Neurophysiological evidence for early modulation of amygdala activity by emotional reappraisal

Original language versus dubbed movies: Effects on our brain and emotions

Converging evidence suggests that emotions are often dulled in one's foreign language. Here, we paired fMRI with a naturalistic viewing paradigm (i.e., original vs. dubbed versions of sad, fun and neutral movie clips) to investigate the neural correlates of emotion perception as a function of native (L1) and foreign (L2) language context. Watching emotional clips in L1 (vs. L2) reflected in activations of anterior temporal cortices involved in semantic cognition, arguably indicating a closer association of emotion concepts with the native language. The processing of fun clips in L1 (vs. L2) reflected in enhanced response of the right amygdala, suggesting a deeper emotional experience of positively valenced stimuli in the L1. Of interest, the amygdala response to fun clips positively correlated with participants' proficiency in the L2, indicating that a higher L2 competence may reduce emotional processing differences across a bilingual's two languages. Our findings are compatible with the view that language provides a context for the construction of emotions.

Implicit, But Not Explicit, Emotion Regulation Relieves Unpleasant Neural Responses Evoked by High-Intensity Negative Images

Evidence suggests that explicit reappraisal has limited regulatory effects on high-intensity emotions, mainly due to the depletion of cognitive resources occupied by the high-intensity emotional stimulus itself. The implicit form of reappraisal has proved to be resource-saving and therefore might be an ideal strategy to achieve the desired regulatory effect in high-intensity situations. In this study, we explored the regulatory effect of explicit and implicit reappraisal when participants encountered low- and high-intensity negative images. The subjective emotional rating indicated that both explicit and implicit reappraisal down-regulated negative experiences, irrespective of intensity. However, the amplitude of the parietal late positive potential (LPP; a neural index of experienced emotional intensity) showed that only implicit reappraisal had significant regulatory effects in the high-intensity context, though both explicit and implicit reappraisal successfully reduced the emotional neural responses elicited by low-intensity negative images. Meanwhile, implicit reappraisal led to a smaller frontal LPP amplitude (an index of cognitive cost) compared to explicit reappraisal, indicating that the implementation of implicit reappraisal consumes limited cognitive control resources. Furthermore, we found a prolonged effect of implicit emotion regulation introduced by training procedures. Taken together, these findings not only reveal that implicit reappraisal is suitable to relieve high-intensity negative experiences as well as neural responses, but also highlight the potential benefit of trained implicit regulation in clinical populations whose frontal control resources are limited.

Emotion regulation strategies differentially modulate neural activity across affective prediction stages: An HD-EEG investigation

Emotion regulation (ER) strategies can influence how affective predictions are constructed by the brain (generation stage) to prearrange action (implementation stage) and update internal models according to incoming stimuli (updating stage). However, neurocomputational mechanisms by which this is achieved are unclear. We investigated through high-density EEG if different ER strategies (expressive suppression vs. cognitive reappraisal) predicted event-related potentials (ERPs) and brain source activity across affective prediction stages, as a function of contextual uncertainty. An S1-S2 paradigm with emotional faces and pictures as S1s and S2s was presented to 36 undergraduates. Contextual uncertainty was manipulated across three blocks with 100, 75, or 50% S1-S2 affective congruency. The effects of ER strategies, as assessed through the Emotion Regulation Questionnaire, on ERP and brain source activity were tested for each prediction stage through linear mixed-effects models. No ER strategy affected prediction generation. During implementation, in the 75% block, a higher tendency to suppress emotions predicted higher activity in the left supplementary motor area at 1,500–2,000 ms post-stimulus, and smaller amplitude of the Contingent Negative Variation at 2,000–2,500 ms. During updating, in the 75% block, a higher tendency to cognitively reappraise emotions predicted larger P2, Late Positive Potential, and right orbitofrontal cortex activity. These results suggest that both ER strategies interact with the levels of contextual uncertainty by differently modulating ERPs and source activity, and that different strategies are deployed in a moderately predictive context, supporting the efficient updating of affective predictive models only in the context in which model updating occurs.

Amygdala function in emotion, cognition, and behavior

The amygdala is a core structure in the anterior medial temporal lobe, with an important role in several brain functions involving memory, emotion, perception, social cognition, and even awareness. As a key brain structure for saliency detection, it triggers and controls widespread modulatory signals onto multiple areas of the brain, with a great impact on numerous aspects of adaptive behavior. Here we discuss the neural mechanisms underlying these functions, as established by animal and human research, including insights provided in both healthy and pathological conditions.

