RESUMO
Alcoholic beverages flavour is complex and unique with different alcohol content, and the application of flavour perception could improve the objectivity of flavour evaluation. This study utilized electroencephalogram (EEG) to assess brain reactions to alcohol percentages (5 %-53 %) and Baijiu's complex flavours. The findings demonstrate the brain's proficiency in discerning between alcohol concentrations, evidenced by increasing physiological signal strength in tandem with alcohol content. When contrasted with alcohol solutions of equivalent concentrations, Baijiu prompts a more significant activation of brain signals, underscoring EEG's capability to detect subtleties due to flavour complexity. Additionally, the study reveals notable correlations, with δ and α wave intensities escalating in response to alcohol stimulation, coupled with substantial activation in the frontal, parietal, and right temporal regions. These insights verify the efficacy of EEG in charting the brain's engagement with alcoholic flavours, setting the stage for more detailed exploration into the neural encoding of these sensory experiences.
Assuntos
Bebidas Alcoólicas , Encéfalo , Eletroencefalografia , Etanol , Humanos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Encéfalo/metabolismo , Adulto , Bebidas Alcoólicas/análise , Masculino , Adulto Jovem , Feminino , Etanol/análise , Paladar , Aromatizantes/química , Percepção GustatóriaRESUMO
Working memory (WM) is essential for the temporary storage and processing of information required for complex cognitive tasks and relies on neuronal theta and gamma oscillations. Given the limited capacity of WM, researchers have investigated various methods to improve it, including transcranial alternating current stimulation (tACS), which modulates brain activity at specific frequencies. One particularly promising approach is theta-gamma peak-coupled-tACS (TGCp-tACS), which simulates the natural interaction between theta and gamma oscillations that occurs during cognitive control in the brain. The aim of this study was to improve WM in healthy young adults with TGCp-tACS, focusing on both behavioral and neurophysiological outcomes. Thirty-one participants completed five WM tasks under both sham and verum stimulation conditions. Electroencephalography (EEG) recordings before and after stimulation showed that TGCp-tACS increased power spectral density (PSD) in the high-gamma region at the stimulation site, while PSD decreased in the theta and delta regions throughout the cortex. From a behavioral perspective, although no significant changes were observed in most tasks, there was a significant improvement in accuracy in the 14-item Sternberg task, indicating an improvement in phonological WM. In conclusion, TGCp-tACS has the potential to promote and improve the phonological component of WM. To fully realize the cognitive benefits, further research is needed to refine the stimulation parameters and account for individual differences, such as baseline cognitive status and hormonal factors.
Assuntos
Memória de Curto Prazo , Estimulação Transcraniana por Corrente Contínua , Humanos , Memória de Curto Prazo/fisiologia , Masculino , Feminino , Adulto Jovem , Estimulação Transcraniana por Corrente Contínua/métodos , Ritmo Teta/fisiologia , Ritmo Gama/fisiologia , Eletroencefalografia , Adulto , Estimulação Elétrica , Comportamento/fisiologiaRESUMO
Brain Complexity (BC) have successfully been applied to study the brain electroencephalographic signal (EEG) in health and disease. In this study, we employed recurrence entropy to quantify BC associated with the neurophysiology of movement by comparing BC in both resting state and cycling movement. We measured EEG in 24 healthy adults and placed the electrodes on occipital, parietal, temporal and frontal sites on both the right and left sides of the brain. We computed the recurrence entropy from EEG measurements during cycling and resting states. Entropy is higher in the resting state than in the cycling state for all brain regions analysed. This reduction in complexity is a result of the repetitive movements that occur during cycling. These movements lead to continuous sensorial feedback, resulting in reduced entropy and sensorimotor processing.
