Orbitofrontal Lesion Alters Brain Dynamics of Emotion-Attention and Emotion-Cognitive Control Interaction in Humans

Association of polygenic risk for bipolar disorder with resting-state network functional connectivity in youth with and without bipolar disorder

Little is known regarding the polygenic underpinnings of anomalous resting-state functional connectivity (rsFC) in youth bipolar disorder (BD). The current study examined the association of polygenic risk for BD (BD-PRS) with whole-brain rsFC at the large-scale network level in youth with and without BD. 99 youth of European ancestry (56 BD, 43 healthy controls [HC]), ages 13-20 years, completed resting-state fMRI scans. BD-PRS was calculated using summary statistics from the latest adult BD genome-wide association study. Data-driven independent component analyses of the resting-state fMRI data were implemented to examine the association of BD-PRS with rsFC in the overall sample, and separately in BD and HC. In the overall sample, higher BD-PRS was associated with lower rsFC of the salience network and higher rsFC of the frontoparietal network with frontal and parietal regions. Within the BD group, higher BD-PRS was associated with higher rsFC of the default mode network with orbitofrontal cortex, and altered rsFC of the visual network with frontal and occipital regions. Within the HC group, higher BD-PRS was associated with altered rsFC of the frontoparietal network with frontal, temporal and occipital regions. In conclusion, the current study found that BD-PRS generated based on adult genetic data was associated with altered rsFC patterns of brain networks in youth. Our findings support the usefulness of BD-PRS to investigate genetically influenced neuroimaging markers of vulnerability to BD, which can be observed in youth with BD early in their course of illness as well as in healthy youth.

Cognitive control subprocess deficits and compensatory modulation mechanisms in patients with frontal lobe injury revealed by EEG markers: a basic study to guide brain stimulation

Background

Frontal lobe injury (FLI) is related to cognitive control impairments, but the influences of FLI on the internal subprocesses of cognitive control remain unclear.

Aims

We sought to identify specific biomarkers for long-term dysfunction or compensatory modulation in different cognitive control subprocesses.

Methods

A retrospective case-control study was conducted. Event-related potentials (ERP), oscillations and functional connectivity were used to analyse electroencephalography (EEG) data from 12 patients with unilateral frontal lobe injury (UFLI), 12 patients with bilateral frontal lobe injury (BFLI) and 26 healthy controls (HCs) during a Go/NoGo task, which included several subprocesses: perceptual processing, anticipatory preparation, conflict monitoring and response decision.

Results

Compared with the HC group, N2 (the second negative peak in the averaged ERP waveform) latency, and frontal and parietal oscillations were decreased only in the BFLI group, whereas P3 (the third positive peak in the averaged ERP waveform) amplitudes and sensorimotor oscillations were decreased in both patient groups. The functional connectivity of the four subprocesses was as follows: alpha connections of posterior networks in the BFLI group were lower than in the HC and UFLI groups, and these alpha connections were negatively correlated with neuropsychological tests. Theta connections of the dorsal frontoparietal network in the bilateral hemispheres of the BFLI group were lower than in the HC and UFLI groups, and these connections in the uninjured hemisphere of the UFLI group were higher than in the HC group, which were negatively correlated with behavioural performances. Delta and theta connections of the midfrontal-related networks in the BFLI group were lower than in the HC group. Theta across-network connections in the HC group were higher than in the BFLI group but lower than in the UFLI group.

Conclusions

The enhancement of low-frequency connections reflects compensatory mechanisms. In contrast, alpha connections are the opposite, therefore revealing more abnormal neural activity and less compensatory connectivity as the severity of injury increases. The nodes of the above networks may serve as stimulating targets for early treatment to restore corresponding functions. EEG biomarkers can measure neuromodulation effects in heterogeneous patients.

Electroconvulsive therapy-induced neuroimaging alterations measured by cerebral blood flow in adolescents with major depressive disorder

BACKGROUND

Electroconvulsive therapy (ECT) is a novel treatment strategy for adolescents with major depressive disorder (MDD). However, its related neurobiological changes associated with ECT remain undetermined.

OBJECTIVE

To elucidate the impact of ECT on the regional cerebral blood flow (CBF), and to identify alterations in the CBF associated with clinical outcomes in adolescents with MDD.

METHODS

Fifty-two treatment-naive adolescents who had experienced their first episode of MDD and 36 healthy controls (HCs) were recruited. To assess baseline parameters, all subjects were scanned with arterial spin labeling resting-state functional magnetic resonance imaging (ASL-fMRI) at the beginning of the study. Subsequently, 27 MDD adolescents were re-scanned after 2 weeks after ECT. CBF imaging was used for the prediction of specific clinical outcomes. Lastly, the associations between alterations seen on brain imaging alterations after ECT and ECT clinical efficacy (ΔHAMD scores) were determined.

