Extinction in multiple virtual reality contexts diminishes fear reinstatement in humans

Increased Generalization, Stronger Acquisition, or Reduced Extinction? Investigation of the Mechanisms Underlying the Acquisition-in-Multiple-Contexts Effect

Prior research has demonstrated that conducting acquisition in multiple contexts results in more responding to the point that it can even nullify the benefit of subsequent extinction in multiple contexts on reducing renewal of excitatory responding. The underlying mechanism to explain why this happens has not been systematically examined. Using self-reported expectancy of the outcome, the current study investigates three mechanisms that potentially explain why acquisition in multiple contexts results in more responding-greater generalization, stronger acquisition learning, or slower extinction learning. Participants (N = 180) received discriminative training with a conditioned stimulus (CS+) and outcome pairing and a CS- → noOutcome pairing in either one or three contexts. This was followed by either extinction treatment in a novel context or no extinction. Finally, testing occurred in the acquisition context, the extinction context, or a novel context. Stronger renewal of extinguished conditioned expectation was observed for participants who received CS+ → Outcome pairings in three contexts relative to one context. There was no effect of the number of contexts on the strength of the excitatory CS+ → Outcome association or degree of inhibitory learning that occurred during extinction. This suggests that generalization is the mechanism responsible for the adverse impact to extinction learning when acquisition is conducted in multiple contexts.

Renewal in human fear conditioning: A systematic review and meta-analysis

Renewal is a 'return of fear' manipulation in human fear conditioning to investigate learning processes underlying anxiety and trauma. Even though renewal paradigms are widely used, no study has compared the strength of different renewal paradigms. We conduct a systematic review (N = 80) and meta-analysis (N = 23) of human fear conditioning studies assessing renewal. Our analysis shows that the classic ABA design is the most effective paradigm, compared to ABC and ABBA designs. We present evidence that conducting extinction in multiple contexts and increasing the similarity between acquisition and extinction contexts reduce renewal. Furthermore, we show that additional cues can be used as safety and 'protection from extinction' cues. The review shows that alcohol weakens the extinction process and that older adults appear less sensitive to context changes and thus show less renewal. The large variability in approaches to study renewal in humans suggests that standardisation of fear conditioning procedures across laboratories would be of great benefit to the field.

The Efficacy and Therapeutic Alliance of Augmented Reality Exposure Therapy in Treating Adults With Phobic Disorders: Systematic Review

BACKGROUND

Phobic disorders are characterized by excessive fear of a stimulus that can affect the quality of a patient's life. The lifetime prevalence in adults is 7.7% to 12.5%. The current literature provides evidence-based inferences about the effectiveness of in-vivo exposure therapy (IVET) in treating phobia. However, this method can put the therapist and the client in danger, with high drop out and refusal rates. A newer approach for exposure therapy using augmented reality technology is under assessment.

OBJECTIVE

This systematic review investigated the novel technology's efficacy, cost-efficacy, and therapeutic alliance in treating adults with phobia.

METHODS

An extensive search was conducted using 4 major databases (MEDLINE, PsycINFO, Embase, and Scopus) using a comprehensive list of synonyms for augmented reality exposure therapy (ARET) and phobic disorders. The search targeted any randomized control trial testing ARET in adults with phobic disorders up to August 8, 2022.

RESULTS

A total of 6 studies were included, with 208 participants providing results. Studies investigating the efficacy of ARET compared to no intervention showed significant results (P<.05) in the ARET group improvement. Head-to-head comparative studies comparing ARET to IVET showed no significant difference (P>.05) in the effectiveness and therapeutic alliance between both therapies. Further, the results demonstrated that the ARET group had a better long-term effect than IVET, with the ability to put the patients in more situations to face the feared object.

CONCLUSIONS

The current data suggest clinically significant efficacy and a promising therapeutic alliance of ARET. However, no data are available investigating the cost-effectiveness of ARET. Further research is warranted to ascertain ARET's cost-effectiveness and examine its efficacy in other populations and anxiety conditions.

Extinction in multiple contexts reduces the return of extinguished responses: A multilevel meta-analysis

Extinguished responses have been shown to reappear under several circumstances, and this reappearance is considered to model behaviors such as relapse after exposure therapy. Conducting extinction in multiple contexts has been explored as a technique to decrease the recovery of extinguished responses. The present meta-analysis aimed to examine whether extinction in multiple contexts can consistently reduce the recovery of extinguished responses. After searching in several databases, experiments were included in the analysis if they presented extinction in multiple contexts, an experimental design, and an adequate statistical report. Cohen's d was obtained for each critical comparison and weighted to obtain the sample's average weighted effect size. Analyses were then performed using a multilevel meta-analytic approach. Twenty-five studies were included, with a total sample of 37 experiments or critical comparisons. The analyses showed a large effect size for the sample, moderated by the length of conditioned stimulus exposure, type of experimental subject, and type of recovery. The robust effect of extinction in multiple contexts on relapse should encourage clinicians to consider extinction in multiple contexts as a useful technique in therapy and research.

