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1.
Hum Brain Mapp ; 45(7): e26703, 2024 May.
Article in English | MEDLINE | ID: mdl-38716714

ABSTRACT

The default mode network (DMN) lies towards the heteromodal end of the principal gradient of intrinsic connectivity, maximally separated from the sensory-motor cortex. It supports memory-based cognition, including the capacity to retrieve conceptual and evaluative information from sensory inputs, and to generate meaningful states internally; however, the functional organisation of DMN that can support these distinct modes of retrieval remains unclear. We used fMRI to examine whether activation within subsystems of DMN differed as a function of retrieval demands, or the type of association to be retrieved, or both. In a picture association task, participants retrieved semantic associations that were either contextual or emotional in nature. Participants were asked to avoid generating episodic associations. In the generate phase, these associations were retrieved from a novel picture, while in the switch phase, participants retrieved a new association for the same image. Semantic context and emotion trials were associated with dissociable DMN subnetworks, indicating that a key dimension of DMN organisation relates to the type of association being accessed. The frontotemporal and medial temporal DMN showed a preference for emotional and semantic contextual associations, respectively. Relative to the generate phase, the switch phase recruited clusters closer to the heteromodal apex of the principal gradient-a cortical hierarchy separating unimodal and heteromodal regions. There were no differences in this effect between association types. Instead, memory switching was associated with a distinct subnetwork associated with controlled internal cognition. These findings delineate distinct patterns of DMN recruitment for different kinds of associations yet common responses across tasks that reflect retrieval demands.


Subject(s)
Default Mode Network , Emotions , Magnetic Resonance Imaging , Mental Recall , Semantics , Humans , Male , Female , Adult , Young Adult , Emotions/physiology , Default Mode Network/physiology , Default Mode Network/diagnostic imaging , Mental Recall/physiology , Cerebral Cortex/physiology , Cerebral Cortex/diagnostic imaging , Nerve Net/physiology , Nerve Net/diagnostic imaging , Brain Mapping , Pattern Recognition, Visual/physiology
2.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38745558

ABSTRACT

Arousal state is regulated by subcortical neuromodulatory nuclei, such as locus coeruleus, which send wide-reaching projections to cortex. Whether higher-order cortical regions have the capacity to recruit neuromodulatory systems to aid cognition is unclear. Here, we hypothesized that select cortical regions activate the arousal system, which, in turn, modulates large-scale brain activity, creating a functional circuit predicting cognitive ability. We utilized the Human Connectome Project 7T functional magnetic resonance imaging dataset (n = 149), acquired at rest with simultaneous eye tracking, along with extensive cognitive assessment for each subject. First, we discovered select frontoparietal cortical regions that drive large-scale spontaneous brain activity specifically via engaging the arousal system. Second, we show that the functionality of the arousal circuit driven by bilateral posterior cingulate cortex (associated with the default mode network) predicts subjects' cognitive abilities. This suggests that a cortical region that is typically associated with self-referential processing supports cognition by regulating the arousal system.


Subject(s)
Arousal , Brain , Cognition , Connectome , Magnetic Resonance Imaging , Rest , Humans , Arousal/physiology , Cognition/physiology , Male , Female , Connectome/methods , Adult , Rest/physiology , Brain/physiology , Brain/diagnostic imaging , Young Adult , Nerve Net/physiology , Nerve Net/diagnostic imaging , Neural Pathways/physiology , Neural Pathways/diagnostic imaging
3.
Biol Lett ; 20(5): 20230576, 2024 May.
Article in English | MEDLINE | ID: mdl-38747685

ABSTRACT

Neural circuits govern the interface between the external environment, internal cues and outwardly directed behaviours. To process multiple environmental stimuli and integrate these with internal state requires considerable neural computation. Expansion in neural network size, most readily represented by whole brain size, has historically been linked to behavioural complexity, or the predominance of cognitive behaviours. Yet, it is largely unclear which aspects of circuit variation impact variation in performance. A key question in the field of evolutionary neurobiology is therefore how neural circuits evolve to allow improved behavioural performance or innovation. We discuss this question by first exploring how volumetric changes in brain areas reflect actual neural circuit change. We explore three major axes of neural circuit evolution-replication, restructuring and reconditioning of cells and circuits-and discuss how these could relate to broader phenotypes and behavioural variation. This discussion touches on the relevant uses and limitations of volumetrics, while advocating a more circuit-based view of cognition. We then use this framework to showcase an example from the insect brain, the multi-sensory integration and internal processing that is shared between the mushroom bodies and central complex. We end by identifying future trends in this research area, which promise to advance the field of evolutionary neurobiology.


