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1.
Medicine (Baltimore) ; 100(25): e26464, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34160450

RESUMO

ABSTRACT: Previous studies have identified inhibitory deficits in dyslexic children, but we have little understanding of their neural mechanisms, especially for Chinese children with developmental dyslexia.We used a double-blind controlled trial to study the electroencephalogram responses of dyslexic and non-dyslexic children when performing the Stroop color-word test.Behavioral data showed differences in response time and accuracy between the 2 groups. In the event-related potentials (ERP) results, dyslexic children displayed larger P2 and P3b on congruent trials, while non-dyslexic children displayed larger P2 and P3b on incongruent trials, the 2 groups showed opposite brain activation patterns on the Stroop test.Dyslexic children have poor inhibitory function, and this poor inhibition may be related to their abnormal brain activation patterns.


Assuntos
Encéfalo/fisiopatologia , Dislexia/fisiopatologia , Potenciais Evocados/fisiologia , Inibição Neural/fisiologia , Teste de Stroop , Estudos de Casos e Controles , Criança , Método Duplo-Cego , Dislexia/diagnóstico , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia
2.
Nat Commun ; 12(1): 2912, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006874

RESUMO

The hippocampal mossy fiber synapse is a key synapse of the trisynaptic circuit. Post-tetanic potentiation (PTP) is the most powerful form of plasticity at this synaptic connection. It is widely believed that mossy fiber PTP is an entirely presynaptic phenomenon, implying that PTP induction is input-specific, and requires neither activity of multiple inputs nor stimulation of postsynaptic neurons. To directly test cooperativity and associativity, we made paired recordings between single mossy fiber terminals and postsynaptic CA3 pyramidal neurons in rat brain slices. By stimulating non-overlapping mossy fiber inputs converging onto single CA3 neurons, we confirm that PTP is input-specific and non-cooperative. Unexpectedly, mossy fiber PTP exhibits anti-associative induction properties. EPSCs show only minimal PTP after combined pre- and postsynaptic high-frequency stimulation with intact postsynaptic Ca2+ signaling, but marked PTP in the absence of postsynaptic spiking and after suppression of postsynaptic Ca2+ signaling (10 mM EGTA). PTP is largely recovered by inhibitors of voltage-gated R- and L-type Ca2+ channels, group II mGluRs, and vacuolar-type H+-ATPase, suggesting the involvement of retrograde vesicular glutamate signaling. Transsynaptic regulation of PTP extends the repertoire of synaptic computations, implementing a brake on mossy fiber detonation and a "smart teacher" function of hippocampal mossy fiber synapses.


Assuntos
Fibras Musgosas Hipocampais/fisiologia , Plasticidade Neuronal/fisiologia , Terminações Pré-Sinápticas/fisiologia , Células Piramidais/fisiologia , Sinapses/fisiologia , Animais , Células Cultivadas , Estimulação Elétrica , Potenciais Evocados/fisiologia , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Masculino , Técnicas de Patch-Clamp , Ratos , Potenciais Sinápticos/fisiologia
3.
J Clin Neurophysiol ; 38(3): 171-180, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33958567

RESUMO

SUMMARY: Evoked potentials (EPs) measure quantitatively and objectively the alterations of central signal propagation in multiple sclerosis and have long been used for diagnosis. More recently, their utility for prognosis has been demonstrated in several studies, summarizing multiple EP modalities in a single score. In particular, visual, somatosensory, and motor EPs are useful because of their sensitivity to pathology in the frequently affected optic nerve, somatosensory tract, and pyramidal system. Quantitative EP scores show higher sensitivity to change than clinical assessment and may be used to monitor disease progression. Visual EP and the visual system have served as a model to study remyelinating therapies in the setting of acute and chronic optic neuritis. This review presents rationale and evidence for using multimodal EP as prognostic and response biomarkers in clinical trials, targeting remyelination or halting disease progression in multiple sclerosis.


