Emotional response in depersonalization: A systematic review of electrodermal activity studies

Using geotagged facial expressions to visualize and characterize different demographic groups' emotion in theme parks

Tourism is an emotional sphere, and researchers focus on emotions to optimize tourism experiences. Tourism studies on emotions mostly ignore differences in emotions across demographic tourist groups by gender and age, thus limiting the understanding of emotions to the explicit characteristics of tourists' emotions. On the basis of geotagged facial expressions on social media platforms, this study aims to visualize the emotions of groups in scenic spots and then reveal the variations between groups' emotions within theme parks. By employing a facial recognition algorithm, an emotion distribution graph was proposed to represent groups' emotions in detail. Some analytical methods were combined to characterize of the emotion distribution of each group. Through a comprehensive comparison, the results suggest that there are unique characteristics of emotion distribution for each group and considerable variations between them. This study helps researchers achieve a deeper understanding of tourists' emotional differences and enhances the theorization of emotions. This research also highlights the advantages and significant practical implications of our method framework.

Emotional arousal pattern (EMAP): A new database for modeling momentary subjective and psychophysiological responding to affective stimuli

This article describes a new database (named "EMAP") of 145 individuals' reactions to emotion-provoking film clips. It includes electroencephalographic and peripheral physiological data as well as moment-by-moment ratings for emotional arousal in addition to overall and categorical ratings. The resulting variation in continuous ratings reflects inter-individual variability in emotional responding. To make use of the moment-by-moment data for ratings as well as neurophysiological activity, we used a machine learning approach. The results show that algorithms that are based on temporal information improve predictions compared to algorithms without a temporal component, both within and across participant modeling. Although predicting moment-by-moment changes in emotional experiences by analyzing neurophysiological activity was more difficult than using aggregated experience ratings, selecting a subset of predictors improved the prediction. This also showed that not only single features, for example, skin conductance, but a range of neurophysiological parameters explain variation in subjective fluctuations of subjective experience.

Prediction of moment-by-moment heart rate and skin conductance changes in the context of varying emotional arousal

Autonomic nervous system (ANS) responses such as heart rate (HR) and galvanic skin responses (GSR) have been linked with cerebral activity in the context of emotion. Although much work has focused on the summative effect of emotions on ANS responses, their interaction in a continuously changing context is less clear. Here, we used a multimodal data set of human affective states, which includes electroencephalogram (EEG) and peripheral physiological signals of participants' moment-by-moment reactions to emotional provoking video clips and modeled HR and GSR changes using machine learning techniques, specifically, long short-term memory (LSTM), decision tree (DT), and linear regression (LR). We found that LSTM achieved a significantly lower error rate compared with DT and LR due to its inherent ability to handle sequential data. Importantly, the prediction error was significantly reduced for DT and LR when used together with particle swarm optimization to select relevant/important features for these algorithms. Unlike summative analysis, and contrary to expectations, we found a significantly lower error rate when the prediction was made across different participants than within a participant. Moreover, the predictive selected features suggest that the patterns predictive of HR and GSR were substantially different across electrode sites and frequency bands. Overall, these results indicate that specific patterns of cerebral activity track autonomic body responses. Although individual cerebral differences are important, they might not be the only factors influencing the moment-by-moment changes in ANS responses.

Differing associations of depersonalization with physiological response during rest and breath-focused mindfulness in a trauma-exposed female population

BACKGROUND

Dissociative and posttraumatic stress disorder (PTSD) symptoms are commonly co-occurring responses to psychological trauma. Yet, these two groups of symptoms appear to be related to diverging patterns of physiological response. To date, few studies have examined how specific dissociative symptoms, namely, depersonalization and derealization, relate to skin conductance response (SCR), a marker of autonomic function, within the context of PTSD symptoms. We examined associations among depersonalization, derealization, and SCR during two conditions - resting control and breath-focused mindfulness - in the context of current PTSD symptoms.

METHODS

Sixty-eight trauma-exposed women (82.4% Black; Mage = 42.5, SDage = 12.1) were recruited from the community for a breath-focused mindfulness study. SCR data were collected during alternating resting control and breath-focused mindfulness conditions. Moderation analyses were conducted to examine relations among dissociative symptoms, SCR, and PTSD for these different conditions.

