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1.
Cogn Affect Behav Neurosci ; 21(4): 736-746, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33796985

RESUMO

The right hemisphere is involved with the integrative processes necessary to achieve global coherence during reasoning and discourse processing. Specifically, the right temporal lobe has been proven to facilitate the processing of distant associate relationships, such as generating novel ideas. Previous studies showed a specific swing of alpha and gamma oscillatory activity over the right parieto-occipital lobe and the right anterior temporal lobe respectively, when people solve semantic problems with a specific strategy, i.e., insight problem-solving. In this study, we investigated the specificity of the right parietal and temporal lobes for semantic integration using transcranial Random Noise Stimulation (tRNS). We administered a set of pure semantics (i.e., Compound Remote Associates [CRA]) and visuo-semantic problems (i.e., Rebus Puzzles) to a sample of 31 healthy volunteers. Behavioral results showed that tRNS stimulation over the right temporal lobe enhances CRA accuracy (+12%), while stimulation on the right parietal lobe causes a decrease of response time on the same task (-2,100 ms). No effects were detected for Rebus Puzzles. Our findings corroborate the involvement of the right temporal and parietal lobes when solving purely semantic problems but not when they involve visuo-semantic material, also providing causal evidence for their postulated different roles in the semantic integration process and promoting tRNS as a candidate tool to boost verbal reasoning in humans.


Assuntos
Semântica , Estimulação Transcraniana por Corrente Contínua , Humanos , Lobo Parietal , Resolução de Problemas , Lobo Temporal
2.
Psychother Res ; 29(2): 171-185, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-28468535

RESUMO

OBJECTIVE: Pascual-Leone and Greenberg's sequential model of emotional processing has been used to explore process in over 24 studies. This line of research shows emotional processing in good psychotherapy often follows a sequential order, supporting a saw-toothed pattern of change within individual sessions (progressing "2-steps-forward, 1-step-back"). However, one cannot assume that local in-session patterns are scalable across an entire course of therapy. Thus, the primary objective of this exploratory study was to consider how the sequential patterns identified by Pascual-Leone, may apply across entire courses of treatment. METHOD: Intensive emotion coding in two separate single-case designs were submitted for quantitative analyses of longitudinal patterns. Comprehensive coding in these cases involved recording observations for every emotional event in an entire course of treatment (using the Classification of Affective-Meaning States), which were then treated as a 9-point ordinal scale. RESULTS: Applying multilevel modeling to each of the two cases showed significant patterns of change over a large number of sessions, and those patterns were either nested at the within-session level or observed at the broader session-by-session level of change. DISCUSSION: Examining successful treatment cases showed several theoretically coherent kinds of temporal patterns, although not always in the same case. Clinical or methodological significance of this article: This is the first paper to demonstrate systematic temporal patterns of emotion over the course of an entire treatment. (1) The study offers a proof of concept that longitudinal patterns in the micro-processes of emotion can be objectively derived and quantified. (2) It also shows that patterns in emotion may be identified on the within-session level, as well as the session-by-session level of analysis. (3) Finally, observed processes over time support the ordered pattern of emotional states hypothesized in Pascual-Leone and Greenberg's (2007) model of emotional processing.


Assuntos
Sintomas Comportamentais/terapia , Terapia Focada em Emoções/métodos , Emoções/fisiologia , Relações Pai-Filho , Resiliência Psicológica , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Angústia Psicológica
3.
Neuroimage ; 157: 34-44, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28572060

RESUMO

Scientists and clinicians have traditionally targeted single brain regions with stimulation to modulate brain function and disease. However, brain regions do not operate in isolation, but interact with other regions through networks. As such, stimulation of one region may impact and be impacted by other regions in its network. Here we test whether the effects of brain stimulation can be enhanced by simultaneously targeting a region and its network, identified with resting state functional connectivity MRI. Fifteen healthy participants received two types of transcranial direct current stimulation (tDCS): a traditional two-electrode montage targeting a single brain region (left primary motor cortex [M1]) and a novel eight-electrode montage targeting this region and its associated resting state network. As a control, 8 participants also received multifocal tDCS mismatched to this network. Network-targeted tDCS more than doubled the increase in left M1 excitability over time compared to traditional tDCS and the multifocal control. Modeling studies suggest these results are unlikely to be due to tDCS effects on left M1 itself, however it is impossible to completely exclude this possibility. It also remains unclear whether multifocal tDCS targeting a network selectively modulates this network and which regions within the network are most responsible for observed effects. Despite these limitations, network-targeted tDCS appears to be a promising approach for enhancing tDCS effects beyond traditional stimulation targeting a single brain region. Future work is needed to test whether these results extend to other resting state networks and enhance behavioral or therapeutic effects.


