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1.
Spinal Cord Ser Cases ; 10(1): 56, 2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39098854

RESUMO

INTRODUCTION: Spinal cord injury (SCI) causes damage to neurons and results in motor and sensory dysfunction. Intermittent theta burst stimulation (iTBS) has been used to induce neuronal and synaptic plasticity by applying a magnetic field in the brain. The plasticity induced in the cortex has an imperative role in the recovery of motor and sensory functioning. However, the effect of iTBS in complete SCI patients is still elusive. CASE PRESENTATION: We report here the case of a 27-year-old female who sustained an L1 complete spinal cord injury (SCI) with an ASIA score of A. The patient lost all the sensory and motor functions below the level of injury. Intermittent theta burst stimulation (iTBS) was administered at 80% of the resting motor threshold over the M1 motor cortex, along with intensive rehabilitation training to promote sensorimotor function. DISCUSSION: There was a partial recovery in functional, electrophysiological, and neurological parameters. The case report also demonstrates the safety and efficacy of iTBS in complete SCI patients. No adverse event has been observed in the patient during intervention sessions.


Assuntos
Traumatismos da Medula Espinal , Estimulação Magnética Transcraniana , Humanos , Traumatismos da Medula Espinal/reabilitação , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/terapia , Traumatismos da Medula Espinal/fisiopatologia , Feminino , Adulto , Estimulação Magnética Transcraniana/métodos , Recuperação de Função Fisiológica/fisiologia , Córtex Motor , Ritmo Teta/fisiologia
2.
Cereb Cortex ; 34(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39110414

RESUMO

Adaptive behavior is fundamental to cognitive control and executive functioning. This study investigates how cognitive control mechanisms and episodic feature retrieval interact to influence adaptiveness, focusing particularly on theta (4 to 8 Hz) oscillatory dynamics. We conducted two variations of the Simon task, incorporating response-incompatible, response-compatible, and neutral trials. Experiment 1 demonstrated that cognitive adjustments-specifically, cognitive shielding following incompatible trials and cognitive relaxation following compatible ones-are reflected in midfrontal theta power modulations associated with the Simon effect. Experiment 2 showed that reducing feature overlap between trials leads to less pronounced sequential modulations in behavior and midfrontal theta activity, supporting the hypothesis that cognitive control and feature integration share a common neural mechanism. These findings highlight the interaction of cognitive control processes and episodic feature integration in modulating behavior. The results advocate for hybrid models that combine top-down and bottom-up processes as a comprehensive framework to understand cognitive control dynamics and adaptive behavior.


Assuntos
Cognição , Conflito Psicológico , Função Executiva , Ritmo Teta , Humanos , Ritmo Teta/fisiologia , Masculino , Feminino , Adulto Jovem , Cognição/fisiologia , Adulto , Função Executiva/fisiologia , Tempo de Reação/fisiologia , Eletroencefalografia , Desempenho Psicomotor/fisiologia , Adaptação Psicológica/fisiologia , Encéfalo/fisiologia
3.
Front Neural Circuits ; 18: 1326609, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947492

RESUMO

Gamma oscillations nested in a theta rhythm are observed in the hippocampus, where are assumed to play a role in sequential episodic memory, i.e., memorization and retrieval of events that unfold in time. In this work, we present an original neurocomputational model based on neural masses, which simulates the encoding of sequences of events in the hippocampus and subsequent retrieval by exploiting the theta-gamma code. The model is based on a three-layer structure in which individual Units oscillate with a gamma rhythm and code for individual features of an episode. The first layer (working memory in the prefrontal cortex) maintains a cue in memory until a new signal is presented. The second layer (CA3 cells) implements an auto-associative memory, exploiting excitatory and inhibitory plastic synapses to recover an entire episode from a single feature. Units in this layer are disinhibited by a theta rhythm from an external source (septum or Papez circuit). The third layer (CA1 cells) implements a hetero-associative net with the previous layer, able to recover a sequence of episodes from the first one. During an encoding phase, simulating high-acetylcholine levels, the network is trained with Hebbian (synchronizing) and anti-Hebbian (desynchronizing) rules. During retrieval (low-acetylcholine), the network can correctly recover sequences from an initial cue using gamma oscillations nested inside the theta rhythm. Moreover, in high noise, the network isolated from the environment simulates a mind-wandering condition, randomly replicating previous sequences. Interestingly, in a state simulating sleep, with increased noise and reduced synapses, the network can "dream" by creatively combining sequences, exploiting features shared by different episodes. Finally, an irrational behavior (erroneous superimposition of features in various episodes, like "delusion") occurs after pathological-like reduction in fast inhibitory synapses. The model can represent a straightforward and innovative tool to help mechanistically understand the theta-gamma code in different mental states.


