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1.
Georgian Med News ; (318): 72-74, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34628382

RESUMO

Lipomatous Hypertrophy of the Interatrial Septum (LHIS) is an unusual and benign condition characterized by the excessive deposition of adipose tissue in the interatrial septum, which is most often detected as an incidental finding on echocardiography. The classic finding is a homogenous, bi-lobed configuration of the interatrial septum with sparing of the fossa ovalis. LHIS has been associated with various atrial arrhythmias, including multifocal atrial tachycardia, multiple premature atrial contractions, atrial fibrillation and rarely sudden death. The prevalence of LHIS is estimated to be between 1-8%. The incidence increases with age, body mass and chronic corticosteroid therapy. There may be a higher incidence in women. Here the authors describe a case report of a 73 year-old obese female who visited the cardiology department for planned cryoablation of paroxysmal atrial fibrillation. Difficulties raised during transseptal punction, a bidimensional tranthoracic echocardiography (TTE) showed the typical findings of LHIS. A 73 year-old asymptomatic woman was found to have an incidental cardiac mass, TTE findings were consistent with lipomatous hypertrophy of the interatrial septum. Given the characteristic appearance on TTE, biopsy or surgery was not indicated, the procedure of cryoablation has been stopped and the patient was managed conservatively.


Assuntos
Fibrilação Atrial , Septo Interatrial , Cardiopatias Congênitas , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Septo Interatrial/diagnóstico por imagem , Septo Interatrial/cirurgia , Eletrofisiologia , Feminino , Humanos , Hipertrofia
2.
Nature ; 598(7879): 214-219, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34616064

RESUMO

The cerebellar cortex is a well-studied brain structure with diverse roles in motor learning, coordination, cognition and autonomic regulation. However,  a complete inventory of cerebellar cell types is currently lacking. Here, using recent advances in high-throughput transcriptional profiling1-3, we molecularly define cell types across individual lobules of the adult mouse cerebellum. Purkinje neurons showed considerable regional specialization, with the greatest diversity occurring in the posterior lobules. For several types of cerebellar interneuron, the molecular variation within each type was more continuous, rather than discrete. In particular, for the unipolar brush cells-an interneuron population previously subdivided into discrete populations-the continuous variation in gene expression was associated with a graded continuum of electrophysiological properties. Notably, we found that molecular layer interneurons were composed of two molecularly and functionally distinct types. Both types show a continuum of morphological variation through the thickness of the molecular layer, but electrophysiological recordings revealed marked differences between the two types in spontaneous firing, excitability and electrical coupling. Together, these findings provide a comprehensive cellular atlas of the cerebellar cortex, and outline a methodological and conceptual framework for the integration of molecular, morphological and physiological ontologies for defining brain cell types.


Assuntos
Córtex Cerebelar/citologia , Perfilação da Expressão Gênica , Transcriptoma , Adulto , Animais , Atlas como Assunto , Eletrofisiologia , Feminino , Humanos , Interneurônios/classificação , Interneurônios/citologia , Interneurônios/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuroglia/classificação , Neuroglia/citologia , Neuroglia/metabolismo , Neurônios/classificação , Neurônios/citologia , Neurônios/metabolismo
3.
Nature ; 598(7879): 151-158, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34616067

RESUMO

The neocortex is disproportionately expanded in human compared with mouse1,2, both in its total volume relative to subcortical structures and in the proportion occupied by supragranular layers composed of neurons that selectively make connections within the neocortex and with other telencephalic structures. Single-cell transcriptomic analyses of human and mouse neocortex show an increased diversity of glutamatergic neuron types in supragranular layers in human neocortex and pronounced gradients as a function of cortical depth3. Here, to probe the functional and anatomical correlates of this transcriptomic diversity, we developed a robust platform combining patch clamp recording, biocytin staining and single-cell RNA-sequencing (Patch-seq) to examine neurosurgically resected human tissues. We demonstrate a strong correspondence between morphological, physiological and transcriptomic phenotypes of five human glutamatergic supragranular neuron types. These were enriched in but not restricted to layers, with one type varying continuously in all phenotypes across layers 2 and 3. The deep portion of layer 3 contained highly distinctive cell types, two of which express a neurofilament protein that labels long-range projection neurons in primates that are selectively depleted in Alzheimer's disease4,5. Together, these results demonstrate the explanatory power of transcriptomic cell-type classification, provide a structural underpinning for increased complexity of cortical function in humans, and implicate discrete transcriptomic neuron types as selectively vulnerable in disease.