Assuntos
Conectoma/métodos , Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Rede Nervosa/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Estimulação Transcraniana por Corrente Contínua/instrumentação , Estimulação Magnética Transcraniana , Adulto Jovem
4.
Spinal Cord ; 55(4): 362-366, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27995943

RESUMO

STUDY DESIGN: A cross-sectional study in chronic spinal cord injury with cervical lesions (cSCI). OBJECTIVE: To determine the corticomotor projection and motor cortex organization of paralyzed forearm muscles that presented only liminal voluntary activation. SETTING: Burke Medical Research Institute, White Plains, NY, USA. METHODS: We identified ten people with chronic SCI who had a wrist flexor or extensor muscle with a motor power (MP) of 1 over 5. We recorded motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) over the primary motor cortex of the hemisphere contralateral to the target muscle. We measured resting motor threshold (RMT), corticomotor latency (LTY), MEP amplitude (AMP) and performed cortical motor mapping to determine the optimal site (OPT) and map area (AREA). Results were compared with the data from 18 controls. RESULTS: A MEP in the target muscle was observed for all cSCI cases. LTY was normal, while corticomotor excitability (as determined by RMT and AMP) was reduced in about half of the group. The OPT site of the motor maps was within control range for all cSCI cases, while AREA was reduced in three cases. CONCLUSIONS: Corticomotor conduction and cortical topography were appreciably normal despite only liminal activation of the target muscle with voluntary effort. Muscles with these characteristics may benefit from a targeted rehabilitation program even in the chronic phase after SCI.


Assuntos
Antebraço/fisiopatologia , Córtex Motor/fisiopatologia , Músculo Esquelético/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Mapeamento Encefálico/métodos , Doença Crônica , Estudos Transversais , Eletromiografia , Potencial Evocado Motor , Feminino , Antebraço/inervação , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Músculo Esquelético/inervação , Condução Nervosa , Vias Neurais/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Adulto Jovem
5.
Cereb Cortex ; 22(2): 286-93, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21653285

RESUMO

Many empiricist theories hold that concepts are composed of sensory-motor primitives. For example, the meaning of the word "run" is in part a visual image of running. If action concepts are partly visual, then the concepts of congenitally blind individuals should be altered in that they lack these visual features. We compared semantic judgments and neural activity during action verb comprehension in congenitally blind and sighted individuals. Participants made similarity judgments about pairs of nouns and verbs that varied in the visual motion they conveyed. Blind adults showed the same pattern of similarity judgments as sighted adults. We identified the left middle temporal gyrus (lMTG) brain region that putatively stores visual-motion features relevant to action verbs. The functional profile and location of this region was identical in sighted and congenitally blind individuals. Furthermore, the lMTG was more active for all verbs than nouns, irrespective of visual-motion features. We conclude that the lMTG contains abstract representations of verb meanings rather than visual-motion images. Our data suggest that conceptual brain regions are not altered by the sensory modality of learning.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Compreensão/fisiologia , Semântica , Visão Ocular , Adulto , Análise de Variância , Encéfalo/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Tempo de Reação
6.
Spinal Cord ; 51(10): 765-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23896664

RESUMO

STUDY DESIGN: Case report. OBJECTIVES: To identify preserved corticomotor connection in chronic spinal cord injury (SCI) in the absence of clinically observable movement. SETTING: Rehabilitation Hospital and Medical Research Institute, NY, USA. METHODS: The motor-evoked potential (MEP) response to transcranial magnetic stimulation (TMS) was recorded using surface electromyography from the right biceps brachii, extersor carpi radialis (ECR), flexor carpi radialis (FCR) and abductor pollicis brevis (APB) muscles in a 31-year-old male traumatic SCI chronic patient-ASIA B, injury level C5. Motor power scores were additionally obtained from a clinician blinded to the results of TMS. RESULTS: TMS could consistently elicit MEPs of normal latency, phase and amplitude, in the severely affected ECR muscle but not the similarly affected FCR muscle. The response in proximal and unaffected biceps muscle was larger than the healthy subject, whereas no response was obtained in the distal APB muscle as expected. CONCLUSION: TMS can identify residual pathways not apparent from clinical assessment alone, which may have prescriptive value for rehabilitation.