Assuntos
Ensaios Clínicos como Assunto , Potenciais Evocados/fisiologia , Esclerose Múltipla , Adulto , Progressão da Doença , Humanos , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/terapia , Prognóstico , Resultado do Tratamento
4.
J Clin Neurophysiol ; 38(3): 181-185, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33958568

RESUMO

SUMMARY: Evoked potentials have assisted in the diagnosis of multiple sclerosis for years, but the potential to demonstrate pathophysiologic change has prompted a reconsideration of their potential role as outcome measures in clinical trials of multiple sclerosis. The use of any surrogate end point or biomarker in clinical trials requires a thorough understanding of that end point's performance characteristics and utility in a particular setting. This article explores regulatory issues regarding the use of biomarkers and surrogate end points in clinical trials of multiple sclerosis with particular emphasis on challenges faced by evoked potential studies.


Assuntos
Ensaios Clínicos como Assunto , Potenciais Evocados/fisiologia , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/terapia , Resultado do Tratamento , Biomarcadores , Humanos
5.
Acta Neurochir (Wien) ; 163(5): 1213-1226, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33686522

RESUMO

Surgical treatment of tumors, epileptic foci or of vascular origin, requires a detailed individual pre-surgical workup and intra-operative surveillance of brain functions to minimize the risk of post-surgical neurological deficits and decline of quality of life. Most attention is attributed to language, motor functions, and perception. However, higher cognitive functions such as social cognition, personality, and the sense of self may be affected by brain surgery. To date, the precise localization and the network patterns of brain regions involved in such functions are not yet fully understood, making the assessment of risks of related post-surgical deficits difficult. It is in the interest of neurosurgeons to understand with which neural systems related to selfhood and personality they are interfering during surgery. Recent neuroscience research using virtual reality and clinical observations suggest that the insular cortex, medial prefrontal cortex, and temporo-parietal junction are important components of a neural system dedicated to self-consciousness based on multisensory bodily processing, including exteroceptive and interoceptive cues (bodily self-consciousness (BSC)). Here, we argue that combined extra- and intra-operative approaches using targeted cognitive testing, functional imaging and EEG, virtual reality, combined with multisensory stimulations, may contribute to the assessment of the BSC and related cognitive aspects. Although the usefulness of particular biomarkers, such as cardiac and respiratory signals linked to virtual reality, and of heartbeat evoked potentials as a surrogate marker for intactness of multisensory integration for intra-operative monitoring has to be proved, systemic and automatized testing of BSC in neurosurgical patients will improve future surgical outcome.


Assuntos
Mapeamento Encefálico , Procedimentos Neurocirúrgicos , Autoimagem , Imagem Corporal , Cognição , Potenciais Evocados/fisiologia , Frequência Cardíaca/fisiologia , Humanos
6.
Soc Cogn Affect Neurosci ; 16(4): 439-452, 2021 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-33527110

RESUMO

Social comparison is a common behavior that largely determines people's experience of decision outcome. Previous research has showed that interpersonal relationship plays a pivotal role in social comparison. In the current study, we investigated whether the manipulation of context-based relationship would affect participants' comparison of self-outcome and other-outcome. Participants first finished a trust game with likeable (dislikeable) partner and then they were involved in a gambling task and observed the outcomes for themselves and for partners. According to self-reports, participants were more satisfied with likeable partner's gains than losses only when they received gains, but they were always more satisfied with dislikeable player's losses compared to gains. Event-related potentials including the feedback-related negativity (FRN), P3 and late positive component (LPC) were sensitive to context-based relationship. Specifically, the prediction error signal (indexed by the FRN) was largest when participants received losses but dislikeable player received gains. Meanwhile, the P3 indicates that participants had stronger motivation to outperform dislikeable player. Finally, the LPC was larger when participants received the same outcomes with dislikeable players. In general, our results support the key point of the self-evaluation maintenance model that personal closeness modulates subjective sensitivity when drawing a comparison of one's outcomes with other's outcomes.


Assuntos
Potenciais Evocados/fisiologia , Relações Interpessoais , Comparação Social , Tomada de Decisões/fisiologia , Eletroencefalografia , Retroalimentação Psicológica , Feminino , Jogo de Azar/psicologia , Humanos , Masculino , Motivação , Inventário de Personalidade , Autorrelato , Confiança/psicologia , Adulto Jovem
7.
Neurosci Lett ; 749: 135755, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33610671

