Multilevel analysis of positive emotional induction: Which is the role of gender and valence on cognitive control processes?

How emotions are processed affects people's cognition and behavior. One of the most used measures to study the physiological component of emotions is heart rate (HR), where greater HR variation (range) implies greater emotional processing. Several investigations established the importance of gender modulation of these processes due to the different cultural treatment given to emotions among genders. However, very heterogeneous results are reported today, and few studies incorporated these parameters when investigating emotion modulation of cognitive processes according to individual factors. The present work consists of two studies. In a pilot study, 97 young adults, through the Self-Assessment Manikin (SAM), ranged the valence and arousal to select two positive and neutral videos. The second study analyses the role of gender and valence in the variation of subjective (SAM) and physiological (HR) indicators of emotional processing associated with performance in two cognitive tasks (Stroop and Tower of London) under two different emotional conditions. Participants were 60 adults, who were randomly assigned to positive or neutral video visualization, and their HR was registered. There was a tendency for women to have higher HR during positive videos than in neutral. While the subjective reports indicated variances in the appraisal of the videos, the heart rate did not exhibit differences across the experimental conditions. Few studies integrate emotional and cognitive components, and include physiological and subjective measures of emotional processing. These findings illustrate the importance of including various measures of emotional and cognitive processing.

Amplification of Positivity Treatment for Anxiety and Depression: A Randomized Experimental Therapeutics Trial Targeting Social Reward Sensitivity to Enhance Social Connectedness

BACKGROUND

Social disconnection is common and causes significant impairment in anxiety and depressive disorders, and it does not respond sufficiently to available treatments. The positive valence system supports social bond formation and maintenance but is often hyporesponsive in people with anxiety or depression. We conducted an experimental therapeutics trial to test the hypothesis that targeting positive valence processes through cognitive and behavioral strategies would enhance responsivity to social rewards, a core mechanism underlying social connectedness.

METHODS

Sixty-eight adults who endorsed clinically elevated anxiety and/or depression with social impairment were randomized 1:1:1 to 5 (n = 23) or 10 (n = 22) sessions of amplification of positivity (AMP) treatment or waitlist (n = 23). Pre- to posttreatment change in striatal activity (primary outcome) during social reward anticipation was measured using functional magnetic resonance imaging, and reactivity to a social affiliation task (secondary) and self-reported social connectedness (exploratory) were examined. Primary analyses compared AMP (doses combined) versus waitlist. A second aim was to compare the effects of different doses.

RESULTS

AMP engaged the hypothesized treatment target, leading to greater striatal activation during anticipation of social rewards versus waitlist (d = 1.01 [95% CI = 0.42-1.61]; largest striatal volume). AMP yielded larger improvements in positive affect and approach behavior during the affiliation task (but not other outcomes) and social connectedness. Larger striatal and social connectedness increases were observed for 5-session versus 10-session AMP (d range = 0.08-1.03).

CONCLUSIONS

Teaching people with anxiety or depression strategies to increase positive thoughts, behaviors, and emotions enhances activity in brain regions that govern social reward processing and promotes social connectedness. Social reward sensitivity may be a transdiagnostic target for remediating social disconnection.

A putative loop connection between VTA dopamine neurons and nucleus accumbens encodes positive valence to compensate for hunger

Dopamine (DA) signal play pivotal roles in regulating motivated behaviors, including feeding behavior, but the role of midbrain DA neurons in modulating food intake and neural circuitry mechanisms remain largely unknown. Here, we found that activating but not inhibiting ventral tegmental area (VTA) DA neurons reduces mouse food intake. Furthermore, DA neurons in ventral VTA, especially neurons projecting to the medial nucleus accumbens (NAc), are activated by refeeding in the 24 h fasted mice. Combing neural circuitry tracing, optogenetic, chemogenetic, and pharmacological manipulations, we established that the VTA→medial NAc→VTA loop circuit is critical for the VTA DA neurons activation-induced food intake reduction. Moreover, activating either VTA DA neurons or dopaminergic axons in medial NAc elevates positive valence, which will compensate for the hungry-induced food intake. Thus, our study identifies a subset of positive valence-encoded VTA DA neurons forming possible loop connections with medial NAc that are anorexigenic.

