Orbital Frontal Cortex Research Articles

Neuroaesthetics in Plastic and Reconstructive Surgery: Opportunities for Interdisciplinary Collaboration.

Neuroaesthetics is a burgeoning discipline concerned with the neural basis for the perception and creation of art1 and neuroscientific mechanisms of human aesthetic experiences.2 Research in this field has combined principles of neurology, neuroanatomy, psychology, and art history to answer questions about the experience of beauty.2 Vision has received particularly close attention, especially human perception of faces, paintings, landscapes, and architecture.3 Neuroaesthetics has made meaningful contributions to unraveling neurologic mechanisms underpinning the aesthetic experience, previously regarded as a philosophical concept. Research has demonstrated aesthetic evaluations are important for human activity in consumer behavior, mate selection, and determination of morality.4 The field has identified neuroanatomic structures implicated in the perception of beauty broadly, notably the medial orbital frontal cortex, as well as cortical and subcortical structures specific to certain visual or auditory experiences.2 Within plastic surgery, neuroaesthetics overlaps with the specialty’s goal of characterizing optimal aesthetic outcomes for people. Plastic surgery research on aesthetic preferences may be augmented through collaboration with our colleagues in neuroaesthetics, who offer valuable expertise in neuroscience and aesthetic principles. In return, plastic surgery offers clinical, anatomic, and human aesthetic perspectives that may broaden the neuroaesthetic scope of inquiry. The fields complement one another to enhance the sophistication of questions posed, data generated, and analyses of those data. One example of such a collaboration is the University of Pennsylvania’s Center for Human Appearance, in which neuroaesthetics, plastic surgery, oral surgery, dermatology, oculoplastic surgery, and ear, nose, and throat play key complementary roles in designing studies that enhance understanding of appearance and clinical outcomes. Examples of the center’s initiatives include employing crowdsourcing to compare layperson aesthetic preferences, applying eye-tracking technology to characterize gaze patterns toward visual stimuli, and leveraging face databases to associate character traits to those with facial anomalies.1 Such studies have had an effect on understanding clinical outcomes in aesthetics, craniofacial surgery, and breast surgery. These clinical studies may be augmented with techniques common to the neuroaesthetics toolbox, including functional magnetic resonance imaging or magnetoencephalography to characterize brain activity in response to visual stimuli or convolutional neural networks to learn image features from datasets.5 Other efforts to leverage architectural and artistic principles are also poised to improve health care infrastructure and optimize the patient experience. Plastic surgery has not been regarded as a subdomain of neuroaesthetics inquiry. Plastic surgery would be an asset to the evolution of neuroaesthetics and should seek opportunities to foster relationships with colleagues in this nascent field. This convergence of interests is an exciting opportunity to continue plastic surgery’s history of collaboration to answer unique, multidisciplinary questions with implications for the outcomes of our patients. Disclosure The authors have no financial interest to declare in relation to the content of this article.

Superior temporal gyrus and cerebellar loops predict nonsuicidal self-injury in major depressive disorder patients by multimodal neuroimaging

In major depressive disorder (MDD) patients, nonsuicidal self-injury (NSSI) is a common comorbidity, and it is important to clarify the underlying neurobiology. Here, we investigated the association of NSSI with brain function and structure in MDD patients. A total of 260 MDD patients and 132 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging and three-dimensional T1-weighted structural scans. NSSI behaviour was assessed through interviews. Voxel-based morphometry analysis (VBM), regional homogeneity analysis (ReHo), functional connectome topology properties and network-based statistics were used to detect the differences in neuroimaging characteristics. Finally, the random forest method was used to evaluate whether these factors could predict NSSI in MDD. Compared with HCs, MDD patients with a history of NSSI showed significant right putamen grey matter volume (GMV), right superior orbital frontal cortex ReHo, left pallidum degree centrality, and putamen-centre function network differences. Compared to MDD subjects without NSSI, those with past NSSI showed significant right superior temporal gyrus (STG) GMV, right lingual gyrus ReHo, sigma and global efficiency, and cerebellum-centre function network differences. The right STG GMV and cerebellum-centre function network were more important than other factors in predicting NSSI behaviour in MDD. MDD patients with a history of NSSI have dysregulated spontaneous brain activity and structure in regions related to emotions, pain regulation, and the somatosensory system. Importantly, right STG GMV and cerebellar loops may play important roles in NSSI in MDD patients.

