Neurocognitive Mechanisms of Fear Conditioning and Vulnerability to Anxiety

A commentary on Fear-conditioning mechanisms associated with trait vulnerability to anxiety in human

Conceptual similarity promotes generalization of higher order fear learning

We tested the hypothesis that conceptual similarity promotes generalization of conditioned fear. Using a sensory preconditioning procedure, three groups of subjects learned an association between two cues that were conceptually similar, unrelated, or mismatched. Next, one of the cues was paired with a shock. The other cue was then reintroduced to test for fear generalization, as measured by the skin conductance response. Results showed enhanced fear generalization that correlated with trait anxiety levels in the group that learned an association between conceptually similar stimuli. These findings suggest that conceptual representations of conditional stimuli influence human fear learning processes

Rethinking Extinction

Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavioral technique, and consider whether traditional understandings warrant a re-examination. We discuss the neurobiology, cognitive factors, and major computational theories, and revisit the predominant view that extinction results in new learning that interferes with expression of the original memory. Additionally, we reconsider the limitations of extinction as a technique to prevent the relapse of maladaptive behavior, and discuss novel approaches, informed by contemporary theoretical advances, that augment traditional extinction methods to target and potentially alter maladaptive memories

Racial stereotypes impair flexibility of emotional learning

Flexibility of associative learning can be revealed by establishing and then reversing cue-outcome discriminations. Here, we used functional MRI to examine whether neurobehavioral correlates of reversal-learning are impaired in White and Asian volunteers when initial learning involves fear-conditioning to a racial out-group. For one group, the picture of a Black male was initially paired with shock (threat) and a White male was unpaired (safe). For another group, the White male was a threat and the Black male was safe. These associations reversed midway through the task. Both groups initially discriminated threat from safety, as expressed through skin conductance responses (SCR) and activity in the insula, thalamus, midbrain and striatum. After reversal, the group initially conditioned to a Black male exhibited impaired reversal of SCRs to the new threat stimulus (White male), and impaired reversals in the striatum, anterior cingulate cortex, midbrain and thalamus. In contrast, the group initially conditioned to a White male showed successful reversal of SCRs and successful reversal in these brain regions toward the new threat. These findings provide new evidence that an aversive experience with a racial out-group member impairs the ability to flexibly and appropriately adjust fear expression towards a new threat in the environment.NIH [RO1 MH097085]NIMH [K99MH106719]National Natural Science Foundation of China [31322022]BEPE FAPESP [2013/10907-3]NYU, Dept Psychol, 6 Washington Pl,Room 890, New York, NY 10003 USANYU, Ctr Neural Sci, New York, NY 10003 USAUniv Chicago, Dept Psychol, 5848 S Univ Ave, Chicago, IL 60637 USAUniv Chicago, Ctr Study Race Polit & Culture, Chicago, IL 60637 USAPeking Univ, Dept Psychol, Beijing, Peoples R ChinaPeking Univ, Beijing Key Lab Behav & Mental Hlth, Beijing, Peoples R ChinaPeking Univ, PKU IDG McGovern Inst Brain Res, Beijing, Peoples R ChinaUniv Fed Sao Paulo, Dept Psicobiol, BR-04023062 Sao Paulo, BrazilNathan S Kline Inst Psychiat Res, Emot Brain Inst, Orangeburg, NY 10962 USAUniv Fed Sao Paulo, Dept Psicobiol, BR-04023062 Sao Paulo, BrazilNIH:RO1 MH097085NIMH:K99MH106719NSFC:31322022FAPESP:2013/10907-3Web of Scienc

Neural correlates of conceptual-level fear generalization in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) may develop when mechanisms for making accurate distinctions about threat relevance have gone awry. Generalization across conceptually related objects has been hypothesized based on clinical observation in PTSD, but the neural mechanisms remain unexplored. Recent trauma-exposed military veterans (n = 46) were grouped into PTSD (n = 23) and non-PTSD (n = 23). Participants learned to generalize fear across conceptual categories (animals or tools) of semantically related items that were partially reinforced by shock during functional magnetic resonance imaging. Conditioned fear learning was quantified by shock expectancy and skin conductance response (SCR). Relative to veteran controls, PTSD subjects exhibited a stronger neural response associated with fear generalization to the reinforced object category in the striatum, anterior cingulate cortex, amygdala, occipitotemporal cortex, and insula (Z > 2.3; p