Neuroscience of affect: brain mechanisms of pleasure and displeasure

Similarities and differences between post-traumatic stress disorder and major depressive disorder: Evidence from task-evoked functional magnetic resonance imaging meta-analysis

BACKGROUND

Post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) are psychiatric disorders that can present with overlapping symptoms and shared risk factors. However, the extent to which these disorders share common underlying neuropathological mechanisms remains unclear. To investigate the similarities and differences in task-evoked brain activation patterns between patients with PTSD and MDD.

METHODS

A coordinate-based meta-analysis was conducted across 35 PTSD studies (564 patients and 543 healthy controls) and 125 MDD studies (4049 patients and 4170 healthy controls) using anisotropic effect-size signed differential mapping software.

RESULTS

Both PTSD and MDD patients exhibited increased neural activation in the bilateral inferior frontal gyrus. However, PTSD patients showed increased neural activation in the right insula, left supplementary motor area extending to median cingulate gyrus and superior frontal gyrus (SFG), and left fusiform gyrus, and decreased neural activation in the right posterior cingulate gyrus, right middle temporal gyrus, right paracentral lobule, and right inferior parietal gyrus relative to MDD patients.

CONCLUSION

Our meta-analysis suggests that PTSD and MDD share some similar patterns of brain activation, but also have distinct neural signatures. These findings contribute to our understanding of the potential neuropathology underlying these disorders and may inform the development of more targeted and effective treatment and intervention strategies. Moreover, these results may provide useful neuroimaging targets for the differential diagnosis of MDD and PTSD.

Different stressors uniquely affect the expression of endocannabinoid-metabolizing enzymes in the central ring ganglia of Lymnaea stagnalis

The endocannabinoid system (ECS) plays an important role in neuroprotection, neuroplasticity, energy balance, modulation of stress, and inflammatory responses, acting as a critical link between the brain and the body's peripheral regions, while also offering promising potential for novel therapeutic strategies. Unfortunately, in humans, pharmacological inhibitors of different ECS enzymes have led to mixed results in both preclinical and clinical studies. As the ECS has been highly conserved throughout the eukaryotic lineage, the use of invertebrate model organisms like the pond snail Lymnaea stagnalis may provide a flexible tool to unravel unexplored functions of the ECS at the cellular, synaptic, and behavioral levels. In this study, starting from the available genome and transcriptome of L. stagnalis, we first identified putative transcripts of all ECS enzymes containing an open reading frame. Each predicted protein possessed a high degree of sequence conservation to known orthologues of other invertebrate and vertebrate organisms. Sequences were confirmed by qualitative PCR and sequencing. Then, we investigated the transcriptional effects induced by different stress conditions (i.e., bacterial LPS injection, predator scent, food deprivation, and acute heat shock) on the expression levels of the enzymes of the ECS in Lymnaea's central ring ganglia. Our results suggest that in Lymnaea as in rodents, the ECS is involved in mediating inflammatory and anxiety-like responses, promoting energy balance, and responding to acute stressors. To our knowledge, this study offers the most comprehensive analysis so far of the ECS in an invertebrate model organism.

The computational structure of consummatory anhedonia

Anhedonia is a reduction in enjoyment, motivation, or interest. It is common across mental health disorders and a harbinger of poor treatment outcomes. The enjoyment aspect, termed 'consummatory anhedonia', in particular poses fundamental questions about how the brain constructs rewards: what processes determine how intensely a reward is experienced? Here, we outline limitations of existing computational conceptualisations of consummatory anhedonia. We then suggest a richer reinforcement learning (RL) account of consummatory anhedonia with a reconceptualisation of subjective hedonic experience in terms of goal progress. This accounts qualitatively for the impact of stress, dysfunctional cognitions, and maladaptive beliefs on hedonic experience. The model also offers new views on the treatments for anhedonia.

Animal play and evolution: Seven timely research issues about enigmatic phenomena

The nature of play in animals has been long debated, but progress is being made in characterizing play and its variants, documenting its distribution across vertebrate and invertebrate taxa, describing its mechanisms and development, and proposing testable theories about its origins, evolution, and adaptive functions. To achieve a deeper understanding of the functions and evolution of play, integrative and conceptual advances are needed in neuroscience, computer modeling, phylogenetics, experimental techniques, behavior development, and inter- and intra-specific variation. The special issue contains papers documenting many of these advances. Here, we describe seven timely areas where further research is needed to understand this still enigmatic class of phenomena more fully. Growing empirical and theoretical evidence reveals that play has been crucial in the evolution of behavior and psychology but has been underestimated, if not ignored, in both empirical and theoretical areas of evolutionary biology and neuroscience. Play research has important ramifications for understanding the evolution of cognition, emotion, and culture, and research on animals can be both informative and transformative.

Conditioned preferences: Gated by experience, context, and endocrine systems

Central to the navigation of an ever-changing environment is the ability to form positive associations with places and conspecifics. The functions of location and social conditioned preferences are often studied independently, limiting our understanding of their interplay. Furthermore, a de-emphasis on natural functions of conditioned preferences has led to neurobiological interpretations separated from ecological context. By adopting a naturalistic and ethological perspective, we uncover complexities underlying the expression of conditioned preferences. Development of conditioned preferences is a combination of motivation, reward, associative learning, and context, including for social and spatial environments. Both social- and location-dependent reward-responsive behaviors and their conditioning rely on internal state-gating mechanisms that include neuroendocrine and hormone systems such as opioids, dopamine, testosterone, estradiol, and oxytocin. Such reinforced behavior emerges from mechanisms integrating past experience and current social and environmental conditions. Moreover, social context, environmental stimuli, and internal state gate and modulate motivation and learning via associative reward, shaping the conditioning process. We highlight research incorporating these concepts, focusing on the integration of social neuroendocrine mechanisms and behavioral conditioning. We explore three paradigms: 1) conditioned place preference, 2) conditioned social preference, and 3) social conditioned place preference. We highlight nonclassical species to emphasize the naturalistic applications of these conditioned preferences. To fully appreciate the complex integration of spatial and social information, future research must identify neural networks where endocrine systems exert influence on such behaviors. Such research promises to provide valuable insights into conditioned preferences within a broader naturalistic context.

Perceptual representations mediate effects of stimulus properties on liking for music

Perceptual pleasure and its concomitant hedonic value play an essential role in everyday life, motivating behavior and thus influencing how individuals choose to spend their time and resources. However, how pleasure arises from perception of sensory information remains relatively poorly understood. In particular, research has neglected the question of how perceptual representations mediate the relationships between stimulus properties and liking (e.g., stimulus symmetry can only affect liking if it is perceived). The present research addresses this gap for the first time, analyzing perceptual and liking ratings of 96 nonmusicians (power of 0.99) and finding that perceptual representations mediate effects of feature-based and information-based stimulus properties on liking for a novel set of melodies varying in balance, contour, symmetry, or complexity. Moreover, variability due to individual differences and stimuli accounts for most of the variance in liking. These results have broad implications for psychological research on sensory valuation, advocating a more explicit account of random variability and the mediating role of perceptual representations of stimulus properties.

