Cognitive control and right ventrolateral prefrontal cortex: reflexive reorienting, motor inhibition, and action updating

Exploring Brain-Body Interactions in Parkinson's Disease: A Study on Dual-Task Performance

Parkinson's disease (PD) leads to impairments in cortical structures, resulting in motor and cognitive symptoms. Given the connection between brain structure deficits and physical symptoms in PD, assessing objective brain activity and body motion could provide valuable insights for PD assessment and understanding its underlying mechanisms. This study aimed to explore the connection between brain activity and body movement metrics in a group of individuals with PD and an age-matched healthy control (HC) group. The goal was to evaluate the feasibility of using brain and body motion measures for assessing PD. Participants from both groups underwent the Timed Up and Go (TUG) test under three conditions: simple TUG, cognitive dual-task TUG (CDTUG), and motor dual-task TUG (MDTUG). Key findings include: Both groups exhibited similar activation patterns in the prefrontal cortex (PFC) during the simple TUG, with motor performance differences observed in cadence. During CDTUG, both groups showed the highest PFC activation with more pronounced motor impairments, such as higher stride and step time. During MDTUG, the HC group exhibited significantly higher PFC activity compared to the PD group. While both groups had similar patterns of activation in PFC area while TUG and CDTUG, they showed distinct behaviour during MDTUG. These results suggest that motor and cognitive impairments in PD are more pronounced during complex activities. While MDTUG effectively differentiated between PD and HC groups, the findings indicate that both cognitive and motor dual-tasks are essential for comprehensive PD assessment.

Functional connectivity-based compensation in the brains of non-demented older adults and the influence of lifestyle: A longitudinal 7-year study

INTRODUCTION

The aging brain is characterized by structural decline and functional connectivity changes towards dedifferentiation, leading to cognitive decline. To some degree, the brain can compensate for structural deterioration. In this study, we aim to answer two questions: Where can we detect longitudinal functional connectivity-based compensation in the brains of cognitively healthy older adults? Can lifestyle predict the strength of this functional compensation?

METHODS

Using longitudinal data from 228 cognitively healthy older adults, we analyzed five measurement points over 7 years. Network-based statistics and latent growth modeling were employed to examine changes in structural and functional connectivity, as well as potential functional compensation for declines in processing speed and memory. Random forest and linear regression were used to predict the amplitude of compensation based on demographic, biological, and lifestyle factors.

RESULTS

Both functional and structural connectivity showed increases and decreases over time, depending on the specific connection and measure. Increased functional connectivity of 27 connections was linked to smaller declines in cognition. Five of those connections showed simultaneous decreases in fractional anisotropy, indicating direct compensation. The degree of compensation depended on the type of compensation and the cognitive ability, with demographic, biological, and lifestyle factors explaining 3.4-8.9% of the variance.

CONCLUSIONS

There are widespread changes in structural and functional connectivity in older adults. Despite the trend of dedifferentiation in functional connectivity, we detected both direct and indirect compensatory subnetworks that mitigated the decline in cognitive performance. The degree of compensation was influenced by demographic, biological, and lifestyle factors.

Neurobiological mechanisms underlying coordinated actions in joint action

BACKGROUND

The coordination of actions in joint action significantly impacts various aspects of daily life. Previous research, utilizing parameters derived from behavioral dynamics, revealed that an individual's jumping behavior is influenced by the proximity of their partner's jump, implying a potential role of action simulation in interpersonal coordinated actions. This study employs functional near-infrared brain imaging technology to directly investigate the neural mechanisms associated with coordinated actions in joint action.

METHOD

Using a modified joint jumping task, participants were instructed to jump varying distances without observing their partner's actions, aiming to achieve a collaborative goal of landing simultaneously. Concurrently collecting behavioral parameters related to jumping, we synchronized the acquisition of cerebral hemodynamic data.

RESULT

At the neural activity level, within the motor-related cortex, regardless of whether one jumped closer or farther, this region exhibited higher concentrations of oxygenated hemoglobin compared to the condition with both participants jumping the same distance. In the dorsolateral prefrontal cortex, only when one needed to jump closer did a higher concentration of oxygenated hemoglobin emerge.

CONCLUSION

The dorsolateral prefrontal cortex, associated with action coordination strategies, and the motor-related cortex may be directly linked to action simulation.

Mind in others' shoes: Neuroscientific protocol for external referent decision awareness (ERDA) in organizations

This study investigates the neural and physiological mechanisms underlying External Referent Decision Awareness (ERDA) within organizational contexts, focusing on hierarchical roles (Head, Peer, Staff). Twenty-two professionals participated, and electroencephalographic (EEG frequency band: Delta, Theta, Alpha, Beta, Gamma) and autonomic indices (skin conductance and cardiovascular indices) were recorded, while personality traits and decision-making styles were assessed. Results revealed higher Delta and Theta activation in the left temporo-parietal junction (TPJ) during Peer-related decisions, reflecting increased social cognition and ambiguity regulation in those contexts. Gamma activity, associated with high-order cognitive processes, was prominent in the left frontal cortex across all roles, indicating complex decision evaluation. These findings underscore the complexity of low-frequency bands (Delta and Theta), involved in emotional regulation and social cognition, while high-frequency bands (Gamma) reflect cognitive integration and decision complexity. Furthermore, autonomic data showed higher Skin Conductance Levels (SCL) for Head decisions, suggesting greater emotional involvement.The findings revealed a significant negative correlation between avoidant decision-making styles and the neural and behavioral evaluations of leader decisions, suggesting reduced engagement of neurocognitive systems involved in reward processing and evaluative judgment in individuals with a tendency to avoid decision-making. Additionally, higher extraversion correlated with more favorable evaluations of decisions made by Staff, potentially indicating greater activation in neural circuits associated with social reward and group dynamics. In conclusion, these findings suggest that neural activity and personality traits interact to shape hierarchical decision-making awareness, highlighting the need for tailored leadership and decision-making strategies in organizations.

Neurocognitive dynamics and behavioral differences of symmetry and asymmetry processing in working memory: insights from fNIRS

Symmetry is a ubiquitous property of the visual world. It facilitates cognitive processing and fosters aesthetic appeal. Despite its importance to aesthetic experience and perceptual prominence, the integration of symmetry in working memory remains underexplored. In our study, participants engaged in a novel working memory task involving both symmetrical and asymmetrical stimuli, while their brain activity was monitored using functional Near Infrared Spectroscopy (fNIRS). The study revealed that symmetry significantly enhances memory performance. Symmetry significantly improves task performance, with symmetrical stimuli leading to higher accuracy and faster recall than asymmetrical ones, especially under high cognitive load. This effect varies with the type of symmetry, with diagonal symmetry being the most effective. Neuroimaging data showed distinct brain activation patterns when participants processed symmetrical stimuli, particularly in the memory-straining condition. Significant differences in brain activity were observed in various brain regions, with lateral occipital, posterior parietal, medial and dorsolateral prefrontal cortices reacting to symmetry with decreased oxygenated hemoglobin (HbO), while in left orbitofrontal (HbO) and right ventrolateral prefrontal cortex (HbO and HbR) hemoglobin concentration increased. Overall, our findings highlight the complex, region-specific brain activation patterns in response to visual symmetry, emphasizing the nuanced role of symmetry in cognitive processing during memory tasks and their potential implication for creative thinking.

How Do Common Marmosets Maintain the Balance Between Response Execution and Action Inhibition?

Socio-dynamic situations require a balance between response execution and action inhibition. Nonadaptive imbalance between response inhibition and execution exists in neurodevelopmental and neuropsychological disorders. To investigate the underlying neural mechanisms of cognitive control and the related deficits, comparative studies in human and nonhuman primates are crucial. Previous stop-signal tasks in humans and macaque monkeys have examined response execution (response time (RT) and accuracy in Go trials) and action inhibition (stop-signal reaction time (SSRT)). Even though marmosets are generally considered suitable translational animal models for research on social and cognitive deficits, their ability to inhibit behavior remains poorly characterized. We developed a marmoset stop-signal task, in which RT could be measured at millisecond resolution. All four marmosets performed many repeated Go trials with high accuracy (≥ 70%). Additionally, all marmosets successfully performed Stop trials. Using a performance-dependent tracking procedure, the accuracy in Stop trials was maintained around 50%, which enabled reliable SSRT estimates in marmosets for the first time. The mean SSRT values across sessions ranged between 677 and 1464 ms across the four marmosets. We also validated the suitability and practicality of this novel task for examining executive functions by testing the effects of a natural hormone, oxytocin, on response execution and action inhibition in marmosets. This marmoset model, for reliable (millisecond resolution) assessment of the balance between response execution and inhibition, will further facilitate studying the developmental alterations in inhibition ability and examining the effects of various contextual and environmental factors on marmosets' executive functions.

