Trait anxiety and perceptual load as determinants of emotion processing in a fear conditioning paradigm

Linking emotional valence and anxiety in a mouse insula-amygdala circuit

Responses of the insular cortex (IC) and amygdala to stimuli of positive and negative valence are altered in patients with anxiety disorders. However, neural coding of both anxiety and valence by IC neurons remains unknown. Using fiber photometry recordings in mice, we uncover a selective increase of activity in IC projection neurons of the anterior (aIC), but not posterior (pIC) section, when animals are exploring anxiogenic spaces, and this activity is proportional to the level of anxiety of mice. Neurons in aIC also respond to stimuli of positive and negative valence, and the strength of response to strong negative stimuli is proportional to mice levels of anxiety. Using ex vivo electrophysiology, we characterized the IC connection to the basolateral amygdala (BLA), and employed projection-specific optogenetics to reveal anxiogenic properties of aIC-BLA neurons. Finally, we identified that aIC-BLA neurons are activated in anxiogenic spaces, as well as in response to aversive stimuli, and that both activities are positively correlated. Altogether, we identified a common neurobiological substrate linking negative valence with anxiety-related information and behaviors, which provides a starting point to understand how alterations of these neural populations contribute to psychiatric disorders.

Facial emotion perception abilities are related to grey matter volume in the culmen of cerebellum anterior lobe in drug-naïve patients with first-episode schizophrenia

Impaired capability for understanding and interpreting the expressions on other people's faces manifests itself as a core feature of schizophrenia, contributing to social dysfunction. With the purpose of better understanding of the neurobiological basis of facial emotion perception deficits in schizophrenia, we investigated facial emotion perception abilities and regional structural brain abnormalities in drug-naïve patients with first-episode schizophrenia, and then examined the correlation between them. Fifty-two drug-naive patients with first-episode schizophrenia and 29 group-matched healthy controls were examined for facial emotion perception abilities assessed with the Facial Emotion Categorization and performed magnetic resonance imaging. The Facial Emotion Categorization data were inserted into a logistic function model so as to calculate shift point and slope as outcome measurements. Voxel-based morphometry was applied to investigate regional grey matter volume (GMV) alterations. The relationship between facial emotion perception and GMV was explored in patients using voxel-wise correlation analysis within brain regions that showed a significant GMV alterations in patients compared with controls. The schizophrenic patients performed differently on Facial Emotion Categorization tasks from the controls and presented a higher shift point and a steeper slope. Relative to the controls, patients showed GMV reductions in the superior temporal gyrus, middle occipital gyrus, parahippocampa gyrus, posterior cingulate, the culmen of cerebellum anterior lobe, cerebellar tonsil, and the declive of cerebellum posterior lobe. Importantly, abnormal performance on Facial Emotion Categorization was found correlated with GMV alterations in the culmen of cerebellum anterior lobe in schizophrenia. This study suggests that reduced GMV in the culmen of cerebellum anterior lobe occurs in first-episode schizophrenia, constituting a potential neuropathological basis for the impaired facial emotion perception in schizophrenia.

Your face scares me: Effects of Perceptual load and Social Anxiety on processing of threatening and neutral faces

Social Anxiety Disorder is among the most widely studied psychiatric conditions. However, the role of attentional and emotional processes in the maintenance of the condition is still not well-established. This study addressed the impact of individual differences in Social Anxiety, by examining the effects of perceptual load and stimulus valence when processing faces vs objects, here used as distractors, within a letter-search task. In addition to RT and accuracy on the letter search task, heart rate, and skin conductance during the task and participants’ self-report emotional evaluation were assessed to help interpret performance effects. Results suggest that distractor stimuli that are either threatening or faces impair performance of high SA participants. Results demonstrate a hypervigilance for threatening faces in SA but indicate that this happens primarily when cognitive resources are available, that is, under low perceptual load.