What is the role of the hippocampus and parahippocampal gyrus in the persistence of tinnitus?

The hippocampus and parahippocampal gyrus have been implicated as part of a tinnitus network by a number of studies. These structures are usually considered in the context of a "limbic system," a concept typically invoked to explain the emotional response to tinnitus. Despite this common framing, it is not apparent from current literature that this is necessarily the main functional role of these structures in persistent tinnitus. Here, we highlight a different role that encompasses their most commonly implicated functional position within the brain-that is, as a memory system. We consider tinnitus as an auditory object that is held in memory, which may be made persistent by associated activity from the hippocampus and parahippocampal gyrus. Evidence from animal and human studies implicating these structures in tinnitus is reviewed and used as an anchor for this hypothesis. We highlight the potential for the hippocampus/parahippocampal gyrus to facilitate maintenance of the memory of the tinnitus percept via communication with auditory cortex, rather than (or in addition to) mediating emotional responses to this percept.

The Endogenous Opioid System as a Pathway of Positive Emotions

Pleasant emotions take a variety of forms and are a key part of the human experience. Although negative emotions have often been a focus of research, positive emotions, e.g., joy, pleasure, and love, have recently gained more attention. Each of these emotions is rich and complex in its own right. However, positive emotions appear to serve key evolutionary functions, which are mediated by complex biological substrates. This chapter summarizes key research and explores the biological underpinnings of positive emotions, with an emphasis on the roles that endogenous opioids play in the experience, expression, and development of positive emotions. The necessity of emphasizing positive emotions in research is also discussed.

Sadism in the context of intergroup aggression

People more readily harm members of outgroups than ingroups, often enjoying the inflicted agony. Yet it remains unclear how these malevolent tendencies towards outgroups relate to sadism. Sadists often harm others, driven by a desire to feel pleasure from their suffering. In attempt to bridge these two lines of research, this work examined relationships between sadism and aggression against ingroup and outgroup members in three studies (total N = 755) that focused on two groups with a history of conflict (i.e., the United Kingdom and the Republic of Ireland). Across all studies, British participants' sadistic tendencies were just as strongly linked to their aggression against ingroup members (i.e., British partners) as to their aggression against outgroup members (i.e., Irish partners). Despite this lack of a preference for greater outgroup aggression, they tended to enjoy outgroup aggression more than ingroup aggression, especially at its extreme levels. These findings extend works linking sadism to aggression into the domain of intergroup relations and bind together research on sadism and intergroup schadenfreude.

The role of emotion in eating behavior and decisions

The present paper aims to provide the latest perspectives and future directions on the association between emotions and eating behavior. We discussed individual differences in the impact of negative emotions on eating, emotional eating as disinhibited eating decisions with heightened reward values of and sensitivity to palatable foods in response to negative emotions and social isolation, in addition to emotional eating as maladaptive coping strategies under negative emotion and stress, hedonic (pleasure-oriented) eating decisions mediated by the brain reward system, and self-controlled (health-oriented) eating decisions mediated by the brain control system. Perspectives on future directions were addressed, including the development of early eating phenotypes in infancy, shared neural mechanisms mediated by the ventromedial prefrontal cortex and the dorsolateral prefrontal cortex in emotion and eating decision regulation, possible roles of interoception incorporating hunger and satiety signals, gut microbiome, the insula and the orbitofrontal cortex, and emotional processing capacities in hedonic eating and weight gain.

Functional architecture of dopamine neurons driving fear extinction learning

The ability to extinguish fear responses to stimuli that no longer predict danger is critical for adaptive behavior and increases the likelihood of survival. During fear extinction, dopamine (DA) neurons signal the absence of the expected aversive outcome, and this extinction prediction error (EPE) signal is crucial for initiating and driving extinction learning. However, the neural circuits underlying the EPE signal have remained elusive. Here, we investigate the input-output circuitry of EPE-encoding DA neurons in male mice. By employing projection-specific fiber photometry and optogenetics, we demonstrate that these neurons project to a restricted subregion of the nucleus accumbens. Comprehensive anatomical analyses, as well as projection-specific chemogenetic manipulations combined with recordings of DA biosensors, further uncover the dorsal raphe as one key input structure critical for generating the EPE signal. Together, our results reveal for the first time the functional architecture of EPE-encoding DA neurons crucial for driving fear extinction learning.

The bright side of words: Norms for 9000 Spanish words in seven discrete positive emotions

In recent years, assumptions about the existence of a single construct of happiness that accounts for all positive emotions have been questioned. Instead, several discrete positive emotions with their own neurobiological and psychological mechanisms have been proposed. Of note, the effects of positive emotions on language processing are not yet properly understood. Here we provide a database for a large set of 9000 Spanish words scored by 3437 participants in the positive emotions of awe, contentment, amusement, excitement, serenity, relief, and pleasure. We also report significant correlations between discrete positive emotions and several affective (e.g., valence, arousal, happiness, negative discrete emotions) and lexico-semantic (e.g., frequency of use, familiarity, concreteness, age of acquisition) characteristics of words. Finally, we analyze differences between words conveying a single emotion ("pure" emotion words) and those denoting more than one emotion ("mixed" emotion words). This study will provide researchers a rich source of information to do research that contributes to expanding the current knowledge on the role of positive emotions in language. The norms are available at https://doi.org/10.6084/m9.figshare.21533571.v2.

Conceptualizing psychological resilience through resting-state functional MRI in a mentally healthy population: a systematic review

Conceptualizations and operational definitions of psychological resilience vary across resilience neuroimaging studies. Data on the neural features of resilience among healthy individuals has been scarce. Furthermore, findings from resting-state functional magnetic resonance imaging (fMRI) studies were inconsistent across studies. This systematic review summarized resting-state fMRI findings in different modalities from various operationally defined resilience in a mentally healthy population. The PubMed and MEDLINE databases were searched. Articles that focused on resting-state fMRI in relation to resilience, and published before 2022, were targeted. Orbitofrontal cortex, anterior cingulate cortex, insula and amygdala, were reported the most from the 19 included studies. Regions in emotional network was reported the most from the included studies. The involvement of regions like amygdala and orbitofrontal cortex indicated the relationships between emotional processing and resilience. No common brain regions or neural pathways were identified across studies. The emotional network appears to be studied the most in association with resilience. Matching fMRI modalities and operational definitions of resilience across studies are essential for meta-analysis.