Assuntos
Ritmo Gama , Imaginação , Modelos Neurológicos , Ritmo Teta , Ritmo Gama/fisiologia , Ritmo Teta/fisiologia , Humanos , Imaginação/fisiologia , Memória/fisiologia , Hipocampo/fisiologia , Redes Neurais de Computação , Animais
4.
Elife ; 122024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037771

RESUMO

Functional interactions between the prefrontal cortex and hippocampus, as revealed by strong oscillatory synchronization in the theta (6-11 Hz) frequency range, correlate with memory-guided decision-making. However, the degree to which this form of long-range synchronization influences memory-guided choice remains unclear. We developed a brain-machine interface that initiated task trials based on the magnitude of prefrontal-hippocampal theta synchronization, then measured choice outcomes. Trials initiated based on strong prefrontal-hippocampal theta synchrony were more likely to be correct compared to control trials on both working memory-dependent and -independent tasks. Prefrontal-thalamic neural interactions increased with prefrontal-hippocampal synchrony and optogenetic activation of the ventral midline thalamus primarily entrained prefrontal theta rhythms, but dynamically modulated synchrony. Together, our results show that prefrontal-hippocampal theta synchronization leads to a higher probability of a correct choice and strengthens prefrontal-thalamic dialogue. Our findings reveal new insights into the neural circuit dynamics underlying memory-guided choices and highlight a promising technique to potentiate cognitive processes or behavior via brain-machine interfacing.


Assuntos
Tomada de Decisões , Hipocampo , Córtex Pré-Frontal , Ritmo Teta , Córtex Pré-Frontal/fisiologia , Tomada de Decisões/fisiologia , Ritmo Teta/fisiologia , Hipocampo/fisiologia , Animais , Masculino , Memória/fisiologia , Interfaces Cérebro-Computador , Humanos , Tálamo/fisiologia , Optogenética
5.
Cereb Cortex ; 34(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38976973

RESUMO

Joint attention is an indispensable tool for daily communication. Abnormalities in joint attention may be a key reason underlying social impairment in schizophrenia spectrum disorders. In this study, we aimed to explore the attentional orientation mechanism related to schizotypal traits in a social situation. Here, we employed a Posner cueing paradigm with social attentional cues. Subjects needed to detect the location of a target that is cued by gaze and head orientation. The power in the theta frequency band was used to examine the attentional process in the schizophrenia spectrum. There were four main findings. First, a significant association was found between schizotypal traits and attention orientation in response to invalid gaze cues. Second, individuals with schizotypal traits exhibited significant activation of neural oscillations and synchrony in the theta band, which correlated with their schizotypal tendencies. Third, neural oscillations and synchrony demonstrated a synergistic effect during social tasks, particularly when processing gaze cues. Finally, the relationship between schizotypal traits and attention orientation was mediated by neural oscillations and synchrony in the theta frequency band. These findings deepen our understanding of the impact of theta activity in schizotypal traits on joint attention and offer new insights for future intervention strategies.


Assuntos
Atenção , Sinais (Psicologia) , Esquizofrenia , Ritmo Teta , Humanos , Masculino , Feminino , Ritmo Teta/fisiologia , Atenção/fisiologia , Adulto Jovem , Esquizofrenia/fisiopatologia , Adulto , Eletroencefalografia , Transtorno da Personalidade Esquizotípica/fisiopatologia , Psicologia do Esquizofrênico
6.
Elife ; 122024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037765

RESUMO

Hippocampal place cells in freely moving rodents display both theta phase precession and procession, which is thought to play important roles in cognition, but the neural mechanism for producing theta phase shift remains largely unknown. Here, we show that firing rate adaptation within a continuous attractor neural network causes the neural activity bump to oscillate around the external input, resembling theta sweeps of decoded position during locomotion. These forward and backward sweeps naturally account for theta phase precession and procession of individual neurons, respectively. By tuning the adaptation strength, our model explains the difference between 'bimodal cells' showing interleaved phase precession and procession, and 'unimodal cells' in which phase precession predominates. Our model also explains the constant cycling of theta sweeps along different arms in a T-maze environment, the speed modulation of place cells' firing frequency, and the continued phase shift after transient silencing of the hippocampus. We hope that this study will aid an understanding of the neural mechanism supporting theta phase coding in the brain.


