Neural activity to threat in ventromedial prefrontal cortex correlates with individual differences in anxiety and reward processing

Trauma and anxiety interactions relate to reward processing in adolescents

Anxiety is highly prevalent among adolescents, often linked to trauma exposure. However, not all youth with trauma develop anxiety, suggesting variability in risk pathways. This study investigates how neural reward system alterations may signal vulnerability to anxiety following trauma. We hypothesized that differences in reward-related connectivity in the ventral striatum and amygdala would distinguish adolescents with higher trauma and higher anxiety (anxiety risk group) from those with higher trauma but lower anxiety (non-anxiety development), as well as from youth with lower trauma and lower anxiety (typical development) and with lower trauma and higher anxiety (non-trauma-related anxiety). We utilized a sample of 44 adolescents (ages 11-19) with varying levels of trauma exposure and anxiety who completed a child-friendly monetary incentive delay task and analyzed their amygdala and ventral striatum functional connectivity during the task to assess the interaction between trauma exposure and anxiety levels. Our findings reveal distinct Trauma x Anxiety neural connectivity patterns in widespread prefrontal, temporal, and occipital clusters, potentially serving as biomarkers for anxiety risk. These results provide insight into potential neurobiological markers associated with anxiety vulnerability, bringing us a step closer to identifying targets for future intervention development. By highlighting unique patterns of reward processing associated with different trauma and anxiety profiles, this study advances our knowledge of the neural mechanisms underlying anxiety risk, laying the groundwork for future research on neurobiologically informed approaches to prevention and treatment.

The neurobiological basis of emotions and their connection to facial expressions in non-human mammals: insights in nonverbal communication

Recognizing that nonhuman animals are sentient beings has increased interest in studying their emotional state. Similar to humans, research has shown that some nonhuman mammals can modify facial expressions by contraction/relaxation of facial muscles according to their affective state. From a neurophysiological perspective, emotions are processed in several brain structures, mainly from the limbic system, such as the hypothalamus, hypophysis, hippocampus, prefrontal cortex, and amygdala. The converged pathways between the amygdala, the motor cortex, and its projections to the facial nerve control the movement of facial or mimetic muscles. Thus, facial expression is suggested to reflect the internal emotional state and could serve as an essential mode of nonverbal communication in mammals. In humans, the Facial Action Coding System (FACS) is a method that objectively analyzes facial movements using an anatomical base. In veterinary medicine, AnimalFACS is an adaptation of this system to eight animal species, including domestic animals (dogs, cats, and horses) and nonhuman primates (chimpanzees, orangutans, gibbons, macaques, and common marmosets). Considering these coded facial movements, current research aims to associate certain facial expressions with the animals' emotional states and affective contexts. Thus, this review aims to discuss recent findings associated with the neurobiology of emotions and facial expressions in non-human mammals, using AnimalFACS to understand nonverbal communication. Characterizing each facial expression according to different contexts might help identify if the animal is expressing a positive or negative emotional response to the event, which can improve nonverbal human-animal communication.

Neuromodulation of risk and reward processing during decision making in individuals with general anxiety disorder (GAD)