Abnormal functional connectivity of the nucleus accumbens subregions mediates the association between anhedonia and major depressive disorder

BACKGROUND

The nucleus accumbens (Nac) is a crucial brain region in the pathophysiology of major depressive disorder (MDD) patients with anhedonia. However, the relationship between the functional imaging characteristics of Nac subregions and anhedonia remains unclear. Thus, this study aimed to investigate the role of resting-state functional connectivity (rsFC) of the Nac subregions between MDD and anhedonia.

METHODS

We performed resting-state functional magnetic resonance imaging (fMRI) to measure the rsFC of Nac subregions in 55 MDD patients and 30 healthy controls (HCs). A two-sample t test was performed to determine the brain regions with varying rsFC among Nac subregions between groups. Then, correlation analyses were carried out to investigate the relationships between the aberrant rsFC of Nac subregions and the severity of anhedonia. Furthermore, we constructed a mediation model to explain the role of the aberrant rsFC of Nac subregions between MDD and the severity of anhedonia.

RESULTS

Compared with the HC group, decreased rsFC of Nac subregions with regions of the prefrontal cortex, insula, lingual gyrus, and visual association cortex was observed in MDD patients. In the MDD group, the rsFC of the right Nac shell-like subregions with the middle frontal gyrus (MFG)/superior frontal gyrus (SFG) was correlated with consummatory anhedonia, and the rsFC of the Nac core-like subdivisions with the inferior frontal gyrus (IFG)/insula and lingual gyrus/visual association cortex was correlated with anticipatory anhedonia. More importantly, the functional alterations in the Nac subregions mediated the association between anhedonia and depression.

CONCLUSIONS

The present findings suggest that the functional alteration of the Nac subregions mediates the association between MDD and anhedonia, which provides evidence for the hypothesis that MDD patients have neurobiological underpinnings of reward systems that differ from those of HCs.

Structural brain alterations in young adult males with narcissistic personality disorder: a diffusion tensor imaging study

PURPOSES

1. To find a difference in white matter (WM) between young adult males with narcissistic personality disorder (NPD) and healthy controls (HCs). 2. To find some correlations between white matter in the abnormal regions of NPD group and the pathological narcissism inventory (PNI).

MATERIALS AND METHODS

Eighteen male participants with NPD (age M = 18.39, SD = 0.164; education M = 12.33, SD = 0.14) were included in our experiment. NPD participants met the DSM-IV criteria for NPD and without other personality disorders evaluated by trained clinical psychiatrists using the Structured Clinical Interview of DSM-IV for Personality Disorders (SCID-II). Moreover, healthy controls were also confirmed to be free of any axis I or II disorders and matched with education level, age and handedness (age M = 18.83 years, SD = 0.246; education M = 12.56, SD = 0.202; all participants were right handed). Those who have had major life events in the last six months, mental and physical illnesses, claustrophobia and oral implants have been excluded. We used tract-based spatial statistics (TBSS) on diffusion tensor images (DTI) and analysis of Pearson correlation between abnormal brain regions of white matter fibers and the pathological narcissism inventory.

RESULTS

There was no significant difference in age and education level between NPD and HCs (p > 0.05). There were significant differences in PNI score and its subscales between NPD group and HCs (p < 0.01). Fractional anisotropy (FA) values were found decreased mainly in the right superior longitudinal fasciculus and the bilateral posterior thalamic radiation (include optic radiation). Lower axial diffusivity (AD) values were identified mostly in the left retrolenticular part of internal capsule and the left posterior thalamic radiation (include optic radiation). There existed a significant correlation between DTI data and pathological narcissism inventory.

CONCLUSIONS

The decreased brain white matter microstructures among three clusters were found in the association, projection/thalamic and connection pathways of white matter in young adult males with NPD. The abnormal white matter brain regions may be one of the neuropathological basis of the pathogenesis of young males with NPD, and it may be related to white matter development in early adulthood.

The satisfaction is mine: revenge seeking following extrinsic reward

The extrinsic reward should impede revenge-seeking if revenge is solely driven by the desire to feel gratified. Study 1 (N = 114) showed that satisfaction from receiving monetary compensation decreased thinking about getting back at the provocateur. However, Study 2 (N = 213) found that insulted participants aggressed against their partners despite fulfillment from receiving the unexpected monetary reward. This evidence indicates that gratification is insufficient to impede revenge following provocation, suggesting that avengers want to feel pleasure when retaliating and want to balance the scales by sending offenders a message.

Gait control by the frontal lobe

The frontal lobe is crucial and contributes to controlling truncal motion, postural responses, and maintaining equilibrium and locomotion. The rich repertoire of frontal gait disorders gives some indication of this complexity. For human walking, it is necessary to simultaneously achieve at least two tasks, such as maintaining a bipedal upright posture and locomotion. Particularly, postural control plays an extremely significant role in enabling the subject to maintain stable gait behaviors to adapt to the environment. To achieve these requirements, the frontal cortex (1) uses cognitive information from the parietal, temporal, and occipital cortices, (2) creates plans and programs of gait behaviors, and (3) acts on the brainstem and spinal cord, where the core posture-gait mechanisms exist. Moreover, the frontal cortex enables one to achieve a variety of gait patterns in response to environmental changes by switching gait patterns from automatic routine to intentionally controlled and learning the new paradigms of gait strategy via networks with the basal ganglia, cerebellum, and limbic structures. This chapter discusses the role of each area of the frontal cortex in behavioral control and attempts to explain how frontal lobe controls walking with special reference to postural control.

Behavioral Variant Frontotemporal Dementia and Social and Criminal Transgressions

OBJECTIVE

Behavioral variant frontotemporal dementia (bvFTD) is associated with social and criminal transgressions; studies from countries around the world have documented such behavior in persons with this condition. An overview and analysis of social and criminal transgressions in bvFTD and their potential neurobiological mechanisms can provide a window for understanding the relationship of antisocial behavior and the brain.

METHODS

This review evaluated the literature on the frequency of social and criminal transgressions in bvFTD and the neurobiological disturbances that underlie them.

RESULTS

There is a high frequency of transgressions among patients with bvFTD due to impairments in neurocognition, such as social perception, behavioral regulation, and theory of mind, and impairments in social emotions, such as self-conscious emotions and empathy. Additionally, there is significant evidence for a specific impairment in an innate sense of morality. Alterations in these neurobiological processes result from predominantly right-hemisphere pathology in frontal (ventromedial, orbitofrontal, inferolateral frontal), anterior temporal (amygdala, temporal pole), limbic (anterior cingulate, amygdala), and insular regions.