Assuntos
Potenciais de Ação , Células de Lugar , Ritmo Teta , Animais , Ritmo Teta/fisiologia , Células de Lugar/fisiologia , Potenciais de Ação/fisiologia , Modelos Neurológicos , Hipocampo/fisiologia , Hipocampo/citologia , Adaptação Fisiológica , Ratos
7.
Cereb Cortex ; 34(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39046456

RESUMO

Implicit visuomotor sequence learning is crucial for acquiring skills that result in automated behaviors. The oscillatory dynamics underpinning this learning process are not well understood. To address this gap, the current study employed electroencephalography with a medium-density array (64 electrodes) to investigate oscillatory activity associated with implicit visuomotor sequence learning in the Serial Reaction Time task. In the task, participants unknowingly learn a series of finger movements. Eighty-five healthy adults participated in the study. Analyses revealed that theta activity at the vertex and alpha/beta activity over the motor areas decreased over the course of learning. No associations between alpha/beta and theta power were observed. These findings are interpreted within a dual-process framework: midline theta activity is posited to regulate top-down attentional processes, whereas beta activity from motor areas underlies the bottom-up encoding of sensory information from movement. From this model, we suggest that during implicit visuomotor sequence learning, top-down processes become disengaged (indicated by a reduction in theta activity), and modality specific bottom-up processes encode the motor sequence (indicated by a reduction in alpha/beta activity).


Assuntos
Eletroencefalografia , Desempenho Psicomotor , Tempo de Reação , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Aprendizagem/fisiologia , Adolescente , Aprendizagem Seriada/fisiologia , Ritmo Teta/fisiologia , Movimento/fisiologia
8.
Proc Natl Acad Sci U S A ; 121(31): e2322869121, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39047043

RESUMO

Choosing whether to exert effort to obtain rewards is fundamental to human motivated behavior. However, the neural dynamics underlying the evaluation of reward and effort in humans is poorly understood. Here, we report an exploratory investigation into this with chronic intracranial recordings from the prefrontal cortex (PFC) and basal ganglia (BG; subthalamic nuclei and globus pallidus) in people with Parkinson's disease performing a decision-making task with offers that varied in levels of reward and physical effort required. This revealed dissociable neural signatures of reward and effort, with BG beta (12 to 20 Hz) oscillations tracking effort on a single-trial basis and PFC theta (4 to 7 Hz) signaling previous trial reward, with no effects of net subjective value. Stimulation of PFC increased overall acceptance of offers and sensitivity to reward while decreasing the impact of effort on choices. This work uncovers oscillatory mechanisms that guide fundamental decisions to exert effort for reward across BG and PFC, supports a causal role of PFC for such choices, and seeds hypotheses for future studies.


Assuntos
Gânglios da Base , Tomada de Decisões , Doença de Parkinson , Córtex Pré-Frontal , Recompensa , Ritmo Teta , Humanos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/fisiopatologia , Tomada de Decisões/fisiologia , Gânglios da Base/fisiologia , Gânglios da Base/fisiopatologia , Masculino , Ritmo Teta/fisiologia , Feminino , Doença de Parkinson/fisiopatologia , Pessoa de Meia-Idade , Ritmo beta/fisiologia , Idoso
9.
eNeuro ; 11(7)2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38977304