Individuals with general anxiety disorder (GAD) have an impaired future-oriented processing and altered reward perception, which might involve the ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC). Twenty-nine adults with GAD performed the balloon analogue risk-taking task (BART) and delay discounting task (DDT) during five sessions of transcranial direct current stimulation (tDCS) with different stimulation conditions. The stimulation conditions were: anodal dlPFC (F3)/cathodal vmPFC (Fp2), anodal vmPFC (Fp2)/cathodal dlPFC (F3), anodal dlPFC (F3)/cathodal right shoulder, anodal vmPFC (Fp2)/cathodal left shoulder, and sham stimulation. Cognitive modeling was used to extract process-based measures. The process-based modeling measures, rather than conventional outcome-based measures, showed a significant effect of stimulation condition. All real stimulation conditions improved the updating rate of prevalence, and risk taking in the BART. Moreover, for anodal dlPFC (F3)/cathodal vmPFC (Fp2), anodal vmPFC (Fp2)/cathodal dlPFC (F3), and anodal vmPFC (Fp2)/cathodal left shoulder stimulations we have observed an improvement in prior beliefs about the explosion. Also, for anodal dlPFC (F3)/cathodal vmPFC (Fp2), anodal dlPFC (F3)/cathodal right shoulder, anodal vmPFC (Fp2)/cathodal left shoulder we have observed more stable choice pattern. the DDT, exponential discounting rate and randomness were improved during anodal dlPFC and anodal vmPFC stimulation with extracranial return electrodes. Different roles of the targeted areas are discussed based on significant performance differences resulting from the specific electrode positions. The results suggest that different domains of reward processing are controlled by the vmPFC and dlPFC. The vmPFC is more relevant for value-based decision making with a positive expectation and chance-based randomness, whereas the dlPFC is more relevant for logic-based decision making.

Task-switching mechanisms under methamphetamine cravings: sex differences in cued and voluntary task-switching

Introduction

This study explored the effects of task-switching type and sex on the task-switching ability of methamphetamine abstainers, as well as the differences in brain mechanisms under drug cravings under drug cravings using near-infrared spectroscopy.

Methods

Craving-inducing videos were used to arouse 20 methamphetamine abstainers (including 10 men), whose switching ability was then assessed using voluntary and cued task-switching exercises.

Results

During task-switching under methamphetamine cravings, the activation of the premotor cortex (PMC), supplementary motor area (SMA), frontal eye field (FEF), and dorsolateral prefrontal cortex (DLPFC) in women was significantly stronger than in men, while the activation of FEF in men was significantly stronger than in women. Voluntary task-switching induced stronger FEF activation than cued task-switching. During the latter, women exhibited stronger activation in the anterior prefrontal cortex (aPFC) than men.

Discussion

Both men and women showed brain lateralization during task-switching under methamphetamine cravings. Men tended to adopt proactive control and use a top-down dominant strategy to start a new task. Women, however, tend to use a bottom-up strategy focusing on inhibiting old tasks and emotional switching. Moreover, in cued task-switching, the result shows women paid more attention to emotional processing than did men, which suggests that different task-switching training programs should be developed according to sex.

A U-shaped relationship between chronic academic stress and the dynamics of reward processing

Despite the potential link between stress-induced reward dysfunctions and the development of mental problems, limited human research has investigated the specific impacts of chronic stress on the dynamics of reward processing. Here we aimed to investigate the relationship between chronic academic stress and the dynamics of reward processing (i.e., reward anticipation and reward consumption) using event-related potential (ERP) technology. Ninety healthy undergraduates who were preparing for the National Postgraduate Entrance Examination (NPEE) participated in the study and completed a two-door reward task, their chronic stress levels were assessed via the Perceived Stress Scale (PSS). The results showed that a lower magnitude of reward elicited more negative amplitudes of cue-N2 during the anticipatory phase, and reward omission elicited more negative amplitudes of FRN compared to reward delivery especially in high reward conditions during the consummatory phase. More importantly, the PSS score exhibited a U-shaped relationship with cue-N2 amplitudes regardless of reward magnitude during the anticipatory phase; and FRN amplitudes toward reward omission in high reward condition during the consummatory phase. These findings suggest that individuals exposed to either low or high levels of chronic stress, as opposed to moderate stress levels, exhibited a heightened reward anticipation, and an augmented violation of expectations or affective response when faced with relatively more negative outcomes.

Sex differences in the effects of individual anxiety state on regional responses to negative emotional scenes

BACKGROUND

Men and women are known to show differences in the incidence and clinical manifestations of mood and anxiety disorders. Many imaging studies have investigated the neural correlates of sex differences in emotion processing. However, it remains unclear how anxiety might impact emotion processing differently in men and women.