Subject(s)
Biological Evolution , Brain , Cognition , Cognition/physiology , Animals , Brain/physiology , Nerve Net/physiology , Insecta/physiology , Mushroom Bodies/physiology
4.
Nat Commun ; 15(1): 3542, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719802

ABSTRACT

Understanding the functional connectivity between brain regions and its emergent dynamics is a central challenge. Here we present a theory-experiment hybrid approach involving iteration between a minimal computational model and in vivo electrophysiological measurements. Our model not only predicted spontaneous persistent activity (SPA) during Up-Down-State oscillations, but also inactivity (SPI), which has never been reported. These were confirmed in vivo in the membrane potential of neurons, especially from layer 3 of the medial and lateral entorhinal cortices. The data was then used to constrain two free parameters, yielding a unique, experimentally determined model for each neuron. Analytic and computational analysis of the model generated a dozen quantitative predictions about network dynamics, which were all confirmed in vivo to high accuracy. Our technique predicted functional connectivity; e. g. the recurrent excitation is stronger in the medial than lateral entorhinal cortex. This too was confirmed with connectomics data. This technique uncovers how differential cortico-entorhinal dialogue generates SPA and SPI, which could form an energetically efficient working-memory substrate and influence the consolidation of memories during sleep. More broadly, our procedure can reveal the functional connectivity of large networks and a theory of their emergent dynamics.


Subject(s)
Entorhinal Cortex , Models, Neurological , Neurons , Entorhinal Cortex/physiology , Animals , Neurons/physiology , Male , Connectome , Nerve Net/physiology , Membrane Potentials/physiology , Neural Pathways/physiology , Computer Simulation , Mice
5.
Commun Biol ; 7(1): 550, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719883

ABSTRACT

Perceptual and cognitive processing relies on flexible communication among cortical areas; however, the underlying neural mechanism remains unclear. Here we report a mechanism based on the realistic spatiotemporal dynamics of propagating wave patterns in neural population activity. Using a biophysically plausible, multiarea spiking neural circuit model, we demonstrate that these wave patterns, characterized by their rich and complex dynamics, can account for a wide variety of empirically observed neural processes. The coordinated interactions of these wave patterns give rise to distributed and dynamic communication (DDC) that enables flexible and rapid routing of neural activity across cortical areas. We elucidate how DDC unifies the previously proposed oscillation synchronization-based and subspace-based views of interareal communication, offering experimentally testable predictions that we validate through the analysis of Allen Institute Neuropixels data. Furthermore, we demonstrate that DDC can be effectively modulated during attention tasks through the interplay of neuromodulators and cortical feedback loops. This modulation process explains many neural effects of attention, underscoring the fundamental functional role of DDC in cognition.


Subject(s)
Attention , Models, Neurological , Attention/physiology , Humans , Cerebral Cortex/physiology , Animals , Nerve Net/physiology , Visual Perception/physiology , Neurons/physiology , Cognition/physiology
6.
BMC Pediatr ; 24(1): 318, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720281

ABSTRACT

Reading learning disability (RLD) is characterized by a specific difficulty in learning to read that is not better explained by an intellectual disability, lack of instruction, psychosocial adversity, or a neurological disorder. According to the domain-general hypothesis, a working memory deficit is the primary problem. Working memory in this population has recently been linked to altered resting-state functional connectivity within the default mode network (DMN), salience network (SN), and frontoparietal network (FPN) compared to that in typically developing individuals. The main purpose of the present study was to compare the within-network functional connectivity of the DMN, SN, FPN, and reading network in two groups of children with RLD: a group with lower-than-average working memory (LWM) and a group with average working memory (AWM). All subjects underwent resting-state functional magnetic resonance imaging (fMRI), and data were analyzed from a network perspective using the network brain statistics framework. The results showed that the LWM group had significantly weaker connectivity in a network that involved brain regions in the DMN, SN, and FPN than the AWM group. Although there was no significant difference between groups in reading network in the present study, other studies have shown relationship of the connectivity of the angular gyrus, supramarginal gyrus, and inferior parietal lobe with the phonological process of reading. The results suggest that although there are significant differences in functional connectivity in the associated networks between children with LWM and AWM, the distinctive cognitive profile has no specific effect on the reading network.


