Inferior Frontal Cortex Research Articles

Mechanisms underlying capsulotomy for refractory obsessive-compulsive disorder: neural correlates of negative affect processing overlap with deep brain stimulation targets

Ablative procedures such as anterior capsulotomy are potentially effective in refractory obsessive-compulsive disorder (OCD). Converging evidence suggests the ventral internal capsule white matter tracts traversing the rostral cingulate and ventrolateral prefrontal cortex and thalamus is the optimal target for clinical efficacy across multiple deep brain stimulation targets for OCD. Here we ask which prefrontal regions and underlying cognitive processes might be implicated in the effects of capsulotomy by using both task fMRI and neuropsychological tests assessing OCD-relevant cognitive mechanisms known to map across prefrontal regions connected to the tracts targeted in capsulotomy. We tested OCD patients at least 6 months post-capsulotomy (n = 27), OCD controls (n = 33) and healthy controls (n = 34). We used a modified aversive monetary incentive delay paradigm with negative imagery and a within session extinction trial. Post-capsulotomy OCD subjects showed improved OCD symptoms, disability and quality of life with no differences in mood or anxiety or cognitive task performance on executive, inhibition, memory and learning tasks. Task fMRI revealed post-capsulotomy decreases in the nucleus accumbens during negative anticipation, and in the left rostral cingulate and left inferior frontal cortex during negative feedback. Post-capsulotomy patients showed attenuated accumbens-rostral cingulate functional connectivity. Rostral cingulate activity mediated capsulotomy improvement on obsessions. These regions overlap with optimal white matter tracts observed across multiple stimulation targets for OCD and might provide insights into further optimizing neuromodulation approaches. Our findings also suggest that aversive processing theoretical mechanisms may link ablative, stimulation and psychological interventions.

Neural substrates of behavioral inhibitory control during the two-choice oddball task: functional neuroimaging evidence.

Behavioral inhibitory control (BIC) depicts a cognitive function of inhibiting inappropriate dominant responses to meet the context requirement. Despite abundant research into neural substrates of BIC during the go/no-go and stop signal tasks, these tasks were consistently shown hard to isolate neural processes of response inhibition, which is of primary interest, from those of response generation. Therefore, it is necessary to explore neural substrates of BIC using the two-choice oddball (TCO) task, whose design of dual responses is thought to produce an inhibition effect free of the confounds of response generation. The current study aims at depicting neural substrates of performing behavioral inhibitory control in the two-choice oddball task, which designs dual responses to balance response generation. Also, neural substrates of performing BIC during this task are compared with those in the go/no-go task, which designs a motor response in a single condition. The present study integrated go/no-go (GNG) and TCO tasks into a new Three-Choice BIC paradigm, which consists of standard (75%), deviant (12.5%), and no-go (12.5%) conditions simultaneously. Forty-eight college students participated in this experiment, which required them to respond to standard (frequent) and deviant stimuli by pressing different keys, while inhibiting motor response to no-go stimuli. Conjunction analysis and ROI (region of interest) analysis were adopted to identify the unique neural mechanisms that subserve the processes of BIC. Both tasks are effective in assessing BIC function, reflected by the significantly lower accuracy of no-go compared to standard condition in GNG, and the significantly lower accuracy and longer reaction time of deviant compared to standard condition in TCO. However, there were no significant differences between deviant and no-go conditions in accuracy. Moreover, functional neuroimaging has demonstrated that the anterior cingulate cortex (ACC) activation was observed for no-go vs. standard contrast in the GNG task, but not in deviant vs. standard contrast in the TCO task, suggesting that ACC involvement is not a necessary component of BIC. Second, ROI analysis of areas that were co-activated in TCO and GNG showed co-activations in the right inferior frontal cortex (triangle and orbital), with the signals in the TCO task significantly higher than those in the GNG task. These findings show that the designed responses to both standard and deviant stimuli in the TCO task, compared to the GNG task, produced a more prominent prefrontal inhibitory processing and extinguished an unnecessary component of ACC activation during BIC. This implies that prefrontal involvement, but not that of ACC, is mandatory for the successful performance of inhibiting prepotent behaviors.

Individual differences in beta-band oscillations predict motor-inhibitory control.

