Stronger reactivity to social gaze in virtual reality compared to a classical laboratory environment

Fear lies in the eyes of the beholder-Robust evidence for reduced gaze dispersion upon avoidable threat

A rapid detection and processing of relevant information in our environment is crucial for survival. The human eyes are drawn to social or threatening stimuli as they may carry essential information on how to behave appropriately in a given context. Recent studies further showed a centralization of gaze that reminded of freezing behaviors in rodents. Probably constituting a component of an adaptive defense mode, centralized eye movements predicted the speed of motor actions. Here we conducted two experiments to examine if and how these presumably survival-relevant gaze patterns interact. Subjects viewed images including social, that is, faces (Experiment 1, N = 50) or threatening stimuli, that is, snakes or spiders (Experiment 2, N = 50) while awaiting an inevitable (shock), no (safety), or an avoidable shock (flight) they could escape from by a fast button press. The social and threatening cues within the scenes differed in their distance from the image center and we acquired eye-tracking and autonomic physiological data. Although we observed an initial orienting toward social and threatening stimulus aspects, this exploration pattern vanished towards the end of flight trials when a pronounced centralization of gaze emerged. Replicating previous findings, the amount of this center bias predicted the speed of motor reactions, and we observed a concurrent activation of the sympathetic and parasympathetic nervous system. Taken together, the exploration of potentially relevant cues seems to be part of a reflexive-orienting response regardless of contextual valence. However, centralization of gaze may be a threat-specific action-preparatory response that occurs across a wide range of stimulus contexts.

VR for Studying the Neuroscience of Emotional Responses

Emotions are frequently considered as the driving force of behavior, and psychopathology is often characterized by aberrant emotional responding. Emotional states are reflected on a cognitive-verbal, physiological-humoral, and motor-behavioral level but to date, human research lacks an experimental protocol for a comprehensive and ecologically valid characterization of such emotional states. Virtual reality (VR) might help to overcome this situation by allowing researchers to study mental processes and behavior in highly controlled but reality-like laboratory settings. In this chapter, we first elucidate the role of presence and immersion as requirements for eliciting emotional states in a virtual environment and discuss different VR methods for emotion induction. We then consider the organization of emotional states on a valence continuum (i.e., from negative to positive) and on this basis discuss the use of VR to study threat processing and avoidance as well as reward processing and approach behavior. Although the potential of VR has not been fully realized in laboratory and clinical settings yet, this technological tool can open up new avenues to better understand the neurobiological mechanisms of emotional responding in healthy and pathological conditions.

Reality in a sphere: A direct comparison of social attention in the laboratory and the real world

Humans often show reduced social attention in real situations, a finding rarely replicated in controlled laboratory studies. Virtual reality is supposed to allow for ecologically valid and at the same time highly controlled experiments. This study aimed to provide initial insights into the reliability and validity of using spherical videos viewed via a head-mounted display (HMD) to assess social attention. We chose five public places in the city of Würzburg and measured eye movements of 44 participants for 30 s at each location twice: Once in a real environment with mobile eye-tracking glasses and once in a virtual environment playing a spherical video of the location in an HMD with an integrated eye tracker. As hypothesized, participants demonstrated reduced social attention with less exploration of passengers in the real environment as compared to the virtual one. This is in line with earlier studies showing social avoidance in interactive situations. Furthermore, we only observed consistent gaze proportions on passengers across locations in virtual environments. These findings highlight that the potential for social interactions and an adherence to social norms are essential modulators of viewing behavior in social situations and cannot be easily simulated in laboratory contexts. However, spherical videos might be helpful for supplementing the range of methods in social cognition research and other fields. Data and analysis scripts are available at https://osf.io/hktdu/ .

What's in a face: Automatic facial coding of untrained study participants compared to standardized inventories

Automatic facial coding (AFC) is a novel research tool to automatically analyze emotional facial expressions. AFC can classify emotional expressions with high accuracy in standardized picture inventories of intensively posed and prototypical expressions. However, classification of facial expressions of untrained study participants is more error prone. This discrepancy requires a direct comparison between these two sources of facial expressions. To this end, 70 untrained participants were asked to express joy, anger, surprise, sadness, disgust, and fear in a typical laboratory setting. Recorded videos were scored with a well-established AFC software (FaceReader, Noldus Information Technology). These were compared with AFC measures of standardized pictures from 70 trained actors (i.e., standardized inventories). We report the probability estimates of specific emotion categories and, in addition, Action Unit (AU) profiles for each emotion. Based on this, we used a novel machine learning approach to determine the relevant AUs for each emotion, separately for both datasets. First, misclassification was more frequent for some emotions of untrained participants. Second, AU intensities were generally lower in pictures of untrained participants compared to standardized pictures for all emotions. Third, although profiles of relevant AU overlapped substantially across the two data sets, there were also substantial differences in their AU profiles. This research provides evidence that the application of AFC is not limited to standardized facial expression inventories but can also be used to code facial expressions of untrained participants in a typical laboratory setting.

Selective visual attention during public speaking in an immersive context

It has recently become feasible to study selective visual attention to social cues in increasingly ecologically valid ways. In this secondary analysis, we examined gaze behavior in response to the actions of others in a social context. Participants (N = 84) were asked to give a 5-minute speech to a five-member audience that had been filmed in 360° video, displayed in a virtual reality headset containing a built-in eye tracker. Audience members were coached to make movements that would indicate interest or lack of interest (e.g., nodding vs. looking away). The goal of this paper was to analyze whether these actions influenced the speaker's gaze. We found that participants showed reliable evidence of gaze towards audience member actions in general, and towards audience member actions involving their phone specifically (compared with other actions like looking away or leaning back). However, there were no differences in gaze towards actions reflecting interest (like nodding) compared with actions reflecting lack of interest (like looking away). Participants were more likely to look away from audience member actions as well, but there were no specific actions that elicited looking away more or less. Taken together, these findings suggest that the actions of audience members are broadly influential in motivating gaze behaviors in a realistic, contextually embedded (public speaking) setting. Further research is needed to examine the ways in which these findings can be elucidated in more controlled laboratory environments as well as in the real world.