RESUMO

Shape and spirit similarity are two kinds of common artistic modes in concept visualization. The adoption depends on the designers' subjective preference and judgment, which may cause potential risks for semantic communication. This article used pairs of real image-concrete word as the roots, and contrasted four kinds of multimodal mappings such as shape similarity-concrete concept, shape similarity-abstract concept, spirit similarity-concrete concept, and spirit similarity-abstract concept to compare the matching difference through the S1(picture)-S2(word) paradigm. The behavioral results showed that shape similarity had advantages in both matching rate and reaction time over spirit similarity, but the difference was more significant to the concrete word than to the abstract word. The ERPs showed that the N1, P2, and N400 components had alike effects with the behavioral results, but the mappings of spirit similarity-concrete concept elicited the largest positivity of P600, suggesting the complicated mechanisms of semantic integration and concreteness effect in the multimodal mappings. This study proves that the concrete concept should be visualized according to its appearance, not the most striking feature or function; but the visulization of abstract concept shows less difference after a concreteness transition.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Formação de Conceito/fisiologia , Potenciais Evocados/fisiologia , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Tempo de Reação , Leitura
8.
Proc Natl Acad Sci U S A ; 118(4)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33468671

RESUMO

Humans spend much of their lives engaging with their internal train of thoughts. Traditionally, research focused on whether or not these thoughts are related to ongoing tasks, and has identified reliable and distinct behavioral and neural correlates of task-unrelated and task-related thought. A recent theoretical framework highlighted a different aspect of thinking-how it dynamically moves between topics. However, the neural correlates of such thought dynamics are unknown. The current study aimed to determine the electrophysiological signatures of these dynamics by recording electroencephalogram (EEG) while participants performed an attention task and periodically answered thought-sampling questions about whether their thoughts were 1) task-unrelated, 2) freely moving, 3) deliberately constrained, and 4) automatically constrained. We examined three EEG measures across different time windows as a function of each thought type: stimulus-evoked P3 event-related potentials and non-stimulus-evoked alpha power and variability. Parietal P3 was larger for task-related relative to task-unrelated thoughts, whereas frontal P3 was increased for deliberately constrained compared with unconstrained thoughts. Frontal electrodes showed enhanced alpha power for freely moving thoughts relative to non-freely moving thoughts. Alpha-power variability was increased for task-unrelated, freely moving, and unconstrained thoughts. Our findings indicate distinct electrophysiological patterns associated with task-unrelated and dynamic thoughts, suggesting these neural measures capture the heterogeneity of our ongoing thoughts.


Assuntos
Atenção/fisiologia , Encéfalo/fisiologia , Potencial Evocado P300/fisiologia , Encéfalo/diagnóstico por imagem , Eletroencefalografia , Potenciais Evocados/fisiologia , Humanos
9.
PLoS Biol ; 19(1): e3001038, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33497384

RESUMO

Planning to speak is a challenge for the brain, and the challenge varies between and within languages. Yet, little is known about how neural processes react to these variable challenges beyond the planning of individual words. Here, we examine how fundamental differences in syntax shape the time course of sentence planning. Most languages treat alike (i.e., align with each other) the 2 uses of a word like "gardener" in "the gardener crouched" and in "the gardener planted trees." A minority keeps these formally distinct by adding special marking in 1 case, and some languages display both aligned and nonaligned expressions. Exploiting such a contrast in Hindi, we used electroencephalography (EEG) and eye tracking to suggest that this difference is associated with distinct patterns of neural processing and gaze behavior during early planning stages, preceding phonological word form preparation. Planning sentences with aligned expressions induces larger synchronization in the theta frequency band, suggesting higher working memory engagement, and more visual attention to agents than planning nonaligned sentences, suggesting delayed commitment to the relational details of the event. Furthermore, plain, unmarked expressions are associated with larger desynchronization in the alpha band than expressions with special markers, suggesting more engagement in information processing to keep overlapping structures distinct during planning. Our findings contrast with the observation that the form of aligned expressions is simpler, and they suggest that the global preference for alignment is driven not by its neurophysiological effect on sentence planning but by other sources, possibly by aspects of production flexibility and fluency or by sentence comprehension. This challenges current theories on how production and comprehension may affect the evolution and distribution of syntactic variants in the world's languages.