Characterizing positive and negative valence systems function in adolescent depression: An RDoC-informed approach integrating multiple neural measures

Depression is a prevalent, debilitating, and costly disorder that often manifests in adolescence. There is an urgent need to understand core pathophysiological processes for depression to inform more targeted intervention efforts. The Research Domain Criteria (RDoC) Positive Valence Systems (PVS) and Negative Valence Systems (NVS) have both been implicated in depression symptomatology and vulnerability; however, the nature of NVS alterations is unclear across studies, and associations between single neural measures and symptoms are often small in magnitude and inconsistent. The present study advances characterization of depression in adolescence via an innovative data-driven approach to identifying subgroups of PVS and NVS function by integrating multiple neural measures (assessed by electroencephalogram [EEG]) relevant to depression in adolescents oversampled for clinical depression and depression risk based on maternal history (N = 129; 14-17 years old). Results of the k-means cluster analysis supported a two-cluster solution wherein one cluster was characterized by relatively attenuated reward and emotion responsiveness across valences and the other by relatively intact responsiveness. Youth in the attenuated responsiveness cluster reported significantly greater depressive symptoms and were more likely to have major depressive disorder diagnoses than youth in the intact responsiveness cluster. In contrast, associations of individual neural measures with depressive symptoms were non-significant. The present study highlights the importance of innovative neuroscience approaches to characterize emotional processing in depression across domains, which is imperative to advancing the clinical utility of RDoC-informed research.

Valence processing alterations in SAPAP3 knockout mice and human OCD

Abnormalities in valence processing - the processing of aversive or appetitive stimuli - may be an underrecognized component of obsessive-compulsive disorder (OCD). Preclinical rodent models have been critical in furthering pathophysiological understanding of OCD, yet there is a dearth of investigations examining whether rodent models of compulsive behavior show alterations in valence systems congruent with those seen in individuals with OCD. In this study, we sought to assess valence processing in a preclinical rodent model of compulsive behavior, the SAPAP3 knockout (KO) mouse model, and compare our preclinical findings to similar behavioral phenomena in OCD patients. In SAPAP3 KO mice, we used auditory fear conditioning and extinction to examine alterations in negative valence processing and reward-based operant conditioning to examine alterations in positive valence processing. We find that SAPAP3 KO mice show evidence of heightened negative valence processing through enhanced fear learning and impaired fear extinction. SAPAP3 KO mice also show deficits in reward acquisition and goal-directed behavior, suggesting impaired positive valence processing. In OCD patients, we used validated behavioral tests to assess explicit and implicit processing of fear-related facial expressions (negative valence) and socially-rewarding happy expressions (positive valence). We find similar trends towards enhanced negative and impaired positive valence processing in OCD patients. Overall, our results reveal valence processing abnormalities in a preclinical rodent model of compulsive behavior similar to those seen in OCD patients, with implications for valence processing alterations as novel therapeutic targets across a translational research spectrum.

Refeeding activates neurons in the dorsomedial hypothalamus to inhibit food intake and promote positive valence

Objective

The regulation of food intake is a major research area in the study of obesity, which plays a key role in the development of metabolic syndrome. Gene targeting studies have clarified the roles of hypothalamic neurons in feeding behavior, but the deletion of a gene has a long-term effect on neurophysiology. Our understanding of short-term changes such as appetite under physiological conditions is therefore still limited.

Methods

Targeted recombination in active populations (TRAP) is a newly developed method for labeling active neurons by using tamoxifen-inducible Cre recombination controlled by the promoter of activity-regulated cytoskeleton-associated protein (Arc/Arg3.1), a member of immediate early genes. Transgenic mice for TRAP were fasted overnight, re-fed with normal diet, and injected with 4-hydroxytamoxifen 1 h after the refeeding to label the active neurons. The role of labeled neurons was examined by expressing excitatory or inhibitory designer receptors exclusively activated by designer drugs (DREADDs). The labeled neurons were extracted and RNA sequencing was performed to identify genes that are specifically expressed in these neurons.

Results

Fasting-refeeding activated and labeled neurons in the compact part of the dorsomedial hypothalamus (DMH) that project to the paraventricular hypothalamic nucleus. Chemogenetic activation of the labeled DMH neurons decreased food intake and developed place preference, an indicator of positive valence. Chemogenetic activation or inhibition of these neurons had no influence on the whole-body glucose metabolism. The labeled DMH neurons expressed prodynorphin (pdyn), gastrin-releasing peptide (GRP), cholecystokinin (CCK), and thyrotropin-releasing hormone receptor (Trhr) genes.