A model for recovery-from-extinction effects in Pavlovian conditioning and exposure therapy

Exposure therapy is an effective intervention for anxiety-related problems. The mechanism of this intervention has been the extinction procedure in Pavlovian conditioning, and this application has provided many successful instances for the prevention of relapse. However, traditional associative theories cannot comprehensively explain many findings. In particular, it is difficult to explain the recovery-from-extinction effects, which is the reappearance of the conditioned response following extinction. In this paper, we propose an associative model that is a mathematical extension of Bouton's (1993, Psychological Bulletin, 114, 80-99) model for the extinction procedure. The core of our model is that the asymptotic strength of the inhibitory association depends on the degree of excitatory association retrieved in a context in which a conditioned stimulus (CS) is presented and that the retrieval is determined by the similarity between contexts during both reinforcement and non-reinforcement and the retrieval context. Our model provides an explanation of the recovery-from-extinction effects, and implications for exposure therapy.

Intolerance of uncertainty enhances generalisation of cued conditioned threat: An event-related potential study

Overgeneralisation is one of the aetiologies of anxiety disorders and is closely associated with elevated intolerance of uncertainty (IU) levels. However, the underlying mechanisms are unclear. Considering the inconsistency of previous results and the high sensitivity of IU to uncertainty, the present study investigated the effect of IU on threat generalisation in predictable and unpredictable conditions. We compared self-reported unconditioned stimuli (US) expectancy and event-related potentials (ERPs) during generalisation in high IU (n = 34) and low IU (n = 35) participants. The results indicated that high IU was associated with higher US expectancy for generalisation stimuli (GS) than with low IU. At the electrophysiological level, compared to low IU, high IU showed increased P1 to ambiguous GS as well as decreased early late positive potential (LPP) to GS in unpredictable conditions, and no differential response to GS in late LPP in predictable conditions. These findings suggest that IU enhances threat generalisation and may be related to increased early automatic attention to ambiguous stimulus and inadequate late elaborate processing in a high uncertainty context. These findings might contribute to the treatment of mood disorders characterized by high IU.

Improving the efficacy of exposure therapy using projection-based augmented reality for the treatment of cockroach phobia: a randomised clinical trial protocol

INTRODUCTION

In vivo exposure is the treatment of choice for specific phobia (SP), but this technique presents limitations related to access and acceptability. Augmented reality (AR) offers advantages like maximising strategies such as 'variability' (varying stimuli, durations, levels of intensity or the order of the items), control by the therapist, or 'exposure to multiple contexts', which can produce positive effects in terms of fear renewal and generalisation of the results. The aim of this study is to test the efficacy of varying the phobic stimuli during treatment with AR: using multiple stimuli (MS) versus a single stimulus (SS) in participants with SP.

METHODS AND ANALYSIS

Participants (N=80) with a diagnosis of an SP of cockroaches will be randomised into two conditions: (1) projection-based AR exposure therapy with MS (P-ARET MS); (2) P-ARET with an SS (P-ARET SS). The measures are related to the efficacy results (fear, avoidance and negative thoughts, performance on the behavioural avoidance test (BAT) and preferences). The primary outcome measure is the BAT, and the secondary outcome measures are the BAT through AR, Fear of Cockroaches Questionnaire, Cockroach Phobia Beliefs Questionnaire, Fear and Avoidance Scales Patient's Improvement Scale, and Beck Depression Inventory Second Edition. Five evaluation moments will be included: preintervention, postintervention, and 1-month, 6-month, and 12-month follow-ups. The treatment will follow the guidelines of the 'one-session treatment'. Student's t-tests to compare the two groups on the post-test will be applied. In addition, two-way analysis of variances with repeated measures in one of the two factors (pretest, post-test and follow-ups) will be carried out to compare intragroup differences.

ETHICS AND DISSEMINATION

The Universitat Jaume I Ethics Committee (Castellón, Spain) granted approval for the study (CD/64/2019). Dissemination will include publications and presentations at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT04563403.

VR for Cognition and Memory

This chapter will provide a review of research into human cognition through the lens of VR-based paradigms for studying memory. Emphasis is placed on why VR increases the ecological validity of memory research and the implications of such enhancements.

Neuroimaging of Fear Extinction

Extinguishing fear and defensive responses to environmental threats when they are no longer warranted is a critical learning ability that can promote healthy self-regulation and, ultimately, reduce susceptibility to or maintenance of affective-, trauma-, stressor-,and anxiety-related disorders. Neuroimaging tools provide an important means to uncover the neural mechanisms of effective extinction learning that, in turn, can abate the return of fear. Here I review the promises and pitfalls of functional neuroimaging as a method to investigate fear extinction circuitry in the healthy human brain. I discuss the extent to which neuroimaging has validated the core circuits implicated in rodent models and has expanded the scope of the brain regions implicated in extinction processes. Finally, I present new advances made possible by multivariate data analysis tools that yield more refined insights into the brain-behavior relationships involved.