Assuntos
Eletroencefalografia , Entropia , Humanos , Adulto , Masculino , Feminino , Córtex Cerebral/fisiologia , Neurônios/fisiologia , Adulto Jovem , Ciclismo/fisiologia , Movimento/fisiologia , Descanso/fisiologiaRESUMO
Electroencephalography (EEG) has been used for almost a century in well-equipped medical centers to facilitate the diagnosis of epilepsy and other brain disorders. Lassa fever (LF) and other emerging viral infections (EVI) are known to cause neurological complications, including meningitis, seizures, and encephalopathy, though to date it remains unclear whether these are secondary to metabolic disturbances caused by the disease or by direct involvement of the central nervous system (CNS). To better characterize how Lassa virus (LASV) affects the CNS, we established an EEG diagnostic unit in the LF isolation ward at Irrua Specialist Teaching Hospital in Edo State, Nigeria. Here, we report on the specific difficulties to successful implementation of EEG in this highly challenging setting. Technical artefacts due to electrical interferences and interrupted power supply, artefacts deriving from a partly improvised EEG setup within a high consequence pathogen isolation ward, and environmental factors, such as heat in the endemic West African setting are among the main difficulties encountered when setting up this diagnostic facility. It takes experienced neurophysiologists to distinguish such artefacts from actual EEG abnormalities as many of them are not commonly encountered to this extent in well-equipped EEG laboratories and can easily be confused with pathologies. The EEG recording process is further complicated by biosafety considerations and the necessity of wearing extensive personal protective equipment. Nevertheless, with the help of experienced neurophysiologists, it is possible to correctly set up the facility and interpret recordings. Taking the above into consideration, EEG is valuable in identifying CNS involvement in emerging infections, particularly regarding assessment of encephalitis, differential diagnosis of impaired consciousness and treatment adjustment in patients with symptomatic seizures. Although highly challenging under these circumstances, EEG can be an important, noninvasive diagnostic tool for neurological complications in EVI where other more advanced imaging modalities are not available.
Assuntos
Eletroencefalografia , Febre Lassa , Humanos , Febre Lassa/diagnóstico , Nigéria , Eletroencefalografia/métodos , Vírus Lassa/isolamento & purificação , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/virologia , Masculino , Feminino , AdultoRESUMO
This study investigates the role of morphology during speech planning in Mandarin Chinese. In a long-lag priming experiment, thirty-two Mandarin Chinese native speakers were asked to name target pictures (e.g., "" /shan1/ "mountain"). The design involved pictures referring to morpheme-related compound words (e.g., "" /shan1yang2/ "goat") sharing a morpheme with the first (e.g., "" /shan1/ "mountain") or the second position of the targets (e.g., /nao3/ "brain" with prime /dian4nao3/ "computer"), as well as unrelated control items. Behavioral and electrophysiological data were collected. Interestingly, the behavioral results went against earlier findings in Indo-European languages, showing that the target picture naming was not facilitated by morphologically related primes. This suggests no morphological priming for individual constituents in producing Mandarin Chinese disyllabic compound words. However, targets in the morpheme-related word condition did elicit a reduced N400 compared with targets in the morpheme-unrelated condition for the first position overlap in the ERP analyses but not for the second, suggesting automatic activation of the first individual constituent in noun compound production. Implications of these findings are discussed.
Assuntos
Idioma , Fala , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Fala/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Povo Asiático , China , Tempo de Reação/fisiologia , População do Leste AsiáticoRESUMO
INTRODUCTION: Seizures are the most common neurological emergency and one of the most common reasons for paediatrics hospital admissions. This study aimed to identify the etiology, clinical profile, and immediate outcome of children with the first episode of seizure in Eastern Nepal. METHODS: This was a prospective descriptive study carried out in the Tertiary Care Centre from September 2022 to August 2023. Ethical clearance was taken from the Institutional Review Committee (Ref no:654/2022). Convenience sampling was done to include 170 children presenting with the first episode of seizure at age 6 months to 15 years. Variables collected were demographics, clinical presentations, family history, trauma history, laboratory tests, neuroimaging, EEG, final diagnosis, and immediate outcome. RESULTS: A total of 170 patients were admitted with the first episode of seizure with 123 (72.36%) males and 47 (27.64%) females. The mean age of the patients was 5.13±2.95 years with 104 (61.18%) patients under 5 years of age. The most common seizure was generalized tonic-clonic type in 132 (77.64%) patients. The most common associated symptom was fever in 150 (88.23%) children. Neuroimaging was abnormal in 52 (30.59%) patients, with neurocysticercosis seen in 27 (15.88%). The most common etiology was febrile seizure in 92 (54.17%) patients, neurocysticercosis in 27 (15.88%), and meningitis in 12 (7.05%). CONCLUSIONS: Febrile seizures, neurocysticercosis, infection, and trauma were the major causes of seizures in children. When simple febrile seizures were unlikely, lumbar puncture, neuroimaging, and laboratory tests were useful tools for diagnosing etiologies of seizures.
