Sensation seeking and neuroticism in fear conditioning and extinction: The role of avoidance behaviour

The effect of transcranial direct current and magnetic stimulation on fear extinction and return of fear: A meta-analysis and systematic review

BACKGROUND

We conducted a meta-analysis and qualitative review on the randomized controlled trials investigating the effects of transcranial direct current stimulation and transcranial magnetic stimulation on fear extinction and the return of fear in non-primate animals and humans.

METHODS

The meta-analysis was conducted by searching PubMed, Web of science, PsycINFO, and Cochrane Library and extracting fear response in the active and sham groups in the randomized controlled trials. The pooled effect size was quantified by Hedges' g using a three-level meta-analytic model in R.

RESULTS

We identified 18 articles on the tDCS effect and 5 articles on the TMS effect, with 466 animal subjects and 621 human subjects. Our findings show that tDCS of the prefrontal cortex significantly inhibit fear retrieval in animal models (Hedges' g = -0.50). In human studies, TMS targeting the dorsolateral/ventromedial prefrontal cortex has an inhibiting effect on the return of fear (Hedges' g = -0.24).

LIMITATIONS

The limited number of studies and the heterogeneous designs of the selected studies made cross-study and cross-species comparison difficult.

CONCLUSIONS

Our findings shed light on the optimal non-invasive brain stimulation protocols for targeting the neural circuitry of threat extinction in humans.

Understanding clinical fear and anxiety through the lens of human fear conditioning

Fear is an adaptive emotion that mobilizes defensive resources upon confrontation with danger. However, fear becomes maladaptive and can give rise to the development of clinical anxiety when it exceeds the degree of threat, generalizes broadly across stimuli and contexts, persists after the danger is gone or promotes excessive avoidance behaviour. Pavlovian fear conditioning has been the prime research instrument that has led to substantial progress in understanding the multi-faceted psychological and neurobiological mechanisms of fear in past decades. In this Perspective, we suggest that fruitful use of Pavlovian fear conditioning as a laboratory model of clinical anxiety requires moving beyond the study of fear acquisition to associated fear conditioning phenomena: fear extinction, generalization of conditioned fear and fearful avoidance. Understanding individual differences in each of these phenomena, not only in isolation but also in how they interact, will further strengthen the external validity of the fear conditioning model as a tool with which to study maladaptive fear as it manifests in clinical anxiety.

Power Distance Belief and Workplace Communication: The Mediating Role of Fear of Authority

Power distance is the degree of acceptance of unequal distribution of power in societies. In a high power distance context, the acceptance of inequality conflicts with the operation of modern organizations, which causes obstacles to workplace communication or even triggers workplace accidents due to ineffective communication. We conducted four studies (N = 1063) to explore the relations between and mechanisms of power distance belief and workplace communication. In Study 1, the participants with high power distance belief had ineffective workplace communication—specifically ineffective communication with superiors—but no difference in communication with subordinates and colleagues. We further focused on the mechanism underlying the relationship between power distance belief and communication with superiors. A questionnaire study (Study 2) was conducted in three stages over a three-month period, and an experimental study (Study 3) indicated that fear of authority mediated the negative effect of high power distance on communication with superiors. A cross-culture study (Study 4) re-tested the hypotheses among Chinese and U.S. participants. This research provides insight into the mechanisms that explain the relationship between power distance belief and workplace communication, indicating that fear of authority is significant. Organizations should pay attention to power distance belief and fear of authority, as they may lead to workplace accidents due to communication disasters.

Correlation between laboratory-based vicarious threat learning and emotional disorder symptom dimensions

BACKGROUND AND OBJECTIVES

Vicarious threat conditioning abnormalities are theorized to confer vulnerability to a wide range of emotional problems. We tested two different conceptual models of this non-specificity. First, hypersensitivity to socially conditioned danger cues might predict standing on a general internalizing dimension that represents commonalities among various forms of anxiety and depression. Second, this hypersensitivity might predict specific symptom clusters, such as panic or social anxiety.

METHODS

We examined university students' (N = 150) defensive responses during a vicarious threat conditioning task in relation to both broad and specific components of the internalizing domain.

RESULTS

Vicarious conditioning was successful, such that participants exhibited larger subjective and skin conductance responses during their first direct encounters with threatening, as compared to nonthreatening, conditioned stimuli. But, contrary to hypotheses, individual differences in this threat learning process were not robustly correlated with any internalizing dimension.

LIMITATIONS

The threat value of the conditioned stimuli was readily apparent, possibly limiting individual differences in defensive responding and, in turn, the correlations between conditioned responses and symptom dimensions. Also, results may differ in clinical populations.

CONCLUSIONS

Our findings suggest that the association between vicarious threat learning and emotional disorder risk-whether it is conceptualized in terms of broad symptom dimensions that span many categorical diagnoses or more fine-grain symptom processes-is weaker than previously believed, at least in this population. Data, analysis code, and stimulus materials are available at https://osf.io/m3xst/.