Assuntos
Braço/fisiopatologia , Potencial Evocado Motor/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Estimulação Elétrica/métodos , Humanos , Masculino , Córtex Motor/fisiopatologia , Movimento/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Traumatismos da Medula Espinal/terapia , Estimulação Magnética Transcraniana/métodos
7.
Epidemiol Psychiatr Sci ; 32: e19, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37066626

RESUMO

AIMS: Our study aimed to (1) identify trajectories on different mental health components during a two-year follow-up of the COVID-19 pandemic and contextualise them according to pandemic periods; (2) investigate the associations between mental health trajectories and several exposures, and determine whether there were differences among the different mental health outcomes regarding these associations. METHODS: We included 5535 healthy individuals, aged 40-65 years old, from the Barcelona Brain Health Initiative (BBHI). Growth mixture models (GMM) were fitted to classify individuals into different trajectories for three mental health-related outcomes (psychological distress, personal growth and loneliness). Moreover, we fitted a multinomial regression model for each outcome considering class membership as the independent variable to assess the association with the predictors. RESULTS: For the outcomes studied we identified three latent trajectories, differentiating two major trends, a large proportion of participants was classified into 'resilient' trajectories, and a smaller proportion into 'chronic-worsening' trajectories. For the former, we observed a lower susceptibility to the changes, whereas, for the latter, we noticed greater heterogeneity and susceptibility to different periods of the pandemic. From the multinomial regression models, we found global and cognitive health, and coping strategies as common protective factors among the studied mental health components. Nevertheless, some differences were found regarding the risk factors. Living alone was only significant for those classified into 'chronic' trajectories of loneliness, but not for the other outcomes. Similarly, secondary or higher education was only a risk factor for the 'worsening' trajectory of personal growth. Finally, smoking and sleeping problems were risk factors which were associated with the 'chronic' trajectory of psychological distress. CONCLUSIONS: Our results support heterogeneity in reactions to the pandemic and the need to study different mental health-related components over a longer follow-up period, as each one evolves differently depending on the pandemic period. In addition, the understanding of modifiable protective and risk factors associated with these trajectories would allow the characterisation of these segments of the population to create targeted interventions.


Assuntos
COVID-19 , Saúde Mental , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Pandemias , COVID-19/epidemiologia , Adaptação Psicológica , Nível de Saúde
8.
Clin Neurophysiol ; 141: 101-108, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35798667

RESUMO

Transcranial magnetic stimulation (TMS) has been widely used in both clinical and research practice. However, TMS might induce unintended sensations and undesired effects as well as serious adverse effects. To date, no shared forms are available to report such unintended effects. This study aimed at developing a questionnaire enabling reporting of TMS unintended effects. A Delphi procedure was applied which allowed consensus among TMS experts. A steering committee nominated a number of experts to be involved in the Delphi procedure. Three rounds were conducted before reaching a consensus. Afterwards, the questionnaire was publicized on the International Federation of Clinical Neurophysiology website to collect further suggestions by the wider scientific community. A last Delphi round was then conducted to obtain consensus on the suggestions collected during the publicization and integrate them in the questionnaire. The procedure resulted in a questionnaire, that is the TMSens_Q, applicable in clinical and research settings. Routine use of the structured TMS questionnaire and standard reporting of unintended TMS effects will help to monitor the safety of TMS, particularly when applying new protocols. It will also improve the quality of data collection as well as the interpretation of experimental findings.


Assuntos
Estimulação Magnética Transcraniana , Consenso , Humanos , Inquéritos e Questionários , Estimulação Magnética Transcraniana/efeitos adversos , Estimulação Magnética Transcraniana/métodos
9.
Brain Topogr ; 24(1): 54-64, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21076861