Assuntos
Convulsões , Centros de Atenção Terciária , Humanos , Feminino , Masculino , Pré-Escolar , Criança , Nepal/epidemiologia , Estudos Transversais , Lactente , Estudos Prospectivos , Convulsões/epidemiologia , Convulsões/etiologia , Convulsões/diagnóstico , Adolescente , Neurocisticercose/complicações , Neurocisticercose/epidemiologia , Neurocisticercose/diagnóstico , Neuroimagem , Eletroencefalografia , Febre/etiologia , Febre/epidemiologia , Meningite/epidemiologia , Meningite/diagnóstico , Meningite/complicaçõesRESUMO
BACKGROUND: High levels of physical conditioning are associated with improvements in cognitive performance. In this sense, electroencephalographic (ECG) correlates are used to investigate the enhancing role of physical exercise on executive functions. Oscillations in the ß frequency range are proposed to be evident during sensorimotor activity. OBJECTIVE: To investigate the ECG changes influenced by aerobic and resistance exercises performed in an attention task by analyzing the differences in absolute ß power in the prefrontal and frontal regions before, during, and after the oddball paradigm in practitioners and nonpractitioners of physical exercise. METHODS: There were 15 physical activity practitioners (aged 27 ± 4.71) and 15 nonpractitioners (age 28 ± 1.50) recruited. A two-way analysis of variance (ANOVA) was implemented to observe the main effect and the interaction between groups and moments (rest 1, pre-stimulus, and rest 2). RESULTS: An interaction between group and moment factors was observed for Fp1 (p < 0.001); Fp2 (p = 0.001); F7 (p < 0.001); F8 (p < 0.001); F3 (p < 0.001); Fz (p < 0.001); and F4 (p < 0.001). Electrophysiological findings clarified exercisers' specificity and neural efficiency in each prefrontal and frontal subarea. CONCLUSION: Our findings lend support to the current understanding of the cognitive processes underlying physical exercise and provide new evidence on the relationship between exercise and cortical activity.
ANTECEDENTES: Níveis elevados de condicionamento físico estão associados a melhorias no desempenho cognitivo. Nesse sentido, correlatos eletroencefalográficos são utilizados na investigação do papel aprimorador do exercício físico sobre as funções executivas. Tem sido proposto que as oscilações na faixa de frequência ß são evidenciadas durante a atividade sensório-motora. OBJETIVO: Investigar as alterações eletroencefalográficas influenciadas por exercícios aeróbio e resistido realizados em uma tarefa atencional analisando as diferenças da potência absoluta de ß nas regiões pré-frontal e frontal antes, na preparação e depois do paradigma oddball em praticantes e não praticantes de exercício físico. MéTODOS: Foram recrutados 15 praticantes de atividade física (idade 27 ± 4.71) e 15 não praticantes (idade 28 ± 1.50). Uma análise de variância (ANOVA) de duas vias foi implementada para observação do efeito principal e a interação entre os grupos e os momentos (repouso 1, pré-estímulo e repouso 2). RESULTADOS: Uma interação entre os fatores grupo e momento para Fp1 (p < 0,001); Fp2 (p = 0,001); F7 (p < 0,001); F8 (p < 0,001); F3 (p < 0,001); Fz (p < 0,001); e F4 (p < 0,001) foi observada. Os achados eletrofisiológicos esclareceram a especificidade e a eficiência neural dos praticantes de exercício físico em cada subárea pré-frontal e frontal. CONCLUSãO: Nossos achados promovem o entendimento atual dos processos cognitivos subjacentes ao exercício físico e acrescentam novas evidências sobre a relação exercício e atividade cortical.