Decoding Salience: A Functional Magnetic Resonance Imaging Investigation of Reward and Contextual Unexpectedness in Memory Encoding and Retrieval

The present study investigated the neuromodulatory substrates of salience processing and its impact on memory encoding and behaviour, with a specific focus on two distinct types of salience: reward and contextual unexpectedness. 46 Participants performed a novel task paradigm modulating these two aspects independently and allowing for investigating their distinct and interactive effects on memory encoding while undergoing high-resolution fMRI. By using advanced image processing techniques tailored to examine midbrain and brainstem nuclei with high precision, our study additionally aimed to elucidate differential activation patterns in subcortical nuclei in response to reward-associated and contextually unexpected stimuli, including distinct pathways involving in particular dopaminergic modulation. We observed a differential involvement of the ventral striatum, substantia nigra (SN) and caudate nucleus, as well as a functional specialisation within the subregions of the cingulate cortex for the two salience types. Moreover, distinct subregions within the SN in processing salience could be identified. Dorsal areas preferentially processed salience related to stimulus processing (of both reward and contextual unexpectedness), and ventral areas were involved in salience-related memory encoding (for contextual unexpectedness only). These functional specialisations within SN are in line with different projection patterns of dorsal and ventral SN to brain areas supporting attention and memory, respectively. By disentangling stimulus processing and memory encoding related to two salience types, we hope to further consolidate our understanding of neuromodulatory structures' differential as well as interactive roles in modulating behavioural responses to salient events.

The Development of Socially Directed Attention: A Functional Magnetic Resonance Imaging Study in Infant Monkeys

Socially guided visual attention, such as gaze following and joint attention, represents the building block of higher-level social cognition in primates, although their neurodevelopmental processes are still poorly understood. Atypical development of these social skills has served as early marker of autism spectrum disorder and Williams syndrome. In this study, we trace the developmental trajectories of four neural networks underlying visual and attentional social engagement in the translational rhesus monkey model. Resting-state fMRI (rs-fMRI) data and gaze following skills were collected in infant rhesus macaques from birth through 6 months of age. Developmental trajectories from subjects with both resting-state fMRI and eye-tracking data were used to explore brain-behavior relationships. Our findings indicate robust increases in functional connectivity (FC) between primary visual areas (primary visual cortex [V1] - extrastriate area 3 [V3] and V3 - middle temporal area [MT], MT and anterior superior temporal sulcus area [AST], as well as between anterior temporal area [TE]) and amygdala (AMY) as infants mature. Significant FC decreases were found in more rostral areas of the pathways, such as between temporal area occipital part - TE in the ventral object pathway, V3 - lateral intraparietal (LIP) of the dorsal visual attention pathway and V3 - temporo-parietal area of the ventral attention pathway. No changes in FC were found between cortical areas LIP-FEF and temporo-parietal area - Area 12 of the dorsal and ventral attention pathways or between Anterior Superior Temporal sulcus area (AST)-AMY and AMY-insula. Developmental trajectory of gaze following revealed a period of dynamic changes with gradual increases from 1 to 2 months, followed by slight decreases from 3 to 6 months. Exploratory association findings across the 6-month period showed that infants with higher gaze following had lower FC between primary visual areas V1-V3, but higher FC in the dorsal attention areas V3-LIP, both in the right hemisphere. Together, the first 6 months of life in rhesus macaques represent a critical period for the emergence of gaze following skills associated with maturational changes in FC of socially guided attention pathways.

The neuromuscular basis of functional impairment in schizophrenia: A scoping review

Patients with schizophrenia exhibit functional impairments in their locomotory tasks, which decreases their quality of life. Due to the limited current research, the neuromuscular mechanisms behind the functional impairments in patients is not fully understood. Thus, this review aims to summarize the neuromuscular mechanisms that underlie these deficits in daily functioning. These deficits are speculated to stem from abnormalities at various levels from neurons through to the skeletal muscles. The neurological abnormalities are exhibited as lower motor neuron dysfunction whereas the skeletal muscle pathology is shown as increased muscle fibre (type 1 and type 2) atrophy, reduction in maximal force generation, and increased strength loss per decade. Although antipsychotics effectively reduce positive symptoms, functional impairments remain unresolved. Both endurance and resistance training have shown potential benefits in alleviating deficits in daily functioning by increasing muscular strength, increasing fat-free mass, and preserving neuromuscular properties from degradation. In summary, the review elucidates various possible mechanisms for the onset of functional impairment experienced by patients with schizophrenia and highlights the potential utility of endurance and resistance training to alleviate these deficits in daily functioning.

Impulsivity in ADHD and Borderline Personality Disorder: A Systematic Review of Gray and White Matter Variations

Introduction: Impulsivity is one of the overlapping symptoms common to borderline personality disorder (BPD) and attention deficit hyperactivity disorder (ADHD), but the neurobiological basis of these disorders remains uncertain. This systematic review aims to identify abnormalities in the gray and white matter associated with impulsivity in BPD and ADHD. Methods: We conducted a systematic search of the PubMed, Embase, and SCOPUS databases, adhering to PRISMA guidelines. Studies that investigated gray and white matter alterations in BPD or ADHD populations and their relationship with impulsivity were included. We reviewed information from 23 studies involving 992 participants, which included findings from structural MRI and DTI. Results: The review identified various nonhomogeneous changes associated with impulsivity in BPD and ADHD. BPD was mainly associated with abnormalities in the prefrontal cortex (PFC) and limbic areas, which correlated negatively with impulsivity. In contrast, impulsivity associated with ADHD was associated with structural changes in the caudate nucleus and frontal-striatal pathways. Despite the overlapping symptoms of impulsivity, the neurobiological mechanisms appeared to differ between the two disorders. Conclusions: These findings emphasize the distinct neurostructural correlates of impulsivity in BPD and ADHD. While both disorders show impulsivity as one of their main symptoms, the fundamental brain structures associated with this trait are different. BPD is primarily associated with abnormalities in the prefrontal cortex and limbic system, whereas the alterations seen in ADHD tend to focus on the caudate nucleus and frontostriatal pathways. Further research is needed to clarify these differences and their implications for treatment.

Patterns of abnormal activations in severe mental disorders a transdiagnostic data-driven meta-analysis of task-based fMRI studies

BACKGROUND

Studies suggest severe mental disorders (SMDs), such as schizophrenia, major depressive disorder and bipolar disorder, are associated with common alterations in brain activity, albeit with a graded level of impairment. However, discrepancies between study findings likely to results from both small sample sizes and the use of different functional magnetic resonance imaging (fMRI) tasks. To address these issues, data-driven meta-analytic approach designed to identify homogeneous brain co-activity patterns across tasks was conducted to better characterize the common and distinct alterations between these disorders.

METHODS

A hierarchical clustering analysis was conducted to identify groups of studies reporting similar neuroimaging results, independent of task type and psychiatric diagnosis. A traditional meta-analysis (activation likelihood estimation) was then performed within each of these groups of studies to extract their aberrant activation maps.

RESULTS

A total of 762 fMRI study contrasts were targeted, comprising 13 991 patients with SMDs. Hierarchical clustering analysis identified 5 groups of studies (meta-analytic groupings; MAGs) being characterized by distinct aberrant activation patterns across SMDs: (1) emotion processing; (2) cognitive processing; (3) motor processes, (4) reward processing, and (5) visual processing. While MAG1 was mostly commonly impaired, MAG2 was more impaired in schizophrenia, while MAG3 and MAG5 revealed no differences between disorder. MAG4 showed the strongest between-diagnoses differences, particularly in the striatum, posterior cingulate cortex, and ventromedial prefrontal cortex.

CONCLUSIONS

SMDs are characterized mostly by common deficits in brain networks, although differences between disorders are also present. This study highlights the importance of studying SMDs simultaneously rather than independently.

Low-Frequency Oscillations in Mid-rostral Dorsolateral Prefrontal Cortex Support Response Inhibition

Executive control of movement enables inhibiting impulsive responses critical for successful navigation of the environment. Circuits mediating stop commands involve prefrontal and basal ganglia structures with fMRI evidence demonstrating increased activity during response inhibition in the dorsolateral prefrontal cortex (dlPFC)-often ascribed to maintaining task attentional demands. Using direct intraoperative cortical recordings in male and female human subjects, we investigated oscillatory dynamics along the rostral-caudal axis of dlPFC during a modified Go/No-go task, probing components of both proactive and reactive motor control. We assessed whether cognitive control is topographically organized along this axis and observed that low-frequency power increased prominently in mid-rostral dlPFC when inhibiting and delaying responses. These findings provide evidence for a key role for mid-rostral dlPFC low-frequency oscillations in sculpting motor control.