Testing improves performance as well as assesses learning: A review of the testing effect with implications for models of learning

Taking a test of previously studied material has been shown to improve long-term subsequent test performance in a large variety of well controlled experiments with both human and nonhuman subjects. This phenomenon is called the testing effect. The promise that this benefit has for the field of education has biased research efforts to focus on applied instances of the testing effect relative to efforts to provide detailed accounts of the effect. Moreover, the phenomenon and its theoretical implications have gone largely unacknowledged in the basic associative learning literature, which historically and currently focuses primarily on the role of information processing at the time of acquisition while ignoring the role of processing at the time of testing. Learning is still widely considered to be something that happens during initial training, prior to testing, and tests are viewed as merely assessments of learning. However, the additional processing that occurs during testing has been shown to be relevant for future performance. The present review offers an introduction to the historical development, application, and modern issues regarding the role of testing as a learning opportunity (i.e., the testing effect). We conclude that the testing effect is seen to be sufficiently robust across tasks and parameters to serve as a compelling challenge for theories of learning to address. Our hope is that this review will inspire new research, particularly with nonhuman subjects, aimed at identifying the basic underlying mechanisms which are engaged during retrieval processes and will fuel new thinking about the learning-performance distinction. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A Case for Translation From the Clinic to the Laboratory

Laboratory procedures have been used for decades as analogues for clinical processes with the goal of improving our understanding of psychological treatments for emotional disorders and identifying strategies to make treatments more effective. This research has often focused on translation from the laboratory to the clinic. Although this approach has notable successes, it has not been seamless. There are many examples of strategies that work in the laboratory that fail to lead to improved outcomes when applied clinically. One possible reason for this gap between experimental and clinical research is a failure to focus on translation from the clinic to the laboratory. Here, we discuss potential benefits of translation from the clinic to the laboratory and provide examples of how this might be implemented. We first consider two well-established laboratory analogues (extinction and cognitive reappraisal), identify critical aspects of the related clinical procedures (exposure and cognitive restructuring) that are missing from these analogues, and propose variations to better capture the clinical process. Second, we discuss two clinical procedures that have more recently been brought into the laboratory (eye-movement desensitization and reprocessing and imagery rescripting). We conclude by highlighting potential implications of this proposed shift in focus for translational research.

Virtual Reality in the Neurosciences: Current Practice and Future Directions

Virtual reality has made numerous advancements in recent years and is used with increasing frequency for education, diversion, and distraction. Beginning several years ago as a device that produced an image with only a few pixels, virtual reality is now able to generate detailed, three-dimensional, and interactive images. Furthermore, these images can be used to provide quantitative data when acting as a simulator or a rehabilitation device. In this article, we aim to draw attention to these areas, as well as highlight the current settings in which virtual reality (VR) is being actively studied and implemented within the field of neurosurgery and the neurosciences. Additionally, we discuss the current limitations of the applications of virtual reality within various settings. This article includes areas in which virtual reality has been used in applications both inside and outside of the operating room, such as pain control, patient education and counseling, and rehabilitation. Virtual reality's utility in neurosurgery and the neurosciences is widely growing, and its use is quickly becoming an integral part of patient care, surgical training, operative planning, navigation, and rehabilitation.

Contextual modulation of conditioned responses in humans: A review on virtual reality studies

Conditioned response (CRs) triggered by stimuli predicting aversive consequences have been confirmed across various species including humans, and were found to be exaggerated in anxious individuals and anxiety disorder patients. Importantly, contextual information may strongly modulate such conditioned responses (CR), however, there are several methodological boundaries in the translation of animal findings to humans, and from healthy individuals to patients. Virtual Reality (VR) is a useful technological tool for overcoming such boundaries. In this review, we summarize and evaluate human VR conditioning studies exploring the role of the context as conditioned stimulus or occasion setter for CRs. We observe that VR allows successful acquisition of conditioned anxiety and conditioned fear in response to virtual contexts and virtual cues, respectively. VR studies also revealed that spatial or temporal contextual information determine whether conditioned anxiety and conditioned fear become extinguished and/or return. Novel contexts resembling the threatening context foster conditioned fear but not conditioned anxiety, suggesting distinct context-related generalization processes. We conclude VR contexts are able to strongly modulate CRs and therefore allow a comprehensive investigation of the modulatory role of the context over CR in humans leading to conclusions relevant for non-VR and clinical studies.

Post-traumatic growth as positive personality change: Challenges, opportunities, and recommendations

OBJECTIVE

Post-traumatic growth typically refers to enduring positive psychological change experienced as a result of adversity, trauma, or highly challenging life circumstances. Critics have challenged insights from much of the prior research on this topic, pinpointing its significant methodological limitations. In response to these critiques, we propose that post-traumatic growth can be more accurately captured in terms of personality change-an approach that affords a more rigorous examination of the phenomenon.

