INSTRESS – Interoception and chronic stress

Interoception, the perception of physical symptoms, plays an important role for health, stress and disease. Accurate interoception is associated with factors that contribute to mental health, such as emotion regulation or emotional experience. Disturbed interoception can be observed in mental disorders, which are associated with physical symptoms, such as panic disorder or somatoform disorders. Chronic stress represents a major risk factor for the development of those disorders. While interoception implies the perception of signals on the ascending brain-body axis, stress represents a prominent example for descending signals on the brain-body axis. Dysregulated signal transmission on the ascending and/or the descending branch of the brain-body axes may underlie the generation of physical symptoms. The effects of acute stress on interoception are well-documented. Nevertheless, since acute stress may be a model of only limited ecological validity, the aim of the current project is to investigate psychophysiological mechanism underlying interoception in chronic stress. We, therefore, intend to investigate highly stressed (HS) schoolteachers compared to a group of schoolteachers with low self-reported stress levels (LS). It is well established that the teaching profession represents a highly stressful occupation due to enduring psychosocial demands at the workplace. As a consequence, HS schoolteachers may show dysregulation in the reactivity of both physiological stress systems, namely (1) the autonomic nervous system (ANS), and (2) the hypothalamic-pituitary-adrenocortical (HPA) axis. The project comprises a multi-method approach to assess interoception including (1) heartbeat-evoked brain potentials, which are considered to reflect cortical processing of cardiac interoceptive neural signals, cardiac modulation of startle (CMS), which is assumed to index cardiac interoceptive signals at the level of the brainstem, and (3) heartbeat perception tasks to reflect attention focused on cardiac sensation. HS and LS Schoolteachers will be tested with these experimental paradigms during rest and after a social stressor. Furthermore, psychophysiological data used as indicators of ANS activity will be recorded during rest and in response to a stressor, as well as diurnal measurements of salivary cortisol. In summary, the current project aims at elucidating the contribution of both physiological stress systems for altered processing of physical symptoms in highly stressed schoolteachers.