences, during which we measured self-reported arousal and sympathy of the facial stimuli, pupil dilation, and changes in the brain-oxygen-level dependent signal. Four-factor mixed analyses of variance with the between-subjects factors group (high socially anxious vs. low socially anxious), substance (oxytocin vs. placebo), and sex (male vs. female) and the within-subjects factor sentence valence (positive vs. neutral vs. negative) were conducted for each measure, respectively.

RESULTS

Administration of intranasal oxytocin yielded an increase in sympathy ratings in high socially anxious compared to low socially anxious individuals and decreased arousal ratings for positively-conditioned faces in low socially anxious participants. As an objective physiological measure of arousal, pupil dilation mirrored the behavioral results. Oxytocin effects on neural activation in the insula interacted with anxiety levels and sex: low socially anxious individuals yielded lower activation under oxytocin than placebo; the converse was observed in high socially anxious individuals. This interaction also differed between sexes, as men yielded higher activation levels than women. These findings were more prominent for positively- and negatively-conditioned faces. Within the amygdala, high socially anxious men yielded higher activation than high socially anxious women in the left hemisphere, and low socially anxious men yielded higher activation than low socially anxious women from positively- and negatively-conditioned faces, though no influence of oxytocin was detected.

CONCLUSION

These results suggest oxytocin-induced behavioral, physiological, and neural changes as a function of social learning in socially low and high anxious individuals. These findings challenge the amygdalocentric view of the role of emotions in social learning, instead contributing to the growing body of findings implicating the insula therein, revealing an interaction between oxytocin, sex, and emotional valence. Such discoveries raise an interesting set of questions regarding the computational goals of regions such as the insula in emotional learning and how neural activity can play a diagnostic or prognostic role in social anxiety, potentially leading to new treatment opportunities that may combine oxytocin and neurofeedback differentially for men and women.

The effect of social anxiety on threat acquisition and extinction: a systematic review and meta-analysis

Although exposure-based therapy has been found to be effective at alleviating symptoms of social anxiety disorder, it often does not lead to full remission, and relapse after treatment is common. Exposure therapy is based on theoretical principles of extinction of conditioned fear responses. However, there are inconsistencies in findings across experiments that have investigated the effect of social anxiety on threat conditioning and extinction processes. This systematic review and meta-analysis aimed to examine whether elevated levels of social anxiety are associated with abnormalities in threat conditioning and extinction processes. A second aim was to examine the sensitivity of various study designs and characteristics to detect social anxiety-related differences in threat conditioning and extinction. A systematic search was conducted, which identified twenty-three experiments for inclusion in the review. The findings did not demonstrate compelling evidence that high levels of social anxiety are associated with atypical threat conditioning or extinction. Further, when systematically examining the data, there was no convincing support that the use of a particular psychophysiological measure, subjective rating, or experimental parameter yields more consistent associations between social anxiety and conditioning processes during threat acquisition or extinction. Meta-analyses demonstrated that during threat extinction, the use of anxiety ratings as a dependent variable, socially relevant unconditioned stimuli, and a higher reinforcement schedule produced more detectable effects of social anxiety on compromised extinction processes compared to any other dependent variable (subjective or physiological) or experimental parameter. Overall, the results of this study suggest that social anxiety is not reliably related to deficits in conditioning and extinction processes in the context of laboratory-based Pavlovian conditioning paradigms.

Extinction of negative conditioned stimulus valence in human fear conditioning

Fear conditioning is a common experimental paradigm for modelling the development, and exposure-based treatment, of anxiety disorders. Measures of fear such as threat-expectancy, physiological arousal, and fear ratings typically extinguish, however feared stimuli may still be evaluated negatively (i.e. retain negative valence). This systematic review provides the first investigation of the relationship between fear conditioning methodology and extinction of negative stimulus valence. Principal findings were that type of CS (conditioned stimulus) and the CS-US pairing (i.e. specific combination of CS and unconditioned stimulus) predicted extinction outcome. Extinction of absolute negative CS valence was always achieved with shape CSs; often achieved with low fear-relevant animals as CSs, and less frequently achieved with faces as CSs - particularly neutral faces paired with a shock US. Modified extinction procedures typically achieved the same outcome as standard extinction procedures, except for partially-reinforced extinction, which was less effective than standard extinction, and positive imagery training, which was more effective than standard extinction. Further studies are warranted to evaluate the influence of fear conditioning methodology on extinction of absolute negative CS valence.

Neural correlates of context-dependent extinction recall in social anxiety disorder: relevance of intrusions in response to aversive social experiences

BACKGROUND

There are phenomenological similarities between social anxiety disorder (SAD) and posttraumatic stress disorder, such as a provoking aversive event, posttraumatic stress symptoms (e.g. intrusions) in response to these events and deficient (context-dependent) fear conditioning processes. This study investigated the neural correlates of context-dependent extinction recall and fear renewal in SAD, specifically in patients with intrusions in response to an etiologically relevant aversive social event.

METHODS

During functional magnetic resonance imaging a two-day context-dependent fear conditioning paradigm was conducted in 54 patients with SAD and 54 healthy controls (HC). This included fear acquisition (context A) and extinction learning (context B) on one day, and extinction recall (context B) as well as fear renewal (contexts C and A) one day later. The main outcome measures were blood oxygen level-dependent responses in regions of interest and skin conductance responses.

RESULTS

Patients with SAD showed reduced differential conditioned amygdala activation during extinction recall in the safe extinction context and during fear renewal in the acquisition context compared to HC. Patients with clinically relevant intrusions moreover exhibited hypoactivation of the ventromedial prefrontal cortex (vmPFC) during extinction learning, extinction recall, and fear renewal in a novel context, while amygdala activation more strongly decreased during extinction learning and increased during fear renewal in the acquisition context compared with patients without intrusions.

CONCLUSIONS

Our study provides first evidence that intrusions in SAD are associated with similar deficits in context-dependent regulation of conditioned fear via the vmPFC as previously demonstrated in posttraumatic stress disorder.