Different Features of a Metabolic Connectivity Map and the Granger Causality Method in Revealing Directed Dopamine Pathways: A Study Based on Integrated PET/MR Imaging.

Exploring the directionality of neural information in the brain is important for understanding brain mechanisms and neurodisease development. Granger causality analysis and the metabolic connectivity map can be used to investigate directional transmission of information between brain regions, but their differences in depicting functional effective connectivity are not clear. Using the Monash rs-PET/MR imaging data set, we conducted Granger causality and metabolic connectivity map analyses of the dopamine reward circuit in the brain. The dopamine reward circuit is a well-known system consisting primarily of the bilateral orbital frontal cortex, caudate, nucleus accumbens, thalamus, and substantia nigra. We validated these circuit pathways using Granger causality and the metabolic connectivity map for identifying effective connectivities against a priori knowledge by testing the significance of directed pathways (P < .05, false discovery rate-corrected). We found 3 types of effective connectivities in the dopamine reward circuit: long-range, neighborhood, and symmetric. Granger causality analysis revealed long-range connections in the orbital frontal cortex-caudate and orbital frontal cortex-nucleus accumbens regions. Metabolic connectivity map analysis revealed neighborhood connections in the nucleus accumbens-caudate, substantia nigra-thalamus, and thalamus-caudate regions. Metabolic connectivity map analysis also found symmetric connections in each of the bilateral nucleus accumbens, caudate, thalamus, and orbital frontal cortex-caudate regions. Different patterns in directional networks of the dopamine reward circuit were revealed by Granger causality and metabolic connectivity map analyses. Granger causality analysis primarily identified bidirectional cortico-nucleus connections, while the metabolic connectivity map primarily identified direct connections among neighborhood and symmetric regions. The results of this study indicated that investigations of effective connectivities should use an appropriate analysis method depending on the purpose of the study.

Food appearance affects reward-related brain activity in healthy adults: a functional magnetic resonance imaging study

A good appearance of food increases appetite. A new food product called iEat® resembles the appearance and softness of familiar foods. Previous studies have reported that iEat® foods increase appetite. However, the neuronal substrates underlying the increase in appetite following the observation of iEat® foods remain unknown. In the present study, the brain activity of 20 healthy adults during the visual presentation of iEat® and pureed foods and non-food objects was examined using functional magnetic resonance imaging. Compared with pureed foods and non-food objects, iEat® foods showed significantly greater activation in regions of the brain reward system, such as the amygdala, ventral striatum and orbital frontal cortex. In addition, individual differences in the activity of the left amygdala were positively correlated with subjective appetite ratings. These results suggest that the good appearance of foods, such as iEat® foods, may be useful for stimulating the appetite of patients with poor appetite.

Association of the plasma complement system with brain volume deficits in bipolar and major depressive disorders.

Inflammation plays a crucial role in the pathogenesis of major depressive disorder (MDD) and bipolar disorder (BD). This study aimed to examine whether the dysregulation of complement components contributes to brain structural defects in patients with mood disorders. A total of 52 BD patients, 35 MDD patients, and 53 controls were recruited. The human complement immunology assay was used to measure the levels of complement factors. Whole brain-based analysis was performed to investigate differences in gray matter volume (GMV) and cortical thickness (CT) among the BD, MDD, and control groups, and relationships were explored between neuroanatomical differences and levels of complement components. GMV in the medial orbital frontal cortex (mOFC) and middle cingulum was lower in both patient groups than in controls, while the CT of the left precentral gyrus and left superior frontal gyrus were affected differently in the two disorders. Concentrations of C1q, C4, factor B, factor H, and properdin were higher in both patient groups than in controls, while concentrations of C3, C4 and factor H were significantly higher in BD than in MDD. Concentrations of C1q, factor H, and properdin showed a significant negative correlation with GMV in the mOFC at the voxel-wise level. BD and MDD are associated with shared and different alterations in levels of complement factors and structural impairment in the brain. Structural defects in mOFC may be associated with elevated levels of certain complement factors, providing insight into the shared neuro-inflammatory pathogenesis of mood disorders.