Assuntos
Ritmo beta , Exercício Físico , Humanos , Adulto , Masculino , Exercício Físico/fisiologia , Análise de Variância , Ritmo beta/fisiologia , Feminino , Adulto Jovem , Atenção/fisiologia , Córtex Pré-Frontal/fisiologia , Cognição/fisiologia , Função Executiva/fisiologia , Fatores de Tempo , Eletroencefalografia , EletrocardiografiaRESUMO
Delirium is a multifactorial medical condition of waxing and waning impairment across various domains of mental functioning over time. Importantly, delirium is also one of the greatest risk factors for prolonged hospitalization, morbidity, and mortality. Studying this important condition is challenging due to the difficulty in both objective diagnosis in patients and validation of laboratory models. As a result, there is a lack of protective treatments for delirium. Our recent studies report the efficacy of bispectral electroencephalography (BSEEG) in diagnosing delirium in patients and predicting patient outcomes, advancing the concept that this simple measure could represent an additional vital sign for patients. Here, we applied BSEEG to characterize and validate a novel lipopolysaccharide (LPS) mouse model of infection-related delirium. We then applied this model to evaluate the protective efficacy of three putative therapeutic agents: the conventional antipsychotic medication haloperidol, the neuroprotective compound P7C3-A20, and the antibiotic minocycline. Aged mice were more susceptible than young mice to LPS-induced aberration in BSEEG, reminiscent of the greater vulnerability of older adults to delirium. In both young and old mice, P7C3-A20 and minocycline administration prevented LPS-induced BSEEG abnormality. By contrast, haloperidol did not. P7C3-A20 and minocycline have been shown to limit different aspects of LPS toxicity, and our data offers proof of principle that these agents might help protect patients from developing infection-related delirium. Thus, utilization of BSEEG in a mouse model for infection-related delirium can identify putative therapeutic agents for applications in patient clinical trials.
Assuntos
Delírio , Modelos Animais de Doenças , Eletroencefalografia , Lipopolissacarídeos , Animais , Camundongos , Delírio/tratamento farmacológico , Masculino , Minociclina/farmacologia , Haloperidol/farmacologia , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Antipsicóticos/farmacologiaRESUMO
Chronobiological rhythms, such as the circadian rhythm, have long been linked to neurological disorders, but it is currently unknown how pathological processes affect the expression of biological rhythms in the brain. Here, we use the unique opportunity of long-term, continuous intracranially recorded EEG from 38 patients (totalling 6338 hours) to delineate circadian (daily) and ultradian (minute to hourly) rhythms in different brain regions. We show that functional circadian and ultradian rhythms are diminished in pathological tissue, independent of regional variations. We further demonstrate that these diminished rhythms are persistent in time, regardless of load or occurrence of pathological events. These findings provide evidence that brain pathology is functionally associated with persistently diminished chronobiological rhythms in vivo in humans, independent of regional variations or pathological events. Future work interacting with, and restoring, these modulatory chronobiological rhythms may allow for novel therapies.
Assuntos
Encéfalo , Ritmo Circadiano , Ritmo Ultradiano , Humanos , Ritmo Circadiano/fisiologia , Encéfalo/fisiopatologia , Encéfalo/metabolismo , Masculino , Feminino , Ritmo Ultradiano/fisiologia , Pessoa de Meia-Idade , Adulto , Eletroencefalografia , IdosoRESUMO
Disruption of SYNGAP1 directly causes a genetically identifiable neurodevelopmental disorder (NDD) called SYNGAP1-related intellectual disability (SRID). Without functional SynGAP1 protein, individuals are developmentally delayed and have prominent features of intellectual disability (ID), motor impairments, and epilepsy. Over the past two decades, there have been numerous discoveries indicating the critical role of Syngap1. Several rodent models with a loss of Syngap1 have been engineered, identifying precise roles in neuronal structure and function, as well as key biochemical pathways key for synapse integrity. Homozygous loss of SYNGAP1/Syngap1 is lethal. Heterozygous mutations of Syngap1 result in a broad range of behavioral phenotypes. Our in vivo functional data, using the original mouse model from the Huganir laboratory, corroborated behaviors including robust hyperactivity and deficits in learning and memory in young adults. Furthermore, we described impairments in the domain of sleep, characterized using neurophysiological data that was collected with wireless, telemetric electroencephalography (EEG). Syngap1+/- mice exhibited elevated spiking events and spike trains, in addition to elevated power, most notably in the delta power frequency. For the first time, we illustrated that primary neurons from Syngap1+/- mice displayed: 1) increased network firing activity, 2) greater bursts, 3) and shorter inter-burst intervals between peaks, by utilizing high density microelectrode arrays (HD-MEA). Our work bridges in vitro electrophysiological neuronal activity and function with in vivo neurophysiological brain activity and function. These data elucidate quantitative, translational biomarkers in vivo and in vitro that can be utilized for the development and efficacy assessment of targeted treatments for SRID.
