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Introduction: Percussionists stand out for their expertise in rhythm, with the network for musical rhythm (NMR) serving a vital neurological function in their improvisation, which is deeply rooted in comprehensive musical knowledge. Our research examines the central representations of various improvisation tactics used by percussionists and investigates the interactions between the NMR and other relevant neural networks. Methods: Twenty-five percussionists participated in functional magnetic resonance imaging (fMRI) sessions, which included two cognitive strategies of improvisation. Structural improvisation (SIMP) emphasized rhythmic patterns, while free improvisation (FIMP) focused on musical spontaneity. Sight-reading scenario served as the reference condition. Paired t-tests were utilized for comparative analyses. Results: The findings revealed a dynamic interplay characterized by increased activity in the executive control network and NMR, along with decreased activity in the default mode network during SIMP. During FIMP, heightened activity was observed in the executive control network, NMR, limbic, and memory systems. In both SIMP vs. sight-reading and FIMP vs. sight-reading comparisons, the visual network's activity decreased, a trend also observed in the comparative analysis of FIMP vs. SIMP. Discussion: In SIMP, percussionists leverage external rhythmic signals, resulting in heightened NMR and ECN activity and reduced DMN activity. In contrast, FIMP is characterized by a rise in activity within the NMR, ECN, limbic system, memory system, and reward system, underscoring the vital roles of motivation and memory in the rapid production of spontaneous musical ideas within set frameworks. The diminished activity in the visual network during FIMP compared to SIMP suggests less reliance on visual stimuli in FIMP. These findings suggest that various improvisational tactics may engage different neural pathways.
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Background: Multidomain intervention may delay or ameliorate cognitive decline in older adults at risk of Alzheimer's disease, particularly in the memory and inhibitory functions. However, no study systematically investigates the changes of brain function in cognitively-normal elderly with subjective cognitive decline (SCD) when they receive multidomain intervention. Objective: We aimed to examine whether a multidomain intervention could improve neuropsychological function and neurophysiological activities related to memory and inhibitory function in SCD subjects. Methods: Eight clusters with a total of 50 community-dwelling SCD older adults were single-blind, randomized into intervention group, which received physical and cognitive training, or control group, which received treatment as usual. For the neuropsychological function, a composite Z score from six cognitive tests was calculated and compared between two groups. For the neurophysiological activities, event-related potentials (ERPs) of memory function, including mismatch negativity (MMN) and memory-P3, as well as ERPs of inhibitory function, including sensory gating (SG) and inhibition-P3, were measured. Assessments were performed at baseline (T1), end of the intervention (T2), and 6 months after T2 (T3). Results: For the neuropsychological function, the effect was not observed after the intervention. For the neurophysiological activities, improved MMN responses of ΔT2-T1 were observed in the intervention group versus the control group. The multidomain intervention produced a sustained effect on memory-P3 latencies of ΔT3-T1. However, there were no significant differences in changes of SG and inhibition-P3 between intervention and control groups. Conclusions: While not impactful on neuropsychological function, multidomain intervention enhances specific neurophysiological activities associated with memory function.
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Disfunção Cognitiva , Potenciais Evocados , Testes Neuropsicológicos , Idoso , Feminino , Humanos , Masculino , Terapia Cognitivo-Comportamental/métodos , Disfunção Cognitiva/terapia , Disfunção Cognitiva/reabilitação , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Treino Cognitivo , Eletroencefalografia , Terapia por Exercício , Memória , Método Simples-CegoRESUMO
Introduction: Dance education fosters embodied metacognition, enhancing student's creativity. This study examines the crucial role of functional connectivity (FC) between the neural correlates of metacognition (NCM) and dance (NCD) as the neurological foundation for dancers' embodied metacognition. The investigation also explores whether these consolidated FCs inform the general creativity in dancers. Methods: The research involved 29 dancers and 28 non-dancer controls. The study examined resting-state connections of the NCM through seed-based FC analysis. Correlation analyses were employed to investigate the connections between the targeted NCM-NCD FCs, initiated from the a priori NCM seed, and general creativity. Results: Dancers demonstrated heightened FC between NCM and NCD compared to non-dancer controls. The targeted regions included the putamen, globus pallidus, posterior cerebellum, and anterior insula of NCD. The dancers exhibited higher originality scores. In dancers, the enhanced FC showed a negative correlation with originality and a positive correlation with flexibility. Conversely, the controls exhibited no significant correlations. Discussion: Extended dance training enhances the NCM-NCD connection signifying embodied metacognition. This interconnectedness may serve as the neural predisposition for fostering general creativity performance in dancers. Dancers with heightened levels of originality could leverage the relatively weaker NCM-NCD FCs to facilitate better integration and coordination of creative cognitive processes. Our findings suggest that the consolidated functional connections as sculpted by domain-specific training may inform general creativity.