Subject(s)
Dyslexia , Magnetic Resonance Imaging , Memory, Short-Term , Humans , Memory, Short-Term/physiology , Child , Male , Female , Dyslexia/physiopathology , Dyslexia/diagnostic imaging , Brain/diagnostic imaging , Brain/physiopathology , Nerve Net/diagnostic imaging , Nerve Net/physiopathology , Reading , Case-Control Studies
7.
CNS Neurosci Ther ; 30(5): e14684, 2024 05.
Article in English | MEDLINE | ID: mdl-38739217

ABSTRACT

AIMS: Limited understanding exists regarding the neurobiological mechanisms underlying non-suicidal self-injury (NSSI) and suicide attempts (SA) in depressed adolescents. The maturation of brain network is crucial during adolescence, yet the abnormal alternations in depressed adolescents with NSSI or NSSI+SA remain poorly understood. METHODS: Resting-state functional magnetic resonance imaging data were collected from 114 depressed adolescents, classified into three groups: clinical control (non-self-harm), NSSI only, and NSSI+SA based on self-harm history. The alternations of resting-state functional connectivity (RSFC) were identified through support vector machine-based classification. RESULTS: Convergent alterations in NSSI and NSSI+SA predominantly centered on the inter-network RSFC between the Limbic network and the three core neurocognitive networks (SalVAttn, Control, and Default networks). Divergent alterations in the NSSI+SA group primarily focused on the Visual, Limbic, and Subcortical networks. Additionally, the severity of depressive symptoms only showed a significant correlation with altered RSFCs between Limbic and DorsAttn or Visual networks, strengthening the fact that increased depression severity alone does not fully explain observed FC alternations in the NSSI+SA group. CONCLUSION: Convergent alterations suggest a shared neurobiological mechanism along the self-destructiveness continuum. Divergent alterations may indicate biomarkers differentiating risk for SA, informing neurobiologically guided interventions.


Subject(s)
Brain , Magnetic Resonance Imaging , Self-Injurious Behavior , Suicide, Attempted , Humans , Self-Injurious Behavior/psychology , Adolescent , Male , Female , Suicide, Attempted/psychology , Brain/diagnostic imaging , Brain/physiopathology , Nerve Net/diagnostic imaging , Nerve Net/physiopathology , Depression/psychology , Depression/physiopathology , Depression/diagnostic imaging , Neural Pathways/physiopathology , Neural Pathways/diagnostic imaging , Child
8.
J Math Biol ; 89(1): 3, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38740613

ABSTRACT

Dynamical systems on networks typically involve several dynamical processes evolving at different timescales. For instance, in Alzheimer's disease, the spread of toxic protein throughout the brain not only disrupts neuronal activity but is also influenced by neuronal activity itself, establishing a feedback loop between the fast neuronal activity and the slow protein spreading. Motivated by the case of Alzheimer's disease, we study the multiple-timescale dynamics of a heterodimer spreading process on an adaptive network of Kuramoto oscillators. Using a minimal two-node model, we establish that heterogeneous oscillatory activity facilitates toxic outbreaks and induces symmetry breaking in the spreading patterns. We then extend the model formulation to larger networks and perform numerical simulations of the slow-fast dynamics on common network motifs and on the brain connectome. The simulations corroborate the findings from the minimal model, underscoring the significance of multiple-timescale dynamics in the modeling of neurodegenerative diseases.


Subject(s)
Alzheimer Disease , Brain , Computer Simulation , Mathematical Concepts , Models, Neurological , Neurons , Humans , Alzheimer Disease/physiopathology , Neurons/physiology , Brain/physiopathology , Connectome , Neurodegenerative Diseases/physiopathology , Neurodegenerative Diseases/pathology , Nerve Net/physiopathology , Nerve Net/physiology
9.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38741270