RESULTS

Relative to HCs, adolescents with MDD exhibited reduced CBF in the left medial superior frontal gyrus (SFGmed) (cluster = 243, peak t = -3.9373, and P < 0.001) and augmented CBF in the right percental gyrus (PerCG) (cluster = 321, peak t = 4.3332, and P < 0.001) at baseline. Following ECT, MDD adolescents exhibited reduced CBF in the right fusiform gyrus (FFG) (cluster = 309, peak t = -4.346, and P < 0.001) and left hippocampus (HIP) (cluster = 290, peak t = -4.706, and P < 0.001), and enhanced CBF in the left orbital part of the inferior frontal gyrus (ORBinf) (cluster = 214, peak t = 4.073, and P < 0.001). Correlation analysis suggested an inverse association between ΔHAMD scores and CBF values in the left ORBinf (R² = 0.196, P = 0.021).

CONCLUSIONS

It was found that ECT resulted in alterations in CBF in specific brain areas, highlighting the significance of ORBinf in ECT pathophysiology in MDD adolescents.

The Impact of COVID-19 Lockdown Measures and COVID-19 Infection on Cognitive Functions: A Review in Healthy and Neurological Populations

The COVID-19 pandemic severely affected people's mental health all over the world. This review aims to present a comprehensive overview of the literature related to the effects of COVID-19 lockdown measures and COVID-19 infection on cognitive functioning in both healthy people and people with neurological conditions by considering only standardized tests. We performed a narrative review of the literature via two databases, PUBMED and SCOPUS, from December 2019 to December 2022. In total, 62 out of 1356 articles were selected and organized into three time periods: short-term (1-4 months), medium-term (5-8 months), and long-term (9-12 months), according to the time in which the tests were performed. Regardless of the time period, most studies showed a general worsening in cognitive performance in people with neurological conditions due to COVID-19 lockdown measures and in healthy individuals recovered from COVID-19 infection. Our review is the first to highlight the importance of considering standardized tests as reliable measures to quantify the presence of cognitive deficits due to COVID-19. Indeed, we believe that they provide an objective measure of the cognitive difficulties encountered in the different populations, while allowing clinicians to plan rehabilitation treatments that can be of great help to many patients who still, nowadays, experience post-COVID-19 symptoms.

Physical Activity Alters Functional Connectivity of Orbitofrontal Cortex Subdivisions in Healthy Young Adults: A Longitudinal fMRI Study

Physical activity (PA) plays an important role in affect processing. Studies describe the orbitofrontal cortex (OFC) as a major hub for emotion processing and the pathophysiology of affective disorders. Subregions of the OFC show diverse functional connectivity (FC) topographies, but the effect of chronic PA on subregional OFC FC still lacks scientific understanding. Therefore, we aimed at investigating the effects of regular PA on the FC topographies of OFC subregions in healthy individuals within a longitudinal randomized controlled exercise study. Participants (age: 18-35 years) were randomly assigned to either an intervention group (IG; N = 18) or a control group (CG; N = 10). Fitness assessments, mood questionnaires, and resting state functional magnetic resonance imaging (rsfMRI) were performed four times over the duration of 6 months. Using a detailed parcellation of the OFC, we created subregional FC topography maps at each time point and applied a linear mixed model to assess the effects of regular PA. The posterior-lateral right OFC showed a group and time interaction, revealing decreased FC with the left dorsolateral prefrontal cortex in the IG, while FC in the CG increased. Group and time interaction in the anterior-lateral right OFC with the right middle frontal gyrus was driven by increased FC in the IG. The posterior-lateral left OFC showed a group and time interaction based on differential change in FC to the left postcentral gyrus and the right occipital gyrus. This study emphasized regionally distinctive FC changes induced by PA within the lateral OFC territory, while providing aspects for further research.

Family-based care buffers the stress sensitizing effect of early deprivation on executive functioning difficulties in adolescence

We examined whether family care following early-life deprivation buffered the association between stressful life events (SLEs) and executive functioning (EF) in adolescence. In early childhood, 136 institutionally reared children were randomly assigned to foster care or care-as-usual; 72 never-institutionalized children served as a comparison group. At age 16 years, adolescents (n = 143; 54% female; 67.1% Romanian) self-reported recent SLEs, completed a battery of memory and EF tasks, and completed a go/nogo task in which mediofrontal theta power (MFTP) was measured using electroencephalogram. More independent SLEs predicted lower EF and more dependent SLEs predicted lower MFTP, but only among adolescents with prolonged early deprivation. Findings provide preliminary evidence that family care following early deprivation may facilitate resilience against stress during adolescence on EF.