Humans display interindividual differences in the latent mechanisms underlying fear generalization behaviour

Human generalization research aims to understand the processes underlying the transfer of prior experiences to new contexts. Generalization research predominantly relies on descriptive statistics, assumes a single generalization mechanism, interprets generalization from mono-source data, and disregards individual differences. Unfortunately, such an approach fails to disentangle various mechanisms underlying generalization behaviour and can readily result in biased conclusions regarding generalization tendencies. Therefore, we combined a computational model with multi-source data to mechanistically investigate human generalization behaviour. By simultaneously modelling learning, perceptual and generalization data at the individual level, we revealed meaningful variations in how different mechanisms contribute to generalization behaviour. The current research suggests the need for revising the theoretical and analytic foundations in the field to shift the attention away from forecasting group-level generalization behaviour and toward understanding how such phenomena emerge at the individual level. This raises the question for future research whether a mechanism-specific differential diagnosis may be beneficial for generalization-related psychiatric disorders.

Is Fear Extinction Impairment Central to Psychopathology?

As discussed in this chapter, there have been enormous advances in our understanding of how anxiety disorders develop, are maintained, and can be treated. Many of these advances have been the result of translational studies using fear conditioning and extinction models. Despite these successes, we recognize, as a field, that there are important limitations in the extent to which extinction can explain how anxiety disorders and behaviors remit. Clinically speaking, the outstanding challenge for treatment of anxiety disorders is to improve the current suboptimal success rates. Over the past 30 years, we have not improved our treatment success rates despite employing many pharmacological and pharmacological strategies. While extinction and related fear circuitry mechanisms most certainly appear to play a role in treatment of anxiety disorders, they are also apparently insufficient to fully accommodate the varied responses individuals exhibit with this treatment approach. Increasingly diverse and innovative approaches are needed that accommodate the multitude of change mechanisms involved in treating anxiety. However, this is not to suggest ignoring the key role that extinction and memory updating processes play in overcoming anxiety.

Heightened false alarms of conditioned threat predict longitudinal increases in GAD and SAD symptoms over the first year of college

Lab-based fear-conditioning studies have repeatedly implicated exaggerated threat reactivity to benign (unreinforced) stimuli as concurrent markers of clinical anxiety, but little work has examined the strength of false alarms as a longitudinal predictor of anxiety problems. As such, we tested whether heightened false alarms of conditioned threat assessed in participants' first semester of college predicted second-semester symptoms of generalized anxiety disorder (GAD) and social anxiety disorder (SAD) - two anxiety conditions that are common in college students, have been associated with excessive false alarms, and have yet to be assessed with longitudinal conditioning designs. Here, we focused on the predictive effects of behavioral threat responses (threat expectancy, subjective anxiety, avoidance) given their greater potential for translation to the clinic. Results implicate conditioning-related increases in anxiety to safe stimuli resembling the danger-cue as prospective predictors of GAD. In contrast, SAD was predicted by non-specific elevations in anxiety to a broad set of safe stimuli, as well as by increased threat expectancy toward cues least resembling the conditioned danger cue. These findings suggest that risk for GAD and SAD are captured by distinct, behavioral indicators of false-alarms that may be more feasibly collected in clinical settings compared to alternative experimental anxiety measures like psychophysiological responses.

Unique Associations between Conditioned Cognitive and Physiological Threat Responses and Facets of Anxiety Symptomatology in Youth

This study examined associations between anxiety symptomatology and cognitive and physiological threat responses during threat learning in a large sample of children and adolescents. Anxiety symptomatology severity along different dimensions (generalized anxiety, separation anxiety, social anxiety, and panic symptoms) was measured using parental and self-reports. Participants completed differential threat acquisition and extinction using an age-appropriate threat conditioning task. They then returned to the lab after 7-10 days to complete an extinction recall task that also assessed threat generalization. Results indicated that more severe overall anxiety was associated with greater cognitive and physiological threat responses during acquisition, extinction, and extinction recall. During acquisition and extinction, all anxiety dimensions manifested greater cognitive threat responses, while panic, separation anxiety, and social anxiety symptoms, but not generalized anxiety, were related to heightened physiological threat responses. In contrast, when we assessed generalization of cognitive threat responses, we found only generalized anxiety symptoms were associated with greater threat response generalization. The study provides preliminary evidence of specificity in threat responses during threat learning across youth with different anxiety symptoms.

Cognitive control is quickly adapted to actual task requirements despite misleading context cues-Evidence from the N2, CRN, and ERN

Cognitive control is flexibly adapted to task requirements in healthy individuals. Medio-frontal negativities in the event-related potential of the electroencephalogram can serve as indicators of cognitive control. With increasing conflict frequency, stimulus-locked control, as indexed by the N2, is increased and response-locked control, as indexed by the correct-related negativity, is reduced. On the behavioral level, this shift is associated with improved conflict resolution as evident in reduced response times and error rates in incompatible trials and a reduced response time congruency effect. Cognitive control adaptation might be implemented through experience-based task sets specifying advantageous processing strategies. Here, we investigated whether the cognitive control task set will be sustained when coupled with a contextual cue, even when the initial task requirements are no longer present. A flanker task with two conflict frequency conditions (25% incompatible and 75% incompatible trials) was presented. In the training phase, the conflict frequency conditions were paired with a distinct context cue (i.e., background color). In the test phase, the previously associated cues were again presented, but conflict frequency was identical in both conditions (50% incompatible trials). Although typical cognitive control adaptation was observed in the training phase on the behavioral and event-related potentials level, this pattern was not sustained in the test phase. Thus, the present study provides further evidence that cognitive control is flexibly adapted to task requirements even in the presence of misleading cues.

Overgeneralization of fear, but not avoidance, following acute stress

Research has demonstrated the spreading of fear from threat-related stimuli to perceptually similar, but innocuous, stimuli. Less is known, however, about the generalization of avoidance behavior. Given that stress is known to affect learning and memory, we were interested in the effect of acute stress on (over)generalization of fear and avoidance responses. On the first day, one geometrical shape was paired with a mild electrical stimulus (CS+), whereas another shape was not (CS-). One day later, after participants had been exposed to the Maastricht Acute Stress Test or a control task, generalization of avoidance responses and fear (shock expectancy and skin conductance responses) was tested to a range of perceptual generalization stimuli. Generalization gradients were observed across different outcome measures. Stress enhanced generalization of shock expectancy to the stimulus most similar to the CS+. Our findings confirm that stress can affect the generalization of fear, but further studies are warranted.