The ability of motor-inhibitory control is critical in daily life. The physiological mechanisms underlying motor inhibitory control deficits remain to be elucidated. Beta band oscillations have been suggested to be related to motor performance, but whether they relate to motor-inhibitory control remains unclear. This study is aimed at systematically investigating the relationship between beta band oscillations and motor-inhibitory control to determine whether beta band oscillations were related to the ability of motor-inhibitory control. We studied 30 healthy young adults (age: 21.6 ± 1.5 years). Stop-signal reaction time (SSRT) was derived from stop signal task, indicating the ability of motor-inhibitory control. Resting-state electroencephalography (EEG) was recorded for 12 min. Beta band power and functional connectivity (including global efficiency) were calculated. Correlations between beta band oscillations and SSRT were performed. Beta band EEG power in left and right motor cortex (MC), right somatosensory cortex (SC), and right inferior frontal cortex (IFC) was positively correlated with SSRT (P's = 0.031, 0.021, 0.045, and 0.015, respectively). Beta band coherence between bilateral MC, SC, and IFC was also positively correlated with SSRT (P's < 0.05). Beta band global efficiency was positively correlated with SSRT (P = 0.01). This is the first study to investigate the relationship between resting-state cortical beta oscillations and response inhibition. Our findings revealed that individuals with better ability of motor inhibitory control tend to have less cortical beta band power and functional connectivity. This study has clinical significance on the underlying mechanisms of motor inhibitory control deficits.

Neurobiological correlates and attenuated positive social intention attribution during laughter perception associated with degree of autistic traits

Laughter plays an important role in group formation, signaling social belongingness by indicating a positive or negative social intention towards the receiver. In adults without autism, the intention of laughter can be correctly differentiated without further contextual information. In autism spectrum disorder (ASD), however, differences in the perception and interpretation of social cues represent a key characteristic of the disorder. Studies suggest that these differences are associated with hypoactivation and altered connectivity among key nodes of the social perception network. How laughter, as a multimodal nonverbal social cue, is perceived and processed neurobiologically in association with autistic traits has not been assessed previously. We investigated differences in social intention attribution, neurobiological activation, and connectivity during audiovisual laughter perception in association with the degree of autistic traits in adults [N = 31, Mage (SD) = 30.7 (10.0) years, nfemale = 14]. An attenuated tendency to attribute positive social intention to laughter was found with increasing autistic traits. Neurobiologically, autistic trait scores were associated with decreased activation in the right inferior frontal cortex during laughter perception and with attenuated connectivity between the bilateral fusiform face area with bilateral inferior and lateral frontal, superior temporal, mid-cingulate and inferior parietal cortices. Results support hypoactivity and hypoconnectivity during social cue processing with increasing ASD symptoms between socioemotional face processing nodes and higher-order multimodal processing regions related to emotion identification and attribution of social intention. Furthermore, results reflect the importance of specifically including signals of positive social intention in future studies in ASD.

Functional near-infrared spectroscopy shows that object relative clauses are more difficult to process than subject relative clauses in Turkish.

It was suggested that processing subject relative clauses (SRCs) is universally easier than processing object relative clauses (ORCs) based on the studies carried out in head-initial languages such as English and German. However, studies in head-final languages such as Chinese and Basque contradicted this claim. Turkish is also a head-final language. Existing relative clause processing literature in Turkish is based solely on behavioural metrics. Even though an ORC processing disadvantage was suggested for Turkish, the results were not conclusive. Therefore, we aimed to investigate the neural dynamics of relative clause processing in Turkish. We asked 14 native Turkish speakers to answer yes/no questions about 24 sentences each containing either a SRCor ORC while their prefrontal hemodynamic activity was recorded with functional near-infrared spectroscopy. Our findings revealed hemodynamic activity in the lateral portions of the left prefrontal cortex for both conditions. However, hemodynamic activity was more widespread in prefrontal regions in ORCcompared to SRC condition. Even though the behavioural metrics failed to produce a significant difference between the conditions, direct ORC > SRC contrast revealed significant activity in the left inferior frontal cortex, a region heavily involved in language processing, as well as in left and right dorsolateral prefrontal cortices, which are also known to be involved in language processing-related and conflict monitoring-related processes, respectively. Our findings indicate that processing ORCs is more difficult and requires further prefrontal resources than processing SRCs in Turkish, thus refuting the head-directionality-based explanations of relative clause processing asymmetries.