Occupational Burnout Is Linked with Inefficient Executive Functioning, Elevated Average Heart Rate, and Decreased Physical Activity in Daily Life - Initial Evidence from Teaching Professionals

Burnout is becoming a global pandemic jeopardizing brain health, with a huge impact on quality of life, available workforce, and the economy. Knowledge of the impact of burnout on cognition, physiology, and physical activity (PA) in daily life allows for an improved understanding of the health consequences and everyday ramifications of burnout. Twenty-eight volunteers participated in a three-day recording of daily physiology and PA, including heart rate (HR) and daily steps, with a wearable device. They filled in questionnaires screening for burnout (BBI-15), depression (BDI), and executive functions (EFs) in daily life (BRIEF-A). The subjects with burnout had more challenges in EFs, higher average HRs and lower numbers of steps in daily life than those without it. The BBI-15 scores correlated positively with the BDI scores and BRIEF-A indices and negatively with the awake HR variability (HRV) and daily steps. The metacognition index correlated negatively with the HRV. In conclusion, burnout is linked with compromised EFs along with alterations in cardiac physiology and PA in daily life. Such alterations may be easily detected with wearable devices, opening possibilities for novel biomarkers of burnout and other neuropsychiatric disorders. We suggest that physical activity and heart and brain health are intimately intertwined and that burnout interacts with each of them bidirectionally.

Adolescent social isolation induces distinct changes in the medial and lateral OFC-BLA synapse and social and emotional alterations in adult mice

Early-life social isolation is associated with social and emotional problems in adulthood. However, neural mechanisms underlying how social deprivation impairs social and emotional development are poorly understood. Recently, the orbitofrontal cortex (OFC) and basolateral amygdala (BLA) have been highlighted as key nodes for social and emotional functions. Hence, we hypothesize that early social deprivation disrupts the information processing in the OFC-BLA pathway and leads to social and emotional dysfunction. Here, we examined the effects of adolescent social isolation on the OFC-BLA synaptic transmission by optogenetic and whole-cell patch-clamp methods in adult mice. Adolescent social isolation decreased social preference and increased passive stress-coping behaviour in adulthood. Then, we examined excitatory synaptic transmissions to BLA from medial or lateral subregions of the OFC (mOFC or lOFC). Notably, adolescent social isolation decreased the AMPA/NMDA ratio in the mOFC-BLA synapse in adulthood, while the ratio was increased in the lOFC-BLA synapse. Furthermore, we optogenetically manipulated the mOFC-BLA or lOFC-BLA transmission in behaving mice and examined the effects on social and stress-coping behaviours. Optogenetic manipulation of the mOFC-BLA transmission altered social behaviour without affecting passive stress-coping behaviour, while optogenetic manipulation of the lOFC-BLA transmission altered passive stress-coping behaviour without affecting social behaviour. Our results suggest that adolescent social isolation induces distinct postsynaptic changes in the mOFC-BLA and lOFC-BLA synapses, and these changes may separately contribute to abnormalities in social and emotional development.

Cerebral Blood Flow Pattern Changes in Unilateral Sudden Sensorineural Hearing Loss

Objective

This study analyzed the differences in the cerebral blood flow (CBF) between unilateral Sudden Sensorineural Hearing Loss (SSNHL) patients and healthy controls (HCs). We also investigated CBF differences in auditory-related areas in patients with left- and right-sided SSNHL (lSSNHL and rSSNHL) and HCs. We further explore the correlation between unilateral SSNHL characteristics and changes in the CBF.

Methods

36 patients with unilateral SSNHL (15 males and 21 females, 40.39 ± 13.42 years) and 36 HCs (15 males and 21 females, 40.39 ± 14.11 years) were recruited. CBF images were collected and analyzed using arterial spin labeling (ASL). CereFlow software was used for the post-processing of the ASL data to obtain the CBF value of 246 subregions within brainnetome atlas (BNA). The Two-sample t-test was used to compare CBF differences between SSNHL patients and HCs. One-way ANOVA or Kruskal-Wallis test was used to compare the CBF difference of auditory-related areas among the three groups (lSSNHL, rSSNHL, and HCs). Then, the correlation between CBF changes and specific clinical characteristics were calculated.