A meta-analysis of cognitive flexibility in aging: Perspective from functional network and lateralization

Cognitive flexibility, the ability to switch between mental processes to generate appropriate behavioral responses, is reduced with typical aging. Previous studies have found that age-related declines in cognitive flexibility are often accompanied by variations in the activation of multiple regions. However, no meta-analyses have examined the relationship between cognitive flexibility in aging and age-related variations in activation within large-scale networks. Here, we conducted a meta-analysis employing multilevel kernel density analysis to identify regions with different activity patterns between age groups, and determined how these regions fall into functional networks. We also employed lateralization analysis to explore the spatial distribution of regions exhibiting group differences in activation. The permutation tests based on Monte Carlo simulation were used to determine the significance of the activation and lateralization results. The results showed that cognitive flexibility in aging was associated with both decreased and increased activation in several functional networks. Compared to young adults, older adults exhibited increased activation in the default mode, dorsal attention, ventral attention, and somatomotor networks, while displayed decreased activation in the visual network. Moreover, we found a global-level left lateralization for regions with decreased activation, but no lateralization for regions with higher activation in older adults. At the network level, the regions with decreased activation were left-lateralized, while the regions with increased activation showed varying lateralization patterns within different networks. To sum up, we found that networks that support various mental functions contribute to age-related variations in cognitive flexibility. Additionally, the aging brain exhibited network-dependent activation and lateralization patterns in response to tasks involving cognitive flexibility. We highlighted that the comprehensive meta-analysis in this study offered new insights into understanding cognitive flexibility in aging from a network perspective.

Developmental dynamics of the prefrontal cortical SST and PV interneuron networks: Insights from the monkey highlight human-specific features

The primate prefrontal cortex (PFC) is a quintessential hub of cognitive functions. Amidst its intricate neural architecture, the interplay of distinct neuronal subtypes, notably parvalbumin (PV) and somatostatin (SST) interneurons (INs), emerge as a cornerstone in sculpting cortical circuitry and governing cognitive processes. While considerable strides have been made in elucidating the developmental trajectory of these neurons in rodent models, our understanding of their postmigration developmental dynamics in primates still needs to be studied. Disruptions to this developmental trajectory can compromise IN function, impairing signal gating and circuit modulation within cortical networks. This study examined the expression patterns of PV and SST, ion transporter KCC2, and ion channel subtypes Kv3.1b, and Nav1.1 - associated with morphophysiological stages of development in the postnatal marmoset monkey in different frontal cortical regions (granular areas 8aD, 8aV, 9, 46; agranular areas 11, 47L). Our results demonstrate that the maturation of PV+ INs extends into adolescence, characterized by discrete epochs associated with specific expression dynamics of ion channel subtypes. Interestingly, we observed a postnatal decrease in SST interneurons, contrasting with studies in rodents. This endeavor broadens our comprehension of primate cortical development and furnishes invaluable insights into the etiology and pathophysiology of neurodevelopmental disorders characterized by perturbations in PV and SST IN function.

Decrease in reaction time for volleyball athletes during saccadic eye movement task: A preliminary study with evoked potentials

AIM

This preliminary study investigated the differences in event-related potential and reaction time under two groups (athletes vs. non-athletes).

MATERIAL AND METHODS

The P300 was analyzed for Fz, Cz, and Pz electrodes in thirty-one healthy volunteers divided into two groups (volleyball athletes and non-athletes). In addition, the participants performed a saccadic eye movement task to measure reaction time.

RESULTS

The EEG analysis showed that the athletes, in comparison to the no-athletes, have differences in the P300 in the frontal area (p = 0.021). In relation to reaction time, the results show lower reaction time for athletes (p = 0.001).

CONCLUSIONS

The volleyball athletes may present a greater allocation of attention during the execution of the inhibition task, since they have a lower reaction time for responses when compared to non-athletes.

Right ventrolateral and left dorsolateral 10 Hz transcranial magnetic stimulation as an add-on treatment for bipolar I and II depression: a double-blind, randomised, three-arm, sham-controlled study

OBJECTIVES

Despite the clinical importance of bipolar depression (BDE), effective treatment options are still limited. Transcranial magnetic stimulation (rTMS) has proven of moderate efficacy in major depression, but the evidence remains inconclusive for BDE.

METHODS

A 4-week, double-blind, randomised, parallel-group, sham-controlled study (trial ID ISRCTN77188420) explored the benefits of 10 Hz MRI-guided right ventrolateral (RVL) rTMS and left dorsolateral (LDL) rTMS as add-on treatments for BDE. Outcome measures included changes in the Montgomery-Åsberg Depression Rating Scale (MADRS) score, self-assessment, response and remission rates, and side effects.

RESULTS

Sixty patients were randomly assigned to study groups, and forty-six completed the double-blind phase. The mean change from baseline to Week 4 in MADRS was greater in both active groups compared to the sham, yet differences did not achieve significance (RVL vs sham: -4.50, 95%CI -10.63 to 1.64, p = 0.3; LDL vs sham: -4.07, 95%CI -10.24 to 2.10, p = 0.4). None of the other outcome measures yielded significant results.

CONCLUSIONS

While not demonstrating the superiority of either 10 Hz rTMS over sham, with the limited sample size, we can not rule out a moderate yet clinically meaningful effect. Further well-powered studies are essential to elucidate the role of rTMS in managing BDE.

Reduced temporal and spatial stability of neural activity patterns predict cognitive control deficits in children with ADHD

This study explores the neural underpinnings of cognitive control deficits in ADHD, focusing on overlooked aspects of trial-level variability of neural coding. We employed a novel computational approach to neural decoding on a single-trial basis alongside a cued stop-signal task which allowed us to distinctly probe both proactive and reactive cognitive control. Typically developing (TD) children exhibited stable neural response patterns for efficient proactive and reactive dual control mechanisms. However, neural coding was compromised in children with ADHD. Children with ADHD showed increased temporal variability and diminished spatial stability in neural responses in salience and frontal-parietal network regions, indicating disrupted neural coding during both proactive and reactive control. Moreover, this variability correlated with fluctuating task performance and with more severe symptoms of ADHD. These findings underscore the significance of modeling single-trial variability and representational similarity in understanding distinct components of cognitive control in ADHD, highlighting new perspectives on neurocognitive dysfunction in psychiatric disorders.

Simultaneous MEG and EEG source imaging of electrophysiological activity in response to acute transcranial photobiomodulation

Introduction

Transcranial photobiomodulation (tPBM) is a non-invasive neuromodulation technique that improves human cognition. The effects of tPBM of the right forehead on neurophysiological activity have been previously investigated using EEG in sensor space. However, the spatial resolution of these studies is limited. Magnetoencephalography (MEG) is known to facilitate a higher spatial resolution of brain source images. This study aimed to image post-tPBM effects in brain space based on both MEG and EEG measurements across the entire human brain.

Methods

MEG and EEG scans were concurrently acquired for 6 min before and after 8-min of tPBM delivered using a 1,064-nm laser on the right forehead of 25 healthy participants. Group-level changes in both the MEG and EEG power spectral density with respect to the baseline (pre-tPBM) were quantified and averaged within each frequency band in the sensor space. Constrained modeling was used to generate MEG and EEG source images of post-tPBM, followed by cluster-based permutation analysis for family wise error correction (p < 0.05).

Results

The 8-min tPBM enabled significant increases in alpha (8-12 Hz) and beta (13-30 Hz) powers across multiple cortical regions, as confirmed by MEG and EEG source images. Moreover, tPBM-enhanced oscillations in the beta band were located not only near the stimulation site but also in remote cerebral regions, including the frontal, parietal, and occipital regions, particularly on the ipsilateral side.

Discussion

MEG and EEG results shown in this study demonstrated that tPBM modulates neurophysiological activity locally and in distant cortical areas. The EEG topographies reported in this study were consistent with previous observations. This study is the first to present MEG and EEG evidence of the electrophysiological effects of tPBM in the brain space, supporting the potential utility of tPBM in treating neurological diseases through the modulation of brain oscillations.

Cross-cultural differences in prefrontal cortex activity in moral judgment: A functional near-infrared spectroscopy (fNIRS) study based on the CNI model

BACKGROUND

In the past, comparative cultural neurological studies of moral judgments have mainly focused on Eastern and Western groups. We initially examined Japanese and Chinese groups, both East Asian cultures. We utilized a recently proposed polynomial model known as the "consequences, norms, and generalized inaction" (CNI) model to investigate the variations in the overall prefrontal cortex activity between these two groups during moral judgment.

METHODS

We employed functional near-infrared spectroscopy (fNIRS) to analyze the prefrontal cortex (PFC) activity within a CNI model of moral judgment among 23 healthy Japanese and 26 healthy Chinese adults.

RESULTS AND CONCLUSIONS

Our study revealed significant differences in the PFC activation between Japanese and Chinese individuals in the CNI moral judgment task context. Specifically, during the CNI task, Chinese men exhibited higher right dorsolateral prefrontal cortex (R-DLPFC) activity than Chinese women. In contrast, Japanese women showed greater left dorsolateral prefrontal cortex (L-DLPFC) activity than Japanese men. In an international comparison, R-DLPFC activity was higher in Chinese men than in Japanese men. Conversely, the left ventrolateral prefrontal cortex activity was higher in Japanese men compared to Chinese men. Additionally, among women, the right ventromedial prefrontal cortex activity was higher in Japanese women than in Chinese women. In conclusion, our findings support the perspective of cultural psychology and identify cultural and sex differences in PFC activity between Japanese and Chinese individuals.