Intolerance of uncertainty, and not social anxiety, is associated with compromised extinction of social threat

Extinction-resistant threat is regarded as a central hallmark of pathological anxiety. However, it remains relatively under-studied in social anxiety. Here we sought to determine whether self-reported trait social anxiety is associated with compromised threat extinction learning and retention. We tested this hypothesis within two separate, socially relevant conditioning studies. In the first experiment, a Selective Extinction Through Cognitive Evaluation (SECE) paradigm was used, which included a cognitive component during the extinction phase, while experiment 2 used a traditional threat extinction paradigm. Skin conductance responses and subjective ratings of anxiety (experiment 1 and 2) and expectancy (experiment 2) were collected across both experiments. The findings of both studies demonstrated no effect of social anxiety on extinction learning or retention. Instead, results from experiment 1 indicated that individual differences in Intolerance of Uncertainty (IU) were associated with the ability to use contextual cues to decrease a conditioned response during SECE. However, during extinction retention, high IU predicted greater generalisation across context cues. Findings of experiment 2 revealed that higher IU was associated with impaired extinction learning and retention. The results from both studies suggest that compromised threat extinction is likely to be a characteristic of high levels of IU and not social anxiety.

Threat and safety reversal learning in social anxiety disorder - an fMRI study

Social anxiety disorder (SAD) has been linked to maladaptive forms of fear regulation, including flexibly distinguishing between learned threat and safety signals. Few studies have examined this in young, unmedicated SAD patients, including its neural basis. We aimed to characterize the neural, subjective, and autonomic correlates of reversal learning in patients with SAD and compare them to matched patients with major depressive disorder and to healthy control participants. All participants completed a threat-safety reversal learning task during functional magnetic resonance imaging. Successful threat-safety updating was associated with significant activation of primary regions of interest (anterior cingulate, insula and ventromedial prefrontal cortex), however, no significant differences were observed between them, consistent with subjective reports of task-evoked anxiety and affect. Contrary to expectations, we did not observe threat and safety reversal learning to be significantly impaired in young people with SAD.

Heterogeneity in Fear Processing across and within Anxiety, Eating, and Compulsive Disorders

BACKGROUND

To assess within and across diagnosis variability we examined fear processing in healthy controls (HC) and three diagnostic groups that share symptoms of pathological anxiety: obsessive compulsive disorder (OCD); social anxiety disorder (SAD), and anorexia nervosa (AN).

METHODS

Unmedicated adults (N=166) participated in a paradigm assessing associative fear acquisition, extinction, extinction recall, and fear renewal. Data were analyzed from two perspectives: comparison of each disorder to HC and exploratory latent class analysis (LCA) of the combined data.

RESULTS

The diagnosis-based analyses indicated significantly increased fear renewal in OCD and trends toward decreased extinction recall in OCD and increased renewal in SAD. The LCA indicated four Response Types, none of which were congruent with the diagnostic categories. Most participants had a normative response (50%) or a moderate extinction recall deficit (30%). The two remaining groups (8% each) had more extreme responses: one showed complete failure of extinction recall; the other persistent arousal in expectation of, but prior to, actual conditioning (threat sensitivity).

LIMITATIONS

Due to small sample size (N=20) results for AN are regarded as preliminary.

CONCLUSIONS

Our diagnosis-based findings are consistent with previous data suggesting an association between pathological anxiety and difficulties maintaining fear extinction. The LCA reveal substantial within-diagnosis heterogeneity in fear processing and support inclusion of empirically driven approaches as a complement to standard analyses. This heterogeneity may also have implications for treatment, particularly cognitive behavioral therapy, which relies on strengthening extinction recall and requires patients to tolerate anxious expectation in order to engage with feared situations.

Estradiol and Women's Health: Considering the Role of Estradiol as a Marker in Behavioral Medicine

The sex hormone estradiol, as measured through saliva, represents a non-invasive and cost-effective approach to understanding the influence of hormonal factors on physical and psychological well-being among women. Estradiol levels dramatically change at hormonal transitions, such as puberty, menopause, and postpartum. It is at these transitions where women are at increased risk for psychological and somatic distress. Salivary estradiol also has implications for decision-making and has been broadly associated with engagement in health-compromising behaviors which can influence women's ability to cope with and manage chronic health conditions. This review summarizes the evidence for salivary estradiol as a marker of physical and psychological health, and discusses practical information regarding saliva collection and assay. The overall intent is to expand and clarify knowledge of the relation between changes in salivary estradiol and women's health as well as to provide a means of integrating salivary estradiol into future behavioral medicine research.

Mnemonic discrimination and social anxiety: the role of state anxiety

The Mnemonic Similarity Task (MST) measures mnemonic discrimination, or the ability to correctly identify new stimuli from highly similar, old stimuli. Poor mnemonic discrimination is a potential risk or maintenance factor for anxiety, and recent studies suggest state affect may moderate relations between mnemonic discrimination and trait anxiety. No studies have evaluated mnemonic discrimination in specific subtypes of anxiety or with clinically relevant stressors. This preregistered study evaluated the role of social anxiety and the anticipation of a future speech on MST performance. Participants with high (n = 66) and low (n = 64) levels of social anxiety were randomly assigned to a stressor condition or a control condition prior to the MST. State anxiety was measured throughout the study. Results did not indicate significant effects of trait (high vs. low social anxiety) or state anxiety (stressor condition vs. control condition) on mnemonic discrimination. Results are compared with previous research and implications and future directions are discussed.

An Evolutionarily Threat-Relevant Odor Strengthens Human Fear Memory

Olfaction is an evolutionary ancient sense, but it remains unclear to what extent it can influence routine human behavior. We examined whether a threat-relevant predator odor (2-methyl-2-thiazoline) would contextually enhance the formation of human fear memory associations. Participants who learned to associate visual stimuli with electric shock in this predator odor context later showed stronger fear responses to the visual stimuli than participants who learned in an aversiveness-matched control odor context. This effect generalized to testing in another odor context, even after extinction training. Results of a separate experiment indicate that a possible biological mechanism for this effect may be increased cortisol levels in a predator odor context. These results suggest that innate olfactory processes can play an important role in human fear learning. Modulatory influences of odor contexts may partly explain the sometimes maladaptive persistence of human fear memory, e.g., in post-traumatic stress disorders.