ABSTRACT

This study extends the application of the frequency-domain new causality method to functional magnetic resonance imaging analysis. Strong causality, weak causality, balanced causality, cyclic causality, and transitivity causality were constructed to simulate varying degrees of causal associations among multivariate functional-magnetic-resonance-imaging blood-oxygen-level-dependent signals. Data from 1,252 groups of individuals with different degrees of cognitive impairment were collected. The frequency-domain new causality method was employed to construct directed efficient connectivity networks of the brain, analyze the statistical characteristics of topological variations in brain regions related to cognitive impairment, and utilize these characteristics as features for training a deep learning model. The results demonstrated that the frequency-domain new causality method accurately detected causal associations among simulated signals of different degrees. The deep learning tests also confirmed the superior performance of new causality, surpassing the other three methods in terms of accuracy, precision, and recall rates. Furthermore, consistent significant differences were observed in the brain efficiency networks, where several subregions defined by the multimodal parcellation method of Human Connectome Project simultaneously appeared in the topological statistical results of different patient groups. This suggests a significant association between these fine-grained cortical subregions, driven by multimodal data segmentation, and human cognitive function, making them potential biomarkers for further analysis of Alzheimer's disease.


Subject(s)
Brain , Connectome , Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging/methods , Brain/diagnostic imaging , Male , Female , Connectome/methods , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/physiopathology , Cognition/physiology , Aged , Middle Aged , Deep Learning , Nerve Net/diagnostic imaging , Nerve Net/physiology , Neural Pathways/diagnostic imaging , Neural Pathways/physiopathology , Nervous System Diseases/diagnostic imaging , Nervous System Diseases/physiopathology , Adult
10.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38741271

ABSTRACT

This study investigates abnormalities in cerebellar-cerebral static and dynamic functional connectivity among patients with acute pontine infarction, examining the relationship between these connectivity changes and behavioral dysfunction. Resting-state functional magnetic resonance imaging was utilized to collect data from 45 patients within seven days post-pontine infarction and 34 normal controls. Seed-based static and dynamic functional connectivity analyses identified divergences in cerebellar-cerebral connectivity features between pontine infarction patients and normal controls. Correlations between abnormal functional connectivity features and behavioral scores were explored. Compared to normal controls, left pontine infarction patients exhibited significantly increased static functional connectivity within the executive, affective-limbic, and motor networks. Conversely, right pontine infarction patients demonstrated decreased static functional connectivity in the executive, affective-limbic, and default mode networks, alongside an increase in the executive and motor networks. Decreased temporal variability of dynamic functional connectivity was observed in the executive and default mode networks among left pontine infarction patients. Furthermore, abnormalities in static and dynamic functional connectivity within the executive network correlated with motor and working memory performance in patients. These findings suggest that alterations in cerebellar-cerebral static and dynamic functional connectivity could underpin the behavioral dysfunctions observed in acute pontine infarction patients.


Subject(s)
Brain Stem Infarctions , Cerebellum , Magnetic Resonance Imaging , Neural Pathways , Pons , Humans , Male , Female , Middle Aged , Cerebellum/physiopathology , Cerebellum/diagnostic imaging , Neural Pathways/physiopathology , Neural Pathways/diagnostic imaging , Pons/diagnostic imaging , Pons/physiopathology , Brain Stem Infarctions/physiopathology , Brain Stem Infarctions/diagnostic imaging , Aged , Adult , Cerebral Cortex/physiopathology , Cerebral Cortex/diagnostic imaging , Nerve Net/physiopathology , Nerve Net/diagnostic imaging
11.
Brain Cogn ; 177: 106161, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38696928

ABSTRACT

Narrative comprehension relies on basic sensory processing abilities, such as visual and auditory processing, with recent evidence for utilizing executive functions (EF), which are also engaged during reading. EF was previously related to the "supporter" of engaging the auditory and visual modalities in different cognitive tasks, with evidence of lower efficiency in this process among those with reading difficulties in the absence of a visual stimulus (i.e. while listening to stories). The current study aims to fill out the gap related to the level of reliance on these neural circuits while visual aids (pictures) are involved during story listening in relation to reading skills. Functional MRI data were collected from 44 Hebrew-speaking children aged 8-12 years while listening to stories with vs without visual stimuli (i.e., pictures). Functional connectivity of networks supporting reading was defined in each condition and compared between the conditions against behavioral reading measures. Lower reading skills were related to greater functional connectivity values between EF networks (default mode and memory networks), and between the auditory and memory networks for the stories with vs without the visual stimulation. A greater difference in functional connectivity between the conditions was related to lower reading scores. We conclude that lower reading skills in children may be related to a need for greater scaffolding, i.e., visual stimulation such as pictures describing the narratives when listening to stories, which may guide future intervention approaches.