Identifying tripartite relationship among cortical thickness, neuroticism, and mood and anxiety disorders

The number of young adults seeking help for emotional distress, subsyndromal-syndromal mood/anxiety symptoms, including those associated with neuroticism, is rising and can be an early manifestation of mood/anxiety disorders. Identification of gray matter (GM) thickness alterations and their relationship with neuroticism and mood/anxiety symptoms can aid in earlier diagnosis and prevention of risk for future mood and anxiety disorders. In a transdiagnostic sample of young adults (n = 252;177 females; age 21.7 ± 2), Hypothesis (H) 1:regularized regression followed by multiple regression examined relationships among GM cortical thickness and clinician-rated depression, anxiety, and mania/hypomania; H2:the neuroticism factor and its subfactors as measured by NEO Personality Inventory (NEO-PI-R) were tested as mediators. Analyses revealed positive relationships between left parsopercularis thickness and depression (B = 4.87, p = 0.002), anxiety (B = 4.68, p = 0.002), mania/hypomania (B = 6.08, p ≤ 0.001); negative relationships between left inferior temporal gyrus (ITG) thickness and depression (B = - 5.64, p ≤ 0.001), anxiety (B = - 6.77, p ≤ 0.001), mania/hypomania (B = - 6.47, p ≤ 0.001); and positive relationships between left isthmus cingulate thickness (B = 2.84, p = 0.011), and anxiety. NEO anger/hostility mediated the relationship between left ITG thickness and mania/hypomania; NEO vulnerability mediated the relationship between left ITG thickness and depression. Examining the interrelationships among cortical thickness, neuroticism and mood and anxiety symptoms enriches the potential for identifying markers conferring risk for mood and anxiety disorders and can provide targets for personalized intervention strategies for these disorders.

Measurement of event-related potentials from electroencephalography to evaluate emotional processing in Fibromyalgia Syndrome: A systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis intended to: 1) determine the extent of abnormalities in emotional processing linked to emotional event-related potentials (ERPs) in Fibromyalgia Syndrome (FMS) and 2) integrate data from similar emotional tasks into a meta-analysis to clearly demonstrate the scientific and clinical value of measuring emotional ERPs by electroencephalography (EEG) in FMS.

METHODS

A systematic review and meta-analysis of studies comparing emotional processing indicated by ERPs in FMS patients and healthy controls was conducted. Fifteen articles were included in the systematic review after applying the eligibility criteria.

RESULTS

Nine articles demonstrated disturbances in emotional processing in FMS. These emotional disturbances were distributed over the whole range of ERP latencies, mainly over central, parietal, temporal and occipital areas. Despite of this, quantitative analysis revealed only significant differences in N250 and LPP/LPC between FMS patients and healthy controls, with smaller LPP/LPC and greater N250 seen in FMS.

DISCUSSION

N250 and LPP/LPC seem to be the ERPs with the greatest potential to determine emotional alterations in FMS. These ERPs are related to complex cognitive processes such as decoding features relevant to affect recognition (N250) as well differentiation between emotions, persistent engagement, conflict resolution or evaluation of emotional intensity (LPC/LPP). However, differences in task setup had an important impact on the variation of ERP outcomes. Systematization of protocols and tasks is indispensable for future studies.

The pill you don't have to take that is still effective: neural correlates of imaginary placebo intake for regulating disgust

A commonly established protocol for the administration of open-label placebos (OLPs)-placebos honestly prescribed-emphasizes the necessity of ingesting the pill for the placebo effect to manifest. The current functional magnetic resonance imaging study used a novel approach to OLP administration: the imaginary intake of an OLP pill for regulating disgust. A total of 99 females were randomly allocated to one of three groups that either swallowed a placebo pill (OLP Pill), imagined the intake of a placebo pill (Imaginary Pill) or passively viewed (PV) repulsive and neutral images. The imaginary pill reduced reported disgust more effectively than the OLP pill and was also perceived as a more plausible method to reduce emotional distress. Relative to the OLP pill, the imaginary pill lowered neural activity in a region of interest involved in disgust processing: the pallidum. No significant differences in brain activation were found when comparing the OLP pill with PV. These findings highlight that imagining the intake of an OLP emerged as a superior method for regulating feelings of disgust compared to the actual ingestion of a placebo pill. The study's innovative approach sheds new light on the potential of placebo interventions in emotion regulation.

A multi-demand operating system underlying diverse cognitive tasks

The existence of a multiple-demand cortical system with an adaptive, domain-general, role in cognition has been proposed, but the underlying dynamic mechanisms and their links to cognitive control abilities are poorly understood. Here we use a probabilistic generative Bayesian model of brain circuit dynamics to determine dynamic brain states across multiple cognitive domains, independent datasets, and participant groups, including task fMRI data from Human Connectome Project, Dual Mechanisms of Cognitive Control study and a neurodevelopment study. We discover a shared brain state across seven distinct cognitive tasks and found that the dynamics of this shared brain state predicted cognitive control abilities in each task. Our findings reveal the flexible engagement of dynamic brain processes across multiple cognitive domains and participant groups, and uncover the generative mechanisms underlying the functioning of a domain-general cognitive operating system. Our computational framework opens promising avenues for probing neurocognitive function and dysfunction.

Abnormal functional neurocircuitry underpinning emotional processing in fibromyalgia

Fibromyalgia, a condition characterized by chronic pain, is frequently accompanied by emotional disturbances. Here we aimed to study brain activation and functional connectivity (FC) during processing of emotional stimuli in fibromyalgia. Thirty female patients with fibromyalgia and 31 female healthy controls (HC) were included. Psychometric tests were administered to measure alexithymia, affective state, and severity of depressive and anxiety symptoms. Next, participants performed an emotion processing and regulation task during functional magnetic resonance imaging (fMRI). We performed a 2 × 2 ANCOVA to analyze main effects and interactions of the stimuli valence (positive or negative) and group (fibromyalgia or HC) on brain activation. Generalized psychophysiological interaction analysis was used to assess task-dependent FC of brain regions previously associated with emotion processing and fibromyalgia (i.e., hippocampus, amygdala, anterior insula, and pregenual anterior cingulate cortex [pACC]). The left superior lateral occipital cortex showed more activation in fibromyalgia during emotion processing than in HC, irrespective of valence. Moreover, we found an interaction effect (valence x group) in the FC between the left pACC and the precentral and postcentral cortex, and central operculum, and premotor cortex. These results suggest abnormal brain activation and connectivity underlying emotion processing in fibromyalgia, which could help explain the high prevalence of psychopathological symptoms in this condition.

Top-down modulation of DLPFC in visual search: a study based on fMRI and TMS

Effective visual search is essential for daily life, and attention orientation as well as inhibition of return play a significant role in visual search. Researches have established the involvement of dorsolateral prefrontal cortex in cognitive control during selective attention. However, neural evidence regarding dorsolateral prefrontal cortex modulates inhibition of return in visual search is still insufficient. In this study, we employed event-related functional magnetic resonance imaging and dynamic causal modeling to develop modulation models for two types of visual search tasks. In the region of interest analyses, we found that the right dorsolateral prefrontal cortex and temporoparietal junction were selectively activated in the main effect of search type. Dynamic causal modeling results indicated that temporoparietal junction received sensory inputs and only dorsolateral prefrontal cortex →temporoparietal junction connection was modulated in serial search. Such neural modulation presents a significant positive correlation with behavioral reaction time. Furthermore, theta burst stimulation via transcranial magnetic stimulation was utilized to modulate the dorsolateral prefrontal cortex region, resulting in the disappearance of the inhibition of return effect during serial search after receiving continuous theta burst stimulation. Our findings provide a new line of causal evidence that the top-down modulation by dorsolateral prefrontal cortex influences the inhibition of return effect during serial search possibly through the retention of inhibitory tagging via working memory storage.

Correlation and underlying brain mechanisms between rapid eye movement sleep behavior disorder and executive functions in Parkinson's disease: an fNIRS study

Purpose

Rapid eye movement sleep behavior disorder (RBD) affects 30%-40% of patients with Parkinson's disease (PD) and has been linked to a higher risk of cognitive impairment, especially executive dysfunction. The aim of this study was to investigate the brain activation patterns in PD patients with RBD (PD-RBD+) compared to those without RBD (PD-RBD-) and healthy controls (HCs), and to analyze the correlation between changes in cerebral cortex activity and the severity of RBD.

Methods

We recruited 50 PD patients, including 30 PD-RBD+, 20 PD-RBD-, and 20 HCs. We used functional near infrared spectroscopy during a verbal fluency task (VFT-fNIRS) and clinical neuropsychological assessment to explore the correlation between PD-RBD+ and executive function and changes in neural activity.

Results

The VFT-fNIRS analysis revealed a significant reduction in activation among PD-RBD+ patients across multiple channels when compared to both the PD-RBD- and HC groups. Specifically, PD-RBD+ patients exhibited diminished activation in the bilateral dorsolateral prefrontal cortex (DLPFC) and the right ventrolateral prefrontal cortex (VLPFC) relative to their PD-RBD- counterparts. Furthermore, compared to the HC group, PD-RBD+ patients displayed reduced activation specifically in the right DLPFC. Significantly, a noteworthy negative correlation was identified between the average change in oxygenated hemoglobin concentration (ΔHbO2) in the right DLPFC of PD-RBD+ patients and the severity of their RBD.

