Flexibly adapting to emotional cues: Examining the functional and structural correlates of emotional reactivity and emotion control in healthy and depressed individuals

The ability of emotionally significant stimuli to bias our behaviour is an evolutionarily adaptive phenomenon. However, sometimes emotions become excessive, inappropriate, and even pathological, like in major depressive disorder (MDD). Emotional flexibility includes both the neural processes involved in reacting to, or representing, emotional significance, and those involved in controlling emotional reactivity. MDD represents a potentially distinct form of emotion (in)flexibility, and therefore offers a unique perspective for understanding both the integration of conflicting emotional cues and the neural regions involved in actively controlling emotional systems. The present investigation of emotional flexibility began by considering the functional neural correlates of competing socio-emotional cues and effortful emotion regulation in MDD using both negative and positive emotions. Study 1 revealed greater amygdala activity in MDD relative to control participants when negative cues were centrally presented and task-relevant. No significant between-group differences were observed in the amygdala for peripheral task-irrelevant negative distracters. However, controls demonstrated greater recruitment of the ventrolateral (vlPFC) and dorsomedial prefrontal cortices (dmPFC) implicated in emotion control. Conversely, attenuated amygdala activity for task-relevant and irrelevant positive cues was observed in depressed participants. In Study 2, effortful emotion regulation using strategies adapted from cognitive behaviour therapy (CBT) revealed greater activity in regions of the dorsal and lateral prefrontal cortices in both MDD and control participants when attempting to either down-regulate negative or up-regulate positive emotions. During the down-regulation of negative cues, only controls displayed a significant reduction of amygdala activity. In Study 3, an individual differences approach using multiple regression revealed that while greater amygdala-vmPFC structural connectivity was associated with low trait-anxiety, greater connectivity between amygdala and regions of occipitotemporal and parietal cortices was associated with high trait-anxiety. These findings are discussed with respect to current models of emotional reactivity and emotion control derived from studies of both healthy individuals and those with emotional disorders, particularly depression. The focus is on amygdala variability in differing contexts, the role of the vmPFC in the modulation of amygdala activity via learning processes, and the modulation of emotion by attention or cognitive control mechanisms initiated by regions of frontoparietal cortices

Spatially generalizable representations of facial expressions: Decoding across partial face samples

A network of cortical and sub-cortical regions is known to be important in the processing of facial expression. However, to date no study has investigated whether representations of facial expressions present in this network permit generalization across independent samples of face information (e.g. eye region Vs mouth region). We presented participants with partial face samples of five expression categories in a rapid event-related fMRI experiment. We reveal a network of face sensitive regions that contain information about facial expression categories regardless of which part of the face is presented. We further reveal that the neural information present in a subset of these regions: dorsal prefrontal cortex (dPFC), superior temporal sulcus (STS), lateral occipital and ventral temporal cortex, and even early visual cortex, enables reliable generalization across independent visual inputs (faces depicting the 'eyes only' versus 'eyes removed'). Furthermore, classification performance was correlated to behavioral performance in STS and dPFC. Our results demonstrate that both higher (e.g. STS, dPFC) and lower level cortical regions contain information useful for facial expression decoding that go beyond the visual information presented, and implicate a key role for contextual mechanisms such as cortical feedback in facial expression perception under challenging conditions of visual occlusion

Multiple mechanisms of consciousness: the neural correlates of emotional awareness.

Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, increased activity was observed in regions associated with facial expression processing, including the amygdala and fusiform gyrus during emotional awareness. In contrast, awareness of neutral faces and suppression of fearful faces were associated with increased activity in dorsolateral prefrontal and inferior parietal cortices. The amygdala showed increased functional connectivity with ventral visual system regions during fear awareness and increased connectivity with perigenual prefrontal cortex (pgPFC; Brodmann\u27s area 32/10) when fear was suppressed. Despite being prioritized for awareness, emotional items were associated with reduced activity in areas considered critical for consciousness. Contributions to consciousness from bottom-up and top-down neural regions may be additive, such that increased activity in specialized regions within the extended ventral visual system may reduce demands on a frontoparietal system important for awareness. The possibility is raised that interactions between pgPFC and the amygdala, previously implicated in extinction, may also influence whether or not an emotional stimulus is accessible to consciousness

Urban (UMaaS) and Rural (RMaaS) Mobility as a Service (MaaS) : practical insights from international practitioners and experts.

This research was supported by the University of Aberdeen, United Kingdom, ETP (Energy Technology Partnership) and HITRANS (Highlands and Islands Transport Regional Authority). The Grant Number RG14413.Peer reviewedPublisher PD

The neural correlates of regulating positive and negative emotions in medication-free major depression

Depressive cognitive schemas play an important role in the emergence and persistence of major depressive disorder (MDD). The current study adapted emotion regulation techniques to reflect elements of cognitive behavioural therapy (CBT) and related psychotherapies to delineate neurocognitive abnormalities associated with modulating the negative cognitive style in MDD. Nineteen non-medicated patients with MDD and 19 matched controls reduced negative or enhanced positive feelings elicited by emotional scenes while undergoing functional magnetic resonance imaging. Although both groups showed significant emotion regulation success as measured by subjective ratings of affect, the controls were significantly better at modulating both negative and positive emotion. Both groups recruited regions of dorsolateral prefrontal cortex and ventrolateral prefrontal cortex (VLPFC) when regulating negative emotions. Only in controls was this accompanied by reduced activity in sensory cortices and amygdala. Similarly, both groups showed enhanced activity in VLPFC and ventral striatum when enhancing positive affect; however, only in controls was ventral striatum activity correlated with regulation efficacy. The results suggest that depression is associated with both a reduced capacity to achieve relief from negative affect despite recruitment of ventral and dorsal prefrontal cortical regions implicated in emotion regulation, coupled with a disconnect between activity in reward-related regions and subjective positive affect

