Human amygdala function has been traditionally associated with processing the affective valence (negative vs positive) of an emotionally charged event, especially those that signal fear or threat. However, this account of human amygdala function can be explained by alternative views, which posit that the amygdala might be tuned to either (1) general emotional arousal (activation vs deactivation) or (2) specific emotion categories (fear vs happy). Delineating the pure effects of valence independent of arousal or emotion category is a challenging task, given that these variables naturally covary under many circumstances. To circumvent this issue and test the sensitivity of the human amygdala to valence values specifically, we measured the dimension of valence within the single facial expression category of surprise. Given the inherent valence ambiguity of this category, we show that surprised expression exemplars are attributed valence and arousal values that are uniquely and naturally uncorrelated. We then present fMRI data from both sexes, showing that the amygdala tracks these consensus valence values. Finally, we provide evidence that these valence values are linked to specific visual features of the mouth region, isolating the signal by which the amygdala detects this valence information. There is an open question as to whether human amygdala function tracks the valence value of cues in the environment, as opposed to either a more general emotional arousal value or a more specific emotion category distinction. Here, we demonstrate the utility of surprised facial expressions because exemplars within this emotion category take on valence values spanning the dimension of bipolar valence (positive to negative) at a consistent level of emotional arousal. Functional neuroimaging data showed that amygdala responses tracked the valence of surprised facial expressions, unconfounded by arousal. Furthermore, a machine learning classifier identified particular visual features of the mouth region that predicted this valence effect, isolating the specific visual signal that might be driving this neural valence response.

Oversensitivity to uncertain future threat is usefully conceptualized as intolerance of uncertainty (IU). Neuroimaging studies of IU to date have largely focused on its relationship with brain function, but few studies have documented the association between IU and the quantitative properties of brain structure. Here, we examined potential gray and white matter brain structural correlates of IU from 61 healthy participants. Voxel-based morphometric analysis highlighted a robust positive correlation between IU and striatal volume, particularly the putamen. Conversely, tract-based spatial statistical analysis showed no evidence for a relationship between IU and the structural integrity of white matter fiber tracts. Current results converge upon findings from individuals with anxiety disorders such as obsessive-compulsive disorder (OCD) or generalized anxiety disorder (GAD), where abnormally increased IU and striatal volume are consistently reported. They also converge with neurobehavioral data implicating the putamen in predictive coding. Most notably, the relationship between IU and striatal volume is observed at a preclinical level, suggesting that the volumetric properties of the striatum reflect the processing of uncertainty per se as it relates to this dimensional personality characteristic – such a relationship could then potentially contribute to the onset of OCD or GAD, rather than being unique to their pathophysiology.

The events we experience day to day can be described in terms of their affective quality: some are rewarding, others are upsetting, and still others are inconsequential. These natural distinctions reflect an underlying representational structure used to classify affective quality. In affective psychology, many experiments model this representational structure with two dimensions, using either the dimensions of valence and arousal, or alternatively, the dimensions of positivity and negativity. Using fMRI, we show that it is optimal to use all four dimensions to examine the data. Our findings include (1) a gradient representation of valence that is anatomically organized along the fusiform gyrus and (2) distinct sub-regions within bilateral amygdala that track arousal versus negativity. Importantly, these results would have remained concealed had either of the commonly used 2-dimensional approaches been adopted a priori, demonstrating the utility of our approach.

Humans routinely integrate affective information from multiple sources. For example, we rarely interpret an emotional facial expression devoid of context. Here, we describe the neural correlates of an affective computation that involves integrating multiple sources, by leveraging the ambiguity and subtle feature-based valence signals found in surprised faces.Using functional magnetic resonance imaging, participants reported the valence of surprised faces modulated by positive or negative sentences. Amygdala activity corresponded to the valence value assigned to each contextually modulated face, with greater activity reflecting more negative ratings. Amygdala activity did not track the valence of the faces or sentences per se.Moreover, the amygdala was functionally coupled with the nucleus accumbens only during face trials preceded by positive contextual cues. These data suggest 1) valence-related amygdala activity reflects the integrated valence values rather than the valence values of each individual component, and 2) amygdalostriatal coupling underpins positive but not negative coloring of ambiguous affect.

AbstractHumans routinely integrate affective information from multiple sources. For example, we rarely interpret an emotional facial expression devoid of context. Here, we describe the neural correlates of an affective computation that involves integrating multiple sources, by leveraging the ambiguity and subtle feature-based valence signals found in surprised faces. Using functional magnetic resonance imaging, participants reported the valence of surprised faces modulated by positive or negative sentences. Amygdala activity corresponded to the valence value assigned to each contextually modulated face, with greater activity reflecting more negative ratings. Amygdala activity did not track the valence of the faces or sentences per se. Moreover, the amygdala was functionally coupled with the nucleus accumbens only during face trials preceded by positive contextual cues. These data suggest 1) valence-related amygdala activity reflects the integrated valence values rather than the valence values of each individual component, and 2) amygdalostriatal coupling underpins positive but not negative coloring of ambiguous affect.

= Abstract =Objectives: As suicide among the elderly population has been a critical issue in Korea, this study aimed to evaluate correlations of suicidal ideation with protective and risk factors among elderly who reside in a rural community. Methods:A total of 157 elders from Gyeongju city, who had attended senior centers in, were enrolled to answer questionnaires including the Geriatric Depression Scale Short Form-Korea and the Scale for Suicidal Ideation. Data were analyzed using SPSS 18.0K for Windows, and included t-test, Pearson correlation, and a three-step hierarchical multiple regression analyses.Results: Using the hierarchical regression analyses for predicting the elderly's suicidal ideation, male gender and social group variables were entered as predictors in the first step(adjusted R 2 =0.107, P<0.05). Pain, ADLs, family support variables were not entered in the second step. Depression variable was the only predictor in the third step(adjusted R 2 =0.384, P<0.001).Conclusions: Although this study confirmed the impact of depression on the suicidal ideation, elderly with risk factors including male gender and social isolation should receive a special attention from community health care professionals.

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