RESUMO

Low-frequency repetitive transcranial magnetic stimulation (rTMS) can exert local and inter-hemispheric neuromodulatory effects on cortical excitability. These physiologic effects can translate into changes in motor behavior, and may offer valuable therapeutic interventions in recovery from stroke. Neuronavigated TMS can maximize accurate and consistent targeting of a given cortical region, but is a lot more involved that conventional TMS. We aimed to assess whether neuronavigation enhances the physiologic and behavioral effects of low-frequency rTMS. Ten healthy subjects underwent two experimental sessions during which they received 1600 pulses of either navigated or non-navigated 1 Hz rTMS at 90% of the resting motor threshold (RMT) intensity over the motor cortical representation for left first dorsal interosseous (FDI) muscle. We compared the effects of navigated and non-navigated rTMS on motor-evoked potentials (MEPs) to single-pulse TMS, intracortical inhibition (ICI) and intracortical facilitation (ICF) by paired-pulse TMS, and performance in various behavioral tasks (index finger tapping, simple reaction time and grip strength tasks). Following navigated rTMS, the amplitude of MEPs elicited from the contralateral (unstimulated) motor cortex was significantly increased, and was associated with an increase in ICF and a trend to decrease in ICI. In contrast, non-navigated rTMS elicited nonsignificant changes, most prominently ipsilateral to rTMS. Behaviorally, navigated rTMS significantly improved reaction time RT and pinch force with the hand ipsilateral to stimulation. Non-navigated rTMS lead to similar behavioral trends, although the effects did not reach significance. In summary, navigated rTMS leads to more robust modulation of the contralateral (unstimulated) hemisphere resulting in physiologic and behavioral effects. Our findings highlight the spatial specificity of inter-hemispheric TMS effects, illustrate the superiority of navigated rTMS for certain applications, and have implications for therapeutic applications of rTMS.


Assuntos
Comportamento/fisiologia , Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Neuronavegação/métodos , Estimulação Magnética Transcraniana/métodos , Adulto , Vias Eferentes/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/inervação , Adulto Jovem
10.
Eur Spine J ; 20(7): 1069-78, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21499781

RESUMO

The aetiology of idiopathic scoliosis (IS) remains unknown, but there is growing support for the possibility of an underlying neurological disorder. Functional magnetic resonance imaging (fMRI) can characterize the abnormal activation of the sensorimotor brain network in movement disorders and could provide further insights into the neuropathogenesis of IS. Twenty subjects were included in the study; 10 adolescents with IS (mean age of 15.2, 8 girls and 2 boys) and 10 age-matched healthy controls. The average Cobb angle of the primary curve in the IS patients was 35° (range 27°-55°). All participants underwent a block-design fMRI experiment in a 1.5-Tesla MRI scanner to explore cortical activation following a simple motor task. Rest periods alternated with activation periods during which participants were required to open and close their hand at an internally paced rate of approximately 1 Hz. Data were analyzed with Statistical Parametric Mapping (SPM5) including age, sex and laterality as nuisance variables to minimise the presence of bias in the results. Compared to controls, IS patients showed significant increases in blood oxygenation level dependent (BOLD) activity in contralateral supplementary motor area when performing the motor task with either hand. No significant differences were observed when testing between groups in the functional activation in the primary motor cortex, premotor cortex and somatosensory cortex. Additionally, the IS group showed a greater interhemispheric asymmetry index than the control group (0.30 vs. 0.13, p < 0.001). This study demonstrates an abnormal pattern of brain activation in secondary motor areas during movement execution in patients with IS. These findings support the hypothesis that a sensorimotor integration disorder underlies the pathogenesis of IS.


Assuntos
Mapeamento Encefálico , Córtex Motor/fisiopatologia , Escoliose/fisiopatologia , Córtex Somatossensorial/fisiopatologia , Adolescente , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
11.
Rev Neurol (Paris) ; 167(4): 291-316, 2011 Apr.
Artigo em Francês | MEDLINE | ID: mdl-21420698

RESUMO

INTRODUCTION: Non-invasive brain stimulation methods such as transcranial magnetic stimulation (TMS) are starting to be widely used to make causality-based inferences about brain-behavior interactions. Moreover, TMS-based clinical applications are under development to treat specific neurological or psychiatric conditions, such as depression, dystonia, pain, tinnitus and the sequels of stroke, among others. BACKGROUND: TMS works by inducing non-invasively electric currents in localized cortical regions thus modulating their activity levels according to settings, such as frequency, number of pulses, train and regime duration and intertrain intervals. For instance, it is known for the motor cortex that low frequency or continuous patterns of TMS pulses tend to depress local activity whereas high frequency and discontinuous TMS patterns tend to enhance it. Additionally, local cortical effects of TMS can result in dramatic patterns in distant brain regions. These distant effects are mediated via anatomical connectivity in a magnitude that depends on the efficiency and sign of such connections. PERSPECTIVES: An efficient use of TMS in both fields requires however, a deep understanding of its operational principles, its risks, its potential and limitations. In this article, we will briefly present the principles through which non-invasive brain stimulation methods, and in particular TMS, operate. CONCLUSION: Readers will be provided with fundamental information needed to critically discuss TMS studies and design hypothesis-driven TMS applications for cognitive and clinical neuroscience research.