Functional correlates of neurological soft signs in heavy cannabis users.

Sensorimotor dysfunction has been previously reported in persons with cannabis dependence. Such individuals can exhibit increased levels of neurological soft signs (NSS), particularly involving motor coordination, sensorimotor integration and complex motor task performance. Abnormal NSS levels can also be detected in non-dependent individuals with heavy cannabis use (HCU), yet very little is known about the functional correlates underlying such deficits. Here, we used resting-state functional magnetic resonance imaging (MRI) to investigate associations between NSS and intrinsic neural activity (INA) in HCU (n= 21) and controls (n= 26). Compared with controls, individuals with HCU showed significantly higher NSS across all investigated subdomains. Three of these subdomains, that is, motor coordination, sensorimotor integration and complex motor task behaviour, were associated with specific use-dependent variables, particularly age of onset of cannabis use and current cannabis use. Between-group comparisons of INA revealed lower regional homogeneity (ReHo) in left precentral gyrus, left inferior occipital gyrus, right triangular pat of the inferior frontal gyrus and right precentral gyrus in HCU compared with controls. In addition, HCU showed also higher ReHo in right cerebellum and left postcentral gyrus compared with controls. Complex motor task behaviour in HCU was significantly related to INA in postcentral, inferior frontal and occipital cortices. Our findings indicate abnormal ReHo in HCU in regions associated with sensorimotor, executive control and visuomotor-integration processes. Importantly, we show associations between ReHo, cannabis-use behaviour and execution of complex motor tasks. Given convergent findings in manifest psychotic disorders, this study suggests an HCU endophenotype that may present with a cumulative risk for psychosis.

Abnormal resting-state functional connectivity underlies cognitive and clinical symptoms in patients with schizophrenia.

The cognitive and psychotic symptoms in patients with schizophrenia (SZ) are thought to result from disrupted brain network connectivity. We capitalize on the high spatiotemporal resolution of magnetoencephalography imaging (MEG) to record spontaneous neuronal activity in resting state networks in 21 SZ compared with 21 healthy controls (HC). We found that SZ showed significant global disrupted functional connectivity in delta-theta (2-8 Hz), alpha (8-12 Hz), and beta (12-30 Hz) frequencies, compared to HC. Disrupted global connectivity in alpha frequencies with bilateral frontal cortices was associated with more severe clinical psychopathology (i.e., positive psychotic symptoms). Specifically, aberrant connectivity in beta frequencies between the left primary auditory cortex and cerebellum, was linked to greater hallucination severity in SZ. Disrupted connectivity in delta-theta frequencies between the medial frontal and left inferior frontal cortex was associated with impaired cognition. The multivariate techniques employed in the present study highlight the importance of applying our source reconstruction techniques which leverage the high spatial localization abilities of MEG for estimating neural source activity using beamforming methods such as SAM (synthetic aperture morphometry) to reconstruct the source of brain activity, together with functional connectivity assessments, assayed with imaginary coherence metrics, to delineate how neurophysiological dysconnectivity in specific oscillatory frequencies between distinct regions underlie the cognitive and psychotic symptoms in SZ. The present findings employ powerful techniques in spatial and time-frequency domains to provide potential neural biomarkers underlying neuronal network dysconnectivity in SZ that will inform the development of innovations in future neuromodulation treatment development.

A Brain Mechanism for Hate.

A Brain Mechanism for Hate.

Overlapping and unique brain responses to cognitive and response inhibition

Although cognitive inhibition and response inhibition fall under the umbrella term of inhibition, the question remains whether the two aspects of inhibition engage shared or distinct brain regions. The current study is one of the first to examine the neural underpinnings of cognitive inhibition (e.g. the Stroop incongruency effect) and response inhibition (e.g. “no-go” response) within a single task. Adult participants (n = 77) completed an adapted version of the Simon Task in a 3T MRI scanner. The results demonstrated that cognitive and response inhibition recruited a group of overlapping brain regions (inferior frontal cortex, inferior temporal lobe, precentral cortex, parietal cortex). However, a direct comparison of cognitive and response inhibition revealed that the two aspects of inhibition also engaged distinct, task-specific brain regions (voxel-wise FWE corrected p < 0.05). Cognitive inhibition was associated with increases in multiple brain regions within the prefrontal cortex. On the other hand, response inhibition was associated with increases in distinct regions of the prefrontal cortex, right superior parietal cortex, and inferior temporal lobe. Our findings advance the understanding of the brain basis of inhibition by suggesting that cognitive inhibition and response inhibition engage overlapping but distinct brain regions.