Subject(s)
Executive Function , Magnetic Resonance Imaging , Reading , Visual Perception , Humans , Child , Male , Female , Executive Function/physiology , Visual Perception/physiology , Auditory Perception/physiology , Comprehension/physiology , Photic Stimulation/methods , Nerve Net/physiology , Nerve Net/diagnostic imaging , Brain/physiology
12.
Chaos ; 34(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38767461

ABSTRACT

Transient or partial synchronization can be used to do computations, although a fully synchronized network is sometimes related to the onset of epileptic seizures. Here, we propose a homeostatic mechanism that is capable of maintaining a neuronal network at the edge of a synchronization transition, thereby avoiding the harmful consequences of a fully synchronized network. We model neurons by maps since they are dynamically richer than integrate-and-fire models and more computationally efficient than conductance-based approaches. We first describe the synchronization phase transition of a dense network of neurons with different tonic spiking frequencies coupled by gap junctions. We show that at the transition critical point, inputs optimally reverberate through the network activity through transient synchronization. Then, we introduce a local homeostatic dynamic in the synaptic coupling and show that it produces a robust self-organization toward the edge of this phase transition. We discuss the potential biological consequences of this self-organization process, such as its relation to the Brain Criticality hypothesis, its input processing capacity, and how its malfunction could lead to pathological synchronization and the onset of seizure-like activity.


Subject(s)
Homeostasis , Models, Neurological , Nerve Net , Neurons , Homeostasis/physiology , Neurons/physiology , Nerve Net/physiology , Humans , Action Potentials/physiology , Animals , Computer Simulation , Brain/physiology , Synaptic Transmission/physiology
13.
PLoS One ; 19(5): e0293053, 2024.
Article in English | MEDLINE | ID: mdl-38768123

ABSTRACT

Resting-state functional magnetic resonance imaging (rs-fMRI) has increasingly been used to study both Alzheimer's disease (AD) and schizophrenia (SZ). While most rs-fMRI studies being conducted in AD and SZ compare patients to healthy controls, it is also of interest to directly compare AD and SZ patients with each other to identify potential biomarkers shared between the disorders. However, comparing patient groups collected in different studies can be challenging due to potential confounds, such as differences in the patient's age, scan protocols, etc. In this study, we compared and contrasted resting-state functional network connectivity (rs-FNC) of 162 patients with AD and late mild cognitive impairment (LMCI), 181 schizophrenia patients, and 315 cognitively normal (CN) subjects. We used confounder-controlled rs-FNC and applied machine learning algorithms (including support vector machine, logistic regression, random forest, and k-nearest neighbor) and deep learning models (i.e., fully-connected neural networks) to classify subjects in binary and three-class categories according to their diagnosis labels (e.g., AD, SZ, and CN). Our statistical analysis revealed that FNC between the following network pairs is stronger in AD compared to SZ: subcortical-cerebellum, subcortical-cognitive control, cognitive control-cerebellum, and visual-sensory motor networks. On the other hand, FNC is stronger in SZ than AD for the following network pairs: subcortical-visual, subcortical-auditory, subcortical-sensory motor, cerebellum-visual, sensory motor-cognitive control, and within the cerebellum networks. Furthermore, we observed that while AD and SZ disorders each have unique FNC abnormalities, they also share some common functional abnormalities that can be due to similar neurobiological mechanisms or genetic factors contributing to these disorders' development. Moreover, we achieved an accuracy of 85% in classifying subjects into AD and SZ where default mode, visual, and subcortical networks contributed the most to the classification and accuracy of 68% in classifying subjects into AD, SZ, and CN with the subcortical domain appearing as the most contributing features to the three-way classification. Finally, our findings indicated that for all classification tasks, except AD vs. SZ, males are more predictable than females.