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Introduction: The main objective of this research is to explore the core cognitive mechanisms utilized by exceptionally skilled percussionists as they navigate complex rhythms. Our specific focus is on understanding the dynamic interactions among brain regions, respectively, related to externally directed cognition (EDC), internally directed cognition (IDC), and rhythm processing, defined as the neural correlates of rhythm processing (NCRP). Methods: The research involved 26 participants each in the percussionist group (PG) and control group (CG), who underwent task-functional magnetic resonance imaging (fMRI) sessions focusing on rhythm encoding and synchronization. Comparative analyses were performed between the two groups under each of these conditions. Results: Rhythmic encoding showed decreased activity in EDC areas, specifically in the right calcarine cortex, left middle occipital gyrus, right fusiform gyrus, and left inferior parietal lobule, along with reduced NCRP activity in the left dorsal premotor, right sensorimotor cortex, and left superior parietal lobule. During rhythmic synchronization, there was increased activity in IDC areas, particularly in the default mode network, and in NCRP areas including the left inferior frontal gyrus and bilateral putamen. Conversely, EDC areas like the right dorsolateral prefrontal gyrus, right superior temporal gyrus, right middle occipital gyrus, and bilateral inferior parietal lobule showed decreased activity, as did NCRP areas including the bilateral dorsal premotor cortex, bilateral ventral insula, bilateral inferior frontal gyrus, and left superior parietal lobule. Discussion: PG's rhythm encoding is characterized by reduced cognitive effort compared to CG, as evidenced by decreased activity in brain regions associated with EDC and the NCRP. Rhythmic synchronization reveals up-regulated IDC, down-regulated EDC involvement, and dynamic interplay among regions with the NCRP, suggesting that PG engages in both automatic and spontaneous processing simultaneously. These findings provide valuable insights into expert performance and present opportunities for improving music education.
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The recent development of closed-loop EEG phase-triggered transcranial magnetic stimulation (TMS) has advanced potential applications of adaptive neuromodulation based on the current brain state. Closed-loop TMS involves instantaneous acquisition of the EEG rhythm, timing prediction of the target phase, and triggering of TMS. However, the accuracy of EEG phase prediction algorithms is largely influenced by the system's transport delay, and their relationship is rarely considered in related work. This paper proposes a delay analysis that considers the delay of the closed-loop EEG phase-triggered TMS system as a primary factor in the validation of phase prediction algorithms. An in-silico validation using real EEG data was performed to compare the performance of commonly used algorithms. The experimental results indicate a significant influence of the total delay on the algorithm performance, and the performance ranking among algorithms varies at different levels of delay. We conclude that the delay analysis framework should be widely adopted in the design and validation of phase prediction algorithms for closed-loop EEG phase-triggered TMS systems.
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Eletroencefalografia , Estimulação Magnética Transcraniana , Estimulação Magnética Transcraniana/métodos , Eletroencefalografia/métodos , Encéfalo/fisiologia , AlgoritmosRESUMO
Emerging evidence has demonstrated that using a new manufacturing technology to produce γ-aminobutyric acid (GABA)-fortified oolong (GO) tea could relieve human stress and exert versatile physiological benefits. The purpose of this human study was to investigate the therapeutic effects of daily GO tea consumption on improvements in blood pressure, relaxation-related brain waves, and quality of life (QOL) over a period of 28 consecutive days. Total polyphenols, major catechins, and free amino acids were analyzed via an HPLC assay. Changes in heart rate, blood pressure, α brain waves (index of relaxation), and the eight-item QOL score were investigated on days 0, 7, 14, 21, and 28. The chemical analysis results showed that GO tea contained the most abundant amino acids and GABA, contributing to the relaxation activity. Among all study participants, the daily consumption of GO tea could reduce systolic blood pressure on day 21 and diastolic blood pressure on day 28 (p < 0.05 for both). For participants with pre-hypertension, GO tea could effectively reduce heart rate and systolic and diastolic blood pressure on day 28 (p < 0.05). At the end of the study, incremental changes in alpha brain waves and QOL scores were also demonstrated (p < 0.05 for both). This study suggests that GO tea might potentially serve as a natural source for alternative therapy to improve blood pressure, stress relief, and QOL.