RESUMO

We investigated the neural signatures of expert decision-making in the context of police training in a virtual reality-based shoot/don't shoot scenario. Police officers can use stopping force against a perpetrator, which may require using a firearm and each decision made by an officer to discharge their firearm or not has substantial implications. Therefore, it is important to understand the cognitive and underlying neurophysiological processes that lead to such a decision. We used virtual reality-based simulations to elicit ecologically valid behavior from authorized firearms officers (AFOs) in the UK and matched novices in a shoot/don't shoot task and recorded electroencephalography concurrently. We found that AFOs had consistently faster response times than novices, suggesting our task was sensitive to their expertise. To investigate differences in decision-making processes under varying levels of threat and expertise, we analyzed electrophysiological signals originating from the anterior cingulate cortex. In line with similar response inhibition tasks, we found greater increases in preresponse theta power when participants inhibited the response to shoot when under no threat as compared with shooting. Most importantly, we showed that when preparing against threat, theta power increase was greater for experts than novices, suggesting that differences in performance between experts and novices are due to their greater orientation toward threat. Additionally, shorter beta rebounds suggest that experts were "ready for action" sooner. More generally, we demonstrate that the investigation of expert decision-making should incorporate naturalistic stimuli and an appropriate control group to enhance validity.


Assuntos
Tomada de Decisões , Eletroencefalografia , Armas de Fogo , Polícia , Realidade Virtual , Humanos , Tomada de Decisões/fisiologia , Masculino , Adulto , Feminino , Adulto Jovem , Ritmo Teta/fisiologia , Tempo de Reação/fisiologia , Giro do Cíngulo/fisiologia
10.
J Neural Eng ; 21(3)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38834054

RESUMO

Objective. Therapeutic brain stimulation is conventionally delivered using constant-frequency stimulation pulses. Several recent clinical studies have explored how unconventional and irregular temporal stimulation patterns could enable better therapy. However, it is challenging to understand which irregular patterns are most effective for different therapeutic applications given the massively high-dimensional parameter space.Approach. Here we applied many irregular stimulation patterns in a single neural circuit to demonstrate how they can enable new dimensions of neural control compared to conventional stimulation, to guide future exploration of novel stimulation patterns in translational settings. We optogenetically excited the septohippocampal circuit with constant-frequency, nested pulse, sinusoidal, and randomized stimulation waveforms, systematically varying their amplitude and frequency parameters.Main results.We first found equal entrainment of hippocampal oscillations: all waveforms provided similar gamma-power increase, whereas no parameters increased theta-band power above baseline (despite the mechanistic role of the medial septum in driving hippocampal theta oscillations). We then compared each of the effects of each waveform on high-dimensional multi-band activity states using dimensionality reduction methods. Strikingly, we found that conventional stimulation drove predominantly 'artificial' (different from behavioral activity) effects, whereas all irregular waveforms induced activity patterns that more closely resembled behavioral activity.Significance. Our findings suggest that irregular stimulation patterns are not useful when the desired mechanism is to suppress or enhance a single frequency band. However, novel stimulation patterns may provide the greatest benefit for neural control applications where entraining a particular mixture of bands (e.g. if they are associated with different symptoms) or behaviorally-relevant activity is desired.


Assuntos
Hipocampo , Optogenética , Optogenética/métodos , Hipocampo/fisiologia , Animais , Ritmo Teta/fisiologia , Masculino
11.
Proc Natl Acad Sci U S A ; 121(25): e2321614121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38857401

RESUMO

The medial prefrontal cortex (mPFC) is a key brain structure for higher cognitive functions such as decision-making and goal-directed behavior, many of which require awareness of spatial variables including one's current position within the surrounding environment. Although previous studies have reported spatially tuned activities in mPFC during memory-related trajectory, the spatial tuning of mPFC network during freely foraging behavior remains elusive. Here, we reveal geometric border or border-proximal representations from the neural activity of mPFC ensembles during naturally exploring behavior, with both allocentric and egocentric boundary responses. Unlike most of classical border cells in the medial entorhinal cortex (MEC) discharging along a single wall, a large majority of border cells in mPFC fire particularly along four walls. mPFC border cells generate new firing fields to external insert, and remain stable under darkness, across distinct shapes, and in novel environments. In contrast to hippocampal theta entrainment during spatial working memory tasks, mPFC border cells rarely exhibited theta rhythmicity during spontaneous locomotion behavior. These findings reveal spatially modulated activity in mPFC, supporting local computation for cognitive functions involving spatial context and contributing to a broad spatial tuning property of cortical circuits.