Acoustic startle and prepulse inhibition deficits in adult monkeys with neonatal lesions of the hippocampus, amygdala and orbital frontal cortex

Sensory-motor gating, the process of filtering sensory stimuli to modulate motor responses, is impaired in many psychiatric diseases but especially schizophrenia. Sensory-motor gating assessed with the prepulse inhibition paradigm (PPI) measures startle in response to preceding acoustic stimuli. PPI studies in rodents have consistently found that neonatal hippocampal lesions impair sensory-motor gating in adult animals, but its applicability to primates has yet to be tested. The study examined acoustic startle responses and PPI in adult rhesus monkeys with neonatal lesions of the hippocampus (Neo-Hibo), amygdala (Neo-Aibo), and orbital frontal cortex areas 11 and 13 (Neo-Oasp) and with sham-operations (Neo-C). All monkeys were initially habituated to the startle apparatus and assayed for acoustic startle response curves. Subsequently, PPI was measured with the prepulse occurring at 60, 120, 240, 480, 1000 and 5000 msec prior to the pulse onset. No significant group differences in baseline startle were found. Compared to Neo-C monkeys, Neo-Hibo monkeys showed normal startle curves as well as normal PPI at short prepulse delays but prepulse facilitation (PPF) at longer prepulse intervals. Neo-Aibo monkeys displayed enhanced startle responses with only minor changes in PPI, whereas Neo-Oasp monkeys had severe dampening of startle responses and impaired PPI at shorter prepulse intervals. These results support prior evidence from rodent literature of the involvement of each of these areas in the development of the complex cortico-limbic circuit modulating sensory-motor gating and may shade light on the specific neural structures associated with deficits in PPI reported in neuropsychiatric disorders, such as schizophrenia, autism spectrum disorders, and post-traumatic disorders.

Gray matter volume and functional connectivity underlying binge eating in healthy children.

As a maladaptive disordered eating behavior, binge eating (BE) onset has been reported in children as young as eight years old and is linked with a range of negative psychological consequences. However, previous neuroimaging research of BE has mainly focused on adults in clinical conditions, and little is known about the potential neurostructural and neurofunctional bases of BE in healthy children. In this study, we examined these issues in 76 primary school students (mean age = 9.86years) using voxel-based morphometry and resting-state functional connectivity (rsFC) approaches. After controlling for age, sex, and total intracranial volume/head motion, we observed that higher levels of BE were correlated with greater gray matter volumes (GMV) in the left fusiform and right insula and weaker rsFC between the right insula and following three regions: right orbital frontal cortex, left cingulate gyrus, and left superior frontal gyrus. No significant associations were observed between BE and regional white matter volume. Significant sex differences were found only in the relationship between BE and GMV in the left fusiform. Furthermore, the GMV- and rsFC-based predictive models (a machine-learning method) achieved significant correlations between the actual and predicted BE values, demonstrating the robustness of our findings. The present study provides novel evidence for the brain structural and functional substrates of children's BE, and further reveals that the weakened communication between core regions associated with negative affectivity, reward responsivity, and executive function is strongly related to dysregulated eating. Level V, descriptive study.

Molecular examination of the endogenous opioid system in rhesus macaque monkeys with self-injurious behavior.

Self-injurious behavior (SIB) can lead to serious injury and occurs in approximately 1%-4% of the adult population, with higher incidences in adolescent and institutionalized populations, as well as in children with developmental disorders such as Autism. SIB also spontaneously occurs in a low percentage of captive monkeys. Rhesus macaque (Macaca mulatta) monkeys are evolutionarily and physiologically similar to humans, share 93% genetic sequence similarity to humans, and have long been used as testing subjects for vaccine and clinical trials. Previous studies hypothesized that altered endogenous opioid expression occurs in the brains of individuals and animals that self-injure. We examined the regional mRNA expression of opioid signaling genes in sixteen rhesus macaques that exhibited SIB and eight sex- and age- matched controls. The brain regions examined are linked to reward reinforcement and stress adaptation including the hypothalamus, orbital frontal cortex, nucleus accumbens, hippocampus, caudate, and the amygdala. We found decreased μ-opioid receptor (OPRM1) in the amygdala of monkeys with SIB, and reduced prodynorphin (PDYN) in the hypothalamus. Our data suggest dysfunction in the regulation of opioid peptide precursors and calls for further investigation of the endogenous opioid system in SIB.