METHOD

We outline a set of conceptual and methodological questions and considerations for future work on the topic of post-traumatic growth.

RESULTS

We provide a series of recommendations for researchers from across the disciplines of clinical/counseling, developmental, health, personality, and social psychology and beyond, who are interested in improving the quality of research examining resilience and growth in the context of adversity.

CONCLUSION

We are hopeful that these recommendations will pave the way for a more accurate understanding of the ubiquity, durability, and causal processes underlying post-traumatic growth.

Context-dependent memory effects in two immersive virtual reality environments: On Mars and underwater

The context-dependent memory effect, in which memory for an item is better when the retrieval context matches the original learning context, has proved to be difficult to reproduce in a laboratory setting. In an effort to identify a set of features that generate a robust context-dependent memory effect, we developed a paradigm in virtual reality using two semantically distinct virtual contexts: underwater and Mars environments, each with a separate body of knowledge (schema) associated with it. We show that items are better recalled when retrieved in the same context as the study context; we also show that the size of the effect is larger for items deemed context-relevant at encoding, suggesting that context-dependent memory effects may depend on items being integrated into an active schema.

Generalization of conditioned fear along a dimension of increasing positive valence

The amount of fear evoked by potential threats is oftentimes proportional to the overlap in shared features with known threats. An adaptive learning system should therefore extract relevant features from threat stimuli to successfully detect other novel threats in the environment. But what if the most relevant feature of a threat stimulus is emotionally positive? Here, we used Pavlovian fear conditioning to ask whether people extract positive emotional features of a fear conditioned stimulus (CS) to selectively generalize to other stimuli that contain positive features. In a between subjects design, we first paired a picture of a face expressing either a slight amount of happiness or fear with an electrical shock to the wrist. We then tested fear generalization to modified face stimuli of the same identity expressing more or less happiness or fear. Both groups exhibited biased physiological arousal (a peak shift) to a face stimulus with the most exaggerated emotional expression, regardless of valence. Fear generalization diminished to unreinforced happy faces over the course of testing, whereas arousal was maintained to unreinforced fearful faces throughout testing. Finally, subjects fear conditioned to a slightly happy face were accurate at retrospectively identifying the correct CS, whereas subjects fear conditioned to a fearful face retrospectively misidentified a more fearful face as the threat CS. These findings suggest that positive emotional features extracted from a known threat can guide biased fear generalization, but that generalization is maintained by a dimension of increasing fear which also produces retrospective biases in threat intensity estimation.

Neural Pattern Similarity Unveils the Integration of Social Information and Aversive Learning

Attributing intentions to others' actions is important for learning to avoid their potentially harmful consequences. Here, we used functional magnetic resonance imaging multivariate pattern analysis to investigate how the brain integrates information about others' intentions with the aversive outcome of their actions. In an interactive aversive learning task, participants (n = 33) were scanned while watching two alleged coparticipants (confederates)-one making choices intentionally and the other unintentionally-leading to aversive (a mild shock) or safe (no shock) outcomes to the participant. We assessed the trial-by-trial changes in participants' neural activation patterns related to observing the coparticipants and experiencing the outcome of their choices. Participants reported a higher number of shocks, more discomfort, and more anger to shocks given by the intentional player. Intentionality enhanced responses to aversive actions in the insula, anterior cingulate cortex, inferior frontal gyrus, dorsal medial prefrontal cortex, and the anterior superior temporal sulcus. Our findings indicate that neural pattern similarities index the integration of social and threat information across the cortex.

Behavioral and neural processes in counterconditioning: Past and future directions

Counterconditioning refers both to the technique and putative process by which behavior is modified through a new association with a stimulus of an opposite valence. Similar to extinction, counterconditioning is considered a form of inhibition that interferes with the expression of the originally learned response without erasing it. But whereas interest in extinction continues to rise, counterconditioning has received far less attention. Here, we provide an in-depth review of counterconditioning research and detail whether counterconditioning is any more effective than extinction at preventing relapse of the originally learned behavior. We consider the clinical implications of counterconditioning, describe recent neurobiological and neuroimaging research in this area, and consider future avenues in need of further investigation.

Multiple extinction contexts modulate the neural correlates of context-dependent extinction learning and retrieval

Exposure therapy is a successful treatment for patients with anxiety and fear-related disorders. Extinction of conditioned fear comprises one important mechanism underlying the effects of exposure therapy. Yet, relapses frequently occur in the long-term, probably related to difficulties in generalizing the extinction of conditioned fear to new contexts, leading to renewal of conditioned fear. Extinction training in multiple extinction contexts depicts a promising opportunity to reduce this renewal of conditioned fear. However, the underlying neural correlates are unknown yet. In this functional magnetic resonance imaging study, 49 healthy men participated in a fear conditioning paradigm with fear acquisition training in context A on a first day, extinction training in a single context (B1) or in four different contexts (B1-B4) one day later, and fear and extinction recall and reinstatement in context B1 and a novel context C on a third day one week later. Multiple extinction contexts led to a stronger differential activation decrease in the hippocampus during extinction learning compared to a single extinction context. One week later, the multiple context group compared with the single context group showed reduced differential amygdala activation during fear renewal in the novel context C compared with the extinction context B1. Furthermore, multiple extinction contexts diminished amygdala activation during a subsequent reinstatement test in context B1. However, there were no significant differences in differential conditioned SCRs. These results indicate that the use of multiple extinction contexts during extinction training leads to reduced conditioned responses in the amygdala-hippocampus complex.