The Role of Hormonal and Reproductive Status in the Treatment of Anxiety Disorders in Women

Exposure therapy, a key treatment for anxiety disorders, can be modelled in the laboratory using Pavlovian fear extinction. Understanding the hormonal and neurobiological mechanisms underlying fear extinction in females, who are twice more likely than males to present with anxiety disorders, may aid in optimising exposure therapy outcomes in this population. This chapter will begin by discussing the role of the sex hormones, estradiol and progesterone, in fear extinction in females. We will also propose potential mechanisms by which these hormones may modulate fear extinction. The second half of this chapter will discuss the long-term hormonal, neurological and behavioural changes that arise from pregnancy and motherhood and how these changes may alter the features of fear extinction in females. Finally, we will discuss implications of this research for the treatment of anxiety disorders in women with and without prior reproductive experience.

Enhanced noradrenergic activity by yohimbine and differential fear conditioning in patients with major depression with and without adverse childhood experiences

Major depressive disorder (MDD) has been associated with changes in the biological stress systems, including the locus coeruleus-noradrenergic system. Accumulated evidence suggests an upregulation of central alpha2-receptors, leading to decreased noradrenergic activity on a central level in MDD patients. Adverse childhood experiences (ACE) such as physical or sexual abuse might contribute to those changes. Furthermore, noradrenaline can affect cognitive processes, e.g. learning and memory. Cognitive dysfunctions constitute an important symptom of MDD. We aimed to investigate the relationship of alpha2-receptor dysregulation with learning processes in MDD by conducting a differential fear conditioning paradigm after double-blind administration of the alpha2-receptor antagonist yohimbine versus placebo. To investigate the role of ACE systematically, we included four groups of healthy participants and MDD patients with and without ACE (MDD-/ACE-: N = 44, MDD-/ACE+: N = 26, MDD+/ACE-: N = 24, MDD+/ACE+: N = 24; without antidepressant medication). We found increased noradrenergic activity after yohimbine administration across groups as measured by alpha-amylase and blood pressure. Overall, fear responses were higher after yohimbine as indicated by skin conductance responses and fear-potentiated startle responses. While we found no significant MDD effect, ACE had significant impact on the ability to discriminate between both conditioned stimuli (CS+ predicting an aversive stimulus, CS- predicting none), depending on drug condition. After yohimbine, CS discrimination decreased in individuals without ACE, but not in individuals with ACE. Differences in the response to yohimbine might be explained by aberrant alpha2-receptor regulation in individuals with ACE. Impaired discrimination of threat and safety signals might contribute to enhanced vulnerability following ACE.

Generalization of extinction of a generalization stimulus in fear learning

Two experiments examined whether extinction of a generalization stimulus (GS) after single cue fear conditioning would in turn generalize to other stimuli, relative to a control group that received regular extinction of CS + itself. We found only a weak effect of such "generalization of GS extinction" either back to CS + or to a different GS, on either US expectancy or skin conductance measures. In other words, despite extinction trials with a stimulus highly similar to CS+, participants showed a return of fear when tested with CS + or a novel GS. However this responding declined rapidly over non-reinforced test trials. Trait anxious participants showed higher overall US expectancy ratings in the extinction and test phases, and slower extinction of expectancy, relative to low anxious participants. These results may help explain why exposure therapy, which is unlikely to reproduce the exact stimuli present at acquisition, sometimes fails to transfer to other fear-eliciting stimuli subsequently encountered by anxious clients. The generalization of GS extinction paradigm might provide a useful testbed for evaluation of interventions designed to enhance transfer, such as exposure to multiple diverse exemplars.

Men Scare Me More: Gender Differences in Social Fear Conditioning in Virtual Reality

Women nearly twice as often develop social anxiety disorder (SAD) compared to men. The reason for this difference is still being debated. The present study investigates gender differences and the effect of male versus female agents in low (LSA) and high socially anxious (HSA) participants regarding the acquisition and extinction of social fear in virtual reality (VR). In a social fear conditioning (SFC) paradigm, 60 participants actively approached several agents, some of which were paired with an aversive unconditioned stimulus (US) consisting of a verbal rejection and spitting simulated by an aversive air blast (CS+), or without an US (CS-). Primary outcome variables were defined for each of the 4 levels of emotional reactions including experience (fear ratings), psychophysiology (fear-potentiated startle), behavior (avoidance), and cognition (recognition task). Secondary outcome variables were personality traits, contingency ratings, heart rate (HR), and skin conductance response (SCR). As hypothesized, fear ratings for CS+ increased significantly during acquisition and the differentiation between CS+ and CS- vanished during extinction. Additionally, women reported higher fear compared to men. Furthermore, a clear difference in the fear-potentiated startle response between male CS+ and CS- at the end of acquisition indicates successful SFC to male agents in both groups. Concerning behavior, results exhibited successful SFC in both groups and a general larger distance to agents in HSA than LSA participants. Furthermore, HSA women maintained a larger distance to male compared to female agents. No such differences were found for HSA men. Regarding recognition, participants responded with higher sensitivity to agent than object stimuli, suggesting a higher ability to distinguish the target from the distractor for social cues, which were on focus during SFC. Regarding the secondary physiological outcome variables, we detected an activation in HR response during acquisition, but there were no differences between stimuli or groups. Moreover, we observed a gender but no CS+/CS- differences in SCR. SFC was successfully induced and extinguished according to the primary outcome variables. VR is an interesting tool to measure emotional learning processes on different outcome levels with enhanced ecological validity. Future research should further investigate social fear learning mechanisms for developing more efficient treatments of SAD.

Low Perceived Self-Efficacy Impedes Discriminative Fear Learning

Perceived self-efficacy refers to a subject’s expectation about the outcomes his/her behavior will have in a challenging situation. Low self-efficacy has been implicated in the origins and maintenance of phobic behavior. Correlational studies suggest an association between perceived self-efficacy and learning. The experimental manipulation of perceived self-efficacy offers an interesting approach to examine the impact of self-efficacy beliefs on cognitive and emotional functions. Recently, a positive effect of an experimentally induced increased self-efficacy on associative learning has been demonstrated. Changes in associative learning constitute a central hallmark of pathological fear and anxiety. Such alterations in the acquisition and extinction of conditioned fear may be related to cognitive and neurobiological factors that predict a certain vulnerability to anxiety disorders. The present study builds on previous own work by investigating the effect of an experimentally induced low perceived self-efficacy on fear acquisition, extinction and extinction retrieval in a differential fear conditioning task. Our results suggest that a negative verbal feedback, which leads to a decreased self-efficacy, is associated with changes in the acquisition of conditioned fear. During fear acquisition, the negative verbal feedback group showed decreased discrimination of fear responses between the aversive and safe conditioned stimuli (CS) relative to a group receiving a neutral feedback. The effects of the negative verbal feedback on the acquisition of fear discrimination learning were indexed by an impaired ability to discriminate the probability of receiving a shock during acquisition upon presentation of the aversive (CS+) relative to the safe stimuli (CS−). However, the effects of low self-efficacy on discrimination learning were limited to fear acquisition. No differences between the groups were observed during extinction and extinction retrieval. Furthermore, analysis of other outcome measures, i.e., skin conductance responses and CS valence ratings, revealed no group differences during the different phases of fear conditioning. In conclusion, lower perceived self-efficacy alters cognitive/expectancy components of discrimination during fear learning but not evaluative components and physiological responding. The pattern of findings suggests a selective, detrimental role of low(er) self-efficacy on the subject’s ability to learn the association between ambiguous cues and threat/safety.