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Introduction: This study aimed to examine the white matter characteristics of visual artists (VAs) in terms of visual creativity and the structural connectivity within the cortical visual system. Methods: Diffusion spectrum imaging was utilized to examine the changes in white matter within the cortical visual system of a group of VAs (n = 25) in comparison to a group of healthy controls matched for age and education (n = 24). To assess the integrity of white matter and its relationship with visual creativity, we conducted a comprehensive analysis using region-based and track-specific tractographic examinations. Results: Our study uncovered that VAs demonstrated increased normalized quantitative anisotropy in specific brain regions, including the right inferior temporal gyrus and right lateral occipital gyrus, along with the corresponding white matter fiber tracts connecting these regions. These enhancements within the cortical visual system were also found to be correlated with measures of visual creativity obtained through psychological assessments. Discussion: The noted enhancement in the white matter within the cortical visual system of VAs, along with its association with visual creativity, is consistent with earlier research demonstrating heightened functional connectivity in the same system among VAs. Our study's findings suggest a link between the visual creativity of VAs and structural alterations within the brain's visual system.
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[This corrects the article DOI: 10.3389/fnins.2023.1114771.].
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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.
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Introduction: Primary dysmenorrhea (PDM) is a common condition among women of reproductive age, characterized by menstrual pain in the absence of any organic causes. Previous research has established a link between the A118G polymorphism in the mu-opioid receptor (OPRM1) gene and pain experience in PDM. Specifically, carriers of the G allele have been found to exhibit maladaptive functional connectivity between the descending pain modulatory system and the motor system in young women with PDM. This study aims to explore the potential relationship between the OPRM1 A118G polymorphism and changes in white matter in young women with PDM. Methods: The study enrolled 43 individuals with PDM, including 13 AA homozygotes and 30 G allele carriers. Diffusion tensor imaging (DTI) scans were performed during both the menstrual and peri-ovulatory phases, and tract-based spatial statistics (TBSS) and probabilistic tractography were used to explore variations in white matter microstructure related to the OPRM1 A118G polymorphism. The short-form McGill Pain Questionnaire (MPQ) was used to access participants' pain experience during the MEN phase. Results: Two-way ANOVA on TBSS analysis revealed a significant main effect of genotype, with no phase effect or phase-gene interaction detected. Planned contrast analysis showed that during the menstrual phase, G allele carriers had higher fractional anisotropy (FA) and lower radial diffusivity in the corpus callosum and the left corona radiata compared to AA homozygotes. Tractographic analysis indicated the involvement of the left internal capsule, left corticospinal tract, and bilateral medial motor cortex. Additionally, the mean FA of the corpus callosum and the corona radiata was negatively correlated with MPQ scales in AA homozygotes, but this correlation was not observed in G allele carriers. No significant genotype difference was found during the pain-free peri-ovulary phase. Discussion: OPRM1 A118G polymorphism may influence the connection between structural integrity and dysmenorrheic pain, where the G allele could impede the pain-regulating effects of the A allele. These novel findings shed light on the underlying mechanisms of both adaptive and maladaptive structural neuroplasticity in PDM, depending on the specific OPRM1 polymorphism.