Relationship between CSF tau biomarkers and structural brain MRI measures in frontotemporal lobar degeneration

BackgroundRecently in the field neurodegenerative diseases increasing attention has been pointed to CSF biomarkers and their integration with neuroimaging (1). Frontotemporal lobar degeneration (FTLD) refers to a heterogeneous group of clinical syndromes with different underlying proteinopathies including tau pathology. CSF biomarkers have been proposed as diagnostic and prognostic factors. Aim of our study was to evaluate the relationship between CSF tau biomarkers and structural MRI brain measures in FTLD. MethodsWe included early FTLD patient. All included patients underwent lumbar puncture to evaluate amyloid, total-tau (t-tau), phospho-tau 181 (p-tau); p-tau/t-tau ratio was also calculated; brain MRI was performed to estimate whole brain volume, volume of principal deep grey matter structures and regional cortical thickness. ResultsDemographic characteristics of the 28 included patients were as follows: female/male: 9/19; mean ± SD age: 68.1 ± 7.8 years. The p-tau/t-tau ratio was significantly correlated with whole brain volume (r = 0.69; p: 0.001), left putamen volume (r = 0.55 p: 0.009), left pallidum volume (r = 0.41; p: 0.01), right accumbens area (r = 0.47; p: 0.02). P-tau/t tau ratio showed also a significant correlation with cortical thickness of left temporal lobe (r = 0.74; p: 0.001) and right lateral orbital frontal cortex (r = 0.45; p: 0.03). Linear regression showed a significant relationship between p-tau/t-tau ratio and left temporal pole (p = 0.01; r2: 0.60) and brain volume (p:0.002; r2: 0.56) after controlling for age and gender. ConclusionsOur data suggest that CSF biomarkers, especially p-tau/t-tau ratio, could play a role as prognostic factor in FTLD. Further longitudinal investigations are needed to confirm these findings.

Transcutaneous auricular vagus nerve immediate stimulation treatment for treatment-resistant depression: A functional magnetic resonance imaging study.

ObjectiveTranscutaneous auricular vagus nerve stimulation (taVNS) is effective for treatment-resistant depression (TRD). In the current study, we observed the immediate modulating brain effect of taVNS in patients with TRD using rest-state functional magnetic resonance imaging (rs-fMRI).MethodForty patients with TRD and forty healthy controls (HCs) were recruited. Rs-fMRI was performed before and after 30 min of taVNS at baseline. The brain regions that presented significantly different the Regional Homogeneity (ReHo) between the TRD patients and HCs were selected as the ROI to calculate the functional connectivity (FC) of full brain. The correlations were estimated between the clinical scales' score and the functional brain changes.ResultsFollowing taVNS stimulation treatment, TRD patients showed significantly reduced ReHo in the medial orbital frontal cortex (mOFC) (F = 18.06, P < 0.0001), ANCOVA of the mOFC-Based FC images revealed a significant interaction effect on the left inferior parietal gyrus (IPG) and left superior marginal gyrus (SMG) (F = 11.6615, P<0.001,F = 16.7520, P<0.0001). Among these regions, the HAMD and HAMA scores and ReHo/FC changes were not correlated.ConclusionThis study applied rs-fMRI technology to examine the effect of taVNS stimulation treatment on the brain activity of TRD. These results suggest that the brain response of TRD patients to taVNS treatment may be associated with the functional modulation of cortical regions including the medial orbital frontal cortex, the left inferior parietal gyrus, and the left superior marginal regions. Changes in these neuroimaging indices may represent the neural mechanisms underlying taVNS Immediate Stimulation treatment in TRD.