Assuntos
Modelos Animais de Doenças , Deficiência Intelectual , Fenótipo , Proteínas Ativadoras de ras GTPase , Animais , Deficiência Intelectual/genética , Deficiência Intelectual/fisiopatologia , Camundongos , Proteínas Ativadoras de ras GTPase/genética , Eletroencefalografia , Neurônios/fisiologia , Masculino , Comportamento Animal , FemininoRESUMO
Mu rhythm (â¼8-12 Hz) in the somatosensory cortex has traditionally been linked with doing and seeing motor activities. Here, we aimed to learn how the medium (physical or screened) in which motor actions are seen could impact on that specific brain rhythm. To do so, we presented to 40 participants the very same narrative content both in a one-shot movie with no cuts and in a real theatrical performance. We recorded subjects' brain activities with electroencephalographic (EEG) procedures, and analyzed Mu rhythm present in left (C3) and right (C4) somatosensory areas in relation to the 24 motor activities included in each visual stimulus (screen vs. reality) (24 motor and grasping actions x 40 participants x 2 conditions = 1920 trials). We found lower Mu spectral power in the somatosensory area after the onset of the motor actions in real performance than on-screened content, more pronounced in the left hemisphere. In our results, the sensorimotor Mu-ERD (event-related desynchronization) was stronger during the real-world observation compared to screen observation. This could be relevant in research areas where the somatosensory cortex is important, such as online learning, virtual reality, or brain-computer interfaces.
Assuntos
Eletroencefalografia , Força da Mão , Córtex Somatossensorial , Humanos , Masculino , Feminino , Adulto , Eletroencefalografia/métodos , Córtex Somatossensorial/fisiologia , Força da Mão/fisiologia , Adulto Jovem , Desempenho Psicomotor/fisiologia , Estimulação Luminosa , Ondas Encefálicas/fisiologia , Percepção Visual/fisiologia , Interfaces Cérebro-Computador , Atividade Motora/fisiologiaRESUMO
BACKGROUND: Structural income inequality - the uneven income distribution across regions or countries - could affect brain structure and function, beyond individual differences. However, the impact of structural income inequality on the brain dynamics and the roles of demographics and cognition in these associations remains unexplored. METHODS: Here, we assessed the impact of structural income inequality, as measured by the Gini coefficient on multiple EEG metrics, while considering the subject-level effects of demographic (age, sex, education) and cognitive factors. Resting-state EEG signals were collected from a diverse sample (countries = 10; healthy individuals = 1394 from Argentina, Brazil, Colombia, Chile, Cuba, Greece, Ireland, Italy, Turkey and United Kingdom). Complexity (fractal dimension, permutation entropy, Wiener entropy, spectral structure variability), power spectral and aperiodic components (1/f slope, knee, offset), as well as graph-theoretic measures were analysed. FINDINGS: Despite variability in samples, data collection methods, and EEG acquisition parameters, structural inequality systematically predicted electrophysiological brain dynamics, proving to be a more crucial determinant of brain dynamics than individual-level factors. Complexity and aperiodic activity metrics captured better the effects of structural inequality on brain function. Following inequality, age and cognition emerged as the most influential predictors. The overall results provided convergent multimodal metrics of biologic embedding of structural income inequality characterised by less complex signals, increased random asynchronous neural activity, and reduced alpha and beta power, particularly over temporoposterior regions. CONCLUSION: These findings might challenge conventional neuroscience approaches that tend to overemphasise the influence of individual-level factors, while neglecting structural factors. Results pave the way for neuroscience-informed public policies aimed at tackling structural inequalities in diverse populations.
