Cognitive Processing and Regulation Modulates Analogue Trauma Symptoms in a Virtual Reality Paradigm

Intranasal oxytocin administration impacts the acquisition and consolidation of trauma-associated memories: a double-blind randomized placebo-controlled experimental study in healthy women

Intrusive memories are a hallmark symptom of post-traumatic stress disorder (PTSD) and oxytocin has been implicated in the formation of intrusive memories. This study investigates how oxytocin influences the acquisition and consolidation of trauma-associated memories and whether these effects are influenced by individual neurobiological and genetic differences. In this randomized, double-blind, placebo-controlled study, 220 healthy women received either a single dose of intranasal 24IU oxytocin or a placebo before exposure to a trauma film paradigm that solicits intrusive memories. We used a "general random forest" machine learning approach to examine whether differences in the noradrenergic and hypothalamic-pituitary-adrenal axis activity, polygenic risk for psychiatric disorders, and genetic polymorphism of the oxytocin receptor influence the effect of oxytocin on the acquisition and consolidation of intrusive memories. Oxytocin induced significantly more intrusive memories than placebo did (t(188.33) = 2.12, p = 0.035, Cohen's d = 0.30, 95% CI 0.16-0.44). As hypothesized, we found that the effect of oxytocin on intrusive memories was influenced by biological covariates, such as salivary cortisol, heart rate variability, and PTSD polygenic risk scores. The five factors that were most relevant to the oxytocin effect on intrusive memories were included in a Poisson regression, which showed that, besides oxytocin administration, higher polygenic loadings for PTSD and major depressive disorder were directly associated with a higher number of reported intrusions after exposure to the trauma film stressor. These results suggest that intranasal oxytocin amplifies the acquisition and consolidation of intrusive memories and that this effect is modulated by neurobiological and genetic factors. Trial registration: NCT03031405.

Where is emotional feeling felt in the body? An integrative review

Contemporary research on "embodied emotion" emphasizes the role of the body in emotional feeling. The evidence base on interoception, arguably the most prominent strand of embodied emotion research, places emphasis on the cardiac, respiratory and gastrointestinal systems. In turn, interoception has evidence-based links with improved emotion regulation. Despite the focus on separate bodily systems, it is unclear whether particular interoceptive locations play a greater role in emotional feeling and emotion regulation. Further, according to Gross' "process model", the sooner that regulation of an emotion occurs, the better; hence, it is additionally important to identify the first body areas to activate. These issues are investigated in a two-stage integrative review. The first stage was preliminary, giving an overview of the evidence base to highlight the distribution of measured body areas. This indicated that 86% of publications (n = 88) measured cardiac activity, 26% measured the respiratory system, and six percent the gastrointestinal system. Given the emphasis placed on all three systems in interoception theory and research on emotion, this suggests a dearth of comprehensive findings pertaining to feeling locations. The second stage investigated the core issues of where emotional feelings are felt in the body and time-related implications for regulation. This was based on ten texts, which together suggested that the head, throat and chest are the most consistently detected locations across and within numerous emotional contexts. Caution is required, however, since-among other reasons discussed-measurement was not time-restricted in these latter publications, and direct physiological measurement was found in only a minority of cases.

Addressing virtual reality misclassification: A hardware-based qualification matrix for virtual reality technology

Through its unique sensory synchronized design, virtual reality (VR) provides a convincing, user-centred experience of highly controllable scenarios. Importantly, VR is a promising modality for healthcare, where treatment efficacy has been recognized for a range of conditions. It is equally valuable across wider research disciplines. However, there is a lack of suitable criteria and consistent terminology with which to define VR technology. A considerable number of studies have misclassified VR hardware (e.g. defining laptops as VR), hindering validity and research comparisons. This review addresses these limitations and establishes a standardized VR qualification framework. As a result of a comprehensive theoretical and literature review, the hardware-based VR qualification matrix is proposed. The matrix criteria consist of (1) three-dimensional (3D) synchronized sensory stimulation; (2) degrees of freedom tracking; and (3) visual suppression of physical stimuli. To validate the model and quantify the current scale/diversity of VR misclassification, a 2019 sectional review of health-related studies was conducted. Of the 115 studies examined against standardized criteria, 35.7% utilized VR, 31.3% misclassified VR, 18.3% were considered quasi-VR, and 14.8% omitted critical specifications. The proposed model demonstrates good validity and reliability for qualifying and classifying VR. Key Practitioner Messages Virtual reality (VR) therapy has gained rapid empirical support, although many practitioners do not understand the difference between genuine and less-realistic VR variations. That has resulted from an evident lack of suitable criteria to define VR across a range of studies and protocols. Our proposed hardware-based virtual reality qualification matrix addresses issues to do with misclassification, via the introduction of standardised criteria. Applying the matrix to existing literature has revealed that more than 30% of VR studies use hardware that does not fit the high standards of rigour required for immersion in a simulated space. The model is a practical tool researchers and practitioners can use to quality and verify VR standards across research studies.

The effect of attachment security priming and oxytocin on physiological responses to trauma films and subsequent intrusions

To further understand protective mechanisms to prevent post-traumatic stress disorder or assist recovery from psychological trauma, this study investigated whether pharmacological and psychological activation of a secure attachment representation elicits higher felt-security and a related response pattern of reduced physiological arousal and increased parasympathetic activation; and whether it protects individuals from developing intrusions and experiencing distress in the week following exposure to a trauma film. Using a double-blind, experimental mixed factorial design, 101 volunteers received either oxytocin or placebo and either secure attachment or neutral priming before watching a trauma film. We measured felt security as an indicator of the strength of activation of a secure attachment representation, skin conductance and heart rate as indicators of physiological arousal, and high frequency heart rate variability as an indicator of parasympathetic activation during the priming and the film. Participants then completed a seven-day intrusion diary. Secure attachment priming, but not oxytocin administration or the combination of both, was associated with reduced physiological arousal and increased parasympathetic activity during priming. Although secure attachment priming was not related to the absolute number of intrusions or to less perceived distress or physiological arousal during the trauma film, it was associated with lower intrusion-related distress in the 7-days post-testing. Our findings extend previous research that suggests the importance of interventions that address intrusion-related distress for recovery from trauma, and suggest a promising role for secure attachment priming in trauma-focused psychological therapies. We contribute to the growing literature that finds that higher subjective distress during a trauma is associated with higher intrusion-related distress. We discuss theoretical implications and possible mechanisms through which secure attachment priming may exert potential beneficial effects.

Emotion Recognition in Immersive Virtual Reality: From Statistics to Affective Computing

Emotions play a critical role in our daily lives, so the understanding and recognition of emotional responses is crucial for human research. Affective computing research has mostly used non-immersive two-dimensional (2D) images or videos to elicit emotional states. However, immersive virtual reality, which allows researchers to simulate environments in controlled laboratory conditions with high levels of sense of presence and interactivity, is becoming more popular in emotion research. Moreover, its synergy with implicit measurements and machine-learning techniques has the potential to impact transversely in many research areas, opening new opportunities for the scientific community. This paper presents a systematic review of the emotion recognition research undertaken with physiological and behavioural measures using head-mounted displays as elicitation devices. The results highlight the evolution of the field, give a clear perspective using aggregated analysis, reveal the current open issues and provide guidelines for future research.