CONCLUSIONS

Overlapping disturbances in neurocognition, social emotions, and moral reasoning result from disease in the mostly mesial and right-sided frontotemporal network necessary for responding emotionally to others and for behavioral control. With increased sophistication in neurobiological interventions, future goals may be the routine evaluation of these processes among individuals with bvFTD who engage in social and criminal transgressions and the targeting of these neurobiological mechanisms with behavioral, pharmacological, and other interventions.

Do we enjoy what we sense and perceive? A dissociation between aesthetic appreciation and basic perception of environmental objects or events

This integrative review rearticulates the notion of human aesthetics by critically appraising the conventional definitions, offerring a new, more comprehensive definition, and identifying the fundamental components associated with it. It intends to advance holistic understanding of the notion by differentiating aesthetic perception from basic perceptual recognition, and by characterizing these concepts from the perspective of information processing in both visual and nonvisual modalities. To this end, we analyze the dissociative nature of information processing in the brain, introducing a novel local-global integrative model that differentiates aesthetic processing from basic perceptual processing. This model builds on the current state of the art in visual aesthetics as well as newer propositions about nonvisual aesthetics. This model comprises two analytic channels: aesthetics-only channel and perception-to-aesthetics channel. The aesthetics-only channel primarily involves restricted local processing for quality or richness (e.g., attractiveness, beauty/prettiness, elegance, sublimeness, catchiness, hedonic value) analysis, whereas the perception-to-aesthetics channel involves global/extended local processing for basic feature analysis, followed by restricted local processing for quality or richness analysis. We contend that aesthetic processing operates independently of basic perceptual processing, but not independently of cognitive processing. We further conjecture that there might be a common faculty, labeled as aesthetic cognition faculty, in the human brain for all sensory aesthetics albeit other parts of the brain can also be activated because of basic sensory processing prior to aesthetic processing, particularly during the operation of the second channel. This generalized model can account not only for simple and pure aesthetic experiences but for partial and complex aesthetic experiences as well.

A Comprehensive Review on the Effects of Humor in Patients With Depression

Depression is a leading cause of disability worldwide and a major contributor to the overall global burden of disease. Although there are known, effective treatments for depression, people in low- and middle-income areas experience multiple barriers which limit their ability to receive adequate treatment. Some known barriers to effective care include a lack of resources, lack of trained healthcare providers, and social stigma associated with mental disorders and this creates gaps in mental health care and the need for more treatment modalities and adjuvant therapies to address these gaps. This review article was conducted using the scale for the assessment of non-systematic review articles (SANRA). We searched three databases; EMBASE, PubMed (MEDLINE), and Google Scholar using specified search terms. We had a total of nine articles with sample sizes ranging from 37 to 1551, and the age of participants ranged from 23 to 93 years. Articles were diverse in race and geographical locations. The articles were derived from cross-sectional studies, randomized studies, and experimental studies, and they focused on the relationship between humor and depression, and the reduced risk of depression in the study population. The articles identified different aspects of the relationship between humor and depression. The willingness of patients with depression to recognize or participate in humor could be defective resulting in abnormal social interactions such as withdrawal. However, there was some significant influence of humor or its styles on patients with depression either mitigating depressive symptoms or having no impact at all.

Individual Differences in Hemispheric Emotional Valence by Computerized Test Correlate with Lateralized Differences in Nucleus Accumbens, Hippocampal and Amygdala Volumes

Purpose

Conventional theories of hemispheric emotional valence (HEV) postulate fixed hemispheric differences in emotional processing. Schiffer’s dual brain psychology proposes that there are prominent individual differences with a substantial subset showing a reversed laterality pattern. He further proposed that hemispheric differences were more akin to differences in personality than in emotional processing. This theory is supported by findings that unilateral treatments, such as transcranial magnetic stimulation, are effective if they accurately target individual differences in laterality. The aim of this paper was to assess if a computer test of hemispheric emotional valence (CTHEV) could effectively identify individual differences in HEV and to ascertain if these individual differences were associated with underlying differences in brain structure and connectivity.

Patients and Methods

The CTHEV was administered to 50 (18 male/32 female) right-handed participants, aged 18–19 years, enrolled in a study assessing the neurobiological effects of childhood maltreatment. Based on a literature review, we determined whether CTHEV correlated with lateralized volumes of the nucleus accumbens, amygdala, hippocampus, and subgenual anterior cingulate as well as volume of the corpus callosum.

Results

CTHEV scores correlated with laterality indices of the nucleus accumbens (p = 0.00016), amygdala (p = 0.0138) and hippocampus (p = 0.031). A positive left hemispheric valence was associated with a larger left-sided nucleus accumbens and hippocampus and a smaller left amygdala. We identified four eigenvector network centrality DTI measures that predict CTHEV, most notably the left amygdala, and found that CTHEV results correlated with total and segment-specific corpus callosal volumes.

Conclusion

Individual differences in HEV can be readily assessed by computer test and correlate with differences in brain structure and connectivity that could provide a mechanistic understanding. These findings provide further support for a revised understanding of HEV and provide a tool that could be used to guide lateralized brain treatments.

Activation of the Nucleus Taeniae of the Amygdala by Umami Taste in Domestic Chicks (Gallus gallus)

In chickens, the sense of taste plays an important role in detecting nutrients and choosing feed. The molecular mechanisms underlying the taste-sensing system of chickens are well studied, but the neural mechanisms underlying taste reactivity have received less attention. Here we report the short-term taste behaviour of chickens towards umami and bitter (quinine) taste solutions and the associated neural activity in the nucleus taeniae of the amygdala, nucleus accumbens and lateral septum. We found that chickens had more contact with and drank greater volumes of umami than bitter or a water control, and that chicks displayed increased head shaking in response to bitter compared to the other tastes. We found that there was a higher neural activity, measured as c-Fos activation, in response to umami taste in the right hemisphere of the nucleus taeniae of the amygdala. In the left hemisphere, there was a higher c-Fos activation of the nucleus taeniae of the amygdala in response to bitter than in the right hemisphere. Our findings provide clear evidence that chickens respond differently to umami and bitter tastes, that there is a lateralised response to tastes at the neural level, and reveals a new function of the avian nucleus taeniae of the amygdala as a region processing reward information.