Conclusion

Our study offers compelling evidence that RBD exacerbates cognitive impairment in PD, manifested as executive dysfunction, primarily attributed to reduced prefrontal activation. These aberrations in brain activation may potentially correlate with the severity of RBD.

Brain-behavior analysis of transcranial direct current stimulation effects on a complex surgical motor task

Transcranial Direct Current Stimulation (tDCS) has demonstrated its potential in enhancing surgical training and performance compared to sham tDCS. However, optimizing its efficacy requires the selection of appropriate brain targets informed by neuroimaging and mechanistic understanding. Previous studies have established the feasibility of using portable brain imaging, combining functional near-infrared spectroscopy (fNIRS) with tDCS during Fundamentals of Laparoscopic Surgery (FLS) tasks. This allows concurrent monitoring of cortical activations. Building on these foundations, our study aimed to explore the multi-modal imaging of the brain response using fNIRS and electroencephalogram (EEG) to tDCS targeting the right cerebellar (CER) and left ventrolateral prefrontal cortex (PFC) during a challenging FLS suturing with intracorporeal knot tying task. Involving twelve novices with a medical/premedical background (age: 22-28 years, two males, 10 females with one female with left-hand dominance), our investigation sought mechanistic insights into tDCS effects on brain areas related to error-based learning, a fundamental skill acquisition mechanism. The results revealed that right CER tDCS applied to the posterior lobe elicited a statistically significant (q < 0.05) brain response in bilateral prefrontal areas at the onset of the FLS task, surpassing the response seen with sham tDCS. Additionally, right CER tDCS led to a significant (p < 0.05) improvement in FLS scores compared to sham tDCS. Conversely, the left PFC tDCS did not yield a statistically significant brain response or improvement in FLS performance. In conclusion, right CER tDCS demonstrated the activation of bilateral prefrontal brain areas, providing valuable mechanistic insights into the effects of CER tDCS on FLS peformance. These insights motivate future investigations into the effects of CER tDCS on error-related perception-action coupling through directed functional connectivity studies.

The severity of addiction mediates loneliness and cortical volume in internet gaming disorder

Internet gaming disorder (IGD) subjects reported higher loneliness scores than healthy controls. However, the neural correlates underlying the association between loneliness and IGD remain unclear. Thus, the aim of this study was to explore the relationship between loneliness, online gaming addiction and brain structure. In the current study, structural MRI data were acquired from 84 IGD subjects and 103 matched recreational game users (RGUs). We assessed and compared their addiction severity, loneliness scores, and cortical volumes and analyzed the correlations among these values. Significant correlations were found between loneliness scores and brain volumes in the postcentral cortex, the medial orbitofrontal cortex, the rostral anterior cingulate cortex, and the temporal cortex. In addition, the addiction severity scores partly mediated the relationship between loneliness score and cortical volume in IGD. The results showed that participants with extreme loneliness had significant correlations with brain regions responsible for executive control, social threat surveillance and avoidance. More importantly, the severity of addiction mediates loneliness and cortical volume. The findings shed new insight into the neural mechanisms of loneliness and IGD and have implications for potential treatment.

Transcranial focused ultrasound to human rIFG improves response inhibition through modulation of the P300 onset latency

Response inhibition in humans is important to avoid undesirable behavioral action consequences. Neuroimaging and lesion studies point to a locus of inhibitory control in the right inferior frontal gyrus (rIFG). Electrophysiology studies have implicated a downstream event-related potential from rIFG, the fronto-central P300, as a putative neural marker of the success and timing of inhibition over behavioral responses. However, it remains to be established whether rIFG effectively drives inhibition and which aspect of P300 activity uniquely indexes inhibitory control-ERP timing or amplitude. Here, we dissect the connection between rIFG and P300 for inhibition by using transcranial-focused ultrasound (tFUS) to target rIFG of human subjects while they performed a Stop-Signal task. By applying tFUS simultaneously with different task events, we found behavioral inhibition was improved, but only when applied to rIFG simultaneously with a 'stop' signal. Improved inhibition through tFUS to rIFG was indexed by faster stopping times that aligned with significantly shorter N200/P300 onset latencies. In contrast, P300 amplitude was modulated during tFUS across all groups without a paired change in behavior. Using tFUS, we provide evidence for a causal connection between anatomy, behavior, and electrophysiology underlying response inhibition.

Electro-Acupuncture Effects Measured by Functional Magnetic Resonance Imaging-A Systematic Review of Randomized Clinical Trials

INTRODUCTION

Electro-acupuncture, an innovative adaptation of traditional acupuncture, combines electrical stimulation with acupuncture needles to enhance therapeutic effects. While acupuncture is widely used, its biological mechanisms remain incompletely understood. Recent research has explored the neurophysiological aspects of acupuncture, particularly through functional magnetic resonance imaging (fMRI) to investigate its effects on brain activity.

METHODS

In this systematic review, we conducted an extensive search for randomized clinical trials examining electro-acupuncture effects measured by fMRI. We employed strict eligibility criteria, quality assessment, and data extraction.

RESULTS

Five studies met our inclusion criteria and were analyzed. The selected studies investigated electro-acupuncture in various medical conditions, including carpal tunnel syndrome, fibromyalgia, Crohn's disease, irritable bowel syndrome, and obesity. Notably, electro-acupuncture was found to modulate brain activity and connectivity in regions associated with pain perception, emotional regulation, and cognitive processing. These findings align with the holistic approach of traditional Chinese medicine, emphasizing the interconnectedness of body and mind.

DISCUSSION

In carpal tunnel syndrome, electro-acupuncture at both local and distal sites showed neurophysiological improvements, suggesting distinct neuroplasticity mechanisms. In fibromyalgia, somatosensory electro-acupuncture correlated with reduced pain severity, enhanced brain connectivity, and increased gamma-aminobutyric acid levels. For Crohn's disease, electro-acupuncture influenced the homeostatic afferent processing network, potentially mitigating gut inflammation. Electro-acupuncture for irritable bowel syndrome led to decreased activity in the anterior cingulate cortex, offering pain relief, while electro-acupuncture for obesity impacted brain regions associated with dietary inhibition and emotional regulation.

CONCLUSION

This systematic review provides evidence that electro-acupuncture can positively impact a range of medical conditions, possibly by modulating brain activity and connectivity. While the quality of the reviewed studies is generally good, further research with larger sample sizes and longer-term assessments is needed to better understand the mechanisms and optimize electro-acupuncture protocols for specific health conditions. The limited number of studies in this review emphasizes the need for broader investigations in this promising field. The research protocol was registered in PROSPERO (CRD42023465866).

Distinguishing Laparoscopic Surgery Experts from Novices Using EEG Topographic Features

The study aimed to differentiate experts from novices in laparoscopic surgery tasks using electroencephalogram (EEG) topographic features. A microstate-based common spatial pattern (CSP) analysis with linear discriminant analysis (LDA) was compared to a topography-preserving convolutional neural network (CNN) approach. Expert surgeons (N = 10) and novice medical residents (N = 13) performed laparoscopic suturing tasks, and EEG data from 8 experts and 13 novices were analysed. Microstate-based CSP with LDA revealed distinct spatial patterns in the frontal and parietal cortices for experts, while novices showed frontal cortex involvement. The 3D CNN model (ESNet) demonstrated a superior classification performance (accuracy > 98%, sensitivity 99.30%, specificity 99.70%, F1 score 98.51%, MCC 97.56%) compared to the microstate based CSP analysis with LDA (accuracy ~90%). Combining spatial and temporal information in the 3D CNN model enhanced classifier accuracy and highlighted the importance of the parietal-temporal-occipital association region in differentiating experts and novices.

Computational modelling of reinforcement learning and functional neuroimaging of probabilistic reversal for dissociating compulsive behaviours in gambling and cocaine use disorders

BACKGROUND

Individuals with cocaine use disorder or gambling disorder demonstrate impairments in cognitive flexibility: the ability to adapt to changes in the environment. Flexibility is commonly assessed in a laboratory setting using probabilistic reversal learning, which involves reinforcement learning, the process by which feedback from the environment is used to adjust behavior.

AIMS

It is poorly understood whether impairments in flexibility differ between individuals with cocaine use and gambling disorders, and how this is instantiated by the brain. We applied computational modelling methods to gain a deeper mechanistic explanation of the latent processes underlying cognitive flexibility across two disorders of compulsivity.

METHOD

We present a re-analysis of probabilistic reversal data from individuals with either gambling disorder (n = 18) or cocaine use disorder (n = 20) and control participants (n = 18), using a hierarchical Bayesian approach. Furthermore, we relate behavioural findings to their underlying neural substrates through an analysis of task-based functional magnetic resonanceimaging (fMRI) data.