Assuntos
Neurociências/métodos , Estimulação Magnética Transcraniana , Animais , Comportamento/fisiologia , Pesquisa Biomédica , Encéfalo/fisiologia , Encefalopatias/diagnóstico , Encefalopatias/terapia , Campos Eletromagnéticos , Humanos , Pesquisa , Estimulação Magnética Transcraniana/efeitos adversos , Estimulação Magnética Transcraniana/instrumentação
12.
Sci Rep ; 11(1): 21170, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34707206

RESUMO

Theta-burst stimulation (TBS) is a patterned form of repetitive transcranial magnetic stimulation (rTMS) that has been used to induce long-term modulation (plasticity) of corticospinal excitability in a drastically shorter duration protocol than conventional rTMS protocols. In this study we tested the reliability of the effects of two well defined TBS protocols, continuous TBS (cTBS) and intermittent TBS (iTBS), especially in relation to sham TBS, within and across the same 24 participants. All TBS protocols were repeated after approximately 1 month to assess the magnitude and reliability of the modulatory effects of each TBS protocol. Baseline and post-TBS changes in motor evoked potentials (MEP-measure of corticospinal excitability) amplitudes were compared across the cTBS, iTBS and sham TBS protocols and between the initial and retest visits. Overall, across participants, at the initial visit, iTBS facilitated MEPs as compared to baseline excitability, with sham eliciting the same effect. cTBS did not show a significant suppression of excitability compared to baseline MEPs at either visit, and even facilitated MEPs above baseline excitability at a single time point during the repeat visit. Otherwise, effects of TBS were generally diminished in the repeat visit, with iTBS and sham TBS replicating facilitation of MEPs above baseline excitability at similar time points. However, no protocol demonstrated consistent intra-individual modulation of corticospinal excitability upon retest. As the first study to test both iTBS and cTBS against sham TBS across repeat visits, our findings challenge the efficacy and reliability of TBS protocols and emphasize the importance of accounting for sham effects of TBS. Furthermore, given that therapeutic effects of TBS are hypothetically derived from consistent and repeated modulation of brain activity, the non-replicability of plasticity and sham effects call into question these basic mechanisms.


Assuntos
Potencial Evocado Motor , Ritmo Teta , Estimulação Magnética Transcraniana/métodos , Adolescente , Adulto , Encéfalo/fisiologia , Feminino , Humanos , Potenciação de Longa Duração , Masculino , Pessoa de Meia-Idade , Junção Neuromuscular/fisiologia , Reprodutibilidade dos Testes , Estimulação Magnética Transcraniana/normas
13.
Clin Neurophysiol ; 131(6): 1287-1310, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32302946

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly with a progressive decline in cognitive function significantly affecting quality of life. Both the prevalence and emotional and financial burdens of AD on patients, their families, and society are predicted to grow significantly in the near future, due to a prolongation of the lifespan. Several lines of evidence suggest that modifications of risk-enhancing life styles and initiation of pharmacological and non-pharmacological treatments in the early stage of disease, although not able to modify its course, helps to maintain personal autonomy in daily activities and significantly reduces the total costs of disease management. Moreover, many clinical trials with potentially disease-modifying drugs are devoted to prodromal stages of AD. Thus, the identification of markers of conversion from prodromal form to clinically AD may be crucial for developing strategies of early interventions. The current available markers, including volumetric magnetic resonance imaging (MRI), positron emission tomography (PET), and cerebral spinal fluid (CSF) analysis are expensive, poorly available in community health facilities, and relatively invasive. Taking into account its low cost, widespread availability and non-invasiveness, electroencephalography (EEG) would represent a candidate for tracking the prodromal phases of cognitive decline in routine clinical settings eventually in combination with other markers. In this scenario, the present paper provides an overview of epidemiology, genetic risk factors, neuropsychological, fluid and neuroimaging biomarkers in AD and describes the potential role of EEG in AD investigation, trying in particular to point out whether advanced analysis of EEG rhythms exploring brain function has sufficient specificity/sensitivity/accuracy for the early diagnosis of AD.