The CODA Model: A Review and Skeptical Extension of the Constructionist Model of Emotional Episodes Induced by Music

This paper discusses contemporary advancements in the affective sciences (described together as skeptical theories) that can inform the music-emotion literature. Key concepts in these theories are outlined, highlighting their points of agreement and disagreement. This summary shows the importance of appraisal within the emotion process, provides a greater emphasis upon goal-directed accounts of (emotion) behavior, and a need to move away from discrete emotion “folk” concepts and toward the study of an emotional episode and its components. Consequently, three contemporary music emotion theories (BRECVEMA, Multifactorial Process Approach, and a Constructionist Account) are examined through a skeptical lens. This critique highlights the over-reliance upon categorization and a lack of acknowledgment of appraisal processes, specifically goal-directed appraisal, in examining how individual experiences of music emerge in different contexts. Based on this critique of current music-emotion models, we present our skeptically informed CODA model - Constructivistly-Organised Dimensional-Appraisal model. This model addresses skeptical limitations of existing theories, reinstates the role of goal-directed appraisal as central to what makes music relevant and meaningful to an individual in different contexts and brings together different theoretical frameworks into a single model. From the development of the CODA model, several hypotheses are proposed and applied to musical contexts. These hypotheses address theoretical issues such as acknowledging individual and contextual differences in emotional intensity and valence, as well as differentiating between induced and perceived emotions, and utilitarian and aesthetic emotions. We conclude with a sections of recommendations for future research. Altogether, this theoretical critique and proposed model points toward a positive future direction for music-emotion science. One where researchers can take forward testable predictions about what makes music relevant and meaningful to an individual.

Individual differences in threat and reward neural circuitry activation: Testing dimensional models of early adversity, anxiety and depression

Altered functioning of the brain's threat and reward circuitry has been linked to early life adversity and to symptoms of anxiety and depression. To date, however, these relationships have been studied largely in isolation and in categorical-based approaches. It is unclear to what extent early life adversity and psychopathology have unique effects on brain functioning during threat and reward processing. We examined functional brain activity during a face processing task in threat (amygdala and ventromedial prefrontal cortex) and reward (ventral striatum and orbitofrontal cortex) regions of interest among a sample (N = 103) of young adults (aged 18-19 years) in relation to dimensional measures of early life adversity and symptoms of anxiety and depression. Results demonstrated a significant association between higher scores on the deprivation adversity dimension and greater activation of reward neural circuitry during viewing of happy faces, with the largest effect sizes observed in the orbitofrontal cortex. We found no significant associations between the threat adversity dimension, or symptom dimensions of anxiety and depression, and neural activation in threat or reward circuitries. These results lend partial support to theories of adversity-related alterations in neural activation and highlight the importance of testing dimensional models of adversity and psychopathology in large sample sizes to further our understanding of the biological processes implicated.

Food wanting is mediated by transient activation of dopaminergic signaling in the honey bee brain

The biological bases of wanting have been characterized in mammals, but whether an equivalent wanting system exists in insects remains unknown. In this study, we focused on honey bees, which perform intensive foraging activities to satisfy colony needs, and sought to determine whether foragers leave the hive driven by specific expectations about reward and whether they recollect these expectations during their waggle dances. We monitored foraging and dance behavior and simultaneously quantified and interfered with biogenic amine signaling in the bee brain. We show that a dopamine-dependent wanting system is activated transiently in the bee brain by increased appetite and individual recollection of profitable food sources, both en route to the goal and during waggle dances. Our results show that insects share with mammals common neural mechanisms for encoding wanting of stimuli with positive hedonic value.

Why do animals want what they like?

As in mammals, honey bee motivation for wanting rewards is modulated by dopamine.

Children's value-based decision making

To effectively navigate their environments, infants and children learn how to recognize events predict salient outcomes, such as rewards or punishments. Relatively little is known about how children acquire this ability to attach value to the stimuli they encounter. Studies often examine children’s ability to learn about rewards and threats using either classical conditioning or behavioral choice paradigms. Here, we assess both approaches and find that they yield different outcomes in terms of which individuals had efficiently learned the value of information presented to them. The findings offer new insights into understanding how to assess different facets of value learning in children.

Hemispheric asymmetry of motor cortex excitability in mood disorders - Evidence from a systematic review and meta-analysis

OBJECTIVE

Mood disorders have been associated with lateralized brain dysfunction, on the left-side for depression and right-side for mania. Consistently, asymmetry of cortical excitability, as measured by transcranial magnetic stimulation (TMS) has been reported. Here, we reviewed and summarized work assessing such measures bilaterally in mood disorders.

METHODS

We performed a systematic review and extracted data to perform meta-analyses of interhemispheric asymmetry of motor cortex excitability, assessed with TMS, across different mood disorders and in healthy subjects. Additionally, potential predictors of interhemispheric asymmetry were explored.

RESULTS

Asymmetry of resting motor threshold (MT) among healthy volunteers was significant, favoring lower right relative to left-hemisphere excitability. MT was also significantly asymmetric in major depressive disorder (MDD), but with lower excitability of the left -hemisphere, when compared to the right, no longer observed in recovered patients. Findings on intracortical facilitation were similar. The few trials including bipolar depression revealed similar trends for imbalance, but with lower right hemisphere excitability, relative to the left.

CONCLUSIONS

There is interhemispheric asymmetry of motor cortical excitability in MDD, with lower excitability on left when compared to right-side. Interhemispheric asymmetry, with lower right relative to left-sided excitability, was found for bipolar depression and was also suggested for healthy volunteers, in a pattern that is clearly distinct from MDD.

SIGNIFICANCE

Mood disorders display asymmetric motor cortical excitability that is distinct from that found in healthy volunteers, supporting the presence of lateralized brain dysfunction in these disorders.

Temporal dynamics of affect in the brain: Evidence from human imaging and animal models

Emotions are time-varying internal states that promote survival in the face of dynamic environments and shifting homeostatic needs. Research in non-human organisms has recently afforded specific insights into the neural mechanisms that support the emergence, persistence, and decay of affective states. Concurrently, a separate affective neuroscience literature has begun to dissect the neural bases of affective dynamics in humans. However, the circuit-level mechanisms identified in animals lack a clear mapping to the human neuroscience literature. As a result, critical questions pertaining to the neural bases of affective dynamics in humans remain unanswered. To address these shortcomings, the present review integrates findings from humans and non-human organisms to highlight the neural mechanisms that govern the temporal features of emotional states. Using the theory of affective chronometry as an organizing framework, we describe the specific neural mechanisms and modulatory factors that arbitrate the rise-time, intensity, and duration of emotional states.

Hypocretin/Orexin Interactions with Norepinephrine Contribute to the Opiate Withdrawal Syndrome

We previously found that human heroin addicts and mice chronically exposed to morphine exhibit a significant increase in the number of detected hypocretin/orexin (Hcrt)-producing neurons. However, it remains unknown how this increase affects target areas of the hypocretin system involved in opioid withdrawal, including norepinephrine containing structures locus coeruleus (LC) and A1/A2 medullary regions. Using a combination of immunohistochemical, biochemical, imaging, and behavioral techniques, we now show that the increase in detected hypocretin cell number translates into a significant increase in hypocretin innervation and tyrosine hydroxylase (TH) levels in the LC without affecting norepinephrine-containing neuronal cell number. We show that the increase in TH is completely dependent on Hcrt innervation. The A1/A2 regions were unaffected by morphine treatment. Manipulation of the Hcrt system may affect opioid addiction and withdrawal.SIGNIFICANCE STATEMENT Previously, we have shown that the hypothalamic hypocretin system undergoes profound anatomic changes in human heroin addicts and in mice exposed to morphine, suggesting a role of this system in the development of addictive behaviors. The locus coeruleus plays a key role in opioid addiction. Here we report that the hypothalamic hypocretin innervation of the locus coeruleus increases dramatically with morphine administration to mice. This increase is correlated with a massive increase in tyrosine hydroxylase expression in locus coeruleus. Elimination of hypocretin neurons prevents the tyrosine hydroxylase increase in locus coeruleus and dampens the somatic and affective components of opioid withdrawal.