Effect of acupuncture on brain functional connectivity strength in patients with primary dysmenorrhea

To investigate the effect of acupuncture on the brain functional activities of the patients with primary dysmenorrhea based on the resting-state functional magnetic resonance imaging (rs-fMRI), and to provide visual evidence for the central mechanism of acupuncture in treatment of primary dysmenorrhea. Forty-two patients of primary dysmenorrhea were enrolled and randomly divided into an observation group (21 cases, 1 case dropped off) and a control group (21 cases, 2 cases dropped off, 3 cases withdrawal). In the observation group, acupuncture was exerted at Sanyinjiao (SP 6) and Guanyuan (CV 4), started 5-7 days before menstrual flow, once a day till menstrual onset, for a total of 3 menstrual cycles. No intervention was applied in the control group. The scores of visual analogue scale (VAS) and Cox menstrual symptom scale (CMSS) were observed in both groups before and after treatment. Based on rs-fMRI, the data of resting-state functional magnetic resonance were collected from two groups before and after treatment. Combined with functional connectivity strength (FCS) and functional connectivity (FC) analysis, the differences of brain regions before and after treatment were compared between the two groups and the correlation was analyzed between their functional connectivity changes and the improvements in VAS and CMSS scores of the patients in the observation group. In the observation group, the scores of VAS and CMSS were all decreased after treatment (P<0.05), while the scores related to the symptom time in CMSS was reduced in comparison with that before treatment in the control group (P<0.05). The score reducing ranges of VAS and CMSS in the observation group were larger than the control group (P<0.05). Compared before treatment, FCS of the right middle cingulate cortex and the left cuneus was increased, while FCS of the left inferior parietal lobule was decreased after treatment in the observation group. In the control group, FCS of the left orbital frontal cortex was increased after treatment. Compared with the control group, FCS of the left anterior insula was increased in the observation group after treatment. FC analysis was performed using the left anterior insula as the seed point. In comparison with the control group, FC of the left anterior insula was increased either with the inferior temporal gyrus or with the right hippocampus; and was decreased either with the middle occipital lobe or with the right dorsolateral prefrontal cortex in the observation group after treatment. In the observation group, FC between the left anterior insula and the right hippocampus was positively correlated with the improvements in symptom severity (r =0.385, P<0.05) and symptom time (r =0.510, P<0.05) of CMSS, and FC between the right dorsolateral prefrontal cortex and the left anterior insula was negatively correlated with the improvement in symptom severity of CMSS after treatment (r =-0.373, P<0.05). The anterior insula may be the key brain region in treatment of primary dysmenorrhea with acupuncture. Acupuncture may relieve dysmenorrhea and the related symptoms through strengthening the functional connectivity of anterior insula-limbic system and anterior insula-control network.

Pretreatment Alterations and Acute Medication Treatment Effects on Brain Task-Related Functional Connectivity in Youth With Bipolar Disorder: A Neuroimaging Randomized Clinical Trial.

Disruptions in cognition are a clinically significant feature of bipolar disorder (BD). The effects of different treatments on these deficits and the brain systems that support them remain to be established. A continuous performance test was administered to 55 healthy controls and 71 acutely ill youths with mixed/manic BD to assess vigilance and working memory during task-based functional magnetic resonance imaging studies. Patients, who were untreated for at least 7 days at baseline, and controls were scanned at pretreatment baseline and at weeks 1 and 6. After baseline testing, patients (n = 71) were randomly assigned to 6-week double-blind treatment with lithium (n = 26; 1.0-1.2 mEq/L) or quetiapine (n = 45; 400-600 mg). Weighted seed-based connectivity (wSBC) was used to assess regional brain interactions during the attention task compared with the control condition. At baseline, youths with BD showed reduced connectivity between bilateral anterior cingulate cortex and both left ventral lateral prefrontal cortex and left insula and increased connectivity between left ventral lateral prefrontal cortex and left temporal pole, left orbital frontal cortex and right postcentral gyrus, and right amygdala and right occipital pole compared with controls. At 1-week follow-up, quetiapine, but not lithium, treatment led to a significant shift of connectivity patterns toward those of the controls. At week 6, compared with baseline, there was no difference between treatment conditions, at which time both patient groups showed significant normalization of brain connectivity toward that of controls. Functional alterations in several brain regions associated with cognitive processing and the integration of cognitive and affective processing were demonstrated in untreated youths with BD before treatment. Treatment reduced several of these alterations, with significant effects at week 1 only in the quetiapine treatment group. Normalization of functional connectivity might represent a promising biomarker for early target engagement in youth with BD. Multimodal Neuroimaging of Treatment Effects in Adolescent Mania; https://clinicaltrials.gov/; NCT00893581.