Neural correlates of subjective cognitive decline in adults at high risk for Alzheimer's disease.

Recently, interest has emerged in subjective cognitive decline (SCD) as a potential precursor to Alzheimer's disease (AD) dementia. Whether individuals with SCD harbor brain alterations in midlife, when AD-related pathology begins, is yet to be elucidated. Furthermore, the role of apolipoprotein ε4 (APOE ε4) allele, a robust AD risk factor, in the relationship between SCD and brain alterations is unknown. We examined whether APOE genotype modulates the association of SCD with brain measures in individuals at high AD risk. Middle-aged adults with parental history of AD dementia underwent magnetic resonance imaging (MRI) and the Memory Functioning Questionnaire. Regression analysis tested the extent to which SCD was associated with activation during an functional MRI (fMRI) working-memory task, and white-matter microstructure. APOE ε4 genotype was tested as a moderator. Among APOE ε4 carriers, but not among non-carriers, SCD was associated with higher activation in the anterior cingulate (p = 0.003), inferior, middle, and superior frontal cortices (p = 0.041, p = 0.048, p = 0.037, respectively); and with lower fractional anisotropy in the uncinate fasciculus (p = 0.002), adjusting for age, sex, and education. In middle aged, cognitively normal individuals at high AD risk, higher SCD was associated with greater brain alterations possibly reflecting incipient AD pathology. When accompanied by a family history of AD and an APOE ε4 allele, SCD may have important clinical value, allowing a window for early intervention and for participants' stratification in AD prevention clinical trials.

Mapping spoken language and cognitive deficits in post-stroke aphasia

Aphasia is an acquired disorder caused by damage, most commonly due to stroke, to brain regions involved in speech and language. While language impairment is the defining symptom of aphasia, the co-occurrence of non-language cognitive deficits and their importance in predicting rehabilitation and recovery outcomes is well documented. However, people with aphasia (PWA) are rarely tested on higher-order cognitive functions, making it difficult for studies to associate these functions with a consistent lesion correlate. Broca’s area is a particular brain region of interest that has long been implicated in speech and language production. Contrary to classic models of speech and language, cumulative evidence shows that Broca’s area and surrounding regions in the left inferior frontal cortex (LIFC) are involved in, but not specific to, speech production. In this study we aimed to explore the brain-behaviour relationships between tests of cognitive skill and language abilities in thirty-six adults with long-term speech production deficits caused by post-stroke aphasia.Our findings suggest that non-linguistic cognitive functions, namely executive functions and verbal working memory, explain more of the behavioural variance in PWA than classical language models imply. Additionally, lesions to the LIFC, including Broca’s area, were associated with non-linguistic executive (dys)function, suggesting that lesions to this area are associated with non-language-specific higher-order cognitive deficits in aphasia. Whether executive (dys)function – and its neural correlate in Broca’s area – contributes directly to PWA’s language production deficits or simply co-occurs with it, adding to communication difficulties, remains unclear. These findings support contemporary models of speech production that place language processing within the context of domain-general perception, action and conceptual knowledge. An understanding of the covariance between language and non-language deficits and their underlying neural correlates will inform better targeted aphasia treatment and outcomes.

The cloud of unknowing: Cognitive dedifferentiation in whole-body perceptual deprivation.

An altered sensory environment, especially a homogeneous one like a ganzfeld, can induce a wide range of experiences in people immersed in it. The ganzfeld of our current focus is the OVO Whole-Body Perceptual Deprivation chamber (OVO-WBPD). Previous literature has found this specific immersive environment to be capable of softening and dissolving perception of boundaries across time and sensory modalities, among other domains. Since recent published electrophysiological results demonstrated that immersion in the OVO-WBPD significantly increased delta and beta activity, in the left inferior frontal cortex and in the left insula, we sought to better understand the subjective experiences of participants utilizing this altered sensory environment via semi-qualitative methodology. Consequently, semi-structured interviews of participants were analyzed by three independent evaluators focusing on several domains of experience often reported in perceptual deprivation environments. We found a significantly shared consensus on the presence of experiences belonging to semantic domains of altered experience, demonstrating that the OVO-WBPD chamber consistently elicits positively connotated, bodily-oriented and cognitively dedifferentiated subjective states of consciousness in the majority of 32 examined participants.