Assuntos
Compreensão/fisiologia , Idioma , Rede Nervosa/fisiologia , Percepção da Fala/fisiologia , Estimulação Acústica , Adolescente , Adulto , Atenção/fisiologia , Encéfalo/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Índia , Linguística , Masculino , Memória de Curto Prazo/fisiologia , Tempo de Reação , Semântica , Adulto Jovem
10.
J Vis ; 21(1): 3, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33410892

RESUMO

Fixation-related potentials (FRPs), neural responses aligned to the end of saccades, are a promising tool for studying the dynamics of attention and cognition under natural viewing conditions. In the past, four methodological problems have complicated the analysis of such combined eye-tracking/electroencephalogram experiments: (1) the synchronization of data streams, (2) the removal of ocular artifacts, (3) the condition-specific temporal overlap between the brain responses evoked by consecutive fixations, and (4) the fact that numerous low-level stimulus and saccade properties also influence the postsaccadic neural responses. Although effective solutions exist for the first two problems, the latter two are only beginning to be addressed. In the current paper, we present and review a unified regression-based framework for FRP analysis that allows us to deconvolve overlapping potentials while also controlling for both linear and nonlinear confounds on the FRP waveform. An open software implementation is provided for all procedures. We then demonstrate the advantages of this proposed (non)linear deconvolution modeling approach for data from three commonly studied paradigms: face perception, scene viewing, and reading. First, for a traditional event-related potential (ERP) face recognition experiment, we show how this technique can separate stimulus ERPs from overlapping muscle and brain potentials produced by small (micro)saccades on the face. Second, in natural scene viewing, we model and isolate multiple nonlinear effects of saccade parameters on the FRP. Finally, for a natural sentence reading experiment using the boundary paradigm, we show how it is possible to study the neural correlates of parafoveal preview after removing spurious overlap effects caused by the associated difference in average fixation time. Our results suggest a principal way of measuring reliable eye movement-related brain activity during natural vision.


Assuntos
Potenciais Evocados/fisiologia , Medições dos Movimentos Oculares , Tecnologia de Rastreamento Ocular , Movimentos Sacádicos/fisiologia , Adulto , Eletroencefalografia/métodos , Reconhecimento Facial/fisiologia , Feminino , Humanos , Masculino , Leitura , Análise de Regressão , Adulto Jovem
11.
Neuroimage ; 228: 117712, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33387630

RESUMO

In recent years, several ERP components have been identified as potential neural correlates of consciousness (NCC), including early negativities and late positivities. Based on experiments in the visual modality, it has recently been shown that awareness is often confounded with reporting it, possibly overestimating the NCC. It is unknown whether similar constraints also exist in the auditory modality. In order to address this gap, we presented spoken words in a sustained inattentional deafness paradigm. Electrophysiological responses were obtained in three physically identical experimental conditions that differed only with respect to the participants' instructions. Participants were either left uninformed or informed about the presence of spoken words while confronted with an auditory distractor task (U/I condition), informed about the words while exposed to the same task as before (I condition), or requested to respond to the now task-relevant speech stimuli (TR condition). After completion of the U/I condition, only informed participants reported awareness of the words. In ERPs, awareness of words in the U/I and I condition was accompanied by an anterior auditory awareness negativity (AAN). Only when stimuli were task-relevant, i.e., during the TR condition, late positivities emerged. Taken together, these results indicate that early negativities but not late positivities index awareness across sensory modalities. Thus, they provide evidence for a recurrent processing framework, which highlights the importance of early sensory processing in conscious perception.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Conscientização/fisiologia , Estado de Consciência/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Neurosci Lett ; 744: 135625, 2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-33421488

RESUMO

Previous studies studies indicate that individuals tend to integrate positive information into their self-concept. However, whether such self-positivity bias would still be observed without an explicit self-related cue is unknown. In the present study, 29 participants were asked to evaluate a series of positive and negative trait adjectives, after the participants were presented with their own name or another name subliminally. During the task, their electroencephalograms were recorded. The results showed participants responded faster to positive traits than to negative traits in the self-name cue conditions. In addition, both the latencies and the amplitudes of the N400 showed significant interaction between name-cue and valence in N400 (240-440 ms) amplitudes. The earlier N400 latencies and smaller N400 amplitudes were associated with positive traits in the self-name cue. These results suggested that the self-positivity bias can also be observed in a subliminally presenting self-cue, indicating the robustness of self-positivity bias.