Assuntos
Encéfalo , Eletroencefalografia , Humanos , Masculino , Feminino , Encéfalo/fisiologia , Adulto , Eletroencefalografia/métodos , Eletroencefalografia/estatística & dados numéricos , Pessoa de Meia-Idade , Fatores Socioeconômicos , Adulto Jovem , Cognição/fisiologia , Renda/estatística & dados numéricos , IdosoRESUMO
BACKGROUND: Multiple system atrophy (MSA) is recognized as an atypical Parkinsonian syndrome, distinguished by a more rapid progression than that observed in Parkinson's disease. Unfortunately, the prognosis for MSA remains poor, with a notable absence of globally recognized effective treatments. Although preliminary studies suggest that transcranial magnetic stimulation (TMS) could potentially alleviate clinical symptoms in MSA patients, there is a significant gap in the literature regarding the optimal stimulation parameters. Furthermore, the field lacks consensus due to the paucity of robust, large-scale, multicenter trials. METHODS: This investigation is a multi-center, randomized, double-blind, sham-controlled trial. We aim to enroll 96 individuals diagnosed with MSA, categorized into Parkinsonian type (MSA-P) and cerebellar type (MSA-C) according to their predominant clinical features. Participants will be randomly allocated in a 1:1 ratio to either the TMS or sham stimulation group. Utilizing advanced navigation techniques, we will ensure precise targeting for the intervention, applying theta burst stimulation (TBS). To assess the efficacy of TBS on both motor and non-motor functions, a comprehensive evaluation will be conducted using internationally recognized clinical scales and gait analysis. To objectively assess changes in brain connectivity, functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) will be employed as sensitive indicators before and after the intervention. DISCUSSION: The primary aim of this study is to ascertain whether TBS can alleviate both motor and non-motor symptoms in patients with MSA. Additionally, a critical component of our research involves elucidating the underlying mechanisms through which TBS exerts its potential therapeutic effects. ETHICS AND DISSEMINATION: All study protocols have been reviewed and approved by the First Affiliated Medical Ethics Committee of the Air Force Military Medical University (KY20232118-F-1). TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300072658. Registered on 20 June 2023.
Assuntos
Atrofia de Múltiplos Sistemas , Estimulação Magnética Transcraniana , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método Duplo-Cego , Eletroencefalografia , Imageamento por Ressonância Magnética , Estudos Multicêntricos como Assunto , Atrofia de Múltiplos Sistemas/terapia , Atrofia de Múltiplos Sistemas/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Estimulação Magnética Transcraniana/métodos , Resultado do TratamentoRESUMO
Within species, vocal and auditory systems presumably coevolved to converge on a critical temporal acoustic structure that can be best produced and perceived. While dogs cannot produce articulated sounds, they respond to speech, raising the question as to whether this heterospecific receptive ability could be shaped by exposure to speech or remains bounded by their own sensorimotor capacity. Using acoustic analyses of dog vocalisations, we show that their main production rhythm is slower than the dominant (syllabic) speech rate, and that human-dog-directed speech falls halfway in between. Comparative exploration of neural (electroencephalography) and behavioural responses to speech reveals that comprehension in dogs relies on a slower speech rhythm tracking (delta) than humans' (theta), even though dogs are equally sensitive to speech content and prosody. Thus, the dog audio-motor tuning differs from humans', and we hypothesise that humans may adjust their speech rate to this shared temporal channel as means to improve communication efficacy.
Assuntos
Fala , Vocalização Animal , Animais , Cães , Humanos , Vocalização Animal/fisiologia , Fala/fisiologia , Masculino , Feminino , Eletroencefalografia , Percepção Auditiva/fisiologia , Adulto , Interação Humano-Animal , Estimulação Acústica , Percepção da Fala/fisiologiaRESUMO
Flexible action selection requires cognitive control mechanisms capable of mapping the same inputs to different output actions depending on the context. From a neural state-space perspective, this requires a control representation that separates similar input neural states by context. Additionally, for action selection to be robust and time-invariant, information must be stable in time, enabling efficient readout. Here, using EEG decoding methods, we investigate how the geometry and dynamics of control representations constrain flexible action selection in the human brain. Participants performed a context-dependent action selection task. A forced response procedure probed action selection different states in neural trajectories. The result shows that before successful responses, there is a transient expansion of representational dimensionality that separated conjunctive subspaces. Further, the dynamics stabilizes in the same time window, with entry into this stable, high-dimensional state predictive of individual trial performance. These results establish the neural geometry and dynamics the human brain needs for flexible control over behavior.