Assuntos
Córtex Pré-Frontal , Ritmo Teta , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/citologia , Animais , Ritmo Teta/fisiologia , Masculino , Camundongos , Córtex Entorrinal/fisiologia , Neurônios/fisiologia , Hipocampo/fisiologia , Memória Espacial/fisiologia , Camundongos Endogâmicos C57BL , Memória de Curto Prazo/fisiologia
12.
Exp Neurol ; 379: 114860, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38876195

RESUMO

Interictal epileptiform discharges refer to aberrant brain electrographic signals between seizures and feature intermittent interictal spikes (ISs), sharp waves, and/or abnormal rhythms. Recognition of these epileptiform activities by electroencephalographic (EEG) examinations greatly aids epilepsy diagnosis and localization of the seizure onset zone. ISs are a major form of interictal epileptiform discharges recognized in animal models of epilepsy. Progressive changes in IS waveforms, IS rates, and/or associated fast ripple oscillations have been shown to precede the development of spontaneous recurrent seizures (SRS) in various animal models. IS expressions in the kindling model of epilepsy have been demonstrated but IS changes during the course of SRS development in extended kindled animals remain to be detailed. We hence addressed this issue using a mouse model of kindling-induced SRS. Adult C57 black mice received twice daily hippocampal stimulations until SRS occurrence, with 24-h EEG monitoring performed following 50, 80, and ≥ 100 stimulations and after observation of SRS. In the stimulated hippocampus, increases in spontaneous ISs rates, but not in IS waveforms nor IS-associated fast ripples, along with decreased frequencies of hippocampal delta and theta rhythms, were observed before SRS onset. Comparable increases in IS rates were further observed in the unstimulated hippocampus, piriform cortex, and entorhinal cortex, but not in the unstimulated parietal cortex and dorsomedial thalamus. These data provide original evidence suggesting that increases in hippocampal IS rates, together with reductions in hippocampal delta and theta rhythms are closely associated with development of SRS in a rodent kindling model.


Assuntos
Ritmo Delta , Eletroencefalografia , Hipocampo , Excitação Neurológica , Camundongos Endogâmicos C57BL , Convulsões , Ritmo Teta , Animais , Excitação Neurológica/fisiologia , Camundongos , Hipocampo/fisiopatologia , Convulsões/fisiopatologia , Ritmo Teta/fisiologia , Ritmo Delta/fisiologia , Masculino , Recidiva
13.
Neuroreport ; 35(12): 800-804, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-38935073

RESUMO

Accurate predictions and the processing of prediction error signals can be important for efficient interaction with the auditory environment. In a reanalysis of data from Simal et al . (2021), who found that informative tones elicited increased N1 and P2 event-related potential components, we sought to identify electrophysiological indicators in the time-frequency domain associated with disambiguation of the hearing context and prediction of forthcoming stimulation. Participants heard two isochronous sequences of pure tones separated by a silent retention interval. A sequence could contain one, three, or five tones. Fifteen participants heard the three load conditions randomly intermixed. In this case, when sequence length was unknown, the second and fourth tone during encoding contained information allowing the prediction of another tone. Other participants heard the sequences blocked by sequence length, and the second and fourth tone of the sequences provided no new information (and hence were not informative). We used wavelet analysis and Hilbert transform methods to analyse the oscillatory activity related to tone informativeness. We found a significant increase in theta (4-7 Hz) amplitude following a tone that was informative and allowed prediction, in comparison with a tone that carried no predictive information. Previous work suggests increased theta amplitude is linked with task switching and an increase in cognitive control. We suggest informative tones recruit higher-level control processes involved in prediction of upcoming auditory events.


