The amygdala is consistently implicated in biologically relevant learning tasks such as Pavlovian conditioning. In humans, the ability to identify individual faces based on the social outcomes they have predicted in the past constitutes a critical form of associative learning that can be likened to "social conditioning." To capture such learning in a laboratory setting, participants learned about faces that predicted negative, positive, or neutral social outcomes. Participants reported liking or disliking the faces in accordance with their learned social value. During acquisition, we observed differential functional magnetic resonance imaging activation across the human amygdaloid complex consistent with previous lesion, electrophysiological, and functional neuroimaging data. A region of the medial ventral amygdala and a region of the dorsal amygdala/substantia innominata showed signal increases to both Negative and Positive faces, whereas a lateral ventral region displayed a linear representation of the valence of faces such that Negative > Positive > Neutral. This lateral ventral locus also differed from the dorsal and medial loci in that the magnitude of these responses was more resistant to habituation. These findings document a role for the human amygdala in social learning and reveal coarse regional dissociations in amygdala activity that are consistent with previous human and nonhuman animal data.

In this study, we compared the effects of using neutral face masks vs non-face pattern masks on amygdala activity to masked fearful faces. Twenty-seven subjects viewed 18 s blocks of either fearful or happy faces masked with either neutral faces or patterns, while their brain activity was measured using functional magnetic resonance imaging. Results replicated increased amygdala activation to face-masked fearful vs happy faces. In the pattern mask condition, the amygdala discriminated between masked fearful and happy faces, but this effect manifested as a decrease in activation to fearful faces compared to happy faces. This interactive effect between facial expression and mask stimulus shows that amygdala responses to masked fearful faces are influenced by the fearful stimuli per se as well as their interaction with the mask stimulus.

An increasing number of refugees and survivors of torture resettled in the United States are presenting to clinics for treatment related to trauma and postmigration difficulties. Although clinicians experienced in treating trauma with diverse populations may recognize the limitations of a PTSD diagnosis, one of the primary diagnoses received by refugees and survivors of torture remains post-traumatic stress disorder (PTSD). A variety of interventions exist (e.g., supportive, trauma specific, interdisciplinary including physical, social and psychological) for survivors of torture and trauma that move beyond this diagnosis, however, a unifying conceptual model is needed to guide treatment and further the empirical investigation and evidence base in this growing field. In this paper, we propose a broader biopsychosocial framework of the impact of traumatic war events including the measurement of stress related to post migration living difficulties, and daily hassles while highlighting the importance of protective and risk factors. Intervention outcomes emphasize resilience, physical well-being, and mental well-being, along with traumatic stress symptoms. We describe Chronic Traumatic Stress (CTS) as an integrated and unifying framework which provides guidance for the growing number of providers conducting assessment andintervention with refugees and survivors of torture. We also highlight that this model is specifically designed for empirical testing.

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The structure of the mask stimulus is crucial in backward masking studies and we recently demonstrated such an effect when masking faces. Specifically, we showed that activity of the amygdala is increased to fearful facial expressions masked with neutral faces and decreased to fearful expressions masked with a pattern mask—but critically both masked conditions discriminated fearful expressions from happy expressions. Given this finding, we sought to test whether masked fearful eye whites would produce a similar profile of amygdala response in a face vs non-face context. During functional magnetic resonance imaging scanning sessions, 30 participants viewed fearful or happy eye whites masked with either neutral faces or pattern images. Results indicated amygdala activity was increased to fearful vs happy eye whites in the face mask condition, but decreased to fearful vs happy eye whites in the pattern mask condition—effectively replicating and expanding our previous report. Our data support the idea that the amygdala is responsive to fearful eye whites, but that the nature of this activity observed in a backward masking design depends on the mask stimulus.