Correlates of interpersonal emotion regulation problems in Loss of Control eating (LOC) in youth: study protocol of the combined online and App based questionnaire, laboratory and randomized controlled online intervention i-BEAT trial

BACKGROUND

Binge Eating Disorder (BED) represents a common eating disorder associated with marked health impairments. A subclinical variant, loss of control eating (LOC) is prevalent in youth. LOC is associated with similar mental distress as full-blown BED, increases the risk to develop a BED and promotes continuous weight gain. The etiology of LOC is not yet fully understood and specialized treatment for youth is scarce.

METHODS

The i-BEAT study includes a cross-sectional and longitudinal online questionnaire study (N = 600), an App based daily-life approach and a laboratory virtual reality study in N = 60 youths (14-24 years) with and without LOC as well as a controlled randomized online treatment trial to investigate the feasibility, acceptance and efficacy of a CBT and an interpersonal emotion regulation module for youth (N = 120). The primary outcomes include self-reported as well as measured (heart rate variability, gaze behavior, reaction times in stop signal task) associations between emotion regulation problems (such as dealing with RS), psychological impairment and binge eating in a healthy control group and youth with LOC. Secondary outcomes encompass general eating disorder pathology, social anxiety, body mass index, hyperscanning behavior and therapists' rating of patients' condition pre and post treatment. Epigenetic correlates of RS are assessed in healthy controls and youth with LOC and explored before and after treatment.

DISCUSSION

The expected findings will specify the role of interpersonal emotion regulation problems such as coping with the experience of social exclusion and rejection sensitivity (RS) in LOC and clarify, whether including a training to cope with RS adds to the efficacy of a cognitive behavioral treatment (CBT).

TRIAL REGISTRATION

German Clinical Trial Register: DRKS00023706. Registered 27 November 2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023706.

Gaze behavior is associated with the cortisol response to acute psychosocial stress in the virtual TSST

BACKGROUND

The Trier Social Stress Test (TSST) is a reliable tool for psychobiological stress induction. Because of its socio-evaluative nature, it has been useful for investigating gaze behavior. It has been shown that healthy people avoid looking toward faces when under stress, a finding that corroborates studies demonstrating avoidance of eye contact in social anxiety disorder. Yet, little is known about the relationship between gaze behavior and the biological stress response.

METHODS

In a final sample of 74 healthy males, a virtual reality version of the Trier Social Stress Test (TSST-VR) with an integrated eye tracker was implemented to investigate gaze behavior during acute stress induction. Stress response measures were collected via saliva samples and subjective stress ratings. Additional questionnaires were administered for examining the influence of social anxiety traits.

RESULTS

The TSST-VR elicited a significant psychobiological stress response. Overall, higher gaze times on judges compared to surroundings were found in the speech task while this pattern was reversed in the arithmetic task. Critically, there was a significant negative association between gaze time on judges and cortisol output in cortisol responders.

CONCLUSIONS

In a non-clinical sample, avoidance of gaze is associated with a stronger cortisol response to acute stress. This study demonstrates the potential of eye tracking to disentangle the effects of acute stress on social interaction, warranting further investigation in clinical populations characterized by high levels of anxiety in social situations, such as social anxiety and autism spectrum disorder.

Reliability assessment of temporal discounting measures in virtual reality environments

In recent years the emergence of high-performance virtual reality (VR) technology has opened up new possibilities for the examination of context effects in psychological studies. The opportunity to create ecologically valid stimulation in a highly controlled lab environment is especially relevant for studies of psychiatric disorders, where it can be problematic to confront participants with certain stimuli in real life. However, before VR can be confidently applied widely it is important to establish that commonly used behavioral tasks generate reliable data within a VR surrounding. One field of research that could benefit greatly from VR-applications are studies assessing the reactivity to addiction related cues (cue-reactivity) in participants suffering from gambling disorder. Here we tested the reliability of a commonly used temporal discounting task in a novel VR set-up designed for the concurrent assessment of behavioral and psychophysiological cue-reactivity in gambling disorder. On 2 days, thirty-four healthy non-gambling participants explored two rich and navigable VR-environments (neutral: café vs. gambling-related: casino and sports-betting facility), while their electrodermal activity was measured using remote sensors. In addition, participants completed the temporal discounting task implemented in each VR environment. On a third day, participants performed the task in a standard lab testing context. We then used comprehensive computational modeling using both standard softmax and drift diffusion model (DDM) choice rules to assess the reliability of discounting model parameters assessed in VR. Test-retest reliability estimates were good to excellent for the discount rate log(k), whereas they were poor to moderate for additional DDM parameters. Differences in model parameters between standard lab testing and VR, reflecting reactivity to the different environments, were mostly numerically small and of inconclusive directionality. Finally, while exposure to VR generally increased tonic skin conductance, this effect was not modulated by the neutral versus gambling-related VR-environment. Taken together this proof-of-concept study in non-gambling participants demonstrates that temporal discounting measures obtained in VR are reliable, suggesting that VR is a promising tool for applications in computational psychiatry, including studies on cue-reactivity in addiction.