Heterogeneity of the Anxiety-Related Attention Bias: A Review and Working Model for Future Research

The anxiety-related attention bias (AB) has been studied for several decades as a clinically-relevant output of the dynamic and complex threat detection-response system. Despite research enthusiasm for the construct of AB, current theories and measurement approaches cannot adequately account for the growing body of mixed, contradictory, and null findings. Drawing on clinical, neuroscience, and animal models, we argue that the apparent complexity and contradictions in the empirical literature can be attributed to the field's failure to clearly conceptualize AB heterogeneity and the dearth of studies in AB that consider additional cognitive mechanisms in anxiety, particularly disruptions in threat-safety discrimination and cognitive control. We review existing research and propose a working model of AB heterogeneity positing that AB may be best conceptualized as multiple subtypes of dysregulated processing of and attention to threat anchored in individual differences in threat-safety discrimination and cognitive control. We review evidence for this working model and discuss how it can be used to advance knowledge of AB mechanisms and inform personalized prevention and intervention approaches.

Thinking of attachment figures blocks differential fear conditioning

Thinking of attachment figures can potentially impact acquisition and extinction of fear memories. In this study, 50 participants underwent a fear conditioning and extinction paradigm. Half the participants thought about a supportive attachment figure and half thought about a non-attachment positive experience prior to the fear conditioning. All participants then underwent a differential fear conditioning and fear extinction paradigm, and returned 2 days later for an extinction recall task. Fear-potentiated startle and subjective expectancy of shock ratings were measured as the primary indicators of fear learning across trials. The attachment prime significantly reduced the acquisition of fear-potentiated startle, and this lower level of fear was maintained at the extinction recall task. These results demonstrate that attachment primes can modulate the acquisition of conditioned fear. These findings provide preliminary evidence for the protective nature of attachment relationships at times that are characterized by fear learning.

Augmentation of Extinction and Inhibitory Learning in Anxiety and Trauma-Related Disorders

Although the fear response is an adaptive response to threatening situations, a number of psychiatric disorders feature prominent fear-related symptoms caused, in part, by failures of extinction and inhibitory learning. The translational nature of fear conditioning paradigms has enabled us to develop a nuanced understanding of extinction and inhibitory learning based on the molecular substrates to systems neural circuitry and psychological mechanisms. This knowledge has facilitated the development of novel interventions that may augment extinction and inhibitory learning. These interventions include nonpharmacological techniques, such as behavioral methods to implement during psychotherapy, as well as device-based stimulation techniques that enhance or reduce activity in different regions of the brain. There is also emerging support for a number of psychopharmacological interventions that may augment extinction and inhibitory learning specifically if administered in conjunction with exposure-based psychotherapy. This growing body of research may offer promising novel techniques to address debilitating transdiagnostic fear-related symptoms.

The need for standards in the design of differential fear conditioning and extinction experiments in youth: A systematic review and recommendations for research on anxiety

Fear extinction studies in youth have yielded mixed results due to developmental processes and variations in design, methodology and dependent measures. This systematic review focused on studies with healthy youth between 2 and 17 years of age to identify experimental parameters of studies documenting extinction effects. Thirty-five studies met inclusion criteria and the following themes emerged (a) some studies employed parameters and task demands that are complex and require active participant involvement whereas others involved simple stimulus configurations and passive participant involvement, and (b) variation exists among dependent measures in units of measurement, timing and type of measurement. The review identified that studies using geometric shape conditioned stimuli (CS) paired with a tone unconditioned stimulus (US) (e.g., metal scraping on slate), as well as face CSs with a scream US produced the most reliable extinction effects, although the latter combination may be associated with higher drop-out than shape CSs and a tone US. The most commonly used and effective dependent measures for revealing extinction effects were skin conductance responses (SCR) and subjective ratings (SR) of CS valence, fearfulness and arousal. Fear potentiated startle (FPS) blink reflexes were also an effective but less commonly used measure. It is recommended that future studies use shape CSs and the metal scraping on slate US in studies involving children and either shape CSs and the metal scraping on slate US or face CSs paired with a scream US with adolescents. It is also recommended that US expectancy ratings and CS evaluations are assessed trial-by-trial and between-phase, and that startle-eliciting stimuli to measure startle blink reflexes are delivered on every second trial per CS so that SCR and FPS can be examined. However, further research is required to determine whether increased participant involvement due to providing trial-by-trial and between-phase ratings of the CSs and US differentially influences responding, particularly in children relative to adolescents and adults.

Examining the relationships between error-related brain activity (the ERN) and anxiety disorders versus externalizing disorders in young children: Focusing on cognitive control, fear, and shyness

OBJECTIVE

We examine the relationship between individual differences in temperament (cognitive control, fear, and shyness) and the error-related negativity (i.e., the ERN) in a large sample of young children. Furthermore, we explore to what extent variation in temperament may underlie the associations between the ERN and anxiety disorders versus externalizing disorders.

METHOD

Using the Children's Behavior Questionnaire (CBQ), we focus on scales related to cognitive control (attentional focusing, attentional shifting, and inhibitory control) and a fearful/anxious temperament (fearfulness and shyness). We use diagnostic interviews to assess anxiety (specific phobia, separation anxiety disorder, social phobia, generalized anxiety disorder, obsessive-compulsive disorder, and agoraphobia) and externalizing disorders (attention deficit hyperactivity disorder; ADHD, and oppositional defiant disorder; ODD). A go/no-go task was used to measure the ERN.