Results

The SSNHL patients exhibited decreased CBF in the bilateral middle frontal gyrus (MFG, MFG_7_1 and MFG_7_3), the contralateral precentral gyrus (PrG, PrG_6_3) and the bilateral superior parietal lobule (SPL, bilateral SPL_5_1, SPL_5_2, and ipsilateral SPL_5_4), p &lt; 0.0002. Compared with HCs, unilateral SSNHL patients exhibited increased rCBF in the bilateral orbital gyrus (OrG, OrG_6_5), the bilateral inferior temporal gyrus (ITG, contralateral ITG_7_1 and bilateral ITG_7_7), p &lt; 0.0002. lSSNHL showed abnormal CBF in left BA21 caudal (p = 0.02) and left BA37 dorsolateral (p = 0.047). We found that the CBF in ipsilateral MFG_7_1 of SSNHL patients was positively correlated with tinnitus Visual Analog Scale (VAS) score (r = 0.485, p = 0.008).

Conclusion

Our preliminary study explored CBF pattern changes in unilateral SSNHL patients in auditory-related areas and non-auditory areas, suggesting that there may exist reduced attention and some sensory compensation in patients with SSNHL. These findings could advance our understanding of the potential pathophysiology of unilateral SSNHL.

Infant Formula Supplemented With Milk Fat Globule Membrane, Long-Chain Polyunsaturated Fatty Acids, and Synbiotics Is Associated With Neurocognitive Function and Brain Structure of Healthy Children Aged 6 Years: The COGNIS Study

Background

Adequate nutrient intake during the first few months of life plays a critical role on brain structure and function development.

Objectives

To analyze the long-term effects of an experimental infant formula (EF) on neurocognitive function and brain structure in healthy children aged 6 years compared to those fed with a standard infant formula or breastfed.

Methods

The current study involved 108 healthy children aged 6 years and participating in the COGNIS Study. At 0-2 months, infants were randomized to receive up to 18 months of life a standard infant formula (SF) or EF enriched with milk fat globule membrane (MFGM), long-chain polyunsaturated fatty acids (LC-PUFAs) and synbiotics. Furthermore, a reference group of breastfed (BF) infants were also recruited. Children were assessed using neurocognitive tests and structural Magnetic Resonance Imaging (MRI) at 6 years old.

Results

Experimental infant formula (EF) children showed greater volumes in the left orbital cortex, higher vocabulary scores and IQ, and better performance in an attention task than BF children. EF children also presented greater volumes in parietal regions than SF kids. Additionally, greater cortical thickness in the insular, parietal, and temporal areas were found in children from the EF group than those fed with SF or BF groups. Further correlation analyses suggest that higher volumes and cortical thickness of different parietal and frontal regions are associated with better cognitive development in terms of language (verbal comprehension) and executive function (working memory). Finally, arachidonic acid (ARA), adrenic acid (AdA), docosahexaenoic acid (DHA) levels in cheek cell glycerophospholipids, ARA/DHA ratio, and protein, fatty acid, and mineral intake during the first 18 months of life seem to be associated with changes in the brain structures at 6 years old.

Conclusions

Supplemented infant formula with MFGM components, LC-PUFAs, and synbiotics seems to be associated to long-term effects on neurocognitive development and brain structure in children at 6 years old.

Clinical Trial Registration

https://www.clinicaltrials.gov/, identifier: NCT02094547.

Identifying Changes of Brain Regional Homogeneity and Cingulo-Opercular Network Connectivity in First-Episode, Drug-Naïve Depressive Patients With Suicidal Ideation

Objective

Adult patients with major depressive disorder (MDD) may not actively reveal their suicidal ideation (SI). Therefore, this study is committed to finding the alterations in the cingulo-opercular network (CON) that are closely related to SI with multi-imaging methods, thus providing neuroimaging basis for SI.

Method

A total of 198 participants (129 MDD patients and 69 healthy controls) were recruited and evaluated with the Montgomery–Asberg Depression Rating Scale (MADRS). The healthy individuals formed the HC group, while the MDD patients were subdivided into no SI MDD (NSI, n = 32), mild SI MDD (MSI, n = 64), and severe SI MDD (SSI, n = 33) according to their MADRS item 10. We obtained MRI data of all participants and applied regional homogeneity (ReHo) analysis to verify a previous finding that links CON abnormality to SI. In addition, we employed the structural covariance network (SCN) analysis to investigate the correlation between abnormal structural connectivity of CON and SI severity.

Results

Compared to those of the HC group, MDD ReHo values and gray matter volume (GMV) were consistently found abnormal in CON. ReHo values and GMV of the right orbital inferior frontal gyrus (ORBinf.R) in the MDD group decreased with the increase of SI. Compared to the HC group, the MDD patients showed enhanced structural connectivity of three pairs of brain regions in CON [ACC.L–left superior frontal gyrus (SFG.L), SFG.L–left middle temporal gyrus (MTG.L), and the SFG.L–left post-central gyrus (PoCG.L)]. Compared with that of the NSI and MSI groups, the structural connectivity of three pairs of brain regions in CON is enhanced in the SSI groups [ORBinf.L–right ventral posterior cingulate gyrus (VPCC.R), VPCC.R–SFG.R, and SFG.R–PoCG.R].