Assuntos
Sinais (Psicologia) , Potenciais Evocados/fisiologia , Otimismo/psicologia , Desempenho Psicomotor/fisiologia , Autoimagem , Adolescente , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Adulto Jovem
13.
Neuroimage ; 224: 117424, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33035670

RESUMO

Clinical and subclinical (trait) anxiety impairs decision making and interferes with learning. Less understood are the effects of temporary anxious states on learning and decision making in healthy populations, and whether these can serve as a model for clinical anxiety. Here we test whether anxious states in healthy individuals elicit a pattern of aberrant behavioural, neural, and physiological responses comparable with those found in anxiety disorders-particularly when processing uncertainty in unstable environments. In our study, both a state anxious and a control group learned probabilistic stimulus-outcome mappings in a volatile task environment while we recorded their electrophysiological (EEG) signals. By using a hierarchical Bayesian model of inference and learning, we assessed the effect of state anxiety on Bayesian belief updating with a focus on uncertainty estimates. State anxiety was associated with an underestimation of environmental uncertainty, and informational uncertainty about the reward tendency. Anxious individuals' beliefs about reward contingencies were more precise (had smaller uncertainty) and thus more resistant to updating, ultimately leading to impaired reward-based learning. State anxiety was also associated with greater uncertainty about volatility. We interpret this pattern as evidence that state anxious individuals are less tolerant to informational uncertainty about the contingencies governing their environment and more willing to be uncertain about the level of stability of the world itself. Further, we tracked the neural representation of belief update signals in the trial-by-trial EEG amplitudes. In control participants, lower-level precision-weighted prediction errors (pwPEs) about reward tendencies were represented in the ERP signals across central and parietal electrodes peaking at 496 ms, overlapping with the late P300 in classical ERP analysis. The state anxiety group did not exhibit a significant representation of low-level pwPEs, and there were no significant differences between the groups. Smaller variance in low-level pwPE about reward tendencies in state anxiety could partially account for the null results. Expanding previous computational work on trait anxiety, our findings establish that temporary anxious states in healthy individuals impair reward-based learning in volatile environments, primarily through changes in uncertainty estimates, which play a central role in current Bayesian accounts of perceptual inference and learning.


Assuntos
Ansiedade/fisiopatologia , Meio Ambiente , Potenciais Evocados/fisiologia , Aprendizagem/fisiologia , Aprendizagem por Probabilidade , Recompensa , Incerteza , Adolescente , Adulto , Transtornos de Ansiedade/fisiopatologia , Teorema de Bayes , Tomada de Decisões , Eletroencefalografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
14.
Neuroimage ; 226: 117605, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271267

RESUMO

Looking at the eyes informs us about the thoughts and emotions of those around us, and impacts our own emotional state. However, it is unknown how perceiving direct and averted gaze impacts our ability to share the gazer's positive and negative emotions, abilities referred to as positive and negative affective empathy. We presented 44 participants with contextual sentences describing positive, negative and neutral events happening to other people (e.g. "Her newborn was saved/killed/fed yesterday afternoon."). These were designed to elicit positive, negative, or little to no empathy, and were followed by direct or averted gaze images of the individuals described. Participants rated their affective empathy for the individual and their own emotional valence on each trial. Event-related potentials time-locked to face-onset and associated with empathy and emotional processing were recorded to investigate whether they were modulated by gaze direction. Relative to averted gaze, direct gaze was associated with increased positive valence in the positive and neutral conditions and with increased positive empathy ratings. A similar pattern was found at the neural level, using robust mass-univariate statistics. The N100, thought to reflect an automatic activation of emotion areas, was modulated by gaze in the affective empathy conditions, with opposite effect directions in positive and negative conditions.. The P200, an ERP component sensitive to positive stimuli, was modulated by gaze direction only in the positive empathy condition. Positive and negative trials were processed similarly at the early N200 processing stage, but later diverged, with only negative trials modulating the EPN, P300 and LPP components. These results suggest that positive and negative affective empathy are associated with distinct time-courses, and that perceived gaze direction uniquely modulates positive empathy, highlighting the importance of studying empathy with face stimuli.