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BACKGROUND: Evidence has shown a rapid antidepressant and antisuicidal effects of low-dose ketamine infusion among patients with treatment-resistant depression (TRD) and prominent suicidal ideation (SI). The dorsolateral prefrontal cortex (DLPFC) plays a crucial role in the TRD pathomechanisms. OBJECTIVE: Whether the structural and functional changes of the DLPFC, particularly Brodmann area 46, are associated with the antidepressant and antisuicidal effects of ketamine infusion among such patients is unknown. METHODS: We randomized 48 patients with TRD and SI into groups receiving a single infusion of 0.5 mg/kg ketamine or 0.045 mg/kg midazolam. The Hamilton Depression Rating Scale and the Montgomery-Asberg Depression Rating Scale were used to assess symptoms. Positron emission tomography (PET)-magnetic resonance imaging was conducted prior to infusion and on Day 3 postinfusion. We performed longitudinal voxel-based morphometry (VBM) analysis to evaluate the gray matter (GM) volume changes of the DLPFC. The standardized uptake value ratio (SUVr) of 18F-fluorodeoxyglucose PET images was calculated using the SUV of the cerebellum as a reference region. RESULTS: The VBM analysis revealed a small but significant volumetric reduction in the right DLPFC in the ketamine group compared with that in the midazolam group. A greater reduction in depressive symptoms was associated with a smaller decrease in right DLPFC volumes (p = 0.025). However, we found no SUVr changes of the DLPFC between baseline and post-Day 3 ketamine infusion. DISCUSSION: The optimal modulation of the right DLPFC GM volumes may play an essential role in the antidepressant neuromechanisms of low-dose ketamine.
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Transtorno Depressivo Resistente a Tratamento , Ketamina , Humanos , Córtex Pré-Frontal Dorsolateral , Midazolam/uso terapêutico , Imageamento por Ressonância Magnética , Antidepressivos/uso terapêutico , Método Duplo-Cego , Transtorno Depressivo Resistente a Tratamento/diagnóstico por imagem , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/patologia , Tomografia por Emissão de Pósitrons , Resultado do TratamentoRESUMO
This study aimed to explore the efficacy of single and combined effects of exercise and branched-chain amino acid (BCAA) supplements on improving frailty and quality of life in older adults. In total, 120 study participants were allocated into a combined exercise-and-BCAA supplementation group, an exercise-only group, a BCAA supplementation-only group, and a control group. Results showed that Fried's frailty score significantly decreased in the combined exercise-and-BCAA supplementation group (ß= -1.73, p<0.001), exercise-only group (ß= -1.68, p<0.001), and BCAA supplementation-only group (ß= -0.73, p=0.005) compared to the control group. Moreover, the combination of exercise and BCAA supplements and the exercise-only program produced significant improvements in frailty compared to the BCAA supplement-only group and control group (p<0.05). Exercise should be a critical approach for older adults to improve frailty. Healthcare professionals in geriatric care should incorporate exercise programs as frailty management and prevention for older adults.
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Fragilidade , Humanos , Idoso , Idoso Fragilizado , Qualidade de Vida , Exercício Físico , Aminoácidos de Cadeia Ramificada , Suplementos NutricionaisRESUMO
BACKGROUND: Whether cortical excitation and inhibition functions differ between patients with treatment-resistant depression (TRD) and strong suicidal ideation (SI) and healthy subjects and whether 0.5 mg/kg ketamine infusion can modulate cortical excitation and inhibition functions among patients with TRD-SI remain unclear. METHODS: A total of 29 patients with TRD-SI and 35 age- and sex-matched healthy controls were assessed using paired-pulse transcranial magnetic stimulation. The patients were randomly assigned to receive either a single 0.5-mg/kg ketamine or 0.045-mg/kg midazolam infusion. Depressive and suicidal symptoms were assessed at baseline and 240 min after infusion. Intracortical facilitation (ICF), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI), all of which reflect cortical excitability and inhibition functions, were measured at the same time points. RESULTS: The patients with TRD-SI had lower ICF (p < 0.001) estimates (worse cortical excitatory function) and higher SICI (p = 0.032) and LICI (p < 0.001) estimates (worse cortical inhibitory function) compared with the control group. Higher SICI estimates at baseline were associated with greater baseline suicidal symptoms. No differences were found in the SICI, ICF, and LICI estimates at 240 min after the infusion between the two groups. Low-dose ketamine did not alter the cortical excitation and inhibition functions of the patients with TRD-SI. However, decreased SICI estimates (greater cortical inhibition function) were related to the reduction of suicidal symptoms. DISCUSSION: Dysfunction of cortical excitation and inhibition may play a crucial role in the pathomechanisms of TRD and suicidal symptoms. However, we found a lack of predictive ability of the baseline cortical excitation and inhibition parameters on the antidepressant and antisuicidal effect of low-dose ketamine infusion.
