Cognitive, affective & behavioral neuroscience
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Cogn Affect Behav Neurosci · Aug 2019
Contingency awareness as a prerequisite for differential contextual fear conditioning.
Contingency awareness during conditioning describes the phenomenon of becoming consciously aware of the association between a conditioned stimulus (CS) and an unconditioned stimulus (US). Despite the fact that contingency awareness is necessary for associative learning in some conditioning paradigms, its role in contextual fear conditioning, a variant that uses a context-CS (CTX) instead of a cue, has not been characterized thus far. We investigated if contingency awareness is a prerequisite for contextual fear conditioning and if subjects classified as aware differ from unaware subjects on a hemodynamic, autonomic, and behavioral level. ⋯ Finally, the hippocampus was functionally connected to the cingulate cortex and posterior medial frontal gyrus in aware subjects relative to unaware subjects. These task-related differential connectivity patterns suggest that information exchange between the hippocampus and regions involved in the expression of conditioned fear and decision uncertainty is crucial for the acquisition of contingency knowledge. This study demonstrates the importance of contingency awareness for contextual fear conditioning and points to the hippocampus as a potential mediator for contingency learning in contextual learning.
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Cogn Affect Behav Neurosci · Aug 2019
Psychosis risk is associated with decreased resting-state functional connectivity between the striatum and the default mode network.
Psychosis is linked to aberrant salience or to viewing neutral stimuli as self-relevant, suggesting a possible impairment in self-relevance processing. Psychosis is also associated with increased dopamine in the dorsal striatum, especially the anterior caudate (Kegeles et al., 2010). Critically, the anterior caudate is especially connected to (a) the cortical default mode network (DMN), centrally involved in self-relevance processing, and (b) to a lesser extent, the cortical frontoparietal network (FPN; Choi, Yeo, & Buckner, 2012). ⋯ In Study 2, to determine whether the decreased striatal-cortical DMN connectivity was specific to psychosis risk or was related to recent distress more generally, we examined the relationship between connectivity and distress in individuals diagnosed with nonpsychotic emotional distress disorders (N = 25). In contrast to Study 1, here we found that distress was associated with evidence of increased striatal-cortical DMN connectivity. Overall, the present results suggest that decreased striatal-cortical DMN connectivity is associated with psychosis risk and could contribute to aberrant salience.