Orbitofrontal Cortex Functional Connectivity-Based Classification for Chronic Insomnia Disorder Patients With Depression Symptoms.

Depression is a common comorbid symptom in patients with chronic insomnia disorder (CID). Previous neuroimaging studies found that the orbital frontal cortex (OFC) might be the core brain region linking insomnia and depression. Here, we used a machine learning approach to differentiate CID patients with depressive symptoms from CID patients without depressive symptoms based on OFC functional connectivity. Seventy patients with CID were recruited and subdivided into CID with high depressive symptom (CID-HD) and low depressive symptom (CID-LD) groups. The OFC functional connectivity (FC) network was constructed using the altered structure of the OFC region as a seed. A linear kernel SVM-based machine learning approach was carried out to classify the CID-HD and CID-LD groups based on OFC FC features. The predict model was further verified in a new cohort of CID group (n = 68). The classification model based on the OFC FC pattern showed a total accuracy of 76.92% (p = 0.0009). The area under the receiver operating characteristic curve of the classification model was 0.84. The OFC functional connectivity with reward network, salience network and default mode network contributed the highest weights to the prediction model. These results were further validated in an independent CID group with high and low depressive symptom (accuracy = 67.9%). These findings provide a potential biomarker for early diagnosis and intervention in CID patients comorbid with depression based on an OFC FC-based machine learning approach.

Altered Regional Activity and Network Homogeneity within the Fronto-Limbic Network at Rest in Medicine-Free Obsessive-Compulsive Disorder.

Functional abnormalities in brain areas within the fronto-limbic network have been widely reported in obsessive–compulsive disorder (OCD). However, region- and network-level brain activities of the fronto-limbic network at rest have not been simultaneously investigated in OCD. In this study, 40 medicine-free and non-comorbidity patients with OCD and 38 age-, education-, and gender-matched healthy controls (HCs) underwent a resting-state functional magnetic-resonance-imaging scan. Fractional amplitude of low-frequency fluctuations (fALFF), network homogeneity (NH), and support vector machine were used to analyze the data. Patients with OCD showed increased fALFF in the right orbital frontal cortex (OFC), increased NH in the left OFC, and decreased NH in the right putamen. Decreased NH of the right putamen was negatively correlated with the Y-BOCS total and compulsive behavior scores. Furthermore, a combination of NH in the left OFC and right putamen could be applied to differentiate OCD from HCs with optimum specificity and sensitivity. The current findings emphasize the crucial role of the fronto-limbic network in the etiology of OCD.

Different Patterns of Neural Activity Characterize Motor Skill Performance During Acquisition and Retention.

Motor performance and learning have distinct behavioral and neural signatures and can be uniquely modulated by various informational and motivational factors. Contemporary frameworks describe four different motor learning mechanisms mapped onto specific neural regions which are key for motor skill acquisition: error-based learning (cerebellum), reinforcement learning (basal ganglia), cognitive strategies (prefrontal cortex), and use-dependent learning (motor cortex). However, little is known about the neural circuits engaged during skill acquisition that are modulated specifically by practice-based performance improvement and those that predict recall performance. Based on previous work, we hypothesize that brain activity during practice in primary motor cortex and basal ganglia (1) is associated with trial-by-trial practice performance and (2) is predictive of immediate recall performance. Leveraging the contemporary framework, we use a well-known task paradigm that primarily relies upon cognitive strategy, reinforcement, and use-based learning mechanisms to test our hypotheses. Forty neurotypical young adults were asked to practice a pinch force tracking task. Participants received performance feedback after each trial during practice. We used whole brain analysis of functional magnetic resonance imaging (fMRI) and behavioral performance measures (i.e., time-on-target and self-efficacy) during the practice phase to determine which brain activation patterns are (1) associated with trial-by-trial tracking performance and (2) predictive of immediate no-feedback retention performance. We observed brain activations in the frontal orbital cortex, putamen, amygdala, and insula correlated with tracking performance improvement during practice. In contrast, a different set of performance-related activated regions were observed that were associated with immediate retention performance that included the primary motor cortex, superior frontal gyrus, somatosensory cortex, angular gyrus, and parietal gyrus. Our findings demonstrate that improved practice performance and recall of a sensorimotor skill are correlated with distinct neural activity patterns during acquisition, drawing on different motor learning mechanisms during encoding. While motor performance improvements depend on both cortical and subcortical regions, motor skill recall depends primarily on prefrontal and motor cortices. We discuss possible interpretations for why our hypothesis regarding basal ganglia activity and retention performance was not supported. Understanding the different neural mechanisms engaged in motor performance and learning may inform novel interventions to enhance motor skill learning.