Assuntos
Encéfalo , Eletroencefalografia , Humanos , Masculino , Feminino , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Adulto , Adulto Jovem , Modelos Neurológicos , Desempenho Psicomotor/fisiologia , Mapeamento Encefálico/métodosRESUMO
The integration of hippocampal oscillations during non-rapid eye movement (NREM) sleep is crucial for memory consolidation. However, how cardinal sleep oscillations bind across various subfields of the human hippocampus to promote information transfer and synaptic plasticity remains unclear. Using human intracranial recordings from 25 epilepsy patients, we find that hippocampal subfields, including DG/CA3, CA1, and SUB, all exhibit significant delta and spindle power during NREM sleep. The DG/CA3 displays strong coupling between delta and ripple oscillations with all the other hippocampal subfields. In contrast, the regions of CA1 and SUB exhibit more precise coordination, characterized by event-level triple coupling between delta, spindle, and ripple oscillations. Furthermore, we demonstrate that the synaptic plasticity within the hippocampal circuit, as indexed by delta-wave slope, is linearly modulated by spindle power. In contrast, ripples act as a binary switch that triggers a sudden increase in delta-wave slope. Overall, these results suggest that different subfields of the hippocampus regulate one another through diverse layers of sleep oscillation synchronization, collectively facilitating information processing and synaptic plasticity during NREM sleep.
Assuntos
Hipocampo , Plasticidade Neuronal , Humanos , Plasticidade Neuronal/fisiologia , Masculino , Feminino , Adulto , Hipocampo/fisiologia , Adulto Jovem , Sono/fisiologia , Eletroencefalografia , Pessoa de Meia-Idade , Fases do Sono/fisiologia , Epilepsia/fisiopatologia , Sono de Ondas Lentas/fisiologiaRESUMO
BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder featured by progressive cognitive decline, which manifests in severe impairment of memory, attention, emotional processing and daily activities, leading to significant disability and social burden. Investigation on Mild Cognitive Impairment (MCI), the prodromal and transitional stage between normal aging and AD, serves as a key in diagnosing and slowing down the progression of AD. Numerous effects have been made up to date, however, the attentional mechanisms under different external emotion stimuli in MCI and AD are still unexplored in deep. OBJECTIVE: To further explore the attentional mechanisms under different external emotion stimuli in both MCI and AD patients. DESIGN/SETTING/PARTICIPANTS/MEASUREMENTS: In 51 healthy volunteers (Controls, 24 males and 27 females), 52 MCI (19 males and 33 females), and 47 AD (15 males and 32 females) patients, we administered the visual oddball event-related potentials (ERPs) under three types of external emotional stimuli: Neutral, Happiness and Sadness, in which the components N1, P2, N2 and P3 as well as the abnormal cortical activations corresponding to the significant ERP differences in the three groups were observed. RESULTS: Under all three external emotions, in AD patients, N2 and P3 latencies were significantly prolonged compared to both Controls and MCI. In addition, under Happiness, in MCI, P3 latencies were significantly delayed compared to Controls. Meanwhile, under both Happiness and Sadness, in AD patients, P3 amplitudes were significantly decreased compared to Controls and MCI, respectively. During N2 time window, under Neutral emotion, significant hypoactivation in the right superior temporal gyrus was found in AD patients compared to Controls, and under Happiness, the activation of the right inferior frontal gyrus was significantly attenuated in MCI compared to Controls. Under Sadness, in AD patients, the activation of the right superior frontal gyrus was significantly decreased compared to MCI. During P3 time window, under both Happiness and Sadness, when AD patients compared to MCI, the significantly attenuated activations were located in the right fusiform gyrus and the right middle occipital gyrus, respectively. CONCLUSION: Our results demonstrated visual attentional deficits under external emotional stimuli in both MCI and AD patients, highlighting the function of Happiness for early detecting MCI, in which the P3 latency and the hypoactivation of right inferior frontal gyrus during N2 time window can be early signs. The current study sheds further light of attentional mechanisms in MCI and AD patients, and indicates the value of emotional processing in the early detection of cognitive dysfunction.
Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Emoções , Humanos , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Disfunção Cognitiva/diagnóstico , Masculino , Feminino , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Idoso , Emoções/fisiologia , Potenciais Evocados Visuais/fisiologia , Eletroencefalografia , Pessoa de Meia-Idade , Atenção/fisiologiaRESUMO
Background and purpose:
Combined epilepsy (with generalized and focal seizures) is a recently accepted and yet underreported epilepsy type. We intended to review the literature of combined epilepsy and to report the individual findings of the 31 combined epilepsy patients in our database. Thereafter, we investigated the characteristics of the patients at the group level.
. Methods:The individual findings of the 31 patients were tabulated. We characterized the group with special reference to epidemiology, timing and the sequence of generalized and focal seizures, family history of seizures and severity of the electro-clinical phenotype. The variables were compared to those of the generalized epilepsy and the focal epilepsy groups of our database. We carried out statistical analyses by the two-sided Fishers’s exact test and the Kruskal-Wallis and post-hoc Dunn tests.
. Results:The prevalence of combined epilepsy was 1.56% within the total sample of the classifiable epilepsy patients. Females were affected more often than males (67.7% and 32.3%, respectively). Statistically significant associations emerged firstly between the “short interval” subgroup (where the generalized and focal seizures occurred with short time difference) and the lack of other cerebral abnormality, and secondly between the “long interval” subgroup (where 4 to 37 years elapsed between the occurrence of the two seizure types) and the presence of other brain abnormality (p = 0.02). The proportion of patients with positive family history of seizures was greater in the combined epilepsy- than in the generalized epilepsy group (p = 0.03) and the focal epilepsy group (p < 0.0001) of the database. The electro-clinical phenotype of the absence seizures showed more atypical findings (indicating poor prognosis) in combined epilepsy than in the generalized absence epilepsy patients of the database (p < 0,0001). Despite dissimilar patient selection and study design, our main findings were in accord with those of prior studies. The dissection of the combined epilepsy group into the “long interval” and “short interval” subgroups was a novel approach that highlighted the dissimilar pathogenetic and clinical correlates of each.
. Conclusion:The case reports might facilitate the spread of information about combined epilepsy in the medical community. Analyses of the patients at the group level resulted in clinically useful pieces of evidence.
.Assuntos
Epilepsias Parciais , Epilepsia Generalizada , Convulsões , Humanos , Feminino , Masculino , Convulsões/epidemiologia , Adulto , Adolescente , Eletroencefalografia , Pessoa de Meia-Idade , Prevalência , CriançaRESUMO
Microstates represent brief periods of quasi-stable electroencephalography (EEG) scalp topography, offering insights into dynamic fluctuations in event-related potential (ERP) topographies. Despite this, there is a lack of a comprehensive systematic overview of microstate findings concerning cognitive face processing. This review aims to summarize ERP findings on face processing using microstate analyses and assess their effectiveness in characterizing face-related neural representations. A literature search was conducted for microstate ERP studies involving healthy individuals and psychiatric populations, utilizing PubMed, Google Scholar, Web of Science, PsychInfo, and Scopus databases. Twenty-two studies were identified, primarily focusing on healthy individuals (n = 16), with a smaller subset examining psychiatric populations (n = 6). The evidence reviewed in this study suggests that various microstates are consistently associated with distinct ERP stages involved in face processing, encompassing the processing of basic visual facial features to more complex functions such as analytical processing, facial recognition, and semantic representations. Furthermore, these studies shed light on atypical attentional neural mechanisms in Autism Spectrum Disorder (ASD), facial recognition deficits among emotional dysregulation disorders, and encoding and semantic dysfunctions in Post-Traumatic Stress Disorder (PTSD). In conclusion, this review underscores the practical utility of ERP microstate analyses in investigating face processing. Methodologies have evolved towards greater automation and data-driven approaches over time. Future research should aim to forecast clinical outcomes and conduct validation studies to directly demonstrate the efficacy of such analyses in inverse space.