METHOD

We recruited 119 healthy adults and assessed their levels of anxiety using State-Trait Anxiety Inventory (STAI) State score. With functional magnetic resonance imaging (fMRI), we examined regional responses to negative vs. neutral (Neg-Neu) picture matching in the Hariri task. Behavioral data were analyzed using regression and repeated-measures analysis of covariance with age as a covariate, and fMRI data were analyzed using a full-factorial model with sex as a factor and age as a covariate.

RESULTS

Men and women did not differ in STAI score, or accuracy rate or reaction time (RT) (Neg-Neu). However, STAI scores correlated positively with RT (Neg-Neu) in women but not in men. Additionally, in women, STAI score correlated positively with lingual gyrus (LG) and negatively with medial prefrontal cortex (mPFC) and superior frontal gyrus (SFG) activity during Neg vs. Neu trials. The parameter estimates (βs) of mPFC also correlated with RT (Neg-Neu) in women but not in men. Generalized psychophysiological interaction (gPPI) analysis in women revealed mPFC connectivity with the right inferior frontal gyrus, right SFG, and left parahippocampal gyrus during Neg vs. Neu trials in positive correlation with both STAI score and RT (Neg-Neu). In a mediation analysis, mPFC gPPI but not mPFC activity fully mediated the association between STAI scores and RT (Neg-Neu).

CONCLUSION

With anxiety affecting the behavioral and neural responses to negative emotions in women but not in men and considering the known roles of the mPFC in emotion regulation, we discussed heightened sensitivity and regulatory demands during negative emotion processing as neurobehavioral markers of anxiety in women.

Sex differences in the effects of individual anxiety state on regional responses to negative emotional scenes

Background

Men and women are known to show differences in the incidence and clinical manifestations of mood and anxiety disorders. Many imaging studies have investigated the neural correlates of sex differences in emotion processing. However, it remains unclear how anxiety might impact emotion processing differently in men and women.

Method

We recruited 119 healthy adults and assessed their levels of anxiety using State-Trait Anxiety Inventory (STAI) State score. With functional magnetic resonance imaging (fMRI), we examined regional responses to negative vs. neutral (Neg-Neu) picture matching in the Hariri task. Behavioral data were analyzed using regression and repeated-measures analysis of covariance with age as a covariate, and fMRI data were analyzed using a full-factorial model with sex as a factor and age as a covariate.

Results

Men and women did not differ in STAI score, or accuracy rate or reaction time (RT) (Neg-Neu). However, STAI scores correlated positively with RT (Neg-Neu) in women but not in men. Additionally, in women, STAI score correlated positively with lingual gyrus (LG) and negatively with medial prefrontal cortex (mPFC) and superior frontal gyrus (SFG) activity during Neg vs. Neu trials. The parameter estimates (β's) of mPFC also correlated with RT (Neg-Neu) in women but not in men. Generalized psychophysiological interaction (gPPI) analysis in women revealed mPFC connectivity with the right inferior frontal gyrus, right SFG, and left parahippocampal gyrus during Neg vs. Neu trials in positive correlation with both STAI score and RT (Neg-Neu). In a mediation analysis, mPFC gPPI but not mPFC activity fully mediated the association between STAI scores and RT (Neg-Neu).

Conclusion

With anxiety affecting the behavioral and neural responses to negative emotions in women but not in men and considering the known roles of the mPFC in emotion regulation, we discussed heightened sensitivity and regulatory demands during negative emotion processing as neurobehavioral markers of anxiety in women.

Neural habituation during acute stress signals a blunted endocrine response and poor resilience

BACKGROUND

A blunted hypothalamic-pituitary-adrenal (HPA) axis response to acute stress is associated with psychiatric symptoms. Although the prefrontal cortex and limbic areas are important regulators of the HPA axis, whether the neural habituation of these regions during stress signals both blunted HPA axis responses and psychiatric symptoms remains unclear. In this study, neural habituation during acute stress and its associations with the stress cortisol response, resilience, and depression were evaluated.