Neural substrates of the interplay between cognitive load and emotional involvement in bilingual decision making

Prior work has reported that foreign language influences decision making by either reducing access to emotion or imposing additional cognitive demands. In this fMRI study, we employed a cross-task design to assess at the neural level whether and how the interaction between cognitive load and emotional involvement is affected by language (native L1 vs. foreign L2). Participants completed a Lexico-semantic task where in each trial they were presented with a neutrally or a negatively valenced word either in L1 or L2, either under cognitive load or not. We manipulated cognitive load by varying the difficulty of the task: to increase cognitive demands, we used traditional characters instead of simplified ones in L1 (Chinese), and words with capital letters instead of lowercase letters in L2 (English). After each trial, participants decided whether to take a risky decision in a gambling game. During the Gamling task, left amygdala and right insula were more activated after having processed a negative word under cognitive load in the Lexico-semantic task. However, this was true for L1 but not for L2. In particular, in L1, cognitive load facilitated rather than hindered access to emotion. Further suggesting that cognitive load can enhance emotional sensitivity in L1 but not in L2, we found that functional connectivity between reward-related striatum and right insula increased under cognitive load only in L1. Overall, results suggest that cognitive load in L1 can favor access to emotion and lead to impulsive decision making, whereas cognitive load in L2 can attenuate access to emotion and lead to more rational decisions.

Brain circuits signaling the absence of emotion in body language

Adaptive social behavior and mental well-being depend on not only recognizing emotional expressions but also, inferring the absence of emotion. While the neurobiology underwriting the perception of emotions is well studied, the mechanisms for detecting a lack of emotional content in social signals remain largely unknown. Here, using cutting-edge analyses of effective brain connectivity, we uncover the brain networks differentiating neutral and emotional body language. The data indicate greater activation of the right amygdala and midline cerebellar vermis to nonemotional as opposed to emotional body language. Most important, the effective connectivity between the amygdala and insula predicts people's ability to recognize the absence of emotion. These conclusions extend substantially current concepts of emotion perception by suggesting engagement of limbic effective connectivity in recognizing the lack of emotion in body language reading. Furthermore, the outcome may advance the understanding of overly emotional interpretation of social signals in depression or schizophrenia by providing the missing link between body language reading and limbic pathways. The study thus opens an avenue for multidisciplinary research on social cognition and the underlying cerebrocerebellar networks, ranging from animal models to patients with neuropsychiatric conditions.

Temporal dynamics of amygdala response to emotion- and action-relevance

It has been proposed that the human amygdala may not only encode the emotional value of sensory events, but more generally mediate the appraisal of their relevance for the individual’s goals, including relevance for action or task-based needs. However, emotional and non-emotional/action-relevance might drive amygdala activity through distinct neural signals, and the relative timing of both kinds of responses remains undetermined. Here, we recorded intracranial event-related potentials from nine amygdalae of patients undergoing epilepsy surgery, while they performed variants of a Go/NoGo task with faces and abstract shapes, where emotion- and action-relevance were orthogonally manipulated. Our results revealed early amygdala responses to emotion facial expressions starting ~ 130 ms after stimulus-onset. Importantly, the amygdala responded to action-relevance not only with face stimuli but also with abstract shapes (squares), and these relevance effects consistently occurred in later time-windows (starting ~ 220 ms) for both faces and squares. A similar dissociation was observed in gamma activity. Furthermore, whereas emotional responses habituated over time, the action-relevance effect increased during the course of the experiment, suggesting progressive learning based on the task needs. Our results support the hypothesis that the human amygdala mediates a broader relevance appraisal function, with the processing of emotion-relevance preceding temporally that of action-relevance.

Effects of Yoga Respiratory Practice (Bhastrika pranayama) on Anxiety, Affect, and Brain Functional Connectivity and Activity: A Randomized Controlled Trial

Pranayama refers to a set of yoga breathing exercises. Recent evidence suggests that the practice of pranayama has positive effects on measures of clinical stress and anxiety. This study explored the impact of a Bhastrika pranayama training program on emotion processing, anxiety, and affect. We used a randomized controlled trial design with thirty healthy young adults assessed at baseline and after 4 weeks of pranayama practices. Two functional magnetic resonance imaging (MRI) protocols were used both at baseline and post-intervention: an emotion task as well as a resting-state acquisition. Our results suggest that pranayama significantly decreased states of anxiety and negative affect. The practice of pranayama also modulated the activity of brain regions involved in emotional processing, particularly the amygdala, anterior cingulate, anterior insula, and prefrontal cortex. Resting-state functional MRI (fMRI) showed significantly reduced functional connectivity involving the anterior insula and lateral portions of the prefrontal cortex. Correlation analysis revealed that changes in connectivity between the ventrolateral prefrontal cortex and the right anterior insula were associated with changes in anxiety. Although it should be noted that these analyses were preliminary and exploratory, it provides the first evidence that 4 weeks of B. pranayama significantly reduce the levels of anxiety and negative affect, and that these changes are associated with the modulation of activity and connectivity in brain areas involved in emotion processing, attention, and awareness. The study was registered at https://www.ensaiosclinicos.gov.br/rg/RBR-2gv5c2/(RBR-2gv5c2).