The role of hippocampal spatial representations in contextualization and generalization of fear

Using contextual information to predict aversive events is a critical ability that protects from generalizing fear responses to safe contexts. Animal models have demonstrated the importance of spatial context representations within the hippocampal formation in contextualization of fear learning. The ventromedial prefrontal cortex (vmPFC) is known to play an important role in safety learning, possibly also through the incorporation of context information. However, if contextual representations are related to context-dependent expression of fear memory in humans remains unclear. Twenty-one healthy participants underwent functional MRI combined with a cue-context conditioning paradigm within a self-navigated virtual reality environment. The environment included two buildings (Threat and Safe context), which had distinct features outside but were identical inside. Within each context, participants saw two cues (CS+, CS-). The CS+ was consistently (100% reinforcement rate) paired with an electric shock in the Threat context, but never in the Safe context. The CS- was never paired with a shock. We found robust differential skin conductance responses (SCRs; CS+ ​> ​CS-) in the Threat context, but also within the Safe context, indicating fear generalization. Within the Safe context, vmPFC responses to the CS+ were larger than those in the Threat context. We furthermore found environment-specific representations for the two contexts in the training paradigm (i.e., before conditioning took place) in the hippocampus to be related to fear expression and generalization. Namely, participants with a weak context representation (z-score < 1.65) showed stronger fear generalization compared to participants with a strong context representation (z-score > 1.65). Thus, a weak neural representation strength of spatial context may explain overgeneralization of memory to safe contexts. In addition, our findings demonstrate that context-dependent regulation of fear expression engages ventromedial prefrontal pathways suggesting this involves a similar mechanism that is known to be involved in retrieval of extinction memory.

From Extinction Learning to Anxiety Treatment: Mind the Gap

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

Diminishing fear: Optogenetic approach toward understanding neural circuits of fear control

Understanding complex behavioral processes, both learned and innate, requires detailed characterization of the principles governing signal flow in corresponding neural circuits. Previous studies were hampered by the lack of appropriate tools needed to address the complexities of behavior-driving micro- and macrocircuits. The development and implementation of optogenetic methodologies revolutionized the field of behavioral neuroscience, allowing precise spatiotemporal control of specific, genetically defined neuronal populations and their functional connectivity both in vivo and ex vivo, thus providing unprecedented insights into the cellular and network-level mechanisms contributing to behavior. Here, we review recent pioneering advances in behavioral studies with optogenetic tools, focusing on mechanisms of fear-related behavioral processes with an emphasis on approaches which could be used to suppress fear when it is pathologically expressed. We also discuss limitations of these methodologies as well as review new technological developments which could be used in future mechanistic studies of fear behavior.

The Impact of Alcohol and Social Context on the Startle Eyeblink Reflex

BACKGROUND

Researchers have long sought to understand how individuals respond to alcohol in social settings with the aim of elucidating pathways of risk for alcohol use disorder (AUD). But studies that incorporate a social context are still outnumbered by those that examine alcohol's subjective effects among participants drinking alcohol in isolation. Further, perhaps due to the challenges of capturing automatic affective processes in these settings, prior studies of alcohol response in social context have relied mainly on self-report measures, and so relatively little is known about alcohol's psychophysiological effects in social settings.

METHODS

Using a novel paradigm that integrated alcohol-administration procedures, startle methodology, and social context, this study examined the impact of alcohol and social context on startle eyeblink reflex among 40 social drinkers.

RESULTS

Results indicated that there was a significant effect of group presence, indicating that startle magnitude was larger when people were alone than with others. There was a significant group presence-by-alcoholic beverage interaction, with the effect of alcohol being significantly larger when people were alone versus with others. These effects were found both for the startle habituation data and during the picture-viewing task.

CONCLUSIONS

Results of this study highlight the importance of considering the presence of other individuals for understanding alcohol response and mechanisms of AUD risk. Findings are discussed in light of both emotional and cognitive correlates of startle reflex magnitude. Future research should examine these effects within larger samples of participants and further explore mechanisms that might underlie these effects.