METHODS

Seventy-seven participants (17-22 years old, 37 women) were recruited for a ScanSTRESS brain imaging study, and the activation changes between the first and last stress blocks were used as the neural habituation index. Meanwhile, participants' salivary cortisol during test was collected. Individual-level resilience and depression were measured using questionnaires. Correlation and moderation analyses were conducted to investigate the association between neural habituation and endocrine data and mental symptoms. Validated analyses were conducted using a Montreal Image Stress Test dataset in another independent sample (48 participants; 17-22 years old, 24 women).

RESULTS

Neural habituation of the prefrontal cortex and limbic area was negatively correlated with cortisol responses in both datasets. In the ScanSTRESS paradigm, neural habituation was both positively correlated with depression and negatively correlated with resilience. Moreover, resilience moderated the relationship between neural habituation in the ventromedial prefrontal cortex and cortisol response.

CONCLUSIONS

This study suggested that neural habituation of the prefrontal cortex and limbic area could reflect motivation dysregulation during repeated failures and negative feedback, which might further lead to maladaptive mental states.

Cognitive Defusion and Psychological Flexibility Predict Negative Body Image in the Chinese College Students: Evidence from Acceptance and Commitment Therapy

Body dissatisfaction is a global phenomenon. Despite the significant cultural difference, most research on negative body image was conducted in Western countries. How do cognitive fusion and psychological flexibility relate to negative body image in the Chinese population? In the present study, this question was investigated through the intervention technique, Acceptance and Commitment Therapy (ACT). Here, 86 young Chinese university students with high negative physical self were invited, in which 42 students received 10 sessions of group-based ACT intervention in a clinical setting while the remained acted as the control group with no intervention. Pretests showed no statistical differences in negative body image between these two groups, while both cognitive fusion and psychological flexibility predicted negative body image. Post-pre tests showed no change in the control group, while enhanced cognitive defusion and psychological flexibility in the ACT group. Individual differences in psychological flexibility and cognitive defusion enhancement predicted improved body image. A strong association of implicit body image with Fatness and Shortness changes suggested that although with individual differences, those components could be internalized during the intervention in the College students.

Correcting the reward imbalance in binge eating: A pilot randomized trial of reward re-training treatment

Behavioral treatments for psychological disorders characterized by reward-driven maladaptive behaviors (e.g., substance use disorder, eating disorders, behavioral addictions) primarily seek to reduce hyper-reward response to disorder-specific stimuli. Suboptimal outcomes for these treatments highlight the need to also target hypo-reward response to day-to-day life activities. The present study sought to conduct an initial test of a novel behavioral treatment, Reward Re-Training (RRT) to target hyper- and hypo-reward response in individuals with binge eating. Individuals with binge eating (N = 23) were randomly assigned to either 10 weeks of outpatient, group-based RRT treatment or a waitlist control. RRT was found to be feasible and acceptable, demonstrated large impacts on both hypo- and hyper-reward response (measured by self-report (pre-to post-treatment ηp2 range 0.38-0.58) and neural activation via fMRI), and was efficacious in reducing eating disorder pathology (ηp2 range 0.40-0.64, including binge eating, ηp2 = 0.64) compared to waitlist control (ηp2 range 0.00-0.04). This pilot data provides preliminary support for the feasibility, acceptability, and effectiveness of a novel treatment targeting reward imbalance for individuals with binge eating. Future evaluations of RRT may benefit from an active treatment comparison condition and a follow-up assessment to examine persistence of positive outcomes.

An fMRI study of cognitive regulation of reward processing in generalized anxiety disorder (GAD)

BACKGROUND

Cognitive regulation can affect the process of decision making. Generalized anxiety disorder (GAD) patients seem to have an impairment in cognitive regulation of reward processing concerning food stimuli. This study aims to explore the impact of GAD in cognitive regulation of food-related rewards.