RESULTS

Results suggest that while shyness was related to an increased ERN, fearfulness was associated with a decreased ERN. Moreover, increased cognitive control was related to an increased ERN, and an exploratory model suggested that while shyness displayed an independent relationship with the ERN, the relationship between fear and the ERN was accounted for by deficits in cognitive control. Additionally, we found that the ERN was increased in children with anxiety disorders, and that this association was explained by shyness, but not fear or cognitive control. In contrast, the ERN was blunted in children with externalizing disorders (ADHD or ODD), and this association was accounted for by lower levels of both shyness and cognitive control.

CONCLUSIONS

Overall, these results are novel insofar as they suggest that the temperamental factors of shyness and cognitive control may underlie the associations between the ERN and internalizing versus externalizing disorders.

Implications of the Research Domain Criteria project for childhood anxiety and its disorders

Anxiety disorders are among the most prevalent psychiatric disorders in youth; however, progress in treatment for childhood anxiety has stalled over the past decade. The National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) project represents a shift toward a dimensional and interdisciplinary approach to psychiatric disorders; this shift can reframe developmental psychopathology for childhood anxiety and facilitate novel advances in its classification and treatment. Here we highlight constructs in the Systems for Social Processes and the Negative Valence System domains of RDoC, as they relate to childhood anxiety disorders. Childhood anxiety relates to both RDoC domains. In terms of social processes, through natural reliance on parents to reduce children's fear, attachment represents one particular social process, which plays a central role in anxiety among youth. In terms of negative valence, considerable research links threat conditioning to pediatric anxiety. Finally, fronto-amygdala circuitry relates to all three entities, as it has been shown to underly both attachment processes and threat learning, while it also has been consistently implicated in anxiety disorders across development. Through integrative and translational approaches, RDoC provides unique opportunities and simultaneous challenges for advancing the understanding and treatment of childhood anxiety disorders.

Neurobiology of fear and specific phobias

Fear, which can be expressed innately or after conditioning, is triggered when a danger or a stimulus predicting immediate danger is perceived. Its role is to prepare the body to face this danger. However, dysfunction in fear processing can lead to psychiatric disorders in which fear outweighs the danger or possibility of harm. Although recognized as highly debilitating, pathological fear remains insufficiently treated, indicating the importance of research on fear processing. The neurobiological basis of normal and pathological fear reactions is reviewed in this article. Innate and learned fear mechanisms, particularly those involving the amygdala, are considered. These fear mechanisms are also distinguished in specific phobias, which can indeed be nonexperiential (implicating innate, learning-independent mechanisms) or experiential (implicating learning-dependent mechanisms). Poor habituation and poor extinction are presented as dysfunctional mechanisms contributing to persistence of nonexperiential and experiential phobias, respectively.

Intolerance of Uncertainty in eating disorders: An update on the field

Pathological fear and anxiety regarding food, eating, weight and body shape are at the core of eating disorder (ED) psychopathology. To manage anxiety, patients develop complicated repertoires of ritualistic and repetitive behaviours, which can lead to total functional impairment. Yet the cognitive processes underlying anxiety, fear, and anxiety-driven behaviours in EDs remain poorly understood. Intolerance of Uncertainty (IU) is defined as a tendency to react negatively on an emotional, cognitive, and behavioural level to uncertain situations and events. There is substantial evidence that IU is a transdiagnostic process that contributes to the maintenance of anxiety disorders; however, IU may also be relevant to the understanding and treatment of EDs. The current review summarises the growing literature examining IU in relation to ED symptoms, including restriction, bingeing, purging, ritualised behaviours, reassurance-seeking and body checking. Extending from the obsessive-compulsive disorder (OCD) and anxiety disorder literature, we propose that IU provides a novel theoretical and clinical framework from which to understand the anxiety, fixation with rules and rituals, and the cognitively rigid profile that is characteristic of ED presentations. We conclude with suggestions for future research, and discuss IU as a potential treatment target for core features of EDs and comorbid symptoms.

A genetic variant brain-derived neurotrophic factor (BDNF) polymorphism interacts with hostile parenting to predict error-related brain activity and thereby risk for internalizing disorders in children

The error-related negativity (ERN) is a negative deflection in the event-related potential occurring when individuals make mistakes, and is increased in children with internalizing psychopathology. We recently found that harsh parenting predicts a larger ERN in children, and recent work has suggested that variation in the brain-derived neurotrophic factor (BDNF) gene may moderate the impact of early life adversity. Parents and children completed measures of parenting when children were 3 years old (N = 201); 3 years later, the ERN was measured and diagnostic interviews as well as dimensional symptom measures were completed. We found that harsh parenting predicted an increased ERN only among children with a methionine allele of the BDNF genotype, and evidence of moderated mediation: the ERN mediated the relationship between parenting and internalizing diagnoses and dimensional symptoms only if children had a methionine allele. We tested this model with externalizing disorders, and found that harsh parenting predicted externalizing outcomes, but the ERN did not mediate this association. These findings suggest that harsh parenting predicts both externalizing and internalizing outcomes in children; however, this occurs through different pathways that uniquely implicate error-related brain activity in the development of internalizing disorders.

The Influence of State Anxiety on Fear Discrimination and Extinction in Females

Formal theories have linked pathological anxiety to a failure in fear response inhibition. Previously, we showed that aberrant response inhibition is not restricted to anxiety patients, but can also be observed in anxiety-prone adults. However, less is known about the influence of currently experienced levels of anxiety on inhibitory learning. The topic is highly important as state anxiety has a debilitating effect on cognition, emotion, and physiology and is linked to several anxiety disorders. In the present study, healthy female volunteers performed a fear conditioning task, after being informed that they will have to perform the Trier Social Stress Test task (n = 25; experimental group) or a control task (n = 25; control group) upon completion of the conditioning task. The results showed that higher levels of state anxiety corresponded with a reduced discrimination between a stimulus (CS+) typically followed by an aversive event and a stimulus (CS-) that is never followed by an aversive event both during the acquisition and the extinction phase. No effect of state anxiety on the skin conductance response associated with CS+ and CS- was found. Additionally, higher levels of state anxiety coincided with more negative valence ratings of the CSs. The results suggest that increased stress-induced state anxiety might lead to stimulus generalization during fear acquisition, thereby impairing associative learning.