The role of left temporo-parietal and inferior frontal cortex in comprehending syntactically complex sentences: A brain stimulation study

Background and objectivesSyntactic competence relies on a left-lateralized network converging on hubs in inferior-frontal and posterior-temporal cortices. We address the question whether anodal transcranial direct current stimulation (a-tDCS) over these hubs can modulate comprehension of sentences, whose syntactic complexity systematically varied along the factors embedding depths and canonicity. Semantic content and length of the sentences were kept identical and forced choice picture matching was required after the full sentence had been presented. MethodsWe used a single-blind, within-subject, sham-controlled design, applying a-tDCS targeting left posterior tempo-parietal (TP) and left inferior frontal cortex (FC). Stimulation sites were determined by individual neuro-navigation. 20 participants were included of whom 19 entered the analysis. Results were analysed using (generalized) mixed models. In a pilot-experiment in another group of 20 participants we validated the manipulation of syntactic complexity by the two factors embedding depth and argument-order. ResultsReaction times increased and accuracy decreased with higher embedding depth and non-canonical argument order in both experiments. Notably a-tDCS over TP enhanced sentence-to-picture matching, while FC-stimulation showed no consistent effect. Moreover, the analysis disclosed a session effect, indicating improvements of task performance especially regarding speed. ConclusionsWe conclude that the posterior ‘hub’ of the neuronal network affording syntactic analysis represents a ‘bottleneck’, likely due to working-memory capacity and the challenges of mapping semantic to syntactic information allowing for role assignment. While this does not challenge the role of left inferior-frontal cortex for syntax processing and novel-grammar learning, the application of highly established syntactic rules during sentence comprehension may be considered optimized, thus not augmentable by a-tDCS in the uncompromised network. Significance statementAnodal transcranial direct current stimulation (a-tDCS) over left temporo-parietal cortex enhances comprehension of complex sentences in uncompromised young speakers. Since a-tDCS over left frontal cortex did not elicit any change, the ‘bottleneck’ for the understanding of complex sentences seems to be the posterior, temporo-parietal rather than the anterior inferior-frontal ‘hub’ of language processing. Regarding the attested role of inferior-frontal cortex in syntax processing, we suggest that its function is optimized in competent young speakers, preventing further enhancement by (facilitatory) tDCS. Results shed light on the functional anatomy of syntax processing during sentence comprehension; moreover, they open perspectives for research in the lesioned language network of people with syntactic deficits due to aphasia.

Grasp-specific high-frequency broadband mirror neuron activity during reach-and-grasp movements in humans.

Broadly congruent mirror neurons, responding to any grasp movement, and strictly congruent mirror neurons, responding only to specific grasp movements, have been reported in single-cell studies with primates. Delineating grasp properties in humans is essential to understand the human mirror neuron system with implications for behavior and social cognition. We analyzed electrocorticography data from a natural reach-and-grasp movement observation and delayed imitation task with 3 different natural grasp types of everyday objects. We focused on the classification of grasp types from high-frequency broadband mirror activation patterns found in classic mirror system areas, including sensorimotor, supplementary motor, inferior frontal, and parietal cortices. Classification of grasp types was successful during movement observation and execution intervals but not during movement retention. Our grasp type classification from combined and single mirror electrodes provides evidence for grasp-congruent activity in the human mirror neuron system potentially arising from strictly congruent mirror neurons.

Neurophysiological consequences of synapse loss in progressive supranuclear palsy.

Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even in the absence of gross atrophy. Currently, for human disease there are few formal models to explain how cortical networks underlying cognition are affected by synaptic loss. We advocate that biophysical models of neurophysiology offer both a bridge from preclinical to clinical models of pathology and quantitative assays for experimental medicine. Such biophysical models can also disclose hidden neuronal dynamics generating neurophysiological observations such as EEG and magnetoencephalography. Here, we augment a biophysically informed mesoscale model of human cortical function by inclusion of synaptic density estimates as captured by 11C-UCB-J PET, and provide insights into how regional synapse loss affects neurophysiology. We use the primary tauopathy of progressive supranuclear palsy (Richardson's syndrome) as an exemplar condition, with high clinicopathological correlations. Progressive supranuclear palsy causes a marked change in cortical neurophysiology in the presence of mild cortical atrophy and is associated with a decline in cognitive functions associated with the frontal lobe. Using parametric empirical Bayesian inversion of a conductance-based canonical microcircuit model of magnetoencephalography data, we show that the inclusion of regional synaptic density-as a subject-specific prior on laminar-specific neuronal populations-markedly increases model evidence. Specifically, model comparison suggests that a reduction in synaptic density in inferior frontal cortex affects superficial and granular layer glutamatergic excitation. This predicted individual differences in behaviour, demonstrating the link between synaptic loss, neurophysiology and cognitive deficits. The method we demonstrate is not restricted to progressive supranuclear palsy or the effects of synaptic loss: such pathology-enriched dynamic causal models can be used to assess the mechanisms of other neurological disorders, with diverse non-invasive measures of pathology, and is suitable to test the effects of experimental pharmacology.

Classification of Major Depressive Disorder using Machine Learning on brain structure and functional connectivity

Timely identification of the risk of having Major Depressive Disorder (MDD) using the advanced machine learning (ML) approach has been popularized to generate neural indicators of MDD. However, past ML studies have usually employed a comprehensive whole-brain approach, resulting in high computational cost that is hardly affordable in practical and clinical contexts. In this study, we took an alternative approach by first conducting a meta-analysis to identify brain regions of interest (ROIs) where structural and/or functional alterations had been consistently reported in MDD patients. We then utilized a nonlinear multilayer deep neural network method to evaluate the classification accuracies of MDD patients (N = 41, 29 females) and healthy individuals (N = 20, 12 females) based on the structural volume and resting-state functional connectivity (rsFC) of the ROIs. We found that the ML model based on brain volumes, with the inferior frontal cortex (IFC), amygdala, and the pons receiving the highest weights, achieved higher classification accuracy and sensitivity relative to the model based on rsFC. For ethical reasons, people with MDD remained taking antidepressants at the time of the study. Our findings highlight the critical role of the pons-cortico-limbic network in MDD, which is a significant insight for early identification and diagnosis of the illness for timely intervention.

The relationship between cognition and functioning in Bipolar Disorder: An investigation using functional imaging during working memory performance

The psychosocial functioning of individuals suffering from bipolar disorder (BD) has a significant impact on prognosis and quality of life. The aim of this study was to assess brain functional correlates of psychosocial functioning in BD individuals during the performance of a working memory task. Sixty-two subjects (31 euthymic BD individuals and 31 matched healthy controls) underwent structural and functional magnetic resonance imaging scanning while performing the 1- and 2-back versions of the n-back task (1-back and 2-back). The Functional Assessment Short Test (FAST) and its subdomains were used to assess functioning. Whole brain analysis revealed only overall activation differences between BD patients and healthy controls, but the patients showed failure of de-activation in the medial frontal cortex. Six clusters of significant inverse correlation with the FAST scores were found in the dorsolateral prefrontal cortex, the superior parietal cortex, and temporo-occipital regions bilaterally, and in the left inferior frontal cortex. Cognitive and occupational functioning were the subdomains most significantly associated with brain activation in these clusters. The results suggest that poor psychosocial functioning in BD individuals is associated with hypoactivation in a range of cortical regions, including the fronto-parietal working memory network and inferior temporo-occipital regions.

Regular cannabis use modulates the impact of HIV on the neural dynamics serving cognitive control.