Conclusion

Our findings showed the distinctive ReHo, GMV, and SCN pattern of CON in MDD patients with SI; and with the severity of suicide, abnormal brain regions increased. Our finding suggested that MDD patients with different severity of SI have different neuroimaging changes.

Analysis of Correlation Between White Matter Changes and Functional Responses in Post-stroke Depression

Objective: Post-stroke depression (PSD) is one of the most common neuropsychiatric symptoms with high prevalence, however, the mechanism of the brain network in PSD and the relationship between the structural and functional network remain unclear. This research applies graph theory to structural networks and explores the relationship between structural and functional networks.

Methods: Forty-five patients with acute ischemic stroke were divided into the PSD group and post-stroke without depression (non-PSD) group respectively and underwent the magnetic resonance imaging scans. Network construction and Module analysis were used to explore the structural connectivity-functional connectivity (SC-FC) coupling of multi-scale brain networks in patients with PSD.

Results: Compared with non-PSD, the structural network in PSD was related to the reduction of clustering and the increase of path length, but the degree of modularity was lower.

Conclusions: The SC-FC coupling may serve as a biomarker for PSD. The similarity in SC and FC is associated with cognitive dysfunction, retardation, and desperation. Our findings highlighted the distinction in brain structural-functional networks in PSD.

Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT03256305, NCT03256305.

Brain Mechanisms of Virtual Reality Breathing Versus Traditional Mindful Breathing in Pain Modulation: Observational Functional Near-infrared Spectroscopy Study

BACKGROUND

Pain is a complex experience that involves sensory-discriminative and cognitive-emotional neuronal processes. It has long been known across cultures that pain can be relieved by mindful breathing (MB). There is a common assumption that MB exerts its analgesic effect through interoception. Interoception refers to consciously refocusing the mind's attention to the physical sensation of internal organ function.

OBJECTIVE

In this study, we dissect the cortical analgesic processes by imaging the brains of healthy subjects exposed to traditional MB (TMB) and compare them with another group for which we augmented MB to an outside sensory experience via virtual reality breathing (VRB).

METHODS

The VRB protocol involved in-house-developed virtual reality 3D lungs that synchronized with the participants' breathing cycles in real time, providing them with an immersive visual-auditory exteroception of their breathing.

RESULTS

We found that both breathing interventions led to a significant increase in pain thresholds after week-long practices, as measured by a thermal quantitative sensory test. However, the underlying analgesic brain mechanisms were opposite, as revealed by functional near-infrared spectroscopy data. In the TMB practice, the anterior prefrontal cortex uniquely modulated the premotor cortex. This increased its functional connection with the primary somatosensory cortex (S1), thereby facilitating the S1-based sensory-interoceptive processing of breathing but inhibiting its other role in sensory-discriminative pain processing. In contrast, virtual reality induced an immersive 3D exteroception with augmented visual-auditory cortical activations, which diminished the functional connection with the S1 and consequently weakened the pain processing function of the S1.

CONCLUSIONS

In summary, our study suggested two analgesic neuromechanisms of VRB and TMB practices-exteroception and interoception-that distinctively modulated the S1 processing of the ascending noxious inputs. This is in line with the concept of dualism (Yin and Yang).

Emotion-Attention Interaction in the Right Hemisphere

Hemispheric asymmetries in affective and cognitive functions have been extensively studied. While both cerebral hemispheres contribute to most affective and cognitive processes, neuroscientific literature and neuropsychological evidence support an overall right hemispheric dominance for emotion, attention and arousal. Emotional stimuli, especially those with survival value such as threat, tend to be prioritized in attentional resource competition. Arousing unpleasant emotional stimuli have prioritized access, especially to right-lateralized attention networks. Interference of task performance may be observed when limited resources are exhausted by task- and emotion-related processing. Tasks that rely on right hemisphere-dependent processing, like attending to the left visual hemifield or global-level visual features, are especially vulnerable to interference due to attention capture by unpleasant emotional stimuli. The aim of this review is to present literature regarding the special role of the right hemisphere in affective and attentional brain processes and their interaction. Furthermore, clinical and technological implications of this interaction will be presented. Initially, the effects of focal right hemisphere lesion or atrophy on emotional functions will be introduced. Neurological right hemisphere syndromes including aprosodia, anosognosia and neglect, which further point to the predominance of the intact right hemisphere in emotion, attention and arousal will be presented. Then there will be a brief review of electrophysiological evidence, as well as evidence from patients with neglect that support attention capture by emotional stimuli in the right hemisphere. Subsequently, experimental work on the interaction of emotion, attention and cognition in the right hemispheres of healthy subjects will be presented. Finally, clinical implications for better understanding and assessment of alterations in emotion-attention interaction due to brain disorder or treatment, such as neuromodulation, that impact affective brain functions will be discussed. It will be suggested that measuring right hemispheric emotion-attention interactions may provide basis for novel biomarkers of brain health. Such biomarkers allow for improved diagnostics in brain damage and disorders and optimized treatments. To conclude, future technological applications will be outlined regarding brain physiology-based measures that reflect engagement of the right hemisphere in affective and attentional processes.