Assuntos
Doença de Alzheimer/diagnóstico , Encéfalo/fisiopatologia , Eletroencefalografia , Doença de Alzheimer/fisiopatologia , Biomarcadores , Diagnóstico Precoce , Humanos , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador
14.
Restor Neurol Neurosci ; 27(3): 199-207, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19531875

RESUMO

PURPOSE: Anodal transcranial direct current stimulation (tDCS) can transiently increase corticomotor excitability of intrinsic hand muscles and improve upper limb function in patients with chronic stroke. As a preliminary study, we tested whether increased corticomotor excitability would be similarly observed in muscles acting about the wrist, and remain present during robotic training involving active wrist movements, in six chronic stroke patients with residual motor deficit. METHODS: Transcranial magnetic stimulation (TMS) generated motor evoked potentials (MEP) in the flexor carpi radialis (FCR) and provided a measure of corticomotor excitability and short-interval cortical inhibition (SICI) before and immediately after a period of tDCS (1 mA, 20 min, anode and TMS applied to the lesioned hemisphere), and robotic wrist training (1hr). RESULTS: Following tDCS, the same TMS current strength evoked an increased MEP amplitude (mean 168 +/- 22%SEM; p < 0.05), that remained increased after robot training (166 +/- 23%; p < 0.05). Conditioned MEPs were of significantly lower amplitude relative to unconditioned MEPs prior to tDCS (62 +/- 6%, p < 0.05), but not after tDCS (89 +/- 14%, p = 0.40), or robot training (91 +/- 8%, p = 0.28), suggesting that the increased corticomotor excitability is associated with reduced intracortical inhibition. CONCLUSION: The persistence of these effects after robotic motor training, indicates that a motor learning and retraining program can co-exist with tDCS-induced changes in cortical motor excitability, and supports the concept of combining brain stimulation with physical therapy to promote recovery after brain injury.


Assuntos
Estimulação Elétrica/métodos , Potencial Evocado Motor/fisiologia , Antebraço/fisiologia , Robótica/métodos , Reabilitação do Acidente Vascular Cerebral , Punho/inervação , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Estimulação Elétrica/instrumentação , Feminino , Lateralidade Funcional , Humanos , Masculino , Fatores de Tempo , Estimulação Magnética Transcraniana/métodos
15.
Science ; 292(5516): 510-2, 2001 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-11313497

RESUMO

Much is known about the pathways from photoreceptors to higher visual areas in the brain. However, how we become aware of what we see or of having seen at all is a problem that has eluded neuroscience. Recordings from macaque V1 during deactivation of MT+/V5 and psychophysical studies of perceptual integration suggest that feedback from secondary visual areas to V1 is necessary for visual awareness. We used transcranial magnetic stimulation to probe the timing and function of feedback from human area MT+/V5 to V1 and found its action to be early and critical for awareness of visual motion.


Assuntos
Conscientização , Percepção de Movimento , Córtex Visual/fisiologia , Adulto , Mapeamento Encefálico , Retroalimentação , Feminino , Humanos , Imageamento por Ressonância Magnética , Magnetismo , Masculino , Fosfenos , Vias Visuais
16.
Science ; 263(5151): 1287-9, 1994 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-8122113

RESUMO

The excitability of the human motor cortex during the development of implicit and declarative knowledge of a motor task was examined. During a serial reaction time test, subjects developed implicit knowledge of the test sequence, which was reflected by diminishing response times. Motor cortical mapping with transcranial magnetic stimulation revealed that the cortical output maps to the muscles involved in the task became progressively larger until explicit knowledge was achieved, after which they returned to their baseline topography. These results illustrate the rapid functional plasticity of cortical outputs associated with learning and with the transfer of knowledge from an implicit to explicit state.