Neural connectome features of procrastination: Current progress and future direction

Procrastination refers to an irrationally delay for intended courses of action despite of anticipating a negative consequence due to this delay. Previous studies tried to reveal the neural substrates of procrastination in terms of connectome-based biomarkers. Based on this, we proposed a unified triple brain network model for procrastination and pinpointed out what challenges we are facing in understanding neural mechanism of procrastination. Specifically, based on neuroanatomical features, the unified triple brain network model proposed that connectome-based underpinning of procrastination could be ascribed to the abnormalities of self-control network (i.e., dorsolateral prefrontal cortex, DLPFC), emotion-regulation network (i.e., orbital frontal cortex, OFC), and episodic prospection network (i.e., para-hippocampus cortex, PHC). Moreover, based on the brain functional features, procrastination had been attributed to disruptive neural circuits on FPN (frontoparietal network)-SCN (subcortical network) and FPN-SAN (salience network), which led us to hypothesize the crucial roles of interplay between these networks on procrastination in unified triple brain network model. Despite of these findings, poor interpretability and computational model limited further understanding for procrastination from theoretical and neural perspectives. On balance, the current study provided an overview to show current progress on the connectome-based biomarkers for procrastination, and proposed the integrative neurocognitive model of procrastination.

Selective Prefrontal-Amygdala Circuit Interactions Underlie Social and Nonsocial Valuation in Rhesus Macaques.

Lesion studies in macaques suggest dissociable functions of the orbitofrontal cortex (OFC) and medial frontal cortex (MFC), with OFC being essential for goal-directed decision-making and MFC supporting social cognition. Bilateral amygdala damage results in impairments in both of these domains. There are extensive reciprocal connections between these prefrontal areas and the amygdala; however, it is not known whether the dissociable roles of OFC and MFC depend on functional interactions with the amygdala. To test this possibility, we compared the performance of male rhesus macaques (Macaca mulatta) with crossed surgical disconnection of the amygdala and either MFC (MFC × AMY, n = 4) or OFC (OFC × AMY, n = 4) to a group of unoperated controls (CON, n = 5). All monkeys were assessed for their performance on two tasks to measure the following: (1) food-retrieval latencies while viewing videos of social and nonsocial stimuli in a test of social interest and (2) object choices based on current food value using reinforcer devaluation in a test of goal-directed decision-making. Compared with the CON group, the MFC × AMY group, but not the OFC × AMY group, showed significantly reduced food-retrieval latencies while viewing videos of conspecifics, indicating reduced social valuation and/or interest. By contrast, on the devaluation task, group OFC × AMY, but not group MFC × AMY, displayed deficits on object choices following changes in food value. These data indicate that the MFC and OFC must functionally interact with the amygdala to support normative social and nonsocial valuation, respectively.SIGNIFICANCE STATEMENT Ascribing value to conspecifics (social) versus objects (nonsocial) may be supported by distinct but overlapping brain networks. Here, we test whether two nonoverlapping regions of the prefrontal cortex, the medial frontal cortex and the orbitofrontal cortex, must causally interact with the amygdala to sustain social valuation and goal-directed decision-making, respectively. We found that these prefrontal-amygdala circuits are functionally dissociable, lending support for the idea that medial frontal and orbital frontal cortex make independent contributions to cognitive appraisals of the environment. These data provide a neural framework for distinct value assignment processes and may enhance our understanding of the cognitive deficits observed following brain injury or in the development of mental health disorders.