The effects of nalmefene on the impulsive and reflective system in alcohol use disorder: A resting-state fMRI study

RATIONALE

Central aspects of alcohol use disorder (AUD) are the irresistible desire for alcohol and impaired control over its intake. According to the triadic neurocognitive model of addiction, this arises from aberrant functioning of different neural and cognitive systems: an impulsive system, a reflective system, and the abnormal dynamics between both systems based on an insular-dependent system.

OBJECTIVES

In this study, we examined the effects of a single dose of nalmefene on resting-state functional connectivity (rsFC) patterns within and between these addiction-related neural systems in AUD.

METHODS

Non-treatment seeking participants with AUD (N = 17; 19-66 years, 6 female) took part in a randomized, placebo-controlled, double-blind, crossover study and received either a single dose of 18 mg nalmefene or a placebo. Using seed-based correlation analyses on resting-state functional magnetic resonance imaging data, we examined the effects of nalmefene on key nodes related to the (1) impulsive system; (2) reflective system; (3) salience network; and (4) default mode network.

RESULTS

Under nalmefene, participants showed reduced rsFC between components of the impulsive system (Nucleus accumbens-putamen/pallidum/insula). Reduced rsFC was found between elements of the reflective system and impulsive system (orbitofrontal cortex-insula/putamen/pallidum), salience network (orbitofrontal cortex-insula/inferior frontal gyrus), and default mode network (lateral prefrontal cortex-precuneus/cuneus). Components of the salience network showed both increased (anterior cingulate cortex) and decreased (insular cortex) rsFC to elements of the reflective system.

CONCLUSION

A single dose of nalmefene impacts rsFC and alters the interaction between key nodes of addiction-related neural systems in non-treatment seeking participants with AUD. Nalmefene may normalize rsFC patterns by weakening the impulsive system while strengthening the reflective system.

TRIAL REGISTRATION

clinicaltrials.gov: NCT02372318.

Brain Activation During Processing of Depression Emotion in College Students With Premenstrual Syndrome in China: Preliminary Findings

BACKGROUND

This study aimed to investigate the neural substrates of processing depression emotion in premenstrual syndrome (PMS) and healthy subjects of college students using blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI).

METHODS

During BOLD-fMRI scanning, 13 PMS patients and 15 healthy controls (HC) performed a picture visual stimulation task during luteal and follicular phases, in which participants and HC were asked to see pictures containing depression and non-depression emotions. Simultaneously, self-rating depression scales (SDS) were employed to evaluate the emotional status of participants.

RESULTS

Compared to HC, right inferior occipital gyrus, right middle occipital gyrus, right lingual gyrus, right fusiform gyrus, right inferior temporal gyrus, cerebelum_crus1_R, cerebelum_6_R, culmen, the cerebellum anterior lobe, tuber, and cerebellar tonsil of PMS patients showed enhanced activation. In contrast, sub-lobar, sub-gyral, extra-nuclear, right orbit part of superior frontal gyrus, right middle temporal gyrus, right orbit part of inferior frontal gyrus, limbic lobe, right insula, bilateral anterior and adjacent cingulate gyrus, bilateral caudate, caudate head, bilateral putamen, and left globus pallidus exhibited decreased activation.

CONCLUSION

The findings indicate that abnormal functional regulation of brain regions such as occipital lobe and cerebellum leads to abnormal changes in emotional regulation, cognitive ability, and attention distribution in PMS patients, implying significant central pathogenesis.

Anhedonia in Neurodegenerative Diseases

Neurodegenerative diseases are increasingly recognised to be an important cause of brain disorders, particularly in late age. Associated with a wide range of pathologies, they lead to progressive loss of neurons in different regions of the nervous system. Although anhedonia is common in a variety of neurodegenerative diseases, to date it has not been extensively studied in most of these conditions. Here we review the current literature on studies assessing the association between anhedonia and neurodegenerative diseases including Parkinson's Disease, Dementia with Lewy Bodies, Parkinson's Plus Syndromes, Alzheimer's Disease, Vascular Dementia, Frontotemporal Dementia, Amyotrophic Lateral Sclerosis and Huntington's Disease. Much of the research has been conducted in Parkinson's disease where it is evident that there are strong links between apathy (loss of motivation) and anhedonia, although the two syndromes can be dissociated. Intriguingly, drugs that improve apathy can also lead to amelioration of anhedonia in some cases. Overlaps between the two syndromes may also exist across other neurodegenerative conditions, including Frontotemporal Dementia in which imaging has revealed atrophy of both common brain regions associated with anhedonia and apathy, as well as a set of unique brain regions associated with anhedonia. A transdiagnostic perspective might be helpful to investigate whether a common network of brain regions is dysfunctional with anhedonia across neurodegenerative conditions.

Neuroimaging of pleasantness and unpleasantness induced by thermal stimuli

Functional brain imaging techniques provide unique insight into the process of human thermal regulation and its associated hedonics. Similar neuroimaging techniques have predominantly focused on the neural characterization of thermal response separately from hedonics. In this instance, there is a gap in the understanding of hedonics related to regional brain activations. Responses to localized, thermal stimuli are yet to be characterized, but it would appear that thermoregulatory regions are widely distributed throughout the hemispheres of the human brain. The distributed nature of neural activations related to temperature responses is consistent with multiple related functions contributing to thermoregulation. Estimating hedonics of thermal stimulation includes a cognitive process that could potentially interfere with identifying activation specific to hedonics. A future challenge for brain imaging studies is to more accurately dissect the functional neuroanatomy of thermoregulation and related hedonics in hemispheric regions.

Music, mental health, and immunity

Music is a crucial element of everyday life and plays a central role in all human cultures: it is omnipresent and is listened to and played by persons of all ages, races, and ethnic backgrounds. But music is not simply entertainment: scientific research has shown that it can influence physiological processes that enhance physical and mental wellbeing. Consequently, it can have critical adaptive functions. Studies on patients diagnosed with mental disorders have shown a visible improvement in their mental health after interventions using music as primary tool. Other studies have demonstrated the benefits of music, including improved heart rate, motor skills, brain stimulation, and immune system enhancement. Mental and physical illnesses can be costly in terms of medications and psychological care, and music can offer a less expansive addition to an individual's treatment regimen. Interventions using music offers music-based activities in both a therapeutic environment (Music therapy) with the support of a trained professional, and non-therapeutic setting, providing an atmosphere that is positive, supportive, and proactive while learning non-invasive techniques to treat symptoms associated with various disorders – and possibly modulate the immune system.