Conclusions

We identified a novel cell type of DMH neurons that can inhibit food intake and promote feeding-induced positive valence. Our study provides insight into the role of DMH and its molecular mechanism in the regulation of appetite and emotion.

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Fasting-refeeding activates a subset of neurons in the dorsomedial hypothalamus (DMH).

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Chemogenetic inhibition of the DMH neurons increases food intake.

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Chemogenetic activation of the DMH neurons inhibits food intake and promotes positive valence.

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The DMH neurons express pdyn, GRP, CCK and Trhr genes.

Initial Responsiveness to Reward Attainment and Psychopathology in Children and Adults: An RDoC Study

The Research Domain Criteria (RDoC) initiative of the National Institute of Mental Health (NIMH) established a dimensional framework for understanding psychiatric constructs. Initial Responsiveness to Reward Attainment (IRRA) was identified as a dimensional construct relevant to several psychiatric disorders. The current study aimed to (1) examine IRRA as a predictor of psychopathology and impairment in children and their parents, and (2) examine the potential effects of sex and ancestry on the relationship between IRRA and psychopathology. Participants included 1127 children ages 6 to 12, and 1018 of their parents. Parents and children completed self-report measures of IRRA. Psychopathology and impairment were measured using self-report for adults, and parent-report and semi-structured interview for children. In adults, IRRA was significantly, but modestly, related to adaptive functioning. In children, IRRA was significantly, but modestly, related to overall, school, spare time, home, and peer functioning. Findings suggest IRRA may be a helpful construct for understanding adaptive functioning in adults and children, however it may be less helpful for understanding specific dimensions of psychopathology. Additionally, ancestry should be taken into consideration when examining how IRRA relates to psychopathology and functioning.

Developmental trajectories to reduced activation of positive valence systems: A review of biological and environmental contributions

Reduced activation of positive valence systems (PVS), including blunted neural and physiological responses to pleasant stimuli and rewards, has been shown to prospectively predict the development of psychopathology. Yet, little is known about how reduced PVS activation emerges across development or what implications it has for prevention. We review genetic, temperament, parenting, and naturalistic and laboratory stress research on neural measures of PVS and outline developmentally-informed models of trajectories of PVS activation. PVS function is partly heritable and appears to reflect individual differences in early-emerging temperament traits. Although lab-induced stressors blunt PVS activation, effects of parenting and naturalistic stress on PVS are mixed and depend on the type of stressor, developmental timing, and interactions amongst risk factors. We propose that there may be multiple, dynamic developmental trajectories to reduced PVS activation in which combinations of genes, temperament, and exposure to severe, prolonged, or uncontrollable stress may exert direct and interactive effects on PVS function. Critically, these risk factors may alter PVS developmental trajectories and/or PVS sensitivity to proximal stressors. Distinct factors may converge such that PVS activation proceeds along a typical, accelerated, chronically low, or stress-reactive trajectory. Finally, we present directions for future research with translational implications.

A tale of two systems: Testing a positive and negative valence systems framework to understand social disconnection across anxiety and depressive disorders

BACKGROUND

Social disconnection is a common and pernicious feature of anxiety and depressive disorders, yet is insufficiently addressed by our best available treatments. To better understand why people with anxiety and depression feel socially disconnected, we tested a positive and negative valence systems framework informed by research on how normative social connections develop and flourish.

METHOD

Individuals seeking treatment for anxiety or depression (N = 150) completed measures of perceived social connectedness, positive and negative valence temperament, social goals, affect, symptoms, and life satisfaction.

RESULTS

Feeling less socially connected was associated with diminished life satisfaction, beyond clinical symptom severity. Regression analyses revealed that both diminished positive valence and heightened negative valence temperament, and their corresponding motivational and affective outputs, were significantly and uniquely (with no significant interaction between them) associated with lower perceived connectedness.

LIMITATIONS

Data was cross-sectional and based on self-report-limiting conclusions about causality and social disconnection processes at different units of analysis.

CONCLUSIONS

Understanding social disconnection through the lens of a positive and negative valence systems framework may inform transdiagnostic models and treatment approaches.