Higher locus coeruleus MRI contrast is associated with lower parasympathetic influence over heart rate variability

The locus coeruleus (LC) is a key node of the sympathetic nervous system and suppresses parasympathetic activity that would otherwise increase heart rate variability. In the current study, we examined whether LC-MRI contrast reflecting neuromelanin accumulation in the LC was associated with high-frequency heart rate variability (HF-HRV), a measure reflecting parasympathetic influences on the heart. Recent evidence indicates that neuromelanin, a byproduct of catecholamine metabolism, accumulates in the LC through young and mid adulthood, suggesting that LC-MRI contrast may be a useful biomarker of individual differences in habitual LC activation. We found that, across younger and older adults, greater LC-MRI contrast was negatively associated with HF-HRV during fear conditioning and spatial detection tasks. This correlation was not accounted for by individual differences in age or anxiety. These findings indicate that individual differences in LC structure relate to key cardiovascular parameters

Strengthening spatial reasoning: elucidating the attentional and neural mechanisms associated with mental rotation skill development

© 2020, The Author(s). Spatial reasoning is a critical skill in many everyday tasks and in science, technology, engineering, and mathematics disciplines. The current study examined how training on mental rotation (a spatial reasoning task) impacts the completeness of an encoded representation and the ability to rotate the representation. We used a multisession, multimethod design with an active control group to determine how mental rotation ability impacts performance for a trained stimulus category and an untrained stimulus category. Participants in the experimental group (n = 18) showed greater improvement than the active control group (n = 18) on the mental rotation tasks. The number of saccades between objects decreased and saccade amplitude increased after training, suggesting that participants in the experimental group encoded more of the object and possibly had more complete mental representations after training. Functional magnetic resonance imaging data revealed distinct neural activation associated with mental rotation, notably in the right motor cortex and right lateral occipital cortex. These brain areas are often associated with rotation and encoding complete representations, respectively. Furthermore, logistic regression revealed that activation in these brain regions during the post-training scan significantly predicted training group assignment. Overall, the current study suggests that effective mental rotation training protocols should aim to improve the encoding and manipulation of mental representations

Multiple energy sources and metabolic strategies sustain microbial diversity in Antarctic desert soils

Numerous diverse microorganisms reside in the cold desert soils of continental Antarctica, though we lack a holistic understanding of the metabolic processes that sustain them. Here, we profile the composition, capabilities, and activities of the microbial communities in 16 physicochemically diverse mountainous and glacial soils. We assembled 451 metagenome-assembled genomes from 18 microbial phyla and inferred through Bayesian divergence analysis that the dominant lineages present are likely native to Antarctica. In support of earlier findings, metagenomic analysis revealed that the most abundant and prevalent microorganisms are metabolically versatile aerobes that use atmospheric hydrogen to support aerobic respiration and sometimes carbon fixation. Surprisingly, however, hydrogen oxidation in this region was catalyzed primarily by a phylogenetically and structurally distinct enzyme, the group 1l [NiFe]-hydrogenase, encoded by nine bacterial phyla. Through gas chromatography, we provide evidence that both Antarctic soil communities and an axenic Bacteroidota isolate (Hymenobacter roseosalivarius) oxidize atmospheric hydrogen using this enzyme. Based on ex situ rates at environmentally representative temperatures, hydrogen oxidation is theoretically sufficient for soil communities to meet energy requirements and, through metabolic water production, sustain hydration. Diverse carbon monoxide oxidizers and abundant methanotrophs were also active in the soils. We also recovered genomes of microorganisms capable of oxidizing edaphic inorganic nitrogen, sulfur, and iron compounds and harvesting solar energy via microbial rhodopsins and conventional photosystems. Obligately symbiotic bacteria, including Patescibacteria, Chlamydiae, and predatory Bdellovibrionota, were also present. We conclude that microbial diversity in Antarctic soils reflects the coexistence of metabolically flexible mixotrophs with metabolically constrained specialists.DATA AVAILABILTY: All amplicon sequencing data, raw metagenomes, metagenomic assemblies, and metagenome-assembled genomes were deposited to the National Center for Biotechnology Information (NCBI) Sequence Read Archive under the BioProject accession no. PRJNA630822. All other study data are included in the article and/or supporting information.An Australian Research Council Discovery Early Career Researcher Award (ARC DECRA) Fellowship, an Australian Antarctic Division grant, a South African National Antarctic Program grant, a National Health & Medical Research Council Emerging Leadership 2 (NHMRC EL2) Fellowship, an Australian Government Research Training Stipend Scholarship, a Monash International Tuition Scholarship, a Monash Postgraduate Publications Award, a South African National Antarctic Programme (SANAP) postdoctoral grant.https://www.pnas.orghj2022BiochemistryGeneticsMicrobiology and Plant Patholog