Diffusion MRI–guided theta burst stimulation enhances memory and functional connectivity along the inferior longitudinal fasciculus in mild cognitive impairment

Mild cognitive impairment (MCI) during aging is often a harbinger of Alzheimer’s disease, and, therefore, early intervention to preserve cognitive abilities before the MCI symptoms become medically refractory is particularly critical. Functional MRI–guided transcranial magnetic stimulation is a promising approach for modulating hippocampal functional connectivity and enhancing memory in healthy adults. Here, we extend these previous findings to individuals with MCI and leverage theta burst stimulation (TBS) and white matter tractography derived from diffusion-weighted MRI to target the hippocampus. Our preliminary findings suggested that TBS could be used to improve associative memory performance and increase resting-state functional connectivity of the hippocampus and other brain regions, including the occipital fusiform, frontal orbital cortex, putamen, posterior parahippocampal gyrus, and temporal pole, along the inferior longitudinal fasciculus in MCI. Although the sample size is small, these results shed light on how TBS propagates from the superficial cortex around the parietal lobe to the hippocampus.

The association between peer-victimisation and structural and functional brain outcomes: A systematic review.

Peer adversity and aggression are common experiences in childhood and adolescence which lead to poor mental health outcomes. To date, there has been no review conducted on the neurobiological changes associated with relational peer-victimisation, bullying and cyberbullying. This systematic review assessed structural and functional brain changes associated with peer-victimisation, bullying, and cyberbullying from 1 January 2000 to April 2021. A systematic search of Psychoinfo, Pubmed, and Scopus was performed independently by two reviewers using predefined criteria. Twenty-six studies met the selection criteria and were considered for review. The data collected shows altered brain activation of regions implicated in processing reward, social pain, and affect; and heightened sensitivity and more widespread activation of brain regions during acute social exclusion, most notably in the amygdala, left parahippocampal gyrus, and fusiform gyrus, associated with victimisation exposure. In addition, victimised youths also demonstrated greater risk-taking behaviours following acute social exclusion showing greater ventral striatum-inferior frontal gyrus coupling, activation in the bilateral amygdala, orbital frontal cortex (OFC), medial prefrontal cortex (MPFC), temporoparietal junction (TPJ), medial posterior parietal cortex (MPPC) and dorsomedial prefrontal cortex(dmPFC), suggesting greater social monitoring, seeking of inclusion, and moreeffortful cognitive control. The studies included participants from a very broad developmental age range, mostly using cross-sectional measure of peer-victimisation exposure, at varying developmental stages. This review highlights the need for more neuroimaging studies in cyberbullying, as well as longitudinal studies across more diverse samples for investigating gender, age, and developmental interactions with peer-victimising. This also brings to attention the importance of addressing bullying victimisation particularly in adolescence, given the evidence for social stress in heightening developmentally sensitive processes which are associated with depression, anxiety, and externalising symptoms.

In Vivo Molecular Imaging of Neuroinflammation in Patients with Migraine

While the neural correlates of migraine have been widely studied, it remains unclear whether glial cells contribute to neuroinflammation in migraine. One marker of glial activation is the presence of elevated levels of 18 kDa translocator protein (TSPO), and earlier studies have shown that individuals suffering from migraine with aura (MWA) exhibit increased brain TSPO PET signal in a widespread set of regions, compared to healthy controls (Albrecht et al., Neurology 2019, Hadjikhani et al., 2020). The purpose of the present study was to apply [11C]PBR28 PET neuroimaging to extend our initial observations from patients suffering from MWA to include patients with migraine without aura. A total of 24 migraine patients and 17 healthy controls were scanned in a Siemens 3T with PET insert and injected with [11C]PBR28 radioactive tracer. For all subjects, 30-minute static SUV images were acquired ∼60-90 minutes after injection of the tracer. SUV maps were registered to MNI space and smoothed with an 8mm Gaussian filter. SUV ratio (SUVR) images were obtained via intensity-normalization using the cerebellum as pseudo-reference region (showing no statistical difference between the two groups; p>0.5). A non-parametric voxel-wise analysis of the whole brain was performed to evaluate the presence of group differences in the [11C]PBR28 signal. Results show that [11C]PBR28 elevations were observed in the thalamus, insula, hippocampus, pallidum, putamen, SCC and frontal orbital cortex. These cortical and subcortical regions uptake increases were similar to those observed in our previous study in patients with MWA. This work provides in vivo evidence that migraine, with or without aura, may be accompanied by neuroinflammation in humans, paving the way to therapeutic strategies targeting glial activation. Grant support from Boosting mind-body mechanisms and outcomes for chronic pain P01 AT009965-01.