METHODS

GAD patients (n=11) and healthy controls (n=15) performed a cognitive regulation craving task with food images while undergoing a functional magnetic resonance imaging (fMRI) acquisition. Between-group differences in functional connectivity were measured using dorsolateral prefrontal cortex (dlPFC) and ventromedial prefrontal cortex (vmPFC) seeds during cognitive regulation.

RESULTS

During cognitive regulation, there was a significant interaction for functional connectivity between the right dlPFC and bilateral vmPFC with the thalamus. GAD patients had lower functional connectivity for cognitive regulation conditions (distance and indulge) than for the non-regulated condition in these clusters, while control participants presented the opposite pattern. GAD group presented fixed food valuation scores after cognitive regulation.

CONCLUSIONS

GAD participants showed inflexibility while valuating food images, that could be produced by cognitive regulation deficits underpinned by functional connectivity alterations between prefrontal regions and the thalamus. These results show cognitive inflexibility and difficulty in the modulation of cognitive responses during decision making in GAD patients.

The dysregulation of top-down control in individuals with high test anxiety: A resting state fMRI study

BACKGROUND

Individuals with high test anxiety (HTA) have deficits in attentional control and in stress responses when faced with tests. However, little is known about the underlying neural mechanism. Anterior cingulate cortex (ACC) is involved in both attention and emotion networks, therefore this study examined the neural functional dysregulation in test anxiety from the perspective of functional connectivity (FC) using bilateral ACC as the regions of interest.

METHODS

Fifty-one participants were divided into HTA (n = 23) and low test anxiety (LTA, n = 28) group according to their Test Anxiety Scale (TAS) scores. Brain imaging data in resting, preparing, and recovering phases of a modified social evaluative threat task were collected, and emotional changes were assessed.

RESULTS

Compared with the LTA group, the HTA group exhibited significantly lower FCs between the ACC and superior frontal gyrus (SFG) in all 3 phases, significantly lower FCs between the ACC and inferior parietal gyrus (IPG), and significantly higher FCs between the ACC superior temporal gyrus (STG) in the preparing phase. Moreover, in the HTA group, the resting state IPG-ACC FC was associated with their TAS score, the preparing state STG-ACC FC was associated with the increased anxiety.

CONCLUSIONS

Individuals with HTA have general prefrontal control deficits. When facing a test, they tend to recruit more resources to deal with high emotional interference. The dysregulated control of the ACC by the frontal-parietal network may underlie the pathophysiology of test anxiety.

Intrinsic organization of cortical networks predicts state anxiety: an functional near-infrared spectroscopy (fNIRS) study

Although state anxiety has been characterized by hyper-responsive subcortical activity and its bottom-up connectivity with cortical regions, the role of cortical networks in state anxiety is not yet well understood. To this end, we decoded individual state anxiety by using a machine-learning approach based on resting-state functional connectivity (RSFC) with functional near-infrared spectroscopy (fNIRS). Our results showed that the RSFC among a set of cortical networks were highly predictive of state anxiety, rather than trait anxiety. Specifically, these networks included connectivity between cortical areas in the default mode network (DMN) and dorsal attention network (DAN), and connectivity within the DMN, which were negatively correlated with state anxiety; connectivity between cortical areas in the DMN and frontoparietal network (FPN), FPN and salience network (SN), FPN and DAN, DMN and SN, which were positively correlated with state anxiety. These findings suggest a predictive role of intrinsic cortical organization in the assessment of state anxiety. The work provides new insights into potential neural mechanisms of emotion states and implications for prognosis, diagnosis, and treatment of affective disorders.