Assuntos
Encéfalo/fisiologia , Emoções/fisiologia , Empatia/fisiologia , Potenciais Evocados/fisiologia , Fixação Ocular , Adolescente , Eletroencefalografia/métodos , Expressão Facial , Feminino , Humanos , Masculino , Percepção Visual/fisiologia
15.
Neuroimage ; 226: 117569, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33221446

RESUMO

Electrophysiological studies in rodents allow recording neural activity during threats with high temporal and spatial precision. Although fMRI has helped translate insights about the anatomy of underlying brain circuits to humans, the temporal dynamics of neural fear processes remain opaque and require EEG. To date, studies on electrophysiological brain signals in humans have helped to elucidate underlying perceptual and attentional processes, but have widely ignored how fear memory traces evolve over time. The low signal-to-noise ratio of EEG demands aggregations across high numbers of trials, which will wash out transient neurobiological processes that are induced by learning and prone to habituation. Here, our goal was to unravel the plasticity and temporal emergence of EEG responses during fear conditioning. To this end, we developed a new sequential-set fear conditioning paradigm that comprises three successive acquisition and extinction phases, each with a novel CS+/CS- set. Each set consists of two different neutral faces on different background colors which serve as CS+ and CS-, respectively. Thereby, this design provides sufficient trials for EEG analyses while tripling the relative amount of trials that tap into more transient neurobiological processes. Consistent with prior studies on ERP components, data-driven topographic EEG analyses revealed that ERP amplitudes were potentiated during time periods from 33-60 ms, 108-200 ms, and 468-820 ms indicating that fear conditioning prioritizes early sensory processing in the brain, but also facilitates neural responding during later attentional and evaluative stages. Importantly, averaging across the three CS+/CS- sets allowed us to probe the temporal evolution of neural processes: Responses during each of the three time windows gradually increased from early to late fear conditioning, while long-latency (460-730 ms) electrocortical responses diminished throughout fear extinction. Our novel paradigm demonstrates how short-, mid-, and long-latency EEG responses change during fear conditioning and extinction, findings that enlighten the learning curve of neurophysiological responses to threat in humans.


Assuntos
Encéfalo/fisiologia , Condicionamento Clássico/fisiologia , Potenciais Evocados/fisiologia , Medo , Adolescente , Adulto , Condicionamento Psicológico , Eletroencefalografia , Extinção Psicológica , Feminino , Voluntários Saudáveis , Humanos , Masculino , Vias Neurais , Plasticidade Neuronal , Adulto Jovem
16.
Clin EEG Neurosci ; 52(1): 29-37, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32579028

RESUMO

INTRODUCTION: Suicide is the second leading cause of death among adolescents. Suicidal behavior is associated with impairments in attention. Attention can be directed toward relevant events in the environment either actively, under voluntary control, or passively, by external salient events. The extent to which the risk for suicidal behavior affects active and passive attention is largely unknown. METHODS: Event-related potentials (ERPs) were recorded while 14 adolescents with acute suicidal behavior and 14 healthy controls performed an auditory 3-stimulus oddball task. The task consisted of standard (80%), target (10%), and novel (10%) stimuli. The participants were instructed to press a button upon presentation of the target. The novel stimuli were unexpected and irrelevant to the target detection task. RESULTS: Accuracy of target detection was slightly but significantly reduced in the suicidal group. There were no significant differences in the amplitude of the target-N2 or -P3b between groups. There was a slight, but nonsignificant, increase in the amplitude of the novel-N2 and -P3 in the suicidal group. CONCLUSIONS: This is the first study to explore both passive and controlled aspects of attention using ERPs in adolescents with acute suicidal behavior. Although there were no significant ERP group differences, this is an important step in identifying objective markers of suicide risk among adolescents.


Assuntos
Atenção/fisiologia , Potenciais Evocados Auditivos/fisiologia , Potenciais Evocados/fisiologia , Tentativa de Suicídio/psicologia , Adolescente , Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Ideação Suicida
17.
Neurosurg Rev ; 44(2): 709-720, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32291559

RESUMO

The aim of this comprehensive review is to provide an instructional guide for providers regarding the parameters and programming of spinal cord stimulation (SCS) devices. Knowing these fundamentals will aid in providing superior pain relief to patients. SCS has four programmable parameters: contact (electrode) selection, amplitude, pulse width, and frequency. Each parameter needs to be accounted for when assessing which program works for which patient. Traditional open-loop systems allow for different "programs," or combinations of these four parameters, to be pre-set by the provider and medical device representative. These allow for flexibility in the type of stimulation delivered to the patient depending on activity. Patients are also given control over programs and changing the amplitudes of these programs. However, some open-loop systems place the burden of toggling between programs to manage pain control on patients, though this tends to be less in subparesthesia programs. Newer closed-loop systems make it possible for stimulation settings to automatically adjust in response to accelerometry and evoked compound action potential feedback, and therefore have the potential to streamline the patient experience. This article provides practitioners with the basic knowledge of SCS parameters and programming systems. Understanding their use is essential to providing optimal pain relief to patients.