Subject(s)
Alzheimer Disease , Machine Learning , Magnetic Resonance Imaging , Schizophrenia , Humans , Alzheimer Disease/physiopathology , Alzheimer Disease/diagnostic imaging , Female , Schizophrenia/physiopathology , Schizophrenia/diagnostic imaging , Male , Magnetic Resonance Imaging/methods , Aged , Middle Aged , Cognitive Dysfunction/physiopathology , Cognitive Dysfunction/diagnostic imaging , Nerve Net/physiopathology , Nerve Net/diagnostic imaging , Brain/diagnostic imaging , Brain/physiopathology , Connectome/methods , Rest/physiology , Case-Control Studies
14.
Sensors (Basel) ; 24(9)2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38732980

ABSTRACT

Walking encompasses a complex interplay of neuromuscular coordination and cognitive processes. Disruptions in gait can impact personal independence and quality of life, especially among the elderly and neurodegenerative patients. While traditional biomechanical analyses and neuroimaging techniques have contributed to understanding gait control, they often lack the temporal resolution needed for rapid neural dynamics. This study employs a mobile brain/body imaging (MoBI) platform with high-density electroencephalography (hd-EEG) to explore event-related desynchronization and synchronization (ERD/ERS) during overground walking. Simultaneous to hdEEG, we recorded gait spatiotemporal parameters. Participants were asked to walk under usual walking and dual-task walking conditions. For data analysis, we extracted ERD/ERS in α, ß, and γ bands from 17 selected regions of interest encompassing not only the sensorimotor cerebral network but also the cognitive and affective networks. A correlation analysis was performed between gait parameters and ERD/ERS intensities in different networks in the different phases of gait. Results showed that ERD/ERS modulations across gait phases in the α and ß bands extended beyond the sensorimotor network, over the cognitive and limbic networks, and were more prominent in all networks during dual tasks with respect to usual walking. Correlation analyses showed that a stronger α ERS in the initial double-support phases correlates with shorter step length, emphasizing the role of attention in motor control. Additionally, ß ERD/ERS in affective and cognitive networks during dual-task walking correlated with dual-task gait performance, suggesting compensatory mechanisms in complex tasks. This study advances our understanding of neural dynamics during overground walking, emphasizing the multidimensional nature of gait control involving cognitive and affective networks.


Subject(s)
Brain , Electroencephalography , Gait , Walking , Humans , Gait/physiology , Male , Electroencephalography/methods , Brain/physiology , Brain/diagnostic imaging , Female , Adult , Walking/physiology , Nerve Net/physiology , Nerve Net/diagnostic imaging , Young Adult
15.
Sensors (Basel) ; 24(9)2024 May 03.
Article in English | MEDLINE | ID: mdl-38733030

ABSTRACT

This article presents a study on the neurobiological control of voluntary movements for anthropomorphic robotic systems. A corticospinal neural network model has been developed to control joint trajectories in multi-fingered robotic hands. The proposed neural network simulates cortical and spinal areas, as well as the connectivity between them, during the execution of voluntary movements similar to those performed by humans or monkeys. Furthermore, this neural connection allows for the interpretation of functional roles in the motor areas of the brain. The proposed neural control system is tested on the fingers of a robotic hand, which is driven by agonist-antagonist tendons and actuators designed to accurately emulate complex muscular functionality. The experimental results show that the corticospinal controller produces key properties of biological movement control, such as bell-shaped asymmetric velocity profiles and the ability to compensate for disturbances. Movements are dynamically compensated for through sensory feedback. Based on the experimental results, it is concluded that the proposed biologically inspired adaptive neural control system is robust, reliable, and adaptable to robotic platforms with diverse biomechanics and degrees of freedom. The corticospinal network successfully integrates biological concepts with engineering control theory for the generation of functional movement. This research significantly contributes to improving our understanding of neuromotor control in both animals and humans, thus paving the way towards a new frontier in the field of neurobiological control of anthropomorphic robotic systems.


Subject(s)
Hand , Neural Networks, Computer , Robotics , Tendons , Humans , Robotics/methods , Hand/physiology , Tendons/physiology , Movement/physiology , Nerve Net/physiology , Biomechanical Phenomena/physiology , Pyramidal Tracts/physiology , Animals
16.
Sci Rep ; 14(1): 10242, 2024 05 03.
Article in English | MEDLINE | ID: mdl-38702415