During vigilance to painful stimuli: slower response rate is related to high trait anxiety, whereas faster response rate is related to high state anxiety

A pathological increase in vigilance, or hypervigilance, may be related to pain intensity in some clinical pain syndromes and may result from attention bias to salient stimuli mediated by anxiety. During a continuous performance task where subjects discriminated painful target stimuli from painful nontargets, we measured detected targets (hits), nondetected targets (misses), nondetected nontargets (correct rejections), and detected nontargets (false alarms). Using signal detection theory, we calculated response bias, the tendency to endorse a stimulus as a target, and discriminability, the ability to discriminate a target from nontarget. Owing to the relatively slow rate of stimulus presentation, our primary hypothesis was that sustained performance would result in a more conservative response bias reflecting a lower response rate over time on task. We found a more conservative response bias with time on task and no change in discriminability. We predicted that greater state and trait anxiety would lead to a more liberal response bias. A multivariable model provided partial support for our prediction; high trait anxiety related to a more conservative response bias (lower response rate), whereas high state anxiety related to a more liberal bias. This inverse relationship of state and trait anxiety is consistent with reports of effects of state and trait anxiety on reaction times to threatening stimuli. In sum, we report that sustained attention to painful stimuli was associated with a decrease in the tendency of the subject to respond to any stimulus over time on task, whereas the ability to discriminate target from nontarget remains unchanged.NEW & NOTEWORTHY During a series of painful stimuli requiring subjects to respond to targets, we separated response willingness from ability to discriminate targets from nontargets. Response willingness declined during the task, with no change in subjects' ability to discriminate, consistent with previous vigilance studies. High trait anxious subjects were less willing to respond and showed slower reaction times to hits than low anxious subjects. This study reveals an important role of trait anxiety in pain vigilance.

Behavioral inhibition system sensitivity moderates audio-visual neutral information processing

BACKGROUND AND OBJECTIVES

Misperception of other people's intention and emotions could cause and worsen interpersonal problems, thereby increasing the likelihood of developing depression and anxiety disorders among individuals who are already at risk for those conditions. Although multisensory emotional information is ubiquitous in the real world, most previous research focused exclusively on processing facial expressions. Addressing this gap, the current study examined the association between behavioral inhibition system (BIS) sensitivity and audio-visual emotional information processing. Sensitive BIS suggests heightened sensitivity to anxiety provoking stimuli and is a known risk factor for developing emotional disorders. We hypothesized that higher BIS levels would be associated with inefficient multisensory emotional processing, which might be pronounced for neutral stimuli.

METHODS

Seventy-six undergraduates (40 women) completed a task while target faces (disgusted, happy, and neutral) were rendered invisible, and a voice (disgusted, happy, and neutral) or no voice was presented simultaneously. Participants' reaction times to indicate the location of the interocularly suppressed faces were measured.

RESULTS

Individuals with lower BIS levels detected neutral faces faster when accompanied by neutral voices than by no voice; individuals with higher BIS levels, however, did not benefit from congruent auditory information when processing neutral faces.

LIMITATIONS

The current study cannot address whether the finding is due to attentional biases, interpretation biases, or both in individuals who are prone to become anxious.

CONCLUSION

Multisensory processing of neutral information is modulated by individuals' propensity to become anxious.

Personality, Stress, and Intuition: Emotion Regulation Abilities Moderate the Effect of Stress-Dependent Cortisol Increase on Coherence Judgments

Objective

Findings on the relationship between hypothalamus-pituitary-adrenocortical (HPA) activity and cognitive performance are inconsistent. We investigated whether personality in terms of emotion regulation abilities (ERA) moderates the relationship between stress-contingent HPA activity and accuracy of intuitive coherence judgments.

Method

ERA and cortisol responses to social-evaluative stress as induced by a variant of the Trier Social Stress Test were measured in N = 49 participants (32 female, aged 18 to 33 years, M = 22.48, SD = 3.33). Subsequently, in a Remote Associates Task they provided intuitive judgments on whether word triples, primed by either stress-reminding or neutral words, are coherent or not.

Results

Under relative cortisol increase participants low in ERA showed reduced performance whereas individuals high in ERA showed increased performance. By contrast, under conditions of low cortisol change, individuals low in ERA outperformed those high in ERA.

Conclusion

Personality can moderate the link between stress and cognition such as accurate intuition. This can happen to a degree that existing effects may not be become apparent in the main effect (i.e. without considering personality), which highlights the necessity to consider personality in stress research, ERA in particular. We discuss the findings with respect to individual differences in neurobehavioral mechanisms potentially underlying ERA and corresponding interactions with cognitive processing.

Perspectives from affective science on understanding the nature of emotion

Emotions are at the heart of how we understand the human mind and of our relationships within the social world. Yet, there is still no scientific consensus on the fundamental nature of emotion. A central quest within the discipline of affective science is to develop an in-depth understanding of emotions, moods, and feelings and how they are embodied within the brain (affective neuroscience). This article provides a brief overview of the scientific study of emotion with a particular emphasis on psychological and neuroscientific perspectives. Following a selective snapshot of past and present research in this field, some current challenges and controversies in affective science are highlighted.