RESULTS

We observed lower 'stimulus stickiness' in gambling disorder, and report differences in tracking expected values in individuals with gambling disorder compared to controls, with greater activity during reward expected value tracking in the cingulate gyrus and amygdala. In cocaine use disorder, we observed lower responses to positive punishment prediction errors and greater activity following negative punishment prediction errors in the superior frontal gyrus compared to controls.

CONCLUSIONS

Using a computational approach, we show that individuals with gambling disorder and cocaine use disorder differed in their perseverative tendencies and in how they tracked value neurally, which has implications for psychiatric classification.

Examining the effects of prenatal alcohol exposure on performance of the sustained attention to response task in children with an FASD

Prenatal alcohol exposure (PAE), the leading known cause of childhood developmental disability, has long-lasting effects extending throughout the lifespan. It is well documented that children prenatally exposed to alcohol have difficulties inhibiting behavior and sustaining attention. Thus, the Sustained Attention to Response Task (SART), a Go/No-go paradigm, is especially well suited to assess the behavioral and neural functioning characteristics of children with PAE. In this study, we utilized neuropsychological assessment, parent/guardian questionnaires, and magnetoencephalography during SART random and fixed orders to assess characteristics of children 8-12 years old prenatally exposed to alcohol compared to typically developing children. Compared to neurotypical control children, children with a Fetal Alcohol Spectrum Disorder (FASD) diagnosis had significantly decreased performance on neuropsychological measures, had deficiencies in task-based performance, were rated as having increased Attention-Deficit/Hyperactivity Disorder (ADHD) behaviors and as having lower cognitive functioning by their caretakers, and had decreased peak amplitudes in Broadmann's Area 44 (BA44) during SART. Further, MEG peak amplitude in BA44 was found to be significantly associated with neuropsychological test results, parent/guardian questionnaires, and task-based performance such that decreased amplitude was associated with poorer performance. In exploratory analyses, we also found significant correlations between total cortical volume and MEG peak amplitude indicating that the reduced amplitude is likely related in part to reduced overall brain volume often reported in children with PAE. These findings show that children 8-12 years old with an FASD diagnosis have decreased amplitudes in BA44 during SART random order, and that these deficits are associated with multiple behavioral measures.

Dopaminergic D2-like receptor stimulation affects attention on contextual information and modulates BOLD activation of extinction-related brain areas

Contextual information is essential for learning and memory processes and plays a crucial role during the recall of extinction memory, and in the renewal effect, which is the context-dependent recovery of an extinguished response. The dopaminergic system is known to be involved in regulating attentional processes by shifting attention to novel and salient contextual cues. Higher dopamine levels are associated with a better recall of previously learned stimulus-outcome associations and enhanced encoding, as well as retrieval of contextual information which promotes renewal. In this fMRI study, we aimed to investigate the impact of processing contextual information and the influence of dopaminergic D2-like receptor activation on attention to contextual information during a predictive learning task as well as upon extinction learning, memory performance, and activity of extinction-related brain areas. A single oral dose of 1.25 mg bromocriptine or an identical-looking placebo was administered to the participants. We modified a predictive learning task that in previous studies reliably evoked a renewal effect, by increasing the complexity of contextual information. We analysed fixations and dwell on contextual cues by use of eye-tracking and correlated these with behavioural performance and BOLD activation of extinction-related brain areas. Our results indicate that the group with dopaminergic D2-like receptor stimulation had higher attention to task-relevant contextual information and greater/lower BOLD activation of brain regions associated with cognitive control during extinction learning and recall. Moreover, renewal responses were almost completely absent. Since this behavioural effect was observed for both treatment groups, we assume that this was due to the complexity of the altered task design.

Multilingual Language Diversity Protects Native Language Production under Different Control Demands

The use of multiple languages has been found to influence individuals' cognitive abilities. Although some studies have also investigated the effect of multilingualism on non-native language proficiency, fewer studies have focused on how multilingual experience affects native language production. This study investigated the effect of multilingualism on native language production, specifically examining control demands through a semantic Go/No-Go picture naming task. The multilingual experience was quantified using language entropy, which measures the uncertainty and diversity of language use. Control demands were achieved by manipulating the proportion of Go (i.e., naming) trials in different conditions. Results showed that as control demands increased, multilingual individuals exhibited poorer behavioral performance and greater brain activation throughout the brain. Moreover, more diverse language use was associated with higher accuracy in naming and more interconnected brain networks with greater involvement of domain-general neural resources and less domain-specific neural resources. Notably, the varied and balanced use of multiple languages enabled multilingual individuals to respond more efficiently to increased task demands during native language production.

The microstructural change of the brain and its clinical severity association in pediatric Tourette syndrome patients

BACKGROUND

Gilles de la Tourette syndrome (GTS) is a prevalent pediatric neurological disorder. Most studies point to abnormalities in the cortico-striato-thalamocortical (CSTC) circuits. Neuroimaging studies have shown GTS's extensive impact on the entire brain. However, due to participant variability and potential drug and comorbidity impact, the results are inconsistent. To mitigate the potential impact of participant heterogeneity, we excluded individuals with comorbidities or those currently undergoing medication treatments. Based on the hypothesis of abnormality within the CSTC circuit, we investigated microstructural changes in white matter using diffusion spectrum imaging (DSI). This study offers the first examination of microstructural changes in treatment-naïve pediatric patients with pure GTS using diffusion spectrum imaging.

METHODS

This single-center prospective study involved 30 patients and 30 age- and gender-matched healthy volunteers who underwent sagittal T1-weighted MRI and DSI. We analyzed generalized fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity.

RESULTS

No significant differences were observed in mean diffusivity and axial diffusivity values between the two groups. However, the patient group exhibited significantly higher generalized fractional anisotropy values in the right frontostriatal tract of the dorsolateral prefrontal cortex, the right frontostriatal tract of the precentral gyrus, and bilateral thalamic radiation of the dorsolateral prefrontal cortex. Additionally, the generalized fractional anisotropy value of the right frontostriatal tract of the precentral gyrus is inversely correlated with the total tic severity scores at the most severe condition.

CONCLUSION

Treatment-naïve pediatric GTS patients demonstrated increased connectivity within the CSTC circuit as per diffusion spectrum imaging, indicating possible CSTC circuit dysregulation. This finding could also suggest a compensatory change. It thus underscores the necessity of further investigation into the fundamental pathological changes in GTS. Nevertheless, the observed altered connectivity in GTS patients might serve as a potential target for therapeutic intervention.

Working Memory-Related Neurofunctional Correlates Associated with the Frontal Lobe in Children with Familial vs. Non-Familial Attention Deficit/Hyperactivity Disorder

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with high prevalence, heritability, and heterogeneity. Children with a positive family history of ADHD have a heightened risk of ADHD emergence, persistence, and executive function deficits, with the neural mechanisms having been under investigated. The objective of this study was to investigate working memory-related functional brain activation patterns in children with ADHD (with vs. without positive family histories (ADHD-F vs. ADHD-NF)) and matched typically developing children (TDC). Voxel-based and region of interest analyses were conducted on two-back task-based fMRI data of 362 subjects, including 186, 96, and 80 children in groups of TDC, ADHD-NF, and ADHD-F, respectively. Relative to TDC, both ADHD groups had significantly reduced activation in the left inferior frontal gyrus (IFG). And the ADHD-F group demonstrated a significant positive association of left IFG activation with task reaction time, a negative association of the right IFG with ADHD symptomatology, and a negative association of the IFG activation laterality index with the inattention symptom score. These results suggest that working memory-related functional alterations in bilateral IFGs may play distinct roles in ADHD-F, with the functional underdevelopment of the left IFG significantly informing the onset of ADHD symptoms. Our findings have the potential to assist in tailored diagnoses and targeted interventions in children with ADHD-F.

Ventrolateral prefrontal neurons of the monkey encode instructions in the 'pragmatic' format of the associated behavioral outcomes

The prefrontal cortex plays an important role in coding rules and producing context-appropriate behaviors. These processes necessarily require the generation of goals based on current context. Indeed, instructing stimuli are prospectively encoded in prefrontal cortex in relation to behavioral demands, but the coding format of this neural representation is, to date, largely unknown. In order to study how instructions and behaviors are encoded in prefrontal cortex, we recorded the activity of monkeys (Macaca mulatta) ventrolateral prefrontal neurons in a task requiring to perform (Action condition) or withhold (Inaction condition) grasping actions on real objects. Our data show that there are neurons responding in different task phases, and that the neuronal population discharge is stronger in the Inaction condition when the instructing cue is presented, and in the Action condition in the subsequent phases, from object presentation to action execution. Decoding analyses performed on neuronal populations showed that the neural activity recorded during the initial phases of the task shares the same type of format with that recorded during the final phases. We propose that this format has a pragmatic nature, that is instructions and goals are encoded by prefrontal neurons as predictions of the behavioral outcome.