Assuntos
Percepção Auditiva , Ritmo Teta , Humanos , Masculino , Feminino , Adulto Jovem , Ritmo Teta/fisiologia , Adulto , Percepção Auditiva/fisiologia , Eletroencefalografia/métodos , Estimulação Acústica/métodos , Potenciais Evocados Auditivos/fisiologia
14.
Dev Cogn Neurosci ; 67: 101404, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38852382

RESUMO

The theta band is one of the most prominent frequency bands in the electroencephalography (EEG) power spectrum and presents an interesting paradox: while elevated theta power during resting state is linked to lower cognitive abilities in children and adolescents, increased theta power during cognitive tasks is associated with higher cognitive performance. Why does theta power, measured during resting state versus cognitive tasks, show differential correlations with cognitive functioning? This review provides an integrated account of the functional correlates of theta across different contexts. We first present evidence that higher theta power during resting state is correlated with lower executive functioning, attentional abilities, language skills, and IQ. Next, we review research showing that theta power increases during memory, attention, and cognitive control, and that higher theta power during these processes is correlated with better performance. Finally, we discuss potential explanations for the differential correlations between resting/task-related theta and cognitive functioning, and offer suggestions for future research in this area.


Assuntos
Cognição , Eletroencefalografia , Ritmo Teta , Humanos , Ritmo Teta/fisiologia , Cognição/fisiologia , Eletroencefalografia/métodos , Criança , Adolescente , Atenção/fisiologia , Descanso/fisiologia , Função Executiva/fisiologia , Encéfalo/fisiologia
15.
NeuroRehabilitation ; 54(4): 677-690, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38905062

RESUMO

BACKGROUND: Intermittent theta burst stimulation (iTBS) has demonstrated efficacy in patients with cognitive impairment. However, activation patterns and mechanisms of iTBS for post-stroke cognitive impairment (PSCI) remain insufficiently understood. OBJECTIVE: To investigate the activation patterns and potential benefits of using iTBS in patients with PSCI. METHODS: A total of forty-four patients with PSCI were enrolled and divided into an iTBS group (iTBS and cognitive training) or a control group (cognitive training alone). Outcomes were assessed based on the activation in functional near-infrared spectroscopy (fNIRS), as well as Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and the modified Barthel Index (MBI). RESULTS: Thirty-eight patients completed the interventions and assessments. Increased cortical activation was observed in the iTBS group after the interventions, including the right superior temporal gyrus (STG), left frontopolar cortex (FPC) and left orbitofrontal cortex (OFC). Both groups showed significant improvements in LOTCA and MBI after the interventions (p < 0.05). Furthermore, the iTBS group augmented superior improvement in the total score of MBI and LOTCA compared to the control group, especially in visuomotor organization and thinking operations (p < 0.05). CONCLUSION: iTBS altered activation patterns and improved cognitive function in patients with PSCI. The activation induced by iTBS may contribute to the improvement of cognitive function.


Assuntos
Disfunção Cognitiva , Espectroscopia de Luz Próxima ao Infravermelho , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estimulação Magnética Transcraniana , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/reabilitação , Disfunção Cognitiva/terapia , Idoso , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Reabilitação do Acidente Vascular Cerebral/métodos , Ritmo Teta/fisiologia
16.
PeerJ ; 12: e17451, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38854799

RESUMO

Locomotor adaptation to abrupt and gradual perturbations are likely driven by fundamentally different neural processes. The aim of this study was to quantify brain dynamics associated with gait adaptation to a gradually introduced gait perturbation, which typically results in smaller behavioral errors relative to an abrupt perturbation. Loss of balance during standing and walking elicits transient increases in midfrontal theta oscillations that have been shown to scale with perturbation intensity. We hypothesized there would be no significant change in anterior cingulate theta power (4-7 Hz) with respect to pre-adaptation when a gait perturbation is introduced gradually because the gradual perturbation acceleration and stepping kinematic errors are small relative to an abrupt perturbation. Using mobile electroencephalography (EEG), we measured gait-related spectral changes near the anterior cingulate, posterior cingulate, sensorimotor, and posterior parietal cortices as young, neurotypical adults (n = 30) adapted their gait to an incremental split-belt treadmill perturbation. Most cortical clusters we examined (>70%) did not exhibit changes in electrocortical activity between 2-50 Hz. However, we did observe gait-related theta synchronization near the left anterior cingulate cortex during strides with the largest errors, as measured by step length asymmetry. These results suggest gradual adaptation with small gait asymmetry and perturbation magnitude may not require significant cortical resources beyond normal treadmill walking. Nevertheless, the anterior cingulate may remain actively engaged in error monitoring, transmitting sensory prediction error information via theta oscillations.