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Ketamina , Ideação Suicida , Humanos , Ketamina/farmacologia , Ketamina/uso terapêutico , Depressão , Antidepressivos , Estimulação Magnética Transcraniana , Inibição Neural/fisiologia , Potencial Evocado Motor/fisiologiaRESUMO
Introduction: This study sought to elucidate the cognitive traits of visual artists (VAs) from the perspective of visual creativity and the visual system (i.e., the most fundamental neural correlate). Methods: We examined the local and long-distance intrinsic functional connectivity (FC) of the visual system to unravel changes in brain traits among VAs. Twenty-seven university students majoring in visual arts and 27 non-artist controls were enrolled. Results: VAs presented enhanced local FC in the right superior parietal lobule, right precuneus, left inferior temporal gyrus (ITG), left superior parietal lobule, left angular gyrus, and left middle occipital gyrus. VAs also presented enhanced FC with the ITG that targeted the visual area (occipital gyrus and cuneus), which appears to be associated with visual creativity. Discussion: The visual creativity of VAs was correlated with strength of intrinsic functional connectivity in the visual system. Learning-induced neuroplasticity as a trait change observed in VAs can be attributed to the macroscopic consolidation of consociated neural circuits that are engaged over long-term training in the visual arts and aesthetic experience. The consolidated network can be regarded as virtuoso-specific neural fingerprint.
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BACKGROUND: The benefits of low-dose ketamine for patients with treatment-resistant depression (TRD) and prominent suicidal ideation require further investigation. The effects of treatment refractoriness, the duration of the current depressive episode, and the number of prior antidepressant failures on ketamine efficacy also require clarification. METHODS: We recruited 84 outpatients with TRD and prominent suicidal ideation-defined as a score ≥4 on item 10 of the Montgomery-Åsberg Depression Rating Scale (MADRS)-and randomized them into 2 groups to receive 0.5 mg/kg ketamine or 0.045 mg/kg midazolam. We assessed depressive and suicidal symptoms prior to infusion; 240 minutes post infusion; and 2, 3, 5, 7, and 14 days post infusion. RESULTS: According to the MADRS scores, the antidepressant effect (P = .035) was significantly noted in the ketamine group up to 14 days than in the midazolam group. However, the antisuicidal effect of ketamine, as measured by the Columbia-Suicide Severity Rating Scale Ideation Severity Subscale (P = .040) and MADRS item 10 (P = .023), persisted only 5 days post infusion. Furthermore, the antidepressant and antisuicidal effects of ketamine infusion were noted particularly in patients whose current depressive episode lasted <24 months or whose number of failed antidepressants was ≤4. CONCLUSIONS: Low-dose ketamine infusion is a safe, tolerable, and effective treatment for patients with TRD and prominent suicidal ideation. Our study highlights the importance of timing; specifically, ketamine is more likely to achieve therapeutic response when the current depressive episode lasted <24 months and the number of failed antidepressants is ≤4.
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Transtorno Depressivo Maior , Transtorno Depressivo Resistente a Tratamento , Ketamina , Humanos , Ideação Suicida , Ketamina/efeitos adversos , Midazolam/uso terapêutico , Depressão , Transtorno Depressivo Maior/tratamento farmacológico , Resultado do Tratamento , Antidepressivos/uso terapêutico , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/diagnóstico , Método Duplo-CegoRESUMO
Introduction: Primary dysmenorrhea (PDM), the most prevalent gynecological problem among women of reproductive age, presents as a regular pattern of cyclic menstrual pain. The presence or absence of central sensitization (i.e., pain hypersensitivity) in cases of PDM is a contentious issue. Among Caucasians, the presence of dysmenorrhea is associated with pain hypersensitivity throughout the menstrual cycle, indicating pain amplification mediated by the central nervous system. We previously reported on the absence of central sensitization to thermal pain among Asian PDM females. In this study, functional magnetic resonance imaging was used to reveal mechanisms underlying pain processing with the aim of explaining the absence of central sensitization in this population. Methods: Brain responses to noxious heat applied to the left inner forearm of 31 Asian PDM females and 32 controls during their menstrual and periovulatory phases were analyzed. Results and discussion: Among PDM females experiencing acute menstrual pain, we observed a blunted evoked response and de-coupling of the default mode network from the noxious heat stimulus. The fact that a similar response was not observed in the non-painful periovulatory phase indicates an adaptive mechanism aimed at reducing the impact of menstrual pain on the brain with an inhibitory effect on central sensitization. Here we propose that adaptive pain responses in the default mode network may contribute to the absence of central sensitization among Asian PDM females. Variations in clinical manifestations among different PDM populations can be attributed to differences in central pain processing.