Emotional Modulation of Frontal Alpha Asymmetry - a Novel Biomarker of Mild Traumatic Brain Injury

Objective findings of brain injury or dysfunction are typically lacking in mild traumatic brain injury (MTBI) despite prolonged post-concussion symptoms in some patients. Thus, there is a need for objective biomarkers of MTBI that reflect altered brain physiology underlying subjective symptoms. We have previously reported increased attention to threat-related stimuli in subjects with MTBI, suggesting a physiological vulnerability to depression. Vulnerability to depression has been linked with relatively greater activity of the right than left frontal cortex reflected in inverse pattern in frontal alpha with greater power on the left than right. We investigated whether patients with previous MTBI show this pattern of frontal activity reflected in more negative frontal alpha asymmetry (FAA) scores. Furthermore, in search for potential biomarkers of MTBI, we created a novel index, emotional modulation of FAA (eFAA) and investigated whether it correlates with subjective symptoms. EEG was recorded while subjects with previous MTBI and controls performed a computer-based reaction time task integrating different cognitive executive functions and containing either threat-related or emotionally neutral visual stimuli. Post-concussion symptoms and depression were assessed using the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and Beck's depression inventory (BDI). Task-induced FAA was assessed and eFAA calculated by subtracting FAA in the context of neutral stimuli from FAA in the context of emotional stimuli. The MTBI group showed FAA scores reflecting relatively greater right-sided frontal activity compared to healthy controls. eFAA differentiated the symptomatic MTBI from non-symptomatic MTBI group and from healthy controls. eFAA also correlated with RPQ and BDI scores. In conclusion, FAA pattern previously linked with vulnerability to depression, was observed in patients with previous MTBI. Furthermore, eFAA has potential as a biomarker of altered affective brain functions in MTBI.

Patients with Ventromedial Prefrontal Lesions Show an Implicit Approach Bias to Angry Faces

Damage to the ventromedial PFC (VMPFC) can cause maladaptive social behavior, but the cognitive processes underlying these behavioral changes are still uncertain. Here, we tested whether patients with acquired VMPFC lesions show altered approach-avoidance tendencies to emotional facial expressions. Thirteen patients with focal VMPFC lesions and 31 age- and gender-matched healthy controls performed an implicit approach-avoidance task in which they either pushed or pulled a joystick depending on stimulus color. Whereas controls avoided angry faces, VMPFC patients displayed an incongruent response pattern characterized by both increased approach and reduced avoidance of angry facial expressions. The approach bias was stronger in patients with higher self-reported impulsivity and disinhibition and in those with larger lesions. We further used linear ballistic accumulator modeling to investigate latent parameters underlying approach-avoidance decisions. Controls displayed negative drift rates when approaching angry faces, whereas VMPFC lesions abolished this pattern. In addition, VMPFC patients had weaker response drifts than controls during avoidance. Finally, patients showed reduced drift rate variability and shorter nondecision times, indicating impulsive and rigid decision-making. Our findings thus suggest that VMPFC damage alters the pace of evidence accumulation in response to social signals, eliminating a default, protective avoidant bias and facilitating a dysfunctional approach behavior.

Atrophy of right inferior frontal orbital gyrus and frontoparietal functional connectivity abnormality in depressed suicide attempters