Regional cerebral blood flow at rest in schizophrenia and major depressive disorder: A functional neuroimaging meta-analysis

Severe mental disorders (SMDs) such as schizophrenia (SCZ), major depressive disorder (MDD) and bipolar disorder (BD) are associated with altered brain function. Neuroimaging studies have illustrated spontaneous activity alterations across SMDs, but no meta-analysis has directly compared resting-state regional cerebral blood flow (rCBF) with one another. We conducted a meta-analysis of PET, SPECT and ASL neuroimaging studies to identify specific alterations of rCBF at rest in SMDs. Included are 20 studies in MDD, and 18 studies in SCZ. Due to the insufficient number of studies in BD, this disorder was left out of the analyses. Compared to controls, the SCZ group displayed reduced rCBF in the triangular part of the left inferior frontal gyrus and in the medial orbital part of the bilateral superior frontal gyrus. After correction, only a small cluster in the right inferior frontal gyrus exhibited reduced rCBF in MDD, compared to controls. Differences were found in these brain regions between SCZ and MDD. SCZ displayed reduced rCBF at rest in regions associated with default-mode, reward processing and language processing. MDD was associated with reduced rCBF in a cluster involved in response inhibition. Our meta-analysis highlights differences in the resting-state rCBF alterations between SCZ and MDD.

Higher emotional granularity relates to greater inferior frontal cortex cortical thickness in healthy, older adults

Individuals with high emotional granularity make fine-grained distinctions between their emotional experiences. To have greater emotional granularity, one must acquire rich conceptual knowledge of emotions and use this knowledge in a controlled and nuanced way. In the brain, the neural correlates of emotional granularity are not well understood. While the anterior temporal lobes, angular gyri, and connected systems represent conceptual knowledge of emotions, inhibitory networks with hubs in the inferior frontal cortex (i.e., posterior inferior frontal gyrus, lateral orbitofrontal cortex, and dorsal anterior insula) guide the selection of this knowledge during emotions. We investigated the structural neuroanatomical correlates of emotional granularity in 58 healthy, older adults (ages 62-84 years), who have had a lifetime to accrue and deploy their conceptual knowledge of emotions. Participants reported on their daily experience of 13 emotions for 8 weeks and underwent structural magnetic resonance imaging. We computed intraclass correlation coefficients across daily emotional experience surveys (45 surveys on average per participant) to quantify each participant's overall emotional granularity. Surface-based morphometry analyses revealed higher overall emotional granularity related to greater cortical thickness in inferior frontal cortex (pFWE < 0.05) in bilateral clusters in the lateral orbitofrontal cortex and extending into the left dorsal anterior insula. Overall emotional granularity was not associated with cortical thickness in the anterior temporal lobes or angular gyri. These findings suggest individual differences in emotional granularity relate to variability in the structural neuroanatomy of the inferior frontal cortex, an area that supports the controlled selection of conceptual knowledge during emotional experiences.

The different contributions of the eight prefrontal cortex subregions to reactive responses after unpredictable slip perturbations and vibrotactile cueing

Introduction

Recent advancements in functional near-infrared spectroscopy technology have offered a portable, wireless, wearable solution to measure the activity of the prefrontal cortex (PFC) in the human neuroscience field. This study is the first to validate the different contributions made by the PFC's eight subregions in healthy young adults to the reactive recovery responses following treadmill-induced unpredictable slip perturbations and vibrotactile cueing (i.e., precues).

Methods

Our fall-inducing technology platform equipped with a split-belt treadmill provided unpredictable slip perturbations to healthy young adults while walking at their self-selected walking speed. A portable, wireless, wearable, and multi-channel (48 channels) functional near-infrared spectroscopy system evaluated the activity of PFC's eight subregions [i.e., right and left dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), frontopolar prefrontal cortex (FPFC), and orbitofrontal cortex (OFC)] as quantified by oxyhemoglobin and deoxyhemoglobin concentrations. A motion capture system and two force plates beneath the split-belt treadmill were used to quantify participants' kinematic and kinetic behavior. All participants completed 6 trials: 2 consecutive trials without vibrotactile cueing and with a slip perturbation (control trials); 3 trials with vibrotactile cueing [2 trials with the slip perturbation (cueing trial) and 1 trial without the slip perturbation (catch trial)], and 1 trial without vibrotactile cueing and with a slip perturbation (post-control trial). The PFC subregions' activity and kinematic behavior were assessed during the three periods (i.e., standing, walking, and recovery periods).

Results

Compared to the walkers' standing and walking periods, recovery periods showed significantly higher and lower levels of oxyhemoglobin and deoxyhemoglobin concentrations, respectively, in the right and left DLPFC, VLPFC, and FPFC, regardless of the presence of vibrotactile cueing. However, there was no significant difference in the right and left OFC between the three periods. Kinematic analyses confirmed that vibrotactile cueing significantly improved reactive recovery responses without requiring more involvement by the PFC subregions, which suggests that the sum of attentional resources is similar in cued and non-cued motor responses.

Discussion

The results could inform the design of wearable technologies that alert their users to the risks of falling and assist with the development of new gait perturbation paradigms that prompt reactive responses.

A randomized trial that compared brain activity, efficacy and plausibility of open-label placebo treatment and cognitive repappraisal for reducing emotional distress

Placebo pills can reduce emotional distress even when recipients have been informed about the inert nature of the treatment. However, before such open-label placebos (OLPs) can be recommended for general clinical use, their efficacy and acceptability need to be further investigated and compared with established methods for emotion regulation, such as cognitive reappraisal (CR). The current study with functional magnetic resonance imaging compared the effects of an OLP pill with CR for reducing a specific form of emotional distress: disgust. Participants (150 healthy females) were randomly allocated to one of three groups, all of which were exposed to disgusting and neutral images (OLP, CR, PV: passive viewing). It was tested whether the three groups would differ in brain activity and reported disgust. Ratings for the perceived efficacy and plausibility of treatment were also compared between OLP and CR. Both OLP and CR increased the activity in a cognitive control region, the ventrolateral prefrontal cortex. Relative to PV and OLP, CR reduced activity in the putamen and pallidum. These regions play an important role in decoding disgust signals from different modalities. Self-reports indicated that CR was perceived as a more effective and plausible intervention strategy than OLP. In conclusion, CR was a superior method for disgust regulation compared to OLP, both on the subjective as well as the neurobiological level. Future OLP studies are needed to test whether the observed effects generalize to other forms of emotional distress.

Trait representation of embodied cognition in dancers pivoting on the extended mirror neuron system: a resting-state fMRI study

Introduction

Dance is an art form that integrates the body and mind through movement. Dancers develop exceptional physical and mental abilities that involve various neurocognitive processes linked to embodied cognition. We propose that dancers' primary trait representation is movement-actuated and relies on the extended mirror neuron system (eMNS).

Methods

A total of 29 dancers and 28 non-dancer controls were recruited. A hierarchical approach of intra-regional and inter-regional functional connectivity (FC) analysis was adopted to probe trait-like neurodynamics within and between regions in the eMNS during rest. Correlation analyses were employed to examine the associations between dance training, creativity, and the FC within and between different brain regions.

Results

Within the eMNS, dancers exhibited increased intra-regional FC in various brain regions compared to non-dancers. These regions include the left inferior frontal gyrus, left ventral premotor cortex, left anterior insula, left posterior cerebellum (crus II), and bilateral basal ganglia (putamen and globus pallidus). Dancers also exhibited greater intrinsic inter-regional FC between the cerebellum and the core/limbic mirror areas within the eMNS. In dancers, there was a negative correlation observed between practice intensity and the intrinsic FC within the eMNS involving the cerebellum and basal ganglia. Additionally, FCs from the basal ganglia to the dorsolateral prefrontal cortex were found to be negatively correlated with originality in dancers.

Discussion

Our results highlight the proficient communication within the cortical-subcortical hierarchy of the eMNS in dancers, linked to the automaticity and cognitive-motor interactions acquired through training. Altered functional couplings in the eMNS can be regarded as a unique neural signature specific to virtuoso dancers, which might predispose them for skilled dancing performance, perception, and creation.

High-Definition Transcranial Direct Current Stimulation in the Right Ventrolateral Prefrontal Cortex Lengthens Sustained Attention in Virtual Reality

Due to the current limitations of three-dimensional (3D) simulation graphics technology, mind wandering commonly occurs in virtual reality tasks, which has impeded it being applied more extensively. The right ventrolateral prefrontal cortex (rVLPFC) plays a vital role in executing continuous two-dimensional (2D) mental paradigms, and transcranial direct current stimulation (tDCS) over this cortical region has been shown to successfully modulate sustained 2D attention. Accordingly, we further explored the effects of electrical activation of the rVLPFC on 3D attentional tasks using anodal high-definition (HD)-tDCS. A 3D Go/No-go (GNG) task was developed to compare the after effects of real and sham brain stimulation. Specifically, GNG tasks were periodically interrupted to assess the subjective perception of attentional level, behavioral reactions were tracked and decomposed into an underlying decision cognition process, and electroencephalography data were recorded to calculate event-related potentials (ERPs) in rVLPFC. The p-values statistically indicated that HD-tDCS improved the subjective mentality, led to more cautious decisions, and enhanced neuronal discharging in rVLPFC. Additionally, the neurophysiological P300 ERP component and stimulation being active or sham could effectively predict several objective outcomes. These findings indicate that the comprehensive approach including brain stimulation, 3D mental paradigm, and cross-examined performance could significantly lengthen and robustly compare sustained 3D attention.