Assuntos
Adaptação Fisiológica , Eletroencefalografia , Marcha , Ritmo Teta , Humanos , Masculino , Feminino , Marcha/fisiologia , Ritmo Teta/fisiologia , Adaptação Fisiológica/fisiologia , Adulto Jovem , Adulto , Eletroencefalografia/métodos , Equilíbrio Postural/fisiologia , Giro do Cíngulo/fisiologia , Fenômenos Biomecânicos/fisiologia , Caminhada/fisiologia
17.
Cereb Cortex ; 34(6)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38858839

RESUMO

Children with attention-deficit/hyperactivity disorder show deficits in processing speed, as well as aberrant neural oscillations, including both periodic (oscillatory) and aperiodic (1/f-like) activity, reflecting the pattern of power across frequencies. Both components were suggested as underlying neural mechanisms of cognitive dysfunctions in attention-deficit/hyperactivity disorder. Here, we examined differences in processing speed and resting-state-Electroencephalogram neural oscillations and their associations between 6- and 12-year-old children with (n = 33) and without (n = 33) attention-deficit/hyperactivity disorder. Spectral analyses of the resting-state EEG signal using fast Fourier transform revealed increased power in fronto-central theta and beta oscillations for the attention-deficit/hyperactivity disorder group, but no differences in the theta/beta ratio. Using the parameterization method, we found a higher aperiodic exponent, which has been suggested to reflect lower neuronal excitation-inhibition, in the attention-deficit/hyperactivity disorder group. While fast Fourier transform-based theta power correlated with clinical symptoms for the attention-deficit/hyperactivity disorder group only, the aperiodic exponent was negatively correlated with processing speed across the entire sample. Finally, the aperiodic exponent was correlated with fast Fourier transform-based beta power. These results highlight the different and complementary contribution of periodic and aperiodic components of the neural spectrum as metrics for evaluation of processing speed in attention-deficit/hyperactivity disorder. Future studies should further clarify the roles of periodic and aperiodic components in additional cognitive functions and in relation to clinical status.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Encéfalo , Cognição , Eletroencefalografia , Humanos , Criança , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Masculino , Feminino , Encéfalo/fisiopatologia , Cognição/fisiologia , Análise de Fourier , Ondas Encefálicas/fisiologia , Ritmo Teta/fisiologia , Ritmo beta/fisiologia
18.
Behav Brain Res ; 471: 115120, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38905733

RESUMO

Improved pass accuracy is a prominent determinant of success in football. It demands an effective interaction of complex behavioral and cortical dynamics. Exploring differences in the ability to sustain an accurate pass behavior in a stable setting and the associated cortical dynamics at different expertise levels may provide an insight into skilled strategies contributing to superior accuracy in football. The aim of this study is to compare trial-to-trial variability of pass biomechanics and the corresponding cortical dynamics during short-distance passes between novices and experienced football players. Thirty participants (15 novices, 15 football players) performed 90 short-distance passes. The intertrial variability of pass biomechanics (foot acceleration, range of hip flexion, knee flexion and foot rotation) was assessed by means of multiscale entropy. The task-related cortical dynamics were analyzed via source-derived event-related spectral perturbations. Experienced players demonstrated higher accuracy and overall lower entropy values across multiple time scales which was significant for hip flexion. The electroencephalography data revealed group differences in parieto-occipital alpha desynchronization and frontal theta synchronization in successive phases of passes. The current findings suggest that experienced football players may show a skilled ability to recruit and retain pass biomechanics promoting higher accuracy, whereas novices may show an explorative behavior with higher spatial variability. This difference may be associated with distinctive visuospatial and attentional strategies acquired with expertise in football. Our study provides an insight into expertise-specific behavioral and cortical dynamics of superior accuracy in football and a basis for its prospective investigation in enriched contexts.