ABSTRACT

Cerebral infra-slow oscillation (ISO) is a source of vasomotion in endogenic (E; 0.005-0.02 Hz), neurogenic (N; 0.02-0.04 Hz), and myogenic (M; 0.04-0.2 Hz) frequency bands. In this study, we quantified changes in prefrontal concentrations of oxygenated hemoglobin (Δ[HbO]) and redox-state cytochrome c oxidase (Δ[CCO]) as hemodynamic and metabolic activity metrics, and electroencephalogram (EEG) powers as electrophysiological activity, using concurrent measurements of 2-channel broadband near-infrared spectroscopy and EEG on the forehead of 22 healthy participants at rest. After preprocessing, the multi-modality signals were analyzed using generalized partial directed coherence to construct unilateral neurophysiological networks among the three neurophysiological metrics (with simplified symbols of HbO, CCO, and EEG) in each E/N/M frequency band. The links in these networks represent neurovascular, neurometabolic, and metabolicvascular coupling (NVC, NMC, and MVC). The results illustrate that the demand for oxygen by neuronal activity and metabolism (EEG and CCO) drives the hemodynamic supply (HbO) in all E/N/M bands in the resting prefrontal cortex. Furthermore, to investigate the effect of transcranial photobiomodulation (tPBM), we performed a sham-controlled study by delivering an 800-nm laser beam to the left and right prefrontal cortex of the same participants. After performing the same data processing and statistical analysis, we obtained novel and important findings: tPBM delivered on either side of the prefrontal cortex triggered the alteration or reversal of directed network couplings among the three neurophysiological entities (i.e., HbO, CCO, and EEG frequency-specific powers) in the physiological network in the E and N bands, demonstrating that during the post-tPBM period, both metabolism and hemodynamic supply drive electrophysiological activity in directed network coupling of the prefrontal cortex (PFC). Overall, this study revealed that tPBM facilitates significant modulation of the directionality of neurophysiological networks in electrophysiological, metabolic, and hemodynamic activities.


Subject(s)
Electroencephalography , Prefrontal Cortex , Spectroscopy, Near-Infrared , Humans , Prefrontal Cortex/physiology , Prefrontal Cortex/metabolism , Male , Adult , Female , Spectroscopy, Near-Infrared/methods , Low-Level Light Therapy/methods , Young Adult , Rest/physiology , Oxyhemoglobins/metabolism , Electron Transport Complex IV/metabolism , Hemodynamics/physiology , Nerve Net/physiology , Nerve Net/metabolism
17.
Behav Brain Funct ; 20(1): 11, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38724963

ABSTRACT

Procrastination is universally acknowledged as a problematic behavior with wide-ranging consequences impacting various facets of individuals' lives, including academic achievement, social accomplishments, and mental health. Although previous research has indicated that future self-continuity is robustly negatively correlated with procrastination, it remains unknown about the neural mechanisms underlying the impact of future self-continuity on procrastination. To address this issue, we employed a free construction approach to collect individuals' episodic future thinking (EFT) thoughts regarding specific procrastination tasks. Next, we conducted voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) analysis to explore the neural substrates underlying future self-continuity. Behavior results revealed that future self-continuity was significantly negatively correlated with procrastination, and positively correlated with anticipated positive outcome. The VBM analysis showed a positive association between future self-continuity and gray matter volumes in the right ventromedial prefrontal cortex (vmPFC). Furthermore, the RSFC results indicated that the functional connectivity between the right vmPFC and the left inferior parietal lobule (IPL) was positively correlated with future self-continuity. More importantly, the mediation analysis demonstrated that anticipated positive outcome can completely mediate the relationship between the vmPFC-IPL functional connectivity and procrastination. These findings suggested that vmPFC-IPL functional connectivity might prompt anticipated positive outcome about the task and thereby reduce procrastination, which provides a new perspective to understand the relationship between future self-continuity and procrastination.


Subject(s)
Magnetic Resonance Imaging , Parietal Lobe , Prefrontal Cortex , Procrastination , Humans , Procrastination/physiology , Male , Female , Magnetic Resonance Imaging/methods , Young Adult , Adult , Prefrontal Cortex/physiology , Prefrontal Cortex/diagnostic imaging , Parietal Lobe/physiology , Parietal Lobe/diagnostic imaging , Brain Mapping/methods , Neural Pathways/physiology , Adolescent , Nerve Net/diagnostic imaging , Nerve Net/physiology , Thinking/physiology
18.
Hum Brain Mapp ; 45(7): e26666, 2024 May.
Article in English | MEDLINE | ID: mdl-38726831