Specific phobias

Anxiety disorders are among the most prevalent mental disorders, but the subcategory of specific phobias has not been well studied. Phobias involve both fear and avoidance. For people who have specific phobias, avoidance can reduce the constancy and severity of distress and impairment. However, these phobias are important because of their early onset and strong persistence over time. Studies indicate that the lifetime prevalence of specific phobias around the world ranges from 3% to 15%, with fears and phobias concerning heights and animals being the most common. The developmental course of phobias, which progress from fear to avoidance and then to diagnosis, suggests the possibility that interrupting the course of phobias could reduce their prevalence. Although specific phobias often begin in childhood, their incidence peaks during midlife and old age. Phobias persist for several years or even decades in 10-30% of cases, and are strongly predictive of onset of other anxiety, mood, and substance-use disorders. Their high comorbidity with other mental disorders, especially after onset of the phobia, suggests that early treatment of phobias could also alter the risk of other disorders. Exposure therapy remains the treatment of choice, although this approach might be less effective in the long term than previously believed. This Review discusses the literature regarding the prevalence, incidence, course, risk factors, and treatment of specific phobias, and presents epidemiological data from several population-based surveys.

Enhancing the Ecological Validity of fMRI Memory Research Using Virtual Reality

Functional magnetic resonance imaging (fMRI) is a powerful research tool to understand the neural underpinnings of human memory. However, as memory is known to be context-dependent, differences in contexts between naturalistic settings and the MRI scanner environment may potentially confound neuroimaging findings. Virtual reality (VR) provides a unique opportunity to mitigate this issue by allowing memories to be formed and/or retrieved within immersive, navigable, visuospatial contexts. This can enhance the ecological validity of task paradigms, while still ensuring that researchers maintain experimental control over critical aspects of the learning and testing experience. This mini-review surveys the growing body of fMRI studies that have incorporated VR to address critical questions about human memory. These studies have adopted a variety of approaches, including presenting research participants with VR experiences in the scanner, asking participants to retrieve information that they had previously acquired in a VR environment, or identifying neural correlates of behavioral metrics obtained through VR-based tasks performed outside the scanner. Although most such studies to date have focused on spatial or navigational memory, we also discuss the promise of VR in aiding other areas of memory research and facilitating research into clinical disorders.

Anxiety: Here and Beyond

The future harbours the potential for myriad threats to the fitness of organisms, and many species prepare accordingly based on indicators of hazards. Here, we distinguish between defensive responses on the basis of sensed cues and those based on autocues generated by mental simulations of the future in humans. Whereas sensed threat cues usually induce specific responses with reference to particular features of the environment or generalized responses to protect against diffuse threats, autocues generated by mental simulations of the future enable strategic preparation for hazards that may not require an immediate response. The overlap of these mechanisms makes defence effective and versatile, yet can manifest as contemporary anxiety disorders in humans.

Core Mechanisms of Cognitive Behavioral Therapy for Anxiety and Depression: A Review

This article reviews the extant literature on mediators of change in cognitive behavioral therapy (CBT) for anxiety and depression. The authors briefly discuss the efficacy of CBT for anxiety and depression and methods of mediation analysis and detection. Then the authors discuss fear extinction in anxiety treatment and cognitive change in depression treatment.

Social Fear Conditioning Paradigm in Virtual Reality: Social vs. Electrical Aversive Conditioning

In a previous study we could show that social fear can be induced and extinguished using virtual reality (VR). In the present study, we aimed to investigate the belongingness effect in an operant social fear conditioning (SFC) paradigm which consisted of an acquisition and an extinction phase. Forty-three participants used a joystick to approach different virtual male agents that served as conditioned stimuli. Participants were randomly allocated to one of two experimental conditions. In the electroshock condition, the unconditioned stimulus (US) used during acquisition was an electric stimulation. In the social threat condition, the US consisted of an offense: a spit in the face, mimicked by a sound and a weak air blast to the participant's neck combined with an insult. In both groups the US was presented when participants were close to the agent (75% contingency for CS+). Outcome variables included subjective, psychophysiological and behavioral data. As expected, fear and contingency ratings increased significantly during acquisition and the differentiation between CS+ and CS- vanished during extinction. Furthermore, a clear difference in skin conductance between CS+ and CS- at the beginning of the acquisition indicated that SFC had been successful. However, a fast habituation to the US was found toward the end of the acquisition phase for the physiological response. Furthermore, participants showed avoidance behavior toward CS+ in both conditions. The results show that social fear can successfully be induced and extinguished in VR in a human sample. Thus, our paradigm can help to gain insight into learning and unlearning of social fear. Regarding the belongingness effect, the social threat condition benefits from a better differentiation between the aversive and the non-aversive stimuli. As next step we suggest comparing social-phobic patients to healthy controls in order to investigate possible differences in discrimination learning and to foster the development of more efficient treatments for social phobia.