Differential color tuning of the mesolimbic reward system

Visual wavelengths are not only associated with the subjective experience of color but also have long been thought to regulate affect. Here we examined the attracting rewarding properties of opposite ends of the wavelength spectrum, as well as their individual variation. As reward is multifaceted, we sought convergent evidence from subjective and objective behavioral and attentional indices, as well as its neural reward system bases. On average, short (blue) relative to long (red) wavelengths were judged subjectively more pleasant and had objectively greater behavioral and attentional salience, regulating speed of simple color discriminations and perception of temporal order. Consistent with reward, these color effects were magnified following monetary reinforcement. Pronounced individual differences in color effects were related to reward but not punishment sensitivity, with blue relative to red preference associated with high relative to low reward sensitivity. An fMRI study revealed these individual differences were supported by color-dependent functional coupling between the visual cortices and mesolimbic reward circuitry. Our findings reveal the reward bases of color, demonstrating color is a potent regulator of perception, action, and neural dynamics.

Pain modulates neural responses to reward in the medial prefrontal cortex

Pain has been found to promote reward‐seeking behaviors, which might be a consequence of modulated brain activities in the reward neural circuitry in a painful state. The present study investigated how pain affected reward processing and reward‐related neural activities using fMRI technique. A total of 50 healthy participants were recruited and used for data analyses, with half being treated with topical capsaicin cream and the other half with hand cream (treatment: pain or control). The participants were asked to perform a card‐guessing game when their brain activities responding to feedbacks (outcome: win or loss) were recorded. Behavioral results showed that participants in pain group overestimated their correct choices in the card‐guess game. Whole‐brain fMRI analysis revealed that the main effect of outcome (win vs. loss) activated a typical network of the reward neural circuitry, including the medial prefrontal cortex (mPFC) and the bilateral nucleus accumbens (NAcc). Importantly, the region of interest analysis revealed a significant interaction of treatment and outcome in the mPFC, with increased mPFC neural activity responding to win outcome in pain condition. Moreover, the functional connectivity between the mPFC and the NAcc was decreased in pain condition. We conclude that the pain‐induced modulation of the mPFC activity could result in alterations of both the emotional response to and the cognitive evaluation of reward.

Investigations into ventral prefrontal cortex using mediation models

The ventral prefrontal cortex (vPFC) is a major focus of investigation in neuroscience, particularly in the studies of emotion and emotion-cognition integration. A crucial question concerning the regulatory function of vPFC is how it is recruited, especially how the function maps onto the structure and determines appropriate behavior. In social exclusion studies, mediation model analyses suggest that vPFC regulates distress by disrupting anterior cingulate cortex (ACC) activities, whereas I recently report (Hu, 2018; Neuropsychologia) that ventral medial prefrontal cortex appears to defend the organism from acute stress by activating ACC. In this review, I synthesize and highlight functional imaging research with mediation analysis that over the past decades has begun to offer new insights into the brain mechanisms underlying vPFC. Toward this end, the first section of the paper outlines a model of the processes and neural systems involved in the interaction of emotion and cognition. The second and third sections survey recent research on emotional regulation with negative and positive pathways, respectively, emanating from vPFC. The fourth section summarizes the current dynamic network findings. Functional mediation analysis helps to identify signals within vPFC and others that are common and/or specific to particular information processing. Finally, I provide a personal perspective of the adoption of mediation model analysis in the investigations into vPFC.

Yellow is for safety: perceptual and affective perspectives

Is there a link between color and safety? Yellow is often used in safety contexts. Using the Singapore accident record datasets, Ho et al. provided evidence that yellow taxis have fewer accidents than blue taxis (Ho et al. in Proc Natl Acad Sci 114(12):3074-3078, 2017). Does yellow differentially influence attention and action and if so is this related to purely visual or affective factors? Here, we examined the visual priority of yellow relative to luminance matched colors at opposing ends of the wavelength spectrum (i.e., red and blue), using a temporal order judgment task, between color pairs. Despite being matched in arousal, when yellow and blue were pitted against each other, yellow was consistently seen as occurring first, even when objectively appearing second at short stimulus onset asynchronies. Despite being matched in valence, yellow again showed a larger temporal priority when it was pitted against red. Yellow temporal priority bias was modulated by individual differences in regulatory focus, highlighting a potential affective-motivational origin. These results support that yellow is a safety color, having a temporal advantage, and further evidence that colors have special influences on cognition, perception and behavior.