The neuroscience of intergroup threat and violence

The COVID-19 pandemic led to a global increase in hate crimes and xenophobia. In these uncertain times, real or imaginary threats can easily lead to intergroup conflict. Here, we integrate social neuroscience findings with classic social psychology theories into a framework to better understand how intergroup threat can lead to violence. The role of moral disengagement, dehumanization, and intergroup schadenfreude in this process are discussed, together with their underlying neural mechanisms. We outline how this framework can inform social scientists and policy makers to help reduce the escalation of intergroup conflict and promote intergroup cooperation. The critical role of the media and public figures in these unprecedented times is highlighted as an important factor to achieve these goals.

Characterizing anhedonia: A systematic review of neuroimaging across the subtypes of reward processing deficits in depression

Anhedonia is a key symptom of major depressive disorder (MDD) and comprises behavioural deficits in three reward processing subtypes: reward liking, reward wanting, and reward learning. However, neuroimaging findings regarding the neural abnormalities underpinning these deficits are complex. We have conducted a systematic review to update, reframe and summarize neuroimaging findings across the three subtypes of anhedonia in MDD. Using PubMed, The Cochrane Library, PsycINFO, and Web of Science databases, we identified 59 fMRI studies comparing participants with current or remitted MDD with controls, using reward processing tasks. For reward liking and wanting, striatal hypoactivation was observed, alongside hypoactivation and hyperactivation across frontal regions. For reward learning, blunted frontostriatal sensitivity to positive feedback was observed. These findings highlight the importance of studying anhedonia not only as a clinical manifestation but also as a neurobiological mechanism underlying depressive disorder and other broader psychiatric conditions.

Brain reactivity to emotional stimuli in women with premenstrual dysphoric disorder and related personality characteristics

Aims: Premenstrual dysphoric disorder (PMDD) is a psychiatric condition that is associated with the menstrual cycle. Elucidation of the neural regulation mechanisms of brain reactivity to emotional stimuli among women with PMDD may inform PMDD treatment.

Methods: Eighty-six women (42 PMDD, 44 healthy controls) were allocated into two groups (anger-induced group: 23 PMDD vs. 23 controls; depression-induced group: 19 PMDD vs. 21 controls). During the luteal phases of the menstrual cycle, all the women were subjected to functional magnetic resonance imaging (fMRI). fMRI resting-state scans were performed before and after the study participants had performed an emotional stimuli task. After the emotional stimuli task, emotional status of the participants were evaluated by Self-Rating Depression Scales (SDS) and Trait Anger Expression Inventory–II (STAXI-II). In addition, all the participants were requested to complete the Eysenck Personality Questionnaire (EPQ) and the Twenty-Item Toronto Alexithymia Scale (TAS-20).

Results: Compared to healthy controls, all women with PMDD exhibited significantly high scores in Tas-20 (p<0.001), higher neuroticism and psychoticism scores as well as significantly low extraversion and social desirability scores (p<0.05). Compared to the controls, f-MRI revealed that PMDD women had elevated ReHo in the middle frontal gyrus (BA10), temporal lobe (BA42), left cerebellum (BA37), as well as decreased activation in the precuneus (BA7), superior frontal gyrus (BA8), lobulus paracentralis (BA6), and right cerebellum (BA48) (p<0.05). Moreover, depression stimuli showed that women with PMDD had elevated ReHo levels in the middle frontal gyrus (BA11), the middle gyrus (BA47) and in the cingulate gyrus (BA23) vs. healthy controls (p<0.05).

Conclusions: Women with more neuroticism and psychoticism, less extraversion and social desirability tend to report PMDD symptoms. Women with this condition experience difficulties in regulating emotions during the luteal phase of the menstrual cycle. Abnormal ReHo levels in the precuneus, superior frontal gyrus, lobulus paracentralis, and right cerebellum may contribute to anger dysregulation. Hypoactivation in the middle frontal gyrus, the middle gyrus and the cingulate gyrus may be generally associated with depression dysregulation in PMDD.

From Visual Perception to Aesthetic Appeal: Brain Responses to Aesthetically Appealing Natural Landscape Movies

During aesthetically appealing visual experiences, visual content provides a basis for computation of affectively tinged representations of aesthetic value. How this happens in the brain is largely unexplored. Using engaging video clips of natural landscapes, we tested whether cortical regions that respond to perceptual aspects of an environment (e.g., spatial layout, object content and motion) were directly modulated by rated aesthetic appeal. Twenty-four participants watched a series of videos of natural landscapes while being scanned using functional magnetic resonance imaging (fMRI) and reported both continuous ratings of enjoyment (during the videos) and overall aesthetic judgments (after each video). Although landscape videos engaged a greater expanse of high-level visual cortex compared to that observed for images of landscapes, independently localized category-selective visual regions (e.g., scene-selective parahippocampal place area and motion-selective hMT+) were not significantly modulated by aesthetic appeal. Rather, a whole-brain analysis revealed modulations by aesthetic appeal in ventral (collateral sulcus) and lateral (middle occipital sulcus, posterior middle temporal gyrus) clusters that were adjacent to scene and motion selective regions. These findings suggest that aesthetic appeal per se is not represented in well-characterized feature- and category-selective regions of visual cortex. Rather, we propose that the observed activations reflect a local transformation from a feature-based visual representation to a representation of "elemental affect," computed through information-processing mechanisms that detect deviations from an observer's expectations. Furthermore, we found modulation by aesthetic appeal in subcortical reward structures but not in regions of the default-mode network (DMN) nor orbitofrontal cortex, and only weak evidence for associated changes in functional connectivity. In contrast to other visual aesthetic domains, aesthetically appealing interactions with natural landscapes may rely more heavily on comparisons between ongoing stimulation and well-formed representations of the natural world, and less on top-down processes for resolving ambiguities or assessing self-relevance.

Expressions of emotions across species

What are emotions and how should we study them? These questions give rise to ongoing controversy amongst scientists in the fields of neuroscience, psychology and philosophy, and have resulted in different views on emotions [1-6]. In this review, we define emotions as functional states that bear essential roles in promoting survival and thus have emerged through evolution. Emotions trigger behavioral, somatic, hormonal, and neurochemical reactions, referred to as expressions of emotion. We discuss recent studies on emotion expression across species and highlight emerging common principles. We argue that detailed and multidimensional analyses of emotion expressions are key to develop biology-based definitions of emotions and to reveal their neuronal underpinnings.

