Delta-beta cross-frequency coupling as an index of stress regulation during social-evaluative threat

Interactions among stress, behavioral inhibition, and delta-beta coupling predict adolescent anxiety during the COVID-19 pandemic

The COVID-19 pandemic brought about unprecedented changes and uncertainty to the daily lives of youth. The range of adjustment in light of a near-universal experience of COVID restrictions highlights the importance of identifying factors that may render some individuals more susceptible to heightened levels of anxiety during stressful life events than others. Two risk factors to consider are temperamental behavioral inhibition (BI) and difficulties in emotion regulation (ER). As such, the current paper focused on BI examined prior to COVID, because of its developmental link to anxiety and ER, as difficulties may be associated with differences in anxiety. We examined a neurocognitive marker of ER processes, delta-beta coupling (DBC). The current paper had two goals: (1) to examine BI in relation to COVID-related worry and social anxiety experienced during the pandemic, and (2) to explore the role of individual differences in early DBC in the relationship between BI and anxiety outcomes 6 months apart during COVID-19 (n = 86; T1 Mage  = 15.95, SD = 1.73; T6 Mage  = 16.43, SD = 1.73). We found support for the moderating role of DBC in the relationship between BI levels and social anxiety disorder (SAD) symptom severity during the pandemic. Here, high BI was predictive of increased SAD symptom levels in adolescents with stronger DBC.

In the anticipation of threat: Neural regulatory activity indicated by delta-beta correlation and its relation to anxiety

The anticipation of oncoming threats is emotionally challenging and related to anxiety. The current study aimed to investigate the neural regulatory processes during the anticipatory preparations in stressful situations in relation to trait anxiety, especially in an uncertainty-related stressful situation. To this end, we measured within-subjects delta-beta amplitude-amplitude correlation (AAC) and phase-amplitude coupling (PAC) with electroencephalography using a well-defined stress-inducing paradigm in 28 high-trait-anxiety (HTA) and 29 low-trait-anxiety (LTA) college students. Specifically, a threat probability task was conducted, where participants anticipated the future stimuli under the uncertain (i.e., an average of 50% electric shocks), certain (i.e., 100% electric shocks) and no threat conditions, as well as a resting state task. Results showed a generally larger delta-beta AAC in the LTA group relative to the HTA group across conditions, supporting the hypothesis that delta-beta AAC reflects the efficiency of stress regulation and trait anxiety could compromise this adaptive regulatory activity. Furthermore, a larger delta-beta PAC was found under the uncertain threat condition relative to the no threat condition, indicating the sensitivity of delta-beta PAC in reflecting state anxiety. These findings indicate that while delta-beta AAC is more related to trait anxiety and could distinguish between high and low trait anxiety irrespective of conditions, delta-beta PAC is more related to state anxiety and is sensitive enough to detect the uncertainty-related anxious state.

Positive future thinking without task-relevance increases anxiety and frontal stress regulation

Negative anticipatory biases can affect the way we interpret and subjectively experience events. Through its role in emotion regulation, positive future thinking may provide an accessible way to attenuate these biases. However, it is unclear whether positive future thinking works ubiquitously, independent of contextual relevance. Here, we used a positive future thinking intervention (task-relevant; task-irrelevant and control condition) prior to a social stress task to adapt the way this task was experienced. We assessed subjective and objective stress measures and also recorded resting state electroencephalography (EEG) to assess intervention related differences in the level of frontal delta-beta coupling, which is considered a neurobiological substrate of stress regulation. Results show that the intervention reduced subjective stress and anxiety, and increased social fixation behavior and task performance, but only if future thinking was task-relevant. Paradoxically, task-irrelevant positive future thoughts enhanced negative perceptual biases and stress reactivity. This increase in stress reactivity was corroborated by elevated levels of frontal delta-beta coupling during event anticipation, which suggests an increased demand for stress regulation. Together, these findings show that positive future thinking can mitigate the negative emotional, behavioral and neurobiological consequences of a stressful event, but that it should not be applied indiscriminately.

Allostatic-interoceptive anticipation of social rejection

Anticipating social stress evokes strong reactions in the organism, including interoceptive modulations. However, evidence for this claim comes from behavioral studies, often with inconsistent results, and relates almost solely to the reactive and recovery phase of social stress exposure. Here, we adopted an allostatic-interoceptive predictive coding framework to study interoceptive and exteroceptive anticipatory brain responses using a social rejection task. We analyzed the heart-evoked potential (HEP) and task-related oscillatory activity of 58 adolescents via scalp EEG, and 385 human intracranial recordings of three patients with intractable epilepsy. We found that anticipatory interoceptive signals increased in the face of unexpected social outcomes, reflected in larger negative HEP modulations. Such signals emerged from key brain allostatic-interoceptive network hubs, as shown by intracranial recordings. Exteroceptive signals were characterized by early activity between 1-15 Hz across conditions, and modulated by the probabilistic anticipation of reward-related outcomes, observed over distributed brain regions. Our findings suggest that the anticipation of a social outcome is characterized by allostatic-interoceptive modulations that prepare the organism for possible rejection. These results inform our understanding of interoceptive processing and constrain neurobiological models of social stress.