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Numerous studies have reported that long-term musical training can affect brain functionality and induce structural alterations in the brain. Singing is a form of vocal musical expression with an unparalleled capacity for communicating emotion; however, there has been relatively little research on neuroplasticity at the network level in vocalists (i.e., noninstrumental musicians). Our objective in this study was to elucidate changes in the neural network architecture following long-term training in the musical arts. We employed a framework based on graph theory to depict the connectivity and efficiency of structural networks in the brain, based on diffusion-weighted images obtained from 35 vocalists, 27 pianists, and 33 nonmusicians. Our results revealed that musical training (both voice and piano) could enhance connectivity among emotion-related regions of the brain, such as the amygdala. We also discovered that voice training reshaped the architecture of experience-dependent networks, such as those involved in vocal motor control, sensory feedback, and language processing. It appears that vocal-related changes in areas such as the insula, paracentral lobule, supramarginal gyrus, and putamen are associated with functional segregation, multisensory integration, and enhanced network interconnectivity. These results suggest that long-term musical training can strengthen or prune white matter connectivity networks in an experience-dependent manner.
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Música , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Plasticidade Neuronal , EmoçõesRESUMO
Major depressive disorder (MDD) and bipolar disorder (BD) are two major mood disorders with partly overlapped symptoms but different treatments. However, their misdiagnosis and mistreatment are common based on the DSM-V criteria, lacking objective and quantitative indicators. This study aimed to develop a novel approach that accurately classifies MDD and BD based on their resting-state magnetoencephalography (MEG) signals during euthymic phases. A revisited 3D CNN model, Semi-CNN, that could automatically detect brainwave patterns in spatial, temporal, and frequency domains was implemented to classify wavelet-transformed MEG signals of normal controls and MDD and BD patients. The model achieved a test accuracy of 96.05% and an average of 95.71% accuracy for 5-fold cross-validation. Furthermore, saliency maps of the model were estimated using Grad-CAM++ to visualize the proposed classification model and highlight disease-specific brain regions and frequencies. Clinical Relevance - Our model provides a stable pipeline that accurately classifies MDD, BD, and healthy individuals based on resting-state MEG signals during the euthymic phases, opening the potential for quantitative and accurate brain-based diagnosis for the highly misdiagnosed MDD/BD patients.
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Transtorno Bipolar , Transtorno Depressivo Maior , Transtorno Bipolar/diagnóstico , Encéfalo/diagnóstico por imagem , Transtorno Depressivo Maior/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Humanos , MagnetoencefalografiaRESUMO
Purpose: Retinopathy screening via digital imaging is promising for early detection and timely treatment, and tracking retinopathic abnormality over time can help to reveal the risk of disease progression. We developed an innovative physician-oriented artificial intelligence-facilitating diagnosis aid system for retinal diseases for screening multiple retinopathies and monitoring the regions of potential abnormality over time. Approach: Our dataset contains 4908 fundus images from 304 eyes with image-level annotations, including diabetic retinopathy, age-related macular degeneration, cellophane maculopathy, pathological myopia, and healthy control (HC). The screening model utilized a VGG-based feature extractor and multiple-binary convolutional neural network-based classifiers. Images in time series were aligned via affine transforms estimated through speeded-up robust features. Heatmaps of retinopathy were generated from the feature extractor using gradient-weighted class activation mapping++, and individual candidate retinopathy sites were identified from the heatmaps using clustering algorithm. Nested cross-validation with a train-to-test split of 80% to 20% was used to evaluate the performance of the screening model. Results: Our screening model achieved 99% accuracy, 93% sensitivity, and 97% specificity in discriminating between patients with retinopathy and HCs. For discriminating between types of retinopathy, our model achieved an averaged performance of 80% accuracy, 78% sensitivity, 94% specificity, 79% F1-score, and Cohen's kappa coefficient of 0.70. Moreover, visualization results were also shown to provide reasonable candidate sites of retinopathy. Conclusions: Our results demonstrated the capability of the proposed model for extracting diagnostic information of the abnormality and lesion locations, which allows clinicians to focus on patient-centered treatment and untangles the pathological plausibility hidden in deep learning models.