Don't fear 'fear conditioning': Methodological considerations for the design and analysis of studies on human fear acquisition, extinction, and return of fear

The so-called 'replicability crisis' has sparked methodological discussions in many areas of science in general, and in psychology in particular. This has led to recent endeavours to promote the transparency, rigour, and ultimately, replicability of research. Originating from this zeitgeist, the challenge to discuss critical issues on terminology, design, methods, and analysis considerations in fear conditioning research is taken up by this work, which involved representatives from fourteen of the major human fear conditioning laboratories in Europe. This compendium is intended to provide a basis for the development of a common procedural and terminology framework for the field of human fear conditioning. Whenever possible, we give general recommendations. When this is not feasible, we provide evidence-based guidance for methodological decisions on study design, outcome measures, and analyses. Importantly, this work is also intended to raise awareness and initiate discussions on crucial questions with respect to data collection, processing, statistical analyses, the impact of subtle procedural changes, and data reporting specifically tailored to the research on fear conditioning.

Acquisition of CS-US contingencies during Pavlovian fear conditioning and extinction in social anxiety disorder and posttraumatic stress disorder

BACKGROUND

Fear-based disorders, like social anxiety disorder (SAD) and posttraumatic stress disorder (PTSD), are characterized by an exaggerated fear response and avoidance to trigger cues, suggesting a transdiagnostic mechanism of psychopathology. Current theories suggest that abnormalities in conditioned fear is a primary contributor to the pathophysiology of these disorders. The primary goal of this study was to compare acquisition of conditioned stimulus (CS) and aversive unconditioned stimulus (US) contingencies during fear learning and extinction in individuals with SAD and PTSD.

METHODS

In a standard Pavlovian fear conditioning-extinction paradigm we measured subjective US expectancy ratings to different CSs in patients with SAD (n=16) compared to patients with PTSD (n=13) and healthy controls (n=15) RESULTS: Both patient groups (SAD, PTSD) acquired differential conditioning between a CS that predicted US (CS+) and a CS that never predicted the US (CS-), however, both groups reported an increased expectancy that the US would occur following the CS-. Additionally, the PTSD group overestimated that the US would occur in general. Neither patient group showed evidence of successful extinction of the CS+-US contingency nor differentiated their expectation of US occurrence between the CS+ and CS- during extinction learning.

LIMITATIONS

Group sample sizes were small and we did not include a trauma-exposed group without PTSD CONCLUSIONS: Both SAD and PTSD generalize expectations of an aversive outcome across CSs, even when a CS never signals an aversive outcome and PTSD may tend to over-expect threat. Fear learning and extinction abnormalities may be a core feature underlying shared symptoms across fear-based disorders.

The Body and the Brain: Measuring Skin Conductance Responses to Understand the Emotional Experience

In this article, we introduce the method of measuring skin conductance responses (SCR) reflecting peripheral (bodily) signals associated with emotions, decisions, and eventually behavior. While measuring SCR is a well-established, robust, widely used, and relatively inexpensive method, it has been rarely utilized in organizational research. We introduce the basic aspects of SCR methodology and explain the behavioral significance of the signal, especially in connection with the emotional experience. Importantly, we describe in detail a specific research protocol (fear conditioning) that serves as an illustrative example to support the initial steps for organizational scholars who are new to the method. We also provide the related scripts for stimulus presentation and basic data analysis, as well as an instructional video, with the aim to facilitate the dissemination of SCR methodology to organizational research. We conclude by suggesting potential future research questions that can be addressed using SCR measurements.

Fear conditioning and stimulus generalization in patients with social anxiety disorder

Although overgeneralization seems to be a hallmark of several anxiety disorders, this until now has not been investigated in social anxiety disorder (SAD). Therefore, we examined fear generalization in 26 SAD patients and 29 healthy controls (HC) using two faces as conditioned stimuli (CS+, CS-), and a loud scream and a fearful face as unconditioned stimulus (US). Generalization was tested by presenting both CS and four morphs of the two faces (generalization stimuli [GSs]), while ratings, heart rate (HR) and skin conductance responses (SCR) were recorded. Results revealed that SAD patients rated all stimuli as less pleasant and more arousing compared to HC. Moreover, ratings and SCR indicated that both groups generalized their acquired fear from the CS+ to GSs. Remarkably, only SAD patients showed generalization in HR responses (fear bradycardia). Overall, SAD seems not to be characterized by strong overgeneralization but discrepancies in fear responses to both conditioned and generalized threat stimuli.

Social Pavlovian conditioning: Short- and long-term effects and the role of anxiety and depressive symptoms

Today's stressors largely arise from social interactions rather than from physical threat. However, the dominant laboratory model of emotional learning relies on physical stimuli (e.g. electric shock) whereas adequate models of social conditioning are missing, possibly due to more subtle and multilayered biobehavioral responses to such stimuli. To fill this gap, we acquired a broad set of measures during conditioning to negative social unconditioned stimuli, also taking into account long-term maintenance of conditioning and inter-individual differences. Fifty-nine healthy participants underwent a classical conditioning task with videos of actors expressing disapproving (US-neg) or neutral (US-neu) statements. Static images of the corresponding actors with a neutral facial expression served as CS+ and CS-, predicting US-neg and US-neu, respectively. Autonomic and facial-muscular measures confirmed differential unconditioned responding whereas experiential CS ratings, event-related potentials, and evoked theta oscillations confirmed differential conditioned responding. Conditioning was maintained at 1 month and 1 year follow-ups on experiential ratings, especially in individuals with elevated anxiety and depressive symptoms, documenting the efficiency of social conditioning and its clinical relevance. This novel, ecologically improved conditioning paradigm uncovered a remarkably efficient multi-layered social learning mechanism that may represent a risk factor for anxiety and depression.

Learning from other people's fear: amygdala-based social reference learning in social anxiety disorder

BACKGROUND

Social anxiety disorder involves fear of social objects or situations. Social referencing may play an important role in the acquisition of this fear and could be a key determinant in future biomarkers and treatment pathways. However, the neural underpinnings mediating such learning in social anxiety are unknown. Using event-related functional magnetic resonance imaging, we examined social reference learning in social anxiety disorder. Specifically, would patients with the disorder show increased amygdala activity during social reference learning, and further, following social reference learning, show particularly increased response to objects associated with other people's negative reactions?