Assuntos
Eletroencefalografia , Futebol , Humanos , Masculino , Adulto Jovem , Futebol/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Desempenho Psicomotor/fisiologia , Desempenho Atlético/fisiologia , Ritmo alfa/fisiologia , Destreza Motora/fisiologia , Córtex Cerebral/fisiologia , Ritmo Teta/fisiologia
19.
Cortex ; 177: 84-99, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38848652

RESUMO

The visual system operates rhythmically, through timely coordinated perceptual and attentional processes, involving coexisting patterns in the alpha range (7-13 Hz) at ∼10 Hz, and theta (3-6 Hz) range, respectively. Here we aimed to disambiguate whether variations in task requirements, in terms of attentional demand and side of target presentation, might influence the occurrence of either perceptual or attentional components in behavioral visual performance, also uncovering possible differences in the sampling mechanisms of the two cerebral hemispheres. To this aim, visuospatial performance was densely sampled in two versions of a visual detection task where the side of target presentation was fixed (Task 1), with participants monitoring one single hemifield, or randomly varying across trials, with participants monitoring both hemifields simultaneously (Task 2). Performance was analyzed through spectral decomposition, to reveal behavioral oscillatory patterns. For Task 1, when attentional resources where focused on one hemifield only, the results revealed an oscillatory pattern fluctuating at ∼10 Hz and ∼6-9 Hz, for stimuli presented to the left and the right hemifield, respectively, possibly representing a perceptual sampling mechanism with different efficiency within the left and the right hemispheres. For Task 2, when attentional resources were simultaneously deployed to the two hemifields, a ∼5 Hz rhythm emerged both for stimuli presented to the left and the right, reflecting an attentional sampling process, equally supported by the two hemispheres. Overall, the results suggest that distinct perceptual and attentional sampling mechanisms operate at different oscillatory frequencies and their prevalence and hemispheric lateralization depends on task requirements.


Assuntos
Ritmo alfa , Atenção , Ritmo Teta , Percepção Visual , Humanos , Atenção/fisiologia , Ritmo Teta/fisiologia , Percepção Visual/fisiologia , Masculino , Feminino , Adulto , Ritmo alfa/fisiologia , Adulto Jovem , Estimulação Luminosa/métodos , Eletroencefalografia/métodos , Visão Ocular/fisiologia
20.
J Neurophysiol ; 131(6): 1240-1249, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691013

RESUMO

Although many patients with mild traumatic brain injury (mTBI) suffer from postconcussional syndrome (PCS) including abnormal emotional responses, most conventional imaging studies fail to detect any causative brain lesion. We hypothesized that event-related electroencephalography (EEG) recordings with time-frequency analysis would show a distinguishable pattern in patients with mTBI with PCS compared with normal healthy controls. EEG signals were collected from a total of 18 subjects: eight patients with mTBI with PCS and 10 healthy control subjects. The signals were recorded while the subjects were presented with affective visual stimuli, including neutral, pleasant, and unpleasant emotional cues. Event-related spectral perturbation analysis was performed to calculate frontal midline theta activity and posterior midline gamma activity, followed by statistical analysis to identify whether patients with mTBI with PCS have distinct patterns of theta or gamma oscillations in response to affective stimuli. Compared with the healthy control group, patients with mTBI with PCS did not show a significant increase in the power of frontal theta activity in response to the pleasant stimuli, indicating less susceptibility toward pleasant cues. Moreover, the patient group showed attenuated gamma oscillatory activity, with no clear alteration in gamma oscillations in response to either pleasant or unpleasant cues. This study demonstrates that patients with mTBI with PCS exhibited altered patterns of oscillatory activities in the theta and gamma bands in response to affective visual stimuli compared with the normal control group. The current finding implicates that these distinguishable patterns of brain oscillation may represent the mechanism behind various psychiatric symptoms in patients with mTBI.NEW & NOTEWORTHY Patients with mild traumatic brain injury (mTBI) with postconcussional syndrome (PCS) exhibited altered patterns of changes in oscillatory activities in the theta and gamma bands in response to visual affective stimuli. Distinguishable patterns of brain oscillation may represent the mechanism behind various psychiatric symptoms in patients with mTBI.


Assuntos
Ritmo Gama , Síndrome Pós-Concussão , Ritmo Teta , Humanos , Ritmo Gama/fisiologia , Masculino , Adulto , Feminino , Ritmo Teta/fisiologia , Síndrome Pós-Concussão/fisiopatologia , Pessoa de Meia-Idade , Estimulação Luminosa , Emoções/fisiologia , Adulto Jovem , Percepção Visual/fisiologia , Eletroencefalografia
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