How acute stress may enhance subsequent memory for threat stimuli outside the focus of attention: DLPFC-amygdala decoupling

Stress-related disorders, e.g., anxiety and depression, are characterized by decreased top-down control for distracting information, as well as a memory bias for threatening information. However, it is unclear how acute stress biases mnemonic encoding and leads to prioritized storage of threat-related information even if outside the focus of attention. In the current study, healthy adults (N = 53, all male) were randomly assigned to stress induction using the socially evaluated cold-pressor test (SECPT) or a control condition. Participants performed a task in which they were required to identify a target letter within a string of letters that were either identical to the target and thereby facilitating detection (low distractor load) or mixed with other letters to complicate the search (high load). Either a fearful or neutral face was presented on the background, outside the focus of attention. Twenty-four hours later, participants were asked to perform a surprise recognition memory test for those background faces. Stress induction resulted in increased cortisol and negative subjective mood ratings. Stress did not affect visual search performance, however, participants in the stress group showed stronger memory compared to the control group for fearful faces in the low attentional load condition. Critically, the stress induced memory bias was accompanied by decoupling between amygdala and DLFPC during encoding, which may represent a mechanism for decreased ability to filter task-irrelevant threatening background information. The current study provides a potential neural account for how stress can produce a negative memory bias for threatening information even if presented outside the focus of attention. Despite of an adaptive advantage for survival, such tendencies may ultimately also lead to generalized fear, a possibility requiring additional investigation.

Dissociable roles for hippocampal and amygdalar volume in human fear conditioning

Fear conditioning is a basic learning process which involves the association of a formerly neutral conditioned stimulus (CS) with a biologically relevant aversive unconditioned stimulus (US). Previous studies conducted in brain-lesioned patients have shown that while the acquisition of autonomic fear responses requires an intact amygdala, a spared hippocampus is necessary for the development of the CS-US contingency awareness. Although these data have been supported by studies using functional neuroimaging techniques in healthy people, attempts to extend these findings to the morphological aspects of amygdala and hippocampus are missing. Here we tested the hypothesis that amygdalar and hippocampal volumes play dissociable roles in determining autonomic responses and contingency awareness during fear conditioning. Fifty-two healthy individuals (mean age 21.83) underwent high-resolution magnetic resonance imaging. We used a differential delay fear conditioning paradigm while assessing skin conductance responses (SCRs), subjective ratings of CS-US contingency, as well as emotional valence and perceived arousal. Left amygdalar volume significantly predicted the magnitude of differential SCRs during fear acquisition, but had no impact on contingency learning. Conversely, bilateral hippocampal volumes were significantly related to contingency ratings, but not to SCRs. Moreover, left amygdalar volume predicted SCRs to the reinforced CS alone, but not those elicited by the US. Our findings bridge the gap between previous lesion and functional imaging studies, by showing that amygdalar and hippocampal volumes differentially modulate the acquisition of conditioned fear. Further, our results reveal that the morphology of these limbic structures moderate learning and memory already in healthy persons.

Conceptual and methodological concerns in the theory of perceptual load

The present paper provides a short critical review of the theory of perceptual load. It closely examines the basic tenets and assumptions of the theory and identifies major conceptual and methodological problems that have been largely ignored in the literature. The discussion focuses on problems in the definition of the concept of perceptual load, on the circularity in the characterization and manipulation of perceptual load and the confusion between the concept of perceptual load and its operationalization. The paper also selectively reviews evidence supporting the theory as well as inconsistent evidence which proposed alternative dominant factors influencing the efficacy of attentional selection.

Ignored faces produce figural face aftereffects

Following adaptation to faces with contracted (or expanded) internal features, faces previously perceived as normal appear distorted in the opposite direction. This figural face aftereffect suggests face-coding mechanisms adapt to changes in the spatial relations of features and/or the global structure of faces. Here, we investigated whether the figural aftereffect requires spatial attention. Participants ignored a distorted adapting face and performed a highly demanding letter-count task. Before and after adaptation, participants rated the normality of morphed distorted faces ranging from 50% contracted through undistorted to 50% expanded. A robust aftereffect was observed. These results suggest that the figural face aftereffect can occur in the absence of spatial attention, even when the attentional demands of the relevant task are high.