Although structural and functional brain abnormalities have been observed in depressed suicide attempters (DS), structural deficits and functional impairments together with their relationship in DS remain unclear. To clarify this issue, we aimed to examine the differences in gray matter (GM) alteration, corresponding functional connectivity (FC) change, and their relationship between DS and depressed non-suicide attempters (NDS). Sixty-eight DS, 119 NDS and 103 healthy controls were enrolled and subjected to magnetic resonance imaging scans. The patients were evaluated using the 17-item Hamilton Rating Scale for Depression (HRSD) and Nurses' Global Assessment of Suicide Risk (NGASR) scale. Both voxel-based morphometry and resting-state FC analyses were performed based on functional and structural imaging data. Compared with NDS, the DS group showed reduced GM volume in the right inferior frontal orbital gyrus (IFOG) and left caudate (CAU) but increased GM volume in the left calcarine fissure, weaker negative right IFOG-left rectus gyrus (REG) FC, and weaker positive right IFOG-left inferior parietal lobule (IPL) FC. In DS, the GM volume of the right IFOG and left CAU was negatively correlated with NGASR and HRSD scores, respectively; the right IFOG-left IPL FC was negatively correlated with cognitive factor scores; and the GM volume of the right IFOG was positively correlated with IFOG-REG and IFOG-IPL FC. Our findings indicate that structural deficit with its related functional alterations in brain circuits converged in right IFOG centralized pathways and may play a central role in suicidal behaviors in depression.

Doing it Wrong: A Systematic Review on Electrocortical and Behavioral Correlates of Error Monitoring in Patients with Neurological Disorders

Detecting errors in one's own and other's actions is a crucial ability for learning and adapting behavior to everchanging, highly volatile environments. Studies in healthy people demonstrate that monitoring errors in one's own and others' actions are underpinned by specific neural systems that are dysfunctional in a variety of neurological disorders. In this review, we first briefly discuss the main findings concerning error detection and error awareness in healthy subjects, the current theoretical models, and the tasks usually applied to investigate these processes. Then, we report a systematic search for evidence of dysfunctional error monitoring among neurological populations (basal ganglia, neurodegenerative, white-matter diseases and acquired brain injury). In particular, we examine electrophysiological and behavioral evidence for specific alterations of error processing in neurological disorders. Error-related negativity (ERN) amplitude were reduced in most (although not all) neurological patient groups, whereas Positivity Error (Pe) amplitude appeared not to be affected in most patient groups. Also theta activity was reduced in some neurological groups, but consistent evidence on the oscillatory activity has not been provided thus far. Behaviorally, we did not observe relevant patterns of pronounced dysfunctional (post-) error processing. Finally, we discuss limitations of the existing literature, conclusive points, open questions and new possible methodological approaches for clinical studies.

Threat-Modulation of Executive Functions-A Novel Biomarker of Depression?

Background: Alterations in executive functions, emotion regulation, and their interaction are common concomitants of depression. Executive dysfunction frequently lingers after treatment, has adverse effects on daily life, and predisposes to recurrence of depression. Yet, sensitive measures of executive function for reliable assessment of cognitive outcomes are still lacking in clinical practice. To better understand the impact of depression and its most effective treatment, electroconvulsive therapy (ECT), on cognition, we assessed executive functions pre- and post-ECT and whether objective measures reflecting alterations in emotion-executive function interaction correlate with depression severity or with cognitive outcome. Methods: Executive functions were assessed in 21 patients with major depressive disorder (MDD) before and after ECT using subjective measures from the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) and objective cognitive performance measures derived from computer-based test of executive function, Executive Reaction Time (RT) Test. In addition, we created novel indices reflecting emotional modulation of cognitive performance by subtracting different performance measures in the context of neutral distractors from those in the context of threat-related distractors. We correlated these indices with Beck Depression Inventory (BDI) and BRIEF-A scores. Results: Depression was significantly alleviated, and executive functions improved post-ECT, as seen in reduced BDI scores, BRIEF-A scores, and number of errors in Executive RT Test. Pre-ECT BDI scores correlated with threat modulation of RT (tmRT) and threat modulation of working memory (tmWM). Post-ECT tmRT correlated with several Behavioral Regulation scales and tmWM with several Metacognition scales of BRIEF-A. Conclusion: While caution is warranted, results from both subjective and objective measures suggest that ECT significantly improves executive functions and emotion regulation along with alleviation of depression. Novel indices derived from threat modulation of executive function and working memory show promise as objective biomarkers of depression severity pre-ECT and cognitive outcome post-ECT with potential for guiding depression treatments.

Reduced Frontal Nogo-N2 With Uncompromised Response Inhibition During Transcutaneous Vagus Nerve Stimulation-More Efficient Cognitive Control?

