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Morriss, J.

Publications and source records attributed to Morriss, J..

2 recordsLinked to original sources

Out with the old and in with the new: The role of intolerance of uncertainty in reversal of threat and safety

The ability to learn and reverse threat associations is crucial for survival. The extent to which old threat associations are inhibited and new threat associations are formed may depend on sensitivity to future threat uncertainty. To assess the extent to which Intolerance of Uncertainty (IU) predicts threat learning and reversal, we recorded expectancy ratings and skin conductance in 44 healthy participants during an associative learning paradigm, where threat and safety contingencies were reversed. During acquisition and reversal, we observed larger SCR magnitude and expectancy ratings for threat vs. safety cues. However, during reversal higher IU was associated with larger SCR magnitude to new threat vs. new safety cues, compared to lower IU. These results were specific to IU-related variance, over shared variance with trait anxiety (STAIX-2). Overall, these findings suggest that individuals high in IU are able to reverse threat and safety associations in the presence of direct threat. Such findings help us understand the recently revealed link between IU and threat extinction, where direct threat is absent. Moreover, these findings highlight the potential relevance of IU in clinical intervention and treatment for anxiety disorders.

neuroscience

Multimodal evidence for delayed fear extinction in adolescence and young adulthood.

Previous research in rodents and humans points to an evolutionarily conserved profile of blunted fear extinction during adolescence, underpinned by brain structures such as the amygdala and medial prefrontal cortex (mPFC). In this study, we examine age-related effects on the function and structural connectivity of this system in fear extinction in adolescence and young adulthood. Younger age was associated with greater amygdala activity and delayed mPFC engagement to learned threat cues as compared to safety cues. Furthermore, greater structural integrity of the uncinate fasciculus, a white matter tract that connects the amygdala and mPFC, mediated the relationship between age and acceleration of mPFC engagement during extinction. These findings suggest that age-related changes in the structure and function of amygdala-mPFC circuitry may underlie the protracted maturation of fear regulatory processes, rendering younger individuals more vulnerable to anxiety disorders, which emerge during development.

neuroscience