Context conditioning in humans using commercially available immersive Virtual Reality

Despite a wealth of knowledge on how humans and nonhuman animals learn to associate meaningful events with cues in the environment, far less is known about how humans learn to associate these events with the environment itself. Progress on understanding spatiotemporal contextual processes in humans has been slow in large measure by the methodological constraint of generating and manipulating immersive spatial environments in well-controlled laboratory settings. Fortunately, immersive Virtual Reality (iVR) technology has improved appreciably and affords a relatively straightforward methodology to investigate the role of context on learning, memory, and emotion while maintaining experimental control. Here, we review context conditioning literature in humans and describe challenges to study contextual learning in humans. We then provide details for a novel context threat (fear) conditioning paradigm in humans using a commercially available VR headset and a cross-platform game engine. This paradigm resulted in the acquisition of subjective threat, threat-conditioned defensive responses, and explicit threat memory. We make the paradigm publicly available and describe obstacles and solutions to optimize future studies of context conditioning using iVR. As computer technology advances to replicate the sensation of realistic environments, there are increasing opportunities to bridge the translational gap between rodent and human research on how context modulates cognition, which may ultimately lead to more optimal treatment strategies for anxiety- and stress-related disorders.

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.

Recent developments in the behavioural and pharmacological enhancement of extinction of drug seeking

One of the principal barriers to overcoming addiction is the propensity to relapse, even after months or years of abstinence. Relapse can be precipitated by cues and contexts associated with drug use; thus, decreasing the conditioned properties of these cues and contexts may assist in preventing relapse. The predictive power of drug cues and contexts can be reduced by repeatedly presenting them in the absence of the drug reinforcer, a process known as extinction. The potential of extinction to limit relapse has generated considerable interest and research over the past few decades. While pre-clinical animal models suggest extinction learning assists relapse prevention, treatment efficacy is often lacking when extinction learning principles are translated into clinical trials. Conklin and Tiffany (Addiction, 2002) suggest the lack of efficacy in clinical practice may be due to limited translation of procedures demonstrated through animal research and propose several methodological improvements to enhance extinction learning for drug addiction. This review will examine recent advances in the behavioural and pharmacological manipulation of extinction learning, based on research from pre-clinical models. In addition, the translation of pre-clinical findings-both those suggested by Conklin and Tiffany () and novel demonstrations from the past 13 years-into clinical trials and the efficacy of these methods in reducing craving and relapse, where available, will be discussed. Finally, we highlight areas where promising pre-clinical models have not yet been integrated into current clinical practice but, if applied, could improve upon existing behavioural and pharmacological methods.

Circuit dysregulation and circuit-based treatments in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that develops in some individuals in the aftermath of exposure to traumatic events, such as actual or threatened death, serious injury or sexual assault. It has been hypothesized that dysregulations in a number of specific neurocircuits, characterized by heightened responsivity of amygdala, dACC and insula, diminished responsivity of mPFC, impaired hippocampal function and deficits in cortical regions, underlie the development and expression of key PTSD symptoms. Here, we concisely describe three functional neural circuits implicated in PTSD pathophysiology and briefly review selected treatment strategies in the context of these neural circuits. We start with the commonly implicated neurocircuit model, namely, the fear learning and threat detection circuits, and then discuss the context processing circuitry, which plays an important role among others, in fear regulation. We then discuss the emotion regulation circuitry, which can further contribute to PTSD pathophysiology, and conclude with a discussion of the therapeutic approaches that might be targeting dysregulation in these circuits in PTSD patients. Specifically, we discuss how exposure-based treatments might be targeting fear learning circuits, and the pharmacological and brain-stimulation interventions aimed to augment these therapies. Finally, we discuss other pharmacological and cognitive therapeutic approaches that can augment or restore the function of the context processing and emotional regulation circuits.

In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial

Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31) versus an Augmented Reality system (N = 32) in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

Single-session gamified virtual reality exposure therapy for spider phobia vs. traditional exposure therapy: study protocol for a randomized controlled non-inferiority trial

BACKGROUND

Traditional one-session exposure therapy (OST) in which a patient is gradually exposed to feared stimuli for up to 3 h in a one-session format has been found effective for the treatment of specific phobias. However, many individuals with specific phobia are reluctant to seek help, and access to care is lacking due to logistic challenges of accessing, collecting, storing, and/or maintaining stimuli. Virtual reality (VR) exposure therapy may improve upon existing techniques by facilitating access, decreasing cost, and increasing acceptability and effectiveness. The aim of this study is to compare traditional OST with in vivo spiders and a human therapist with a newly developed single-session gamified VR exposure therapy application with modern VR hardware, virtual spiders, and a virtual therapist.

METHODS/DESIGN

Participants with specific phobia to spiders (N = 100) will be recruited from the general public, screened, and randomized to either VR exposure therapy (n = 50) or traditional OST (n = 50). A behavioral approach test using in vivo spiders will serve as the primary outcome measure. Secondary outcome measures will include spider phobia questionnaires and self-reported anxiety, depression, and quality of life. Outcomes will be assessed using a non-inferiority design at baseline and at 1, 12, and 52 weeks after treatment.

DISCUSSION

VR exposure therapy has previously been evaluated as a treatment for specific phobias, but there has been a lack of high-quality randomized controlled trials. A new generation of modern, consumer-ready VR devices is being released that are advancing existing technology and have the potential to improve clinical availability and treatment effectiveness. The VR medium is also particularly suitable for taking advantage of recent phobia treatment research emphasizing engagement and new learning, as opposed to physiological habituation. This study compares a market-ready, gamified VR spider phobia exposure application, delivered using consumer VR hardware, with the current gold standard treatment. Implications are discussed.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02533310. Registered on 25 August 2015.