Cannabis use and HIV are independently associated with decrements in cognitive control. However, the combined effects of HIV and regular cannabis use on the brain circuitry serving higher-order cognition are unclear. Investigate the interaction between cannabis and HIV on neural interference effects during the flanker task and spontaneous activity in regions underlying higher-order cognition. The sample consisted of 100 participants, including people with HIV (PWH) who use cannabis, PWH who do not use cannabis, uninfected cannabis users, and uninfected nonusers. Participants underwent an interview regarding their substance use history and completed the Eriksen flanker task during magnetoencephalography (MEG). MEG data were imaged in the time-frequency domain and oscillatory maps depicting the neural flanker interference effect were probed for group differences. Voxel time series were then assessed for group-level differences in spontaneous activity. Group differences in behavioral performance were identified along with group differences in theta and alpha neural interference responses in higher-order regions across the cortex, with nonusers with HIV generally exhibiting the most aberrant responses. Likewise, time series analyses indicated that nonusers with HIV also had significantly elevated spontaneous alpha activity in the left inferior frontal and dorsolateral prefrontal cortices (dlPFC). Finally, we found that spontaneous and oscillatory alpha activity were significantly coupled in the inferior frontal cortex and dlPFC among cannabis users, but not nonusers. Regular cannabis use appears to suppress the impact of HIV on spontaneous and oscillatory alpha deficits in the left inferior frontal cortex and dlPFC.

From Neuroimaging to Computational Modeling of Burnout: The Traditional versus the Fuzzy Approach—A Review

Occupational burnout, manifested by emotional exhaustion, lack of a sense of personal achievement, and depersonalization, is not a new phenomenon, but thusfar, there is no clear definition or diagnostic guidelines. The aim of this article wasto summarize all empirical studies to date that have used medical neuroimaging techniques to provide evidence or links regarding changes in brain function in occupational burnout syndrome from a neuroscientific perspective, and then use these to propose a fuzzy-based computational model of burnout.A comprehensive literature search was conducted in two major databases (PubMed and Medline Complete). The search period was 2006–2021, and searches were limited to the English language. Each article was carefully reviewed and appropriately selected on the basis of raw data, validity of methods used, clarity of results, and scales for measuring burnout. The results showed that the brain structures of patients with job burnout that are associated with emotion, motivation, and empathy weresignificantly different from healthy controls. These altered brain regions included the thalamus, hippocampus, amygdala, caudate, striatum, dorso-lateral prefrontal cortex, anterior cingulate cortex, posterior cingulate cortex, anterior insula, inferior frontal cingulate cortex, middle frontal cingulate cortex, temporoparietal junction, and grey matter. Deepening our understanding of how these brain structures are related to burnout will pave the way for better approaches fordiagnosis and intervention. As an alternative to the neuroimaging approach, the paper presents a late proposal of the PLUS (personal living usual satisfaction) parameter. It is based on a fuzzy model, wherein the data source is psychological factors—the same or similar to the neuroimaging approach. As the novel approach to searching for neural burnout mechanisms, we have shown that computational models, including those based on fuzzy logic and artificial neural networks, can play an important role in inferring and predicting burnout. Effective computational models of burnout are possible but need further development to ensure accuracy across different populations. There is also a need to identify mechanisms and clinical indicators of chronic fatigue syndrome, stress, burnout, and natural cognitive changes associated with, for example, ageing, in order to introduce more effective differential diagnosis and screening.

Do Psychogenic Erectile Dysfunction and Premature Ejaculation Share a Neural Circuit? Evidence from a fMRI Systematic Review and Meta-Analysis

Background: Several functional magnetic resonance imaging (fMRI) studies investigated the brain correlates of psychogenic erectile dysfunction (PED) and premature ejaculation (PE), representing the most common sexual dysfunctions in men. These studies allowed a wide set of brain regions in PED and PE patients when compared to healthy men. In the present meta-analysis, we aim at assessing the presence of homogeneity in the cerebral underpinnings of PED and PE. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and after the electronic search, duplicate removal and the application of pre-exclusion criteria, nine PED and ten PE studies were considered eligible with a Cohen’s k of 0.84 and 0.75, respectively. The effect sizes of the sociodemographic and psychological/urological dimensions were calculated. We extracted brain clusters from the retrieved studies, comparing patients and controls, and we calculated brain maps with Seed-Based D Mapping software. Results: We found a homogenous involvement of the frontal gyrus and insula in both dysfunctions, suggesting a common network. Conclusions: The anterior insula plays a key role in the processing of emotional features of stimuli, while the posterior insula in interoceptive information is relevant for sexual response. The prefrontal and inferior frontal cortices are important for sexual inhibition/disinhibition.