Assuntos
Dor Crônica/terapia , Manejo da Dor/métodos , Software , Estimulação da Medula Espinal/métodos , Dor Crônica/fisiopatologia , Potenciais Evocados/fisiologia , Humanos , Manejo da Dor/tendências , Software/tendências , Medula Espinal/fisiologia , Medula Espinal/fisiopatologia
18.
Psychol Res ; 85(1): 151-180, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31624919

RESUMO

We used event-related potentials to determine whether lexical access during semantic processing is achieved solely by the letter-based route, or by both a letter-based and word-based route. Participants determined whether words were related or unrelated to a prespecified category. To disrupt the word-based route (i.e., disrupt the processing of overall word shape), we manipulated case type. We measured the N170, assumed to be an index of holistic processing, and the N400, an index of semantic activation. Surprisingly, mixed-case words elicited a larger N170 effect than either consistent lowercase words (Experiment 1) or consistent uppercase words (Experiment 2). The N400, meanwhile, was unaffected by case mixing. In contrast, LEET words (e.g., T4BL3 instead of TABLE), which preserve overall word shape but distort letter shape, increased the N400 but did not reduce the N170 (Experiment 3). The results indicate that the N170 is in fact not a reliable index of holistic word processing. Implications for word recognition models are discussed.


Assuntos
Potenciais Evocados/fisiologia , Semântica , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Leitura , Adulto Jovem
19.
Emotion ; 21(2): 283-296, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31815497

RESUMO

In the present research, we assessed the effects of culture on the ability to regulate affective neural responses. Using an event-related potential design focusing on the centroparietal late positive potential (LPP), we found that cultural groups differed in their ability to intentionally regulate these responses. As a group, European Americans demonstrated successful up-regulation of the LPP in response to positive and negative valence images, as did participants from Mexican cultural backgrounds who also showed successful down-regulation of the LPP in response to positive valence images. As a group, participants from Chinese cultural backgrounds did not show evidence of successful up- or down-regulation of LPP responses. This work confirms and extends preliminary findings of cultural variation in emotion regulation abilities. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Eletroencefalografia/métodos , Regulação Emocional/fisiologia , Potenciais Evocados/fisiologia , Adulto , Cultura , Feminino , Humanos , Masculino , Adulto Jovem
20.
J Clin Neurophysiol ; 38(1): 36-42, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31725033

RESUMO

PURPOSE: The purpose of this study was to examine if depression and fatigue affect event-related brain potentials (ERPs) in patients with relapsing-remitting multiple sclerosis, and to assess the significance of ERP as an indicator of cognitive impairment. METHODS: A total of 81 relapsing-remitting multiple sclerosis patients and 32 healthy control subjects participated in the study. Cognitive functions were evaluated using a standard PASAT, the symbol digit modality test, and ERP. The degrees of depressive symptomatology and fatigue were assessed with Beck Depression Inventory, the Fatigue Severity Scale, and the Fatigue Impact Scale. RESULTS: Fatigue and depression had a negative effect on the cognitive functions examined by neuropsychological tests. Depression and fatigue did not influence ERP amplitude and latency findings. Depression level was negatively correlated with symbol digit modality test score (r = -0.135, P < 0.05). Fatigue level was negatively correlated with the results for PASAT A (r = -0.225, P < 0.05) and PASAT B (r = -0.342, P < 0.01). Reaction time was positively associated with depression (r = 0.246, P = 0.01) and fatigue (r = 0.281, P = 0.01). CONCLUSIONS: Depression and fatigue have no effect on ERP amplitude and latency, so they cannot participate in risk assessment for the development of cognitive impairment in patients with relapsing-remitting multiple sclerosis.


Assuntos
Disfunção Cognitiva/etiologia , Potenciais Evocados/fisiologia , Esclerose Múltipla Recidivante-Remitente/complicações , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/psicologia , Adulto , Estudos Transversais , Depressão/fisiopatologia , Fadiga/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
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