Rethinking Extinction

Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavioral technique, and consider whether traditional understandings warrant a re-examination. We discuss the neurobiology, cognitive factors, and major computational theories, and revisit the predominant view that extinction results in new learning that interferes with expression of the original memory. Additionally, we reconsider the limitations of extinction as a technique to prevent the relapse of maladaptive behavior and discuss novel approaches, informed by contemporary theoretical advances, that augment traditional extinction methods to target and potentially alter maladaptive memories.

The key role of extinction learning in anxiety disorders: behavioral strategies to enhance exposure-based treatments

PURPOSE OF REVIEW

Extinction learning is a major mechanism for fear reduction by means of exposure. Current research targets innovative strategies to enhance fear extinction and thereby optimize exposure-based treatments for anxiety disorders. This selective review updates novel behavioral strategies that may provide cutting-edge clinical implications.

RECENT FINDINGS

Recent studies provide further support for two types of enhancement strategies. Procedural enhancement strategies implemented during extinction training translate to how exposure exercises may be conducted to optimize fear extinction. These strategies mostly focus on a maximized violation of dysfunctional threat expectancies and on reducing context and stimulus specificity of extinction learning. Flanking enhancement strategies target periods before and after extinction training and inform optimal preparation and post-processing of exposure exercises. These flanking strategies focus on the enhancement of learning in general, memory (re-)consolidation, and memory retrieval.

SUMMARY

Behavioral strategies to enhance fear extinction may provide powerful clinical applications to further maximize the efficacy of exposure-based interventions. However, future replications, mechanistic examinations, and translational studies are warranted to verify long-term effects and naturalistic utility. Future directions also comprise the interplay of optimized fear extinction with (avoidance) behavior and motivational antecedents of exposure.

Transforming Experience: The Potential of Augmented Reality and Virtual Reality for Enhancing Personal and Clinical Change

During life, many personal changes occur. These include changing house, school, work, and even friends and partners. However, the daily experience shows clearly that, in some situations, subjects are unable to change even if they want to. The recent advances in psychology and neuroscience are now providing a better view of personal change, the change affecting our assumptive world: (a) the focus of personal change is reducing the distance between self and reality (conflict); (b) this reduction is achieved through (1) an intense focus on the particular experience creating the conflict or (2) an internal or external reorganization of this experience; (c) personal change requires a progression through a series of different stages that however happen in discontinuous and non-linear ways; and (d) clinical psychology is often used to facilitate personal change when subjects are unable to move forward. Starting from these premises, the aim of this paper is to review the potential of virtuality for enhancing the processes of personal and clinical change. First, the paper focuses on the two leading virtual technologies - augmented reality (AR) and virtual reality (VR) - exploring their current uses in behavioral health and the outcomes of the 28 available systematic reviews and meta-analyses. Then the paper discusses the added value provided by VR and AR in transforming our external experience by focusing on the high level of personal efficacy and self-reflectiveness generated by their sense of presence and emotional engagement. Finally, it outlines the potential future use of virtuality for transforming our inner experience by structuring, altering, and/or replacing our bodily self-consciousness. The final outcome may be a new generation of transformative experiences that provide knowledge that is epistemically inaccessible to the individual until he or she has that experience, while at the same time transforming the individual's worldview.

Contextual Change After Fear Acquisition Affects Conditioned Responding and the Time Course of Extinction Learning-Implications for Renewal Research

Context plays a central role in retrieving (fear) memories. Accordingly, context manipulations are inherent to most return of fear (ROF) paradigms (in particular renewal), involving contextual changes after fear extinction. Context changes are, however, also often embedded during earlier stages of ROF experiments such as context changes between fear acquisition and extinction (e.g., in ABC and ABA renewal). Previous studies using these paradigms have however focused exclusively on the context switch after extinction (i.e., renewal). Thus, the possibility of a general effect of context switch on conditioned responding that may not be conditional to preceding extinction learning remains unstudied. Hence, the current study investigated the impact of a context switch between fear acquisition and extinction on immediate conditioned responding and on the time-course of extinction learning by using a multimodal approach. A group that underwent contextual change after fear conditioning (AB; n = 36) was compared with a group without a contextual change from acquisition to extinction (AA; n = 149), while measuring physiological (skin conductance and fear potentiated startle) measures and subjective fear ratings. Contextual change between fear acquisition and extinction had a pronounced effect on both immediate conditioned responding and on the time course of extinction learning in skin conductance responses and subjective fear ratings. This may have important implications for the mechanisms underlying and the interpretation of the renewal effect (i.e., contextual switch after extinction). Consequently, future studies should incorporate designs and statistical tests that disentangle general effects of contextual change from genuine ROF effects.