METHOD

A total of 32 unmedicated patients with social anxiety disorder and 22 age-, intelligence quotient- and gender-matched healthy individuals responded to objects that had become associated with others' fearful, angry, happy or neutral reactions.

RESULTS

During the social reference learning phase, a significant group × social context interaction revealed that, relative to the comparison group, the social anxiety group showed a significantly greater response in the amygdala, as well as rostral, dorsomedial and lateral frontal and parietal cortices during the social, relative to non-social, referencing trials. In addition, during the object test phase, relative to the comparison group, the social anxiety group showed increased bilateral amygdala activation to objects associated with others' fearful reactions, and a trend towards decreased amygdala activation to objects associated with others' happy and neutral reactions.

CONCLUSIONS

These results suggest perturbed observational learning in social anxiety disorder. In addition, they further implicate the amygdala and dorsomedial prefrontal cortex in the disorder, and underscore their importance in future biomarker developments.

Single-session attention bias modification and error-related brain activity

An attentional bias to threat has been implicated in the etiology and maintenance of anxiety disorders. Recently, attention bias modification (ABM) has been shown to reduce threat biases and decrease anxiety. However, it is unclear whether ABM modifies neural activity linked to anxiety and risk. The current study examined the relationship between ABM and the error-related negativity (ERN), a putative biomarker of risk for anxiety disorders, and the relationship between the ERN and ABM-based changes in attention to threat. Fifty-nine participants completed a single-session of ABM and a flanker task to elicit the ERN--in counterbalanced order (i.e., ABM-before vs. ABM-after the ERN was measured). Results indicated that the ERN was smaller (i.e., less negative) among individuals who completed ABM-before relative to those who completed ABM-after. Furthermore, greater attentional disengagement from negative stimuli during ABM was associated with a smaller ERN among ABM-before and ABM-after participants. The present study suggests a direct relationship between the malleability of negative attention bias and the ERN. Explanations are provided for how ABM may contribute to reductions in the ERN. Overall, the present study indicates that a single-session of ABM may be related to a decrease in neural activity linked to anxiety and risk.

Worry and Discrimination of Threat and Safety Cues: An Event-Related Potential Investigation

Overgeneralization of fear to safety cues is increasingly being studied in order to further our understanding of the maintenance of anxiety disorders. The current study used event-related potentials (ERPs) to evaluate whether worry affects anticipation and processing of threat and neutral pictures during a conditioning task. Fifty-two high (n=24) and low (n=28) worriers completed a paradigm in which a neutral stimulus indicated the valence of a second stimulus, either a threat or neutral picture. Results found that worriers displayed reduced anticipatory responses to both stimulus types as indexed by the stimulus preceding negativity, although they displayed an increased stimulus preceding negativity to threatening images during the second half of the task. In addition, high and low worriers differed in processing of threat and neutral images as indexed by the late positive potential. These findings support the overgeneralization of fear literature, suggesting that worriers display difficulty discriminating safety cues from threat cues, and this affects the attentional resources devoted to subsequent stimuli. Implications of these results are discussed.

Conditioned Fear Acquisition and Generalization in Generalized Anxiety Disorder

Abnormal fear conditioning processes (including fear acquisition and conditioned fear-generalization) have been implicated in the pathogenesis of anxiety disorders. Previous research has shown that individuals with panic disorder present enhanced conditioned fear-generalization in comparison to healthy controls. Enhanced conditioned fear-generalization could also characterize generalized anxiety disorder (GAD), but research so far is inconclusive. An important confounding factor in previous research is comorbidity. The present study examined conditioned fear-acquisition and fear-generalization in 28 patients with GAD and 30 healthy controls using a recently developed fear acquisition and generalization paradigm assessing fear-potentiated startle and online expectancies of the unconditioned stimulus. Analyses focused on GAD patients without comorbidity but included also patients with comorbid anxiety disorders. Patients and controls did not differ as regards fear acquisition. However, contrary to our hypothesis, both groups did not differ either in most indexes of conditioned fear-generalization. Moreover, dimensional measures of GAD symptoms were not correlated with conditioned fear-generalization indexes. Comorbidity did not have a significant impact on the results. Our data suggest that conditioned fear-generalization is not enhanced in GAD. Results are discussed with special attention to the possible effects of comorbidity on fear learning abnormalities.

Biases in probabilistic category learning in relation to social anxiety

Instrumental learning paradigms are rarely employed to investigate the mechanisms underlying acquired fear responses in social anxiety. Here, we adapted a probabilistic category learning paradigm to assess information processing biases as a function of the degree of social anxiety traits in a sample of healthy individuals without a diagnosis of social phobia. Participants were presented with three pairs of neutral faces with differing probabilistic accuracy contingencies (A/B: 80/20, C/D: 70/30, E/F: 60/40). Upon making their choice, negative and positive feedback was conveyed using angry and happy faces, respectively. The highly socially anxious group showed a strong tendency to be more accurate at learning the probability contingency associated with the most ambiguous stimulus pair (E/F: 60/40). Moreover, when pairing the most positively reinforced stimulus or the most negatively reinforced stimulus with all the other stimuli in a test phase, the highly socially anxious group avoided the most negatively reinforced stimulus significantly more than the control group. The results are discussed with reference to avoidance learning and hypersensitivity to negative socially evaluative information associated with social anxiety.

Cognitive flexibility mediates the relation between intolerance of uncertainty and safety signal responding in those with panic disorder

There is a growing literature associating anxiety disorders with an inability to inhibit defensive responding during safety conditions of threatening tasks. However, investigations on the relation between panic disorder (PD) and defensive responding to safety have yielded mixed results. A recent study from our laboratory revealed that intolerance of uncertainty (IU) moderates this association, such that only individuals with PD and a high IU exhibit heightened startle potentiation during safety. The mechanism underlying this relationship is unknown. Given that safety conditions typically alternate with periods of threat, cognitive flexibility (i.e., the ability to adjust one's habitual responding to a situation, given the input of new information) may be involved in the ongoing reappraisal of danger and adjustment of defensive responding. Thus, the present study sought to investigate whether deficits in cognitive flexibility mediate the association between IU and defensive responding to safety among a sample of 71 adults diagnosed with PD. As hypothesised, cognitive flexibility mediated the relationship between IU and heightened startle potentiation during safety conditions. This finding suggests that within this subgroup, a failure to inhibit defensive responding during safety conditions may be due to deficits in cognitive flexibility.