Evaluative judgment across domains: Liking balance, contour, symmetry and complexity in melodies and visual designs

Evaluative judgment-i.e., assessing to what degree a stimulus is liked or disliked-is a fundamental aspect of cognition, facilitating comparison and choosing among alternatives, deciding, and prioritizing actions. Neuroimaging studies have shown that evaluative judgment involves the projection of sensory information to the reward circuit. To investigate whether evaluative judgments are based on modality-specific or modality-general attributes, we compared the extent to which balance, contour, symmetry, and complexity affect liking responses in the auditory and visual modalities. We found no significant correlation for any of the four attributes across sensory modalities, except for contour. This suggests that evaluative judgments primarily rely on modality-specific sensory representations elaborated in the brain's sensory cortices and relayed to the reward circuit, rather than abstract modality-general representations. The individual traits art experience, openness to experience, and desire for aesthetics were associated with the extent to which design or compositional attributes influenced liking, but inconsistently across sensory modalities and attributes, also suggesting modality-specific influences.

Well-Being and Cooking Behavior: Using the Positive Emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA) Model as a Theoretical Framework

The prevalence of psychosocial distress is increasing in the United States. At the same time, the American default lifestyle has steadily displaced household food production with industrial food production, despite increased cultural interest in cooking. An important focus of cooking research to date has been on cooking's association with nutrition and dietary quality. Less focus has been placed on how cooking might foster the qualities that allow for mitigation of psychosocial distress and promote well-being. Rooted in its evolutionary role in the human experience, cooking requires skills and knowledge that have the capacity to encourage aspects of well-being as described by Seligman as flourishing. Evidence for a beneficial role of cooking in psychosocial health exists, but the exploration is limited, potentially due to lack of a theoretical context to explain these benefits. From this perspective, we review the current literature showing the application of Seligman's prominent well-being model, Positive emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA), to cooking, defined as the activity related to the preparation of food or a meal. We propose that the PERMA model as applied to cooking may function as a theoretical framework to explore psychosocial outcomes associated with cooking. Broader application of this approach may also help to further the application of positive psychology in the developing literature around psychosocial health and nutrition-related chronic diseases.

Nucleus Accumbens Stimulation Modulates Inhibitory Control by Right Prefrontal Cortex Activation in Obsessive-Compulsive Disorder

Inhibitory control is considered a compromised cognitive function in obsessive-compulsive (OCD) patients and likely linked to corticostriatal circuitry disturbances. Here, 9 refractory OCD patients treated with deep brain stimulation (DBS) were evaluated to address the dynamic modulations of large-scale cortical network activity involved in inhibitory control after nucleus accumbens (NAc) stimulation and their relationship with cortical thickness. A comparison of DBS "On/Off" states showed that patients committed fewer errors and exhibited increased intraindividual reaction time variability, resulting in improved goal maintenance abilities and proactive inhibitory control. Visual P3 event-related potentials showed increased amplitudes during Go/NoGo performance. Go and NoGo responses increased cortical activation mainly over the right inferior frontal gyrus and medial frontal gyrus, respectively. Moreover, increased cortical activation in these areas was equally associated with a higher cortical thickness within the prefrontal cortex. These results highlight the critical role of NAc DBS for preferentially modulating the neuronal activity underlying sustained speed responses and inhibitory control in OCD patients and show that it is triggered by reorganizing brain functions to the right prefrontal regions, which may depend on the underlying cortical thinning. Our findings provide updated structural and functional evidence that supports critical dopaminergic-mediated frontal-striatal network interactions in OCD.

The neuroscience of positive emotions and affect: Implications for cultivating happiness and wellbeing

This review paper provides an integrative account regarding neurophysiological correlates of positive emotions and affect that cumulatively contribute to the scaffolding for happiness and wellbeing in humans and other animals. This paper reviews the associations among neurotransmitters, hormones, brain networks, and cognitive functions in the context of positive emotions and affect. Consideration of lifespan developmental perspectives are incorporated, and we also examine the impact of healthy social relationships and environmental contexts on the modulation of positive emotions and affect. The neurophysiological processes that implement positive emotions are dynamic and modifiable, and meditative practices as well as flow states that change patterns of brain function and ultimately support wellbeing are also discussed. This review is part of "The Human Affectome Project" (http://neuroqualia.org/background.php), and in order to advance a primary aim of the Human Affectome Project, we also reviewed relevant linguistic dimensions and terminology that characterizes positive emotions and wellbeing. These linguistic dimensions are discussed within the context of the neuroscience literature with the overarching goal of generating novel recommendations for advancing neuroscience research on positive emotions and wellbeing.

Multimodal Imaging Analysis Reveals Frontal-Associated Networks in Relation to Individual Resilience Strength

Psychological resilience is regarded as a critical protective factor for preventing the development of mental illness from experienced adverse events. Personal strength is one key element of resilience that reflects an individual's reactions to negative life events and is crucial for successful adaptation. Previous studies have linked unimodal imaging measures with resilience. However, applying multimodal imaging measures could provide comprehensive organization information at the system level to examine whether an individual's resilience strength is reflected in the brain's structural and functional network. In this study, MRI was used to acquire multimodal imaging properties and subscales of personal strength in terms of resilience from 109 participants (48 females and 61 males). We employed a method of fusion independent component analysis to link the association between multimodal imaging components and personal strength of psychological resilience. The results reveal that a fusion component involving multimodal frontal networks in connecting with the parietal, occipital, and temporal regions is associated with the resilience score for personal strength. A multiple regression model further explains the predictive role of frontal-associated regions that cover a visual-related network regulating cognition and emotion to discern the perceived adverse experience. Overall, this study suggests that frontal-associated regions are related to individual resilience strength.

Drosophila reward system - A summary of current knowledge

The fruit fly Drosophila melanogaster brain is the most extensively investigated model of a reward system in insects. Drosophila can discriminate between rewarding and punishing environmental stimuli and consequently undergo associative learning. Functional models, especially those modelling mushroom bodies, are constantly being developed using newly discovered information, adding to the complexity of creating a simple model of the reward system. This review aims to clarify whether its reward system also includes a hedonic component. Neurochemical systems that mediate the 'wanting' component of reward in the Drosophila brain are well documented, however, the systems that mediate the pleasure component of reward in mammals, including those involving the endogenous opioid and endocannabinoid systems, are unlikely to be present in insects. The mushroom body components exhibit differential developmental age and different functional processes. We propose a hypothetical hierarchy of the levels of reinforcement processing in response to particular stimuli, and the parallel processes that take place concurrently. The possible presence of activity-silencing and meta-satiety inducing levels in Drosophila should be further investigated.