Behavioral inhibition (BI) increases vulnerability to develop anxiety disorders and is typified by avoidance and withdrawal from novel objects, people, and situations. The present study considered the relationship between BI and temperamental risk factors, such as trait anxiety and acquisition rate of a classically conditioned eyeblink response. One-hundred seventy-four healthy undergraduate students (mean age 20.3 years, 71.8% female) were given the State-Trait Anxiety Inventory and a battery of self-report measures of BI consisting of the Adult and Retrospective Measures of Behavioral Inhibition (AMBI/RMBI) and the Concurrent and Retrospective Self Report of Inhibition (CSRI/RSRI). Participants then underwent standard delay classical eyeblink conditioning consisting of 45 trials with a 500-ms CS overlapping and co-terminating with a 10-ms airpuff US. Individuals with higher scores on the AMBI and Trait Anxiety Inventory, but not the other measures, showed faster acquisition of a conditioned eyeblink response than individuals with lower scores. Results support a relationship between facilitated acquisition of inter-stimulus relationships and risk for anxiety, and suggest that some measures assessing anxiety vulnerability better capture this relationship than others.

This study characterized cerebellar connectivity with executive intrinsic functional connectivity networks. Using seed regions at the right and left dorsolateral prefrontal cortices (dlPFC) and right orbital frontoinsula, we measured resting-state brain connectivity in healthy college-aged participants. Based on the previous research demonstrating a relationship between the cerebellum and self-report measures of behavioral inhibition, we assessed individual differences in connectivity between groups. Overall, intrinsic activity in cerebellar lobule VIII was significantly correlated with the executive network and cerebellar Crus I with the salience network. Between-group comparisons indicated stronger cerebellar connectivity with the executive network in behaviorally inhibited individuals. Intrinsic activity in Crus I, a region previously implicated in non-motor cerebellar functions, significantly correlated with intrinsic activity in the right dlPFC seed region. These findings support a growing number of studies demonstrating cerebellar influence on higher cognitive processes, extending this relationship to individual differences in anxiety vulnerability.

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