Individual differences in anxiety and automatic amygdala response to fearful faces: A replication and extension of Etkin et al. (2004).

Trait anxiety refers to the stable tendency to attend to threats and experience fears and worries across many situations. According to the widely noticed, pioneering investigation by Etkin et al. (2004) trait anxiety is strongly associated with reactivity in the right basolateral amygdala to non-conscious threat. Although this observation was based on a sample of only 17 individuals, no replication effort has been reported yet. We reexamined automatic amygdala responsiveness as a function of anxiety in a large sample of 107 participants. Besides self-report instruments, we administered an indirect test to assess implicit anxiety. To assess early, automatic stages of emotion processing, we used a color-decision paradigm presenting brief (33 ms) and backward-masked fearful facial expressions. N = 56 participants were unaware of the presence of masked faces. In this subset of unaware participants, the relationship between trait anxiety and basolateral amygdala activation by fearful faces was successfully replicated in region of interest analyses. Additionally, a relation of implicit anxiety with masked fear processing in the amygdala and temporal gyrus was observed. We provide evidence that implicit measures of affect can be valuable predictors of automatic brain responsiveness and may represent useful additions to explicit measures. Our findings support a central role of amygdala reactivity to non-consciously perceived threat in understanding and predicting dispositional anxiety, i.e. the frequency of spontaneously occurring anxiety in everyday life.

Attentional biases to emotional information in clinical depression: A systematic and meta-analytic review of eye tracking findings.

BACKGROUND: In the last decade, eye-tracking technology has been increasingly used to investigate attention orientation in depression. The aim of the current review was to summarize the available eye-tracking research specifying the effects of clinical depression on early and late attention allocation during visual perception of emotional material. METHODS: The literature search identified sixteen relevant publications, including twelve free-viewing studies in which multiple stimulus arrays with images (scenarios) or faces were administered. Meta-analyses were conducted to evaluate the impact of acute depression on attentional maintenance during free viewing as a function of type and emotional quality of stimulus material. RESULTS: Moderate (to large) differences were observed between depressed and healthy individuals in maintained attention to dysphoric images (Hedges' g = .66) and sad faces (g = .58). Moderate group differences were also revealed for maintained attention to positive images (g = -.51) and happy faces (g = -.54). Age of patients explained between study variance in effect sizes for attention to happy faces. No group differences in initial attention orientation were found. LIMITATIONS: The number of free-viewing studies based on images was low (n=4). CONCLUSIONS: Our results suggest that clinical depression is characterized by medium-sized increases of attention maintenance for dysphoric and medium-sized decreases for positive stimuli compared to healthy individuals. Therefore, both alterations represent equally important targets for attention modification programs. Depressed patients seem not to manifest abnormalities in early orienting to emotional stimuli. Differences between patients and healthy subjects in attention to positive stimuli may diminish with age.

Implicitly and explicitly assessed anxiety: No relationships with recognition of and brain response to facial emotions.

Trait anxiety, the disposition to experience anxiety, is known to facilitate perception of threats. Trait anxious individuals seem to identify threatening stimuli such as fearful facial expressions more accurately, especially when presented under temporal constraints. In past studies on anxiety and emotion face recognition, only self-report or explicit measures of anxiety have been administered. Implicit measures represent indirect tests allowing to circumvent problems associated with self-report. In our study, we made use of implicit in addition to explicit measures to investigate the relationships of trait anxiety with recognition of and brain response to emotional faces. 75 healthy young volunteers had to identify briefly presented (67 ms) fearful, angry, happy, and neutral facial expressions masked by neutral faces while undergoing functional magnetic resonance imaging. The Implicit Association Test, the State-Trait Anxiety Inventory and the Beck Anxiety Inventory were applied as implicit and explicit measures of trait anxiety. After corrections for multiple testing, neither implicitly nor explicitly measured anxiety correlated with recognition of emotional facial expressions. Moreover, implicitly and explicitly assessed anxiety was not linked to brain response to emotional faces. Our data suggest links between discrimination accuracy and brain response to facial emotions. Activation of the caudate nucleus seems be of particular importance for recognizing fear and happiness from facial expressions. Processes of somatosensory resonance appear to be involved in identifying fear from facial expressions. The present data indicate that, regardless of assessment method, trait anxiety does not affect the recognition of fear or other emotions as has been proposed previously.