Assuntos
Aprendizagem/fisiologia , Córtex Motor/fisiologia , Transferência de Experiência/fisiologia , Mapeamento Encefálico , Estimulação Elétrica , Eletromiografia , Feminino , Humanos , Masculino , Tempo de Reação
17.
Science ; 284(5411): 167-70, 1999 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-10102821

RESUMO

Visual imagery is used in a wide range of mental activities, ranging from memory to reasoning, and also plays a role in perception proper. The contribution of early visual cortex, specifically Area 17, to visual mental imagery was examined by the use of two convergent techniques. In one, subjects closed their eyes during positron emission tomography (PET) while they visualized and compared properties (for example, relative length) of sets of stripes. The results showed that when people perform this task, Area 17 is activated. In the other, repetitive transcranial magnetic stimulation (rTMS) was applied to medial occipital cortex before presentation of the same task. Performance was impaired after rTMS compared with a sham control condition; similar results were obtained when the subjects performed the task by actually looking at the stimuli. In sum, the PET results showed that when patterns of stripes are visualized, Area 17 is activated, and the rTMS results showed that such activation underlies information processing.


Assuntos
Mapeamento Encefálico , Imaginação/fisiologia , Córtex Visual/fisiologia , Adulto , Humanos , Magnetismo , Masculino , Memória/fisiologia , Tomografia Computadorizada de Emissão , Córtex Visual/diagnóstico por imagem , Percepção Visual/fisiologia
18.
Eur J Neurol ; 16(7): 864-9, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19473363

RESUMO

BACKGROUND AND PURPOSE: To most clinicians, medical problems in musicians, particularly those concerning focal hand dystonia, constitute an unfamiliar domain difficult to manage. The latter can importantly influence diagnostics and the course of treatment. The purpose of this study was to enlighten the issue and to identify possible problems in diagnosing musicians' cramp within the Spanish medical community. METHODS: We used a brief questions' catalog and clinical histories of 665 musicians seen at our clinic for performing artists. We analyzed patients' diagnosis records in 87 cases of focal hand dystonia (13.1%). In so doing, we surveyed previous diagnoses and diverse treatments prescriptions prior to referral to our clinic. RESULTS: Referrals came primarily from orthopaedists and neurologists. The 52.9% arrived at our clinic without a diagnosis or a suspicion of suffering from focal dystonia. The most frequently attempted diagnoses other than musicians' dystonia included nerve compression, tendonitis and trigger fingers. Commonly prescribed treatments included rest, various surgical procedures, physiotherapy and oral anti-inflammatory medication. CONCLUSIONS: This data depicts the diagnostic challenges of medical professionals may encounter when confronted with musician's focal dystonia.


Assuntos
Distonia/diagnóstico , Mãos/fisiopatologia , Música , Exame Neurológico/métodos , Ortopedia/métodos , Eletromiografia , Humanos , Condução Nervosa/fisiologia , Competência Profissional , Desempenho Psicomotor/fisiologia , Estudos Retrospectivos
20.
Neuroscience ; 419: 34-45, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493549

RESUMO

The dorsolateral prefrontal cortex (DLPFC) is a crucial brain region for inhibitory control, an executive function essential for behavioral self-regulation. Recently, inhibitory control has been shown to be important for endurance performance. Improvement in inhibitory control was found following transcranial direct current stimulation (tDCS) applied over the left DLPFC (L-DLPFC). This study examined the effect tDCS on both an inhibitory control and endurance performance in a group of healthy individuals. Twelve participants received either real tDCS (Real-tDCS) or placebo tDCS (Sham-tDCS) in randomized order. The anodal electrode was placed over the L-DLPFC while the cathodal electrode was placed above Fp2. Stimulation lasted 30min with current intensity set at 2mA. A Stroop test was administered to assess inhibitory control. Heart rate (HR), ratings of perceived exertion (RPE), and leg muscle pain (PAIN) were monitored during the cycling time to exhaustion (TTE) test, while blood lactate accumulation (∆B[La-]) was measured at exhaustion. Stroop task performance was improved after Real-tDCS as demonstrated by a lower number of errors for incongruent stimuli (p=0.012). TTE was significantly longer following Real-tDCS compared to Sham-tDCS (p=0.029, 17±8 vs 15±8min), with significantly lower HR (p=0.002) and RPE (p<0.001), while no significant difference was found for PAIN (p>0.224). ∆B[La-] was significantly higher at exhaustion in Real-tDCS (p=0.040). Our findings provide preliminary evidence that tDCS with the anodal electrode over the L-DLPFC can improve both inhibitory control and endurance cycling performance in healthy individuals.


Assuntos
Função Executiva/fisiologia , Córtex Motor/fisiologia , Músculo Esquelético/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Masculino , Dor/fisiopatologia , Estimulação Transcraniana por Corrente Contínua/métodos
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