ABSTRACT

Advanced meditation such as jhana meditation can produce various altered states of consciousness (jhanas) and cultivate rewarding psychological qualities including joy, peace, compassion, and attentional stability. Mapping the neurobiological substrates of jhana meditation can inform the development and application of advanced meditation to enhance well-being. Only two prior studies have attempted to investigate the neural correlates of jhana meditation, and the rarity of adept practitioners has largely restricted the size and extent of these studies. Therefore, examining the consistency and reliability of observed brain responses associated with jhana meditation can be valuable. In this study, we aimed to characterize functional magnetic resonance imaging (fMRI) reliability within a single subject over repeated runs in canonical brain networks during jhana meditation performed by an adept practitioner over 5 days (27 fMRI runs) inside an ultra-high field 7 Tesla MRI scanner. We found that thalamus and several cortical networks, that is, the somatomotor, limbic, default-mode, control, and temporo-parietal, demonstrated good within-subject reliability across all jhanas. Additionally, we found that several other relevant brain networks (e.g., attention, salience) showed noticeable increases in reliability when fMRI measurements were adjusted for variability in self-reported phenomenology related to jhana meditation. Overall, we present a preliminary template of reliable brain areas likely underpinning core neurocognitive elements of jhana meditation, and highlight the utility of neurophenomenological experimental designs for better characterizing neuronal variability associated with advanced meditative states.


Subject(s)
Magnetic Resonance Imaging , Meditation , Nerve Net , Humans , Reproducibility of Results , Nerve Net/physiology , Nerve Net/diagnostic imaging , Adult , Male , Female , Brain/physiology , Brain/diagnostic imaging , Cerebral Cortex/physiology , Cerebral Cortex/diagnostic imaging
19.
Proc Natl Acad Sci U S A ; 121(22): e2316149121, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38768342

ABSTRACT

Speech impediments are a prominent yet understudied symptom of Parkinson's disease (PD). While the subthalamic nucleus (STN) is an established clinical target for treating motor symptoms, these interventions can lead to further worsening of speech. The interplay between dopaminergic medication, STN circuitry, and their downstream effects on speech in PD is not yet fully understood. Here, we investigate the effect of dopaminergic medication on STN circuitry and probe its association with speech and cognitive functions in PD patients. We found that changes in intrinsic functional connectivity of the STN were associated with alterations in speech functions in PD. Interestingly, this relationship was characterized by altered functional connectivity of the dorsolateral and ventromedial subdivisions of the STN with the language network. Crucially, medication-induced changes in functional connectivity between the STN's dorsolateral subdivision and key regions in the language network, including the left inferior frontal cortex and the left superior temporal gyrus, correlated with alterations on a standardized neuropsychological test requiring oral responses. This relation was not observed in the written version of the same test. Furthermore, changes in functional connectivity between STN and language regions predicted the medication's downstream effects on speech-related cognitive performance. These findings reveal a previously unidentified brain mechanism through which dopaminergic medication influences speech function in PD. Our study sheds light into the subcortical-cortical circuit mechanisms underlying impaired speech control in PD. The insights gained here could inform treatment strategies aimed at mitigating speech deficits in PD and enhancing the quality of life for affected individuals.


Subject(s)
Language , Parkinson Disease , Speech , Subthalamic Nucleus , Humans , Parkinson Disease/physiopathology , Parkinson Disease/drug therapy , Subthalamic Nucleus/physiopathology , Subthalamic Nucleus/drug effects , Male , Speech/physiology , Speech/drug effects , Female , Middle Aged , Aged , Magnetic Resonance Imaging , Dopamine/metabolism , Nerve Net/drug effects , Nerve Net/physiopathology , Cognition/drug effects , Dopamine Agents/pharmacology , Dopamine Agents/therapeutic use
20.
Behav Brain Sci ; 47: e92, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38770864

ABSTRACT

By examining the shared neuro-cognitive correlates of curiosity and creativity, we better understand the brain basis of creativity. However, by only examining shared components, important neuro-cognitive correlates are overlooked. Here, we argue that any comprehensive brain model of creativity should consider multiple cognitive processes and, alongside the interplay between brain networks, also the neurochemistry and neural oscillations that underly creativity.


Subject(s)
Brain , Cognition , Creativity , Humans , Brain/physiology , Cognition/physiology , Nerve Net/physiology , Neural Pathways/physiology , Exploratory Behavior/physiology
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