RESULTS

Moderation analyses revealed that depersonalization was linked to lower SCR during resting control, B = 0.0005, SE = 0.0002, p = .006, in participants low-to-moderate PTSD symptoms; however, depersonalization was associated with higher SCR during breath-focused mindfulness, B = -0.0006, SE = 0.0003, p = .029, in individuals with similar levels of PTSD symptoms. No significant interaction between derealization and PTSD symptoms on SCR was observed.

CONCLUSIONS

Depersonalization symptoms may associate with physiological withdrawal during rest, but greater physiological arousal during effortful emotion regulation in individuals with low-to moderate levels of PTSD, which has significant implications for barriers to treatment engagement as well as treatment selection in this population.

Top-Down Influence Leads to a Reduced Sense of Body Ownership in Individuals With Depersonalization Tendencies: A Focus on Full Body Illusion

Sense of body ownership, that is, the feeling that "my body belongs to me," has been examined by both the rubber hand illusion (RHI) and full body illusion (FBI). In a study that examined the relationship between RHI and depersonalization, a symptom in which people experience a lower sense of body ownership, people with a high depersonalization tendency experienced RHI through the bottom-up process of visual-tactile integration. Why is it that people with depersonalization feel a lower sense of body ownership over their bodies? Case studies of depersonalization suggest that the top-down cognition in people with depersonalization may make them less likely to feel a sense of body ownership. However, the top-down influence on the sense of body ownership in depersonalization has not yet been experimentally demonstrated. By incorporating top-down manipulation (e.g., instructing participants to regard a fake body as their own) into the FBI procedure, we aimed to clarify the cause of the reduced sense of body ownership in people with a high depersonalization tendency. The FBI procedure was conducted in a virtual reality environment using an avatar as a fake body. The avatar was presented from a third-person perspective, and visual-tactile stimuli were presented to create an illusion. To examine the degree of illusion, we measured the skin conductance responses to the fear stimulus presented after the visual-tactile stimuli presentation. The degree of depersonalization was measured using the Japanese version of the Cambridge Depersonalization Scale. To manipulate the top-down influence, we provided self-association instructions before the presentation of the visual-tactile stimuli. We predicted that the higher the degree of depersonalization, the lower the degree of illusion in the self-association instruction. The results showed that participants with a higher depersonalization tendency had a lower degree of illusion (rho = -0.424, p = 0.035) in the self-association condition. This indicates that in people with a high depersonalization tendency, top-down cognition of the body as their own leads to a decrease in the sense of body ownership.

Mindfulness and Depersonalization: a Nuanced Relationship

Objectives

Although depersonalization has been described as the antithesis of mindfulness, few studies have empirically examined this relationship, and none have considered how it may differ across various facets of mindfulness, either alone or in interaction. The present study examined the relationship between symptoms of depersonalization and facets of dispositional mindfulness in a general population sample.

Methods

A total of 296 adult participants (139 male, 155 female, 2 other) were recruited online via Qualtrics and completed the Cambridge Depersonalisation Scale; Depression, Anxiety, and Stress Scale; and Five Facet Mindfulness Questionnaire.

Results

Controlling for general distress, depersonalization symptoms were positively associated with Observe, Describe, and Nonreactivity facets and negatively associated with Acting with Awareness and Nonjudgment facets. After controlling for intercorrelations among the facets, depersonalization symptoms remained significantly associated with higher Nonreactivity and lower Acting with Awareness. The overall positive relationship between depersonalization symptoms and the Observe facet was moderated by both Nonjudgment and Nonreactivity. Specifically, higher Observing was related to increased depersonalization symptoms at low levels of Nonjudgment and to decreased symptoms at low levels of Nonreactivity.

Conclusions

The current study provides novel insight into the relationship between depersonalization symptoms and various aspects of mindfulness. Experiences of depersonalization demonstrated divergent relationships with mindfulness facets, alone and in interaction. The results may inform theoretical models of depersonalization and mindfulness-based interventions for depersonalization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12671-022-01890-y.