We have previously shown invasive vagus nerve stimulation to improve attention and working memory and alter emotion-attention interaction in patients with refractory epilepsy, suggesting that VNS might be useful in the treatment of cognitive impairment. The current research focuses on whether non-invasive, transcutaneous vagus nerve stimulation (tVNS) has similar effects to VNS. Furthermore, we aimed to assess whether tVNS has an impact on cognitive control in general or on underlying brain physiology in a task that mimics everyday life demands where multiple executive functions are engaged while encountering intervening emotional stimuli. Event-related potentials (ERP) evoked in such a task, specifically centro-parietal P3 and frontal N2 were used as biomarkers for attention allocation and cognitive control required to carry out the task. A single-blinded, sham-controlled, within-subject study on healthy subjects (n = 25) was conducted using Executive Reaction Time Test (RT-test), a Go/NoGo task engaging multiple executive functions along with intervening threat-related distractors while EEG was recorded. tVNS at the left tragus and sham stimulation at the left ear lobe was alternately delivered throughout the task. To assess the impact of tVNS on neural activity underlying attention and cognitive control, centro-parietal P3 and frontal N2 peak amplitudes were measured in Go and NoGo conditions. Task performance was assessed with RTs and different error types reflecting cognitive control in general and distinct executive functions, such as working memory and response inhibition.No significant effects due to tVNS on performance in the Executive RT-test were observed. For N2 there was a main effect of stimulator status and a significant interaction of trial type (Go, NoGo) and stimulator status. Post hoc analysis revealed that tVNS resulted in a significant reduction of frontal N2 only in the NoGo condition. No significant effects were observed for P3 nor were there any effects of emotion. Diminished NoGo-N2 potential along with unaltered task performance during tVNS suggests fewer cognitive control resources were required to successfully withhold a prepotent response. Though caution is warranted, we suggest that tVNS may lead to more efficient neural processing with fewer resources needed for successful cognitive control, providing promise for its potential use in cognitive enhancement.

ERP study on the associations of peripheral oxytocin and prolactin with inhibitory processes involving emotional distraction

BACKGROUND

Child maltreatment is a major health and social welfare problem, with serious and longstanding consequences. Impulse control ability plays an important role in reducing the risk of child maltreatment. The aim of this study was to investigate the associations of oxytocin (OXT) and prolactin (PRL) with behavior inhibition using children's facial expressions (angry or neutral) as emotional distractions. This may clarify a part of the neuroendocrinological mechanism that modulates impulse control ability in the context of child caregiving.

METHODS

Participants were 16 females who had never been pregnant. Following venous blood sampling for OXT and PRL levels, participants performed an emotional Go/Nogo task during their follicular and luteal phases to test inhibitory control ability. Behavioral performance and event-related potentials (ERPs) during the task were measured.

RESULTS

The results showed that there were significant fixed effects of OXT on behavioral performance, as measured by sensitivity (d-prime). This suggests that high peripheral OXT levels may be associated with better performance on the emotional Go/Nogo task, regardless of emotional distractors. PRL was associated with inhibitory processes as reflected by the Nogo-N2 and Nogo-P3. Particularly, high PRL levels were associated with the Nogo-N2 latency extension with the emotional distractors.

CONCLUSIONS

Our findings suggest that OXT might be associated with improving behavioral performance regardless of emotional processes. It is suggested that processes related to PRL are related to premotor activities of behavioral inhibitions and emotions.

Executive Functions and Emotion-Attention Interaction in Assessment of Brain Health: Reliability of Repeated Testing With Executive RT Test and Correlation With BRIEF-A Questionnaire

Executive functions (EF) rely on intact fronto-subcortical networks. An insult, disorder or treatment compromising brain health may impair the functioning of these widespread networks and consequently disrupt EF. Changes in brain health due to treatment or disorder can be assessed by repeating an EF test at different time points, but practice effect may confound the results. In this study we examined reliability of repeated testing using a computer-based test of EF, Executive Reaction Time (RT) Test, that allows assessment of different executive functions and emotion–attention interaction. In addition, we investigated whether performance measures correlate with scores derived from a clinically validated questionnaire of executive functions, Behavior Rating Inventory of Executive Function, Adult version (BRIEF-A). Healthy subjects performed the test twice, 3–4 weeks apart. When the entire tests were compared, subjects were faster and their odds to make an error reflecting disruption of working memory was lower in the second test. When two (error analysis) or four (RT analysis) blocks out of total eight test blocks were removed from the beginning of the test, the differences disappeared. In the first test emotional distractors prolonged RTs of younger, but not older, participants. In the second test emotional distractors had no effect on RTs of either age group. RTs correlated with Global Executive Composite score of BRIEF-A. Test–retest reliability analysis showed that the Executive RT Test is reliable in repeated testing with 0.83 intraclass correlation coefficient for RTs, 0.72 for total errors and 0.68 for working memory related errors. In summary, performance speed in the Executive RT Test correlate with subjective evaluations of executive functions and is reliable in repeated assessment when enough practice is ensured before the actual test. Thus, the Executive RT test holds promise as a potential indicator of brain health reflecting level of executive functions linked with daily life demands as well as typical emotion–attention interaction or possible aberrations in it.