Decreased inter-brain synchronization in the right middle frontal cortex in alcohol use disorder during social interaction: An fNIRS hyperscanning study

BACKGROUND

Alcohol use disorder (AUD) is a widespread mental disorder and has thrust a heavy burden on the health system all over the world. Social cognition and function are reported to be impaired in AUD, but its neural mechanism is rarely investigated. The current study attempts to fill this gap.

METHODS

28 subjects with AUD and 36 healthy controls (HC) were recruited in this study and were paired into 14 AUD dyads and 18 HC dyads. The drinking problems, depression, anxiety, and impulsivity of subjects were measured. Each dyad completed cooperation and competition tasks with simultaneous frontal functional near-infrared spectroscopy (fNIRS) hyperscanning recording. The inter-brain synchronization (IBS) in the frontal cortex was calculated for each dyad and compared between AUD and HC. The significantly altered IBS in AUD was correlated with clinical measures to explore possible influencing factors.

RESULTS

The IBS in the right middle frontal cortex was significantly decreased in AUD under both cooperation (t = -2.257, P = 0.028) and competition (t = -2.488, P = 0.016) task. The IBS during the cooperation task in the right middle frontal cortex in AUD was negatively correlated with non-planning impulsivity (r = -0.673, P = 0.006).

LIMITATIONS

This study used cross-sectional data, which limited the causal inference. The synchronization between other brain regions besides the frontal cortex should be further explored in patients with AUD.

CONCLUSION

The current study could provide new insights into the neural mechanism of social dysfunction in AUD and facilitate clinical intervention in future practice.

Cognitive flexibility: neurobehavioral correlates of changing one's mind

Behavioral and cognitive flexibility allow adaptation to a changing environment. Most tasks used to investigate flexibility require switching reactively in response to deterministic task-response rules. In daily life, flexibility often involves a volitional decision to change behavior. This can be instigated by environmental signals, but these are frequently unreliable. We report results from a novel "change your mind" task, which assesses volitional switching under uncertainty without the need for rule-based learning. Participants completed a two-alternative choice task, and following spurious feedback, were presented with the same stimulus again. Subjects had the opportunity to repeat or change their response. Forty healthy participants completed the task while undergoing a functional magnetic resonance imaging scan. Participants predominantly repeated their choice but changed more when their first response was incorrect or when the feedback was negative. Greater activations for changing were found in the inferior frontal junction, anterior insula (AI), anterior cingulate, and dorsolateral prefrontal cortex. Changing responses were also accompanied by reduced connectivity from the AI and orbitofrontal cortices to the occipital cortex. Using multivariate pattern analysis of brain activity, we predicted with 77% reliability whether participants would change their mind. These findings extend our understanding of cognitive flexibility in daily life by assessing volitional decision-making.

A review of resting-state fMRI correlations with executive functions and social cognition in bipolar disorder

BACKGROUND

Deficits in executive functions (EF) and social cognition (SC) are often observed in bipolar disorder (BD), leading to a severe impairment in engaging a functional interaction with the others and the surrounding environment. Therefore, in recent years, resting-state functional magnetic resonance imaging (rs-fMRI) studies on BD tried to identify the neural underpinnings of these cognitive domains by exploring the association between the intrinsic functional connectivity (FC) and the scores in clinical scales evaluating these domains.

METHODS

A bibliographic search on PubMed and Scopus of studies evaluating the correlations between rs-fMRI findings and EF and/or SC in BD was conducted until March 2022. Ten studies met the inclusion criteria.

RESULTS

Overall, the results of the reviewed studies showed that BD patients had FC deficits compared to healthy controls (HC) in selective resting-state networks involved in EF and SC, which include the default mode network, especially the link between medial prefrontal cortex and posterior cingulate cortex, and the sensory-motor network. Finally, it also emerged the predominant role of alterations in prefrontal connections in explaining the cognitive deficits in BD patients.

LIMITATIONS

The heterogeneity of the reviewed studies, in terms of cognitive domains explored and neuroimaging acquisitions, limited the comparability of the findings.

CONCLUSIONS

rs-fMRI studies could help deepen the brain network alterations underlying EF and SC deficits in BD, pointing the attention on the neuronal underpinning of cognition, whose knowledge may lead to the development of new neurobiological-based approaches to improve the quality of life of these patients.

Fronto-central resting-state 15-29Hz transient beta events change with therapeutic transcranial magnetic stimulation for posttraumatic stress disorder and major depressive disorder

Repetitive transcranial magnetic stimulation (rTMS) is an established treatment for major depressive disorder (MDD) and shows promise for posttraumatic stress disorder (PTSD), yet effectiveness varies. Electroencephalography (EEG) can identify rTMS-associated brain changes. EEG oscillations are often examined using averaging approaches that mask finer time-scale dynamics. Recent advances show some brain oscillations emerge as transient increases in power, a phenomenon termed "Spectral Events," and that event characteristics correspond with cognitive functions. We applied Spectral Event analyses to identify potential EEG biomarkers of effective rTMS treatment. Resting 8-electrode EEG was collected from 23 patients with MDD and PTSD before and after 5Hz rTMS targeting the left dorsolateral prefrontal cortex. Using an open-source toolbox ( https://github.com/jonescompneurolab/SpectralEvents ), we quantified event features and tested for treatment associated changes. Spectral Events in delta/theta (1-6 Hz), alpha (7-14 Hz), and beta (15-29 Hz) bands occurred in all patients. rTMS-induced improvement in comorbid MDD PTSD were associated with pre-to post-treatment changes in fronto-central electrode beta event features, including frontal beta event frequency spans and durations, and central beta event maxima power. Furthermore, frontal pre-treatment beta event duration correlated negatively with MDD symptom improvement. Beta events may provide new biomarkers of clinical response and advance the understanding of rTMS.

Associations between right inferior frontal gyrus morphometry and inhibitory control in individuals with nicotine dependence

BACKGROUND

The hyperdirect pathway - a circuit involved in executing inhibitory control (IC) - is dysregulated among individuals with nicotine dependence. The right inferior frontal gyrus (rIFG), a cortical input to the hyperdirect circuit, has been shown to be functionally and structurally altered among nicotine-dependent people who smoke. The rIFG is composed of 3 cytoarchitecturally distinct subregions: The pars opercularis, pars triangularis, and pars orbitalis. The present study assessed the relationship between rIFG subregion morphometry and inhibitory control among individuals with nicotine dependence.

METHODS

Behavioral and magnetic resonance brain imaging (MRI) data from 127 nicotine-dependent adults who smoke (MFTND = 5.4, ± 1.9; MCPD = 18.3, ± 7.0; Myears = 25.04, ± 11.97) (Mage = 42.9, ± 11.1) were assessed. Brain morphometry was assessed from T1-weighted MRIs using Freesurfer. IC was assessed with a response-inhibition Go/Go/No-Go (GGNG) task and a smoking relapse analog task (SRT).

RESULTS AND CONCLUSIONS

Vertex-wise analyses revealed that GGNG task scores were positively associated with cortical thickness and volume in the right pars triangularis (cluster-wise p = 0.006, 90% CI = 0.003 - 0.009; cluster-wise p = 0.040, 90% CI = 0.032 - 0.048), and the ability to inhibit ad lib smoking during the SRT was positively associated with cortical thickness in the right pars orbitalis (cluster-wise p = 0.011, 90% CI = 0.007 - 0.015). Our results indicate that cortical thickness of distinct rIFG subregions may serve as biomarkers for unique forms of IC deficits.

β-Bursts over Frontal Cortex Track the Surprise of Unexpected Events in Auditory, Visual, and Tactile Modalities

One of the fundamental ways in which the brain regulates and monitors behavior is by making predictions about the sensory environment and adjusting behavior when those expectations are violated. As such, surprise is one of the fundamental computations performed by the human brain. In recent years, it has been well established that one key aspect by which behavior is adjusted during surprise is inhibitory control of the motor system. Moreover, because surprise automatically triggers inhibitory control without much proactive influence, it can provide unique insights into largely reactive control processes. Recent years have seen tremendous interest in burst-like β frequency events in the human (and nonhuman) local field potential-especially over (p)FC-as a potential signature of inhibitory control. To date, β-bursts have only been studied in paradigms involving a substantial amount of proactive control (such as the stop-signal task). Here, we used two cross-modal oddball tasks to investigate whether surprise processing is accompanied by increases in scalp-recorded β-bursts. Indeed, we found that unexpected events in all tested sensory domains (haptic, auditory, visual) were followed by low-latency increases in β-bursting over frontal cortex. Across experiments, β-burst rates were positively correlated with estimates of surprise derived from Shannon's information theory, a type of surprise that represents the degree to which a given stimulus violates prior expectations. As such, the current work clearly implicates frontal β-bursts as a signature of surprise processing. We discuss these findings in the context of common frameworks of inhibitory and cognitive control after unexpected events.