Counting trees in Random Forests: Predicting symptom severity in psychiatric intake reports

The CEGS N-GRID 2016 Shared Task (Filannino et al., 2017) in Clinical Natural Language Processing introduces the assignment of a severity score to a psychiatric symptom, based on a psychiatric intake report. We present a method that employs the inherent interview-like structure of the report to extract relevant information from the report and generate a representation. The representation consists of a restricted set of psychiatric concepts (and the context they occur in), identified using medical concepts defined in UMLS that are directly related to the psychiatric diagnoses present in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) ontology. Random Forests provides a generalization of the extracted, case-specific features in our representation. The best variant presented here scored an inverse mean absolute error (MAE) of 80.64%. A concise concept-based representation, paired with identification of concept certainty and scope (family, patient), shows a robust performance on the task.

Twice the negativity bias and half the positivity offset: Evaluative responses to emotional information in depression

BACKGROUND AND OBJECTIVES

Humans have the dual capacity to assign a slightly pleasant valence to neutral stimuli (the positivity offset) to encourage approach behaviors, as well as to assign a higher negative valence to unpleasant images relative to the positive valence to equally arousing and extreme pleasant images (the negativity bias) to facilitate defensive strategies. We conducted an experimental psychopathology study to examine the extent to which the negativity bias and the positivity offset differ in participants with and without major depression..

METHOD

Forty-one depressed and thirty-six healthy participants were evaluated using a structured clinical interview for DSM-IV Axis I disorders, questionnaires, and a computerized task designed to measure implicit affective responses to unpleasant, neutral, and pleasant stimuli.

RESULTS

The negativity bias was significantly higher and the positivity offset was significantly lower in depressed relative to healthy participants..

LIMITATIONS

Entry criteria enrolling medication-free participants with minimal DSM-IV comorbidity may limit generalizability of the findings.

CONCLUSIONS

This study advances our understanding of the positive and negative valence systems in depression, highlighting the irregularities in the positive valence system..

Heart rate variability as a potential indicator of positive valence system disturbance: A proof of concept investigation

One promising avenue toward a better understanding of the pathophysiology of positive emotional disturbances is to examine high-frequency heart rate variability (HRV-HF), which has been implicated as a potential physiological index of disturbances in positive emotional functioning. To date, only a few psychopathology relevant studies have systematically quantified HRV-HF profiles using more ecologically valid methods in everyday life. Using an experience-sampling approach, the present study examined both mean levels and intra-individual variability of HRV-HF - as well as comparison measures of cardiovascular arousal, sympathetic activity, and gross somatic movement - in everyday life, using ambulatory psychophysiological measurement across a six-day consecutive period among a spectrum of community adult participants with varying degrees of positive valence system disturbance, including adults with bipolar I disorder (BD; n=21), major depressive disorder (MDD; n=17), and healthy non-psychiatric controls (CTL; n=28). Groups did not differ in mean HRV-HF, but greater HRV-HF instability (i.e., intra-individual variation in HRV-HF) was found in the BD compared to both MDD and CTL groups. Subsequent analyses suggested that group differences in HRV-HF variability were largely accounted for by variations in clinician-rated manic symptoms. However, no association was found between HRV-HF variability and dimensional measures of positive affectivity. This work provides evidence consistent with a quadratic relationship between HRV-HF and positive emotional disturbance and represents a valuable step toward developing a more ecologically valid model of positive valence system disturbances and their underlying psychophysiological mechanisms within an RDoC framework.

Evaluative conditioning of positive and negative valence affects P1 and N1 in verbal processing

The present study examined the effect of contextual learning on the neural processing of previously meaningless pseudowords. During an evaluative conditioning session on 5 consecutive days, participants learned to associate 120 pseudowords with either positive, neutral or negative pictures. In a second session, participants were presented all conditioned pseudowords again together with 40 new pseudowords in a recognition memory task while their event-related potentials (ERPs) were recorded. The behavioral data confirm successful learning of pseudoword valence. At the neural level, early modulations of the ERPs are visible at the P1 and the N1 components discriminating between positively and negatively conditioned pseudowords. Differences to new pseudowords were visible at later processing stages as indicated by modulations of the LPC. These results support a contextual learning hypothesis that is able to explain very early emotional ERP modulations in visual word recognition. Source localization indicates a role of medial-frontal brain regions as a likely origin of these early valence discrimination signals which are discussed to promote top-down signals to sensory processing.