You look stressed: A pilot study on facial action unit activity in the context of psychosocial stress.

Quality and quantity of the human stress response are highly individual. Not only are there differences in terms of psychological and physiological stress reactivity, but also with regard to facial muscle stress reactivity. In a first correlative pilot study to decipher the signature of stress as it presents in the physiognomy of a stressed individual, we investigated how stress-induced muscle movement activity in the face is associated with stress marker activation during a standardized laboratory stress test. Female and male participants (N = 62) completed the Trier Social Stress Test and provided multiple measurements of salivary cortisol, subjective experience, heart rate, and high-frequency heart rate variability. In addition, participants were filmed during stress induction to derive the activation of 13 individual muscles or muscle groups, also termed action units (AU). Mean AU intensity and occurrence rates were measured using the opensource software OpenDBM. We found that facial AU activity correlated with different aspects of the psychosocial stress response. Higher stress-induced cortisol release was associated with more frequent upper eyelid raiser (AU05) and upper lip raiser (AU10) occurrences, while more lip corner pulling (AU12) went along with lower cortisol reactivity. More frequent eyelid tightener (AU07) occurrences were linked to higher subjective stress reactivity but decreased heart rate and HF-HRV reactivity. Last, women showed greater stress-induced smiling intensity and occurrence rates than men. We conclude that psychosocial stress reactivity is systematically linked to facial muscle activity, with distinct facial stress profiles emerging for different stress markers. From all the AUs studied, eyelid tightening (AU07) seems to provide the strongest potential for future attempts of diagnosing phases of acute stress via facial activity.

Associations of social processing abilities with psychosocial stress sensitivity.

Through the long-term activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, chronic psychosocial stress can compromise mental and bodily health. Psychosocial stress is determined by the perception of social interactions as ego-threatening, and thus strongly influenced by individual social processing capacities. In the current study, we investigated whether three key components of social processing are linked to how individuals respond to the experience of acute psychosocial stress exposure. Empathy, compassion, and Theory of Mind (ToM) were assessed using a state-of-the-art paradigm, the EmpaToM. Participants (N = 118) also underwent the Trier Social Stress Test (TSST), a standardized psychosocial laboratory stress test. Stress responses were measured in terms of salivary cortisol and alpha-amylase, heart-rate, high-frequency heart-rate variability (HF-HRV), and subjective stress experience. ToM performance correlated with different aspects of the acute psychosocial stress response. More specifically, higher levels of ToM were linked to increased alpha-amylase and reduced HF-HRV sensitivity to stress. Empathy and compassion levels had no influence on stress sensitivity. We conclude that ToM performance has a stable albeit contradictory association with acute psychosocial stress, while empathy and compassion tendencies appear to be largely unrelated. Overall, the relationship between EmpaToM-derived empathy, compassion, and ToM characteristics with stress sensitivity in the TSST is relatively weak.

Resilience and personality as predictors of the biological stress load during the first wave of the Covid-19 pandemic in Germany.

Since the Covid-19 outbreak, pandemic-specific stressors have potentiated the-already severe-stress load across the world. However, stress is more than an adverse state, and chronic exposure is causally involved in the development of mental and physical disease. We ask the question whether resilience and the Big Five personality traits predict the biological stress response to the first lockdown in Germany. In a prospective, longitudinal, observational study, N = 80 adult volunteers completed an internet-based survey prior to the first Covid-19-related fatality in Germany (T0), during the first lockdown period (T1), and during the subsequent period of contact restrictions (T2). Hair strands for the assessment of systemic cortisol and cortisone levels were collected at T2. Higher neuroticism predicted higher hair cortisol, cortisone and subjective stress levels. Higher extraversion predicted higher hair cortisone levels. Resilience showed no effects on subjective or physiological stress markers. Our study provides longitudinal evidence that neuroticism and extraversion have predictive utility for the accumulation of biological stress over the course of the pandemic. While in pre-pandemic times individuals high in neuroticism are typically at risk for worse health outcomes, extraverted individuals tend to be protected. We conclude that, in the pandemic context, we cannot simply generalize from pre-pandemic knowledge. Neurotic individuals may currently suffer due to their general emotional lability. Extraverted individuals may primarily be socially stressed. Individualized stress management programs need to be developed, and offered in a lockdown-friendly format, to minimize the stress burden caused by Covid-19 or future pandemics and to protect the most severely affected individuals from the development of stress-associated disease.