Assuntos
Ácido Glutâmico/metabolismo , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Neurônios/citologia , Neurônios/metabolismo , Doença de Alzheimer , Animais , Forma Celular , Colágeno/metabolismo , Eletrofisiologia , Proteínas da Matriz Extracelular/metabolismo , Feminino , Humanos , Lisina/análogos & derivados , Masculino , Camundongos , Neocórtex/anatomia & histologia , Neurônios/classificação , Técnicas de Patch-Clamp , Transcriptoma
4.
Phys Med ; 90: 142-149, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34649045

RESUMO

There is a paucity of literature comparing patient and staff dose during coronary angiography (CA), implantable cardiac devices, permanent pacemakers (PPM) and electrophysiology (EP) procedures and little noting dose to staff other than cardiologists. This study sought to compare patient and occupational dose during a range of fluoroscopically guided cardiac procedures. Radiation dose levels for the patients (n = 1651), cardiologists (n = 24), scrub (n = 32) and scout nurses (n = 35) were measured in a prospective single-centre study between February 2017 and August 2019. A comparison of dose during CA, device implantation, PPM insertion and EP studies was performed. Three angiographic units were used, with dosimeters worn on the temple of staff. Results indicated that occupational dose during PPM was significantly higher than other procedures. The cardiologist had the highest mean dose during biventricular implantable cardioverter-defibrillators; levels were approximately five times that of 'normal' pacemaker insertions. Transcatheter aortic valve implantations (TAVI) were associated with relatively high mean doses for both staff and patients and had a statistically significant higher (>2 times) mean patient dose area product than all other categories. TAVI workups were also related to higher mean cardiologist and scrub nurse dose. It was observed that the mean scrub nurse dose can exceed that of the cardiologist. The highest mean dose for Scout nurses were recorded during EP studies. Given the significantly higher temple dose associated with PPM insertion, cardiologists should consider utilizing ceiling mounted lead shields, lead glasses and/or skull caps where possible. Efforts should also be made to minimize the use of DSA during TAVI and TAVI workups to reduce cardiologist, nurse and patient dose.


Assuntos
Desfibriladores Implantáveis , Exposição Ocupacional , Angiografia Coronária , Eletrofisiologia , Humanos , Estudos Prospectivos , Doses de Radiação
5.
Physiol Rep ; 9(18): e14992, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34536067

RESUMO

COVID-19 is a public health emergency with cases increasing globally. Its clinical manifestations range from asymptomatic and acute respiratory disease to multiple organ dysfunction syndromes and effects of COVID-19 in the long term. Interestingly, regardless of variant, all COVID-19 share impairment of the sense of smell and taste. We would like to report, as far as we know, the first comprehensive neurophysiological evaluation of the long-term effects of SARS-CoV-2 on the olfactory system with potential-related neurological damage. The case report concerns a military doctor, with a monitored health history, infected in April 2020 by the first wave of the epidemic expansion while on military duty in Codogno (Milan). In this subject, we find the electrophysiological signal in the periphery, while its correlate is absent in the olfactory bulb region than in whole brain recordings. In agreement with this result is the lack of metabolic signs of brain activation under olfactory stimulation. Consequently, quantitative and qualitative diagnoses of anosmia were made by means of olfactometric tests. We strongly suggest a comprehensive series of olfactometric tests from the first sign of COVID-19 and subsequent patient assessments. In conclusion, electrophysiological and metabolic tests of olfactory function have made it possible to study the long-term effects and the establishment of neurological consequences.


Assuntos
Anosmia/fisiopatologia , Anosmia/virologia , COVID-19/complicações , Adulto , COVID-19/fisiopatologia , Eletrofisiologia/métodos , Potenciais Evocados/fisiologia , Humanos , Masculino , Bulbo Olfatório/fisiopatologia , Nervo Olfatório/fisiopatologia , SARS-CoV-2 , Limiar Sensorial/fisiologia
6.
Nat Commun ; 12(1): 5245, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475396

RESUMO

State-of-the-art silicon probes for electrical recording from neurons have thousands of recording sites. However, due to volume limitations there are typically many fewer wires carrying signals off the probe, which restricts the number of channels that can be recorded simultaneously. To overcome this fundamental constraint, we propose a method called electrode pooling that uses a single wire to serve many recording sites through a set of controllable switches. Here we present the framework behind this method and an experimental strategy to support it. We then demonstrate its feasibility by implementing electrode pooling on the Neuropixels 1.0 electrode array and characterizing its effect on signal and noise. Finally we use simulations to explore the conditions under which electrode pooling saves wires without compromising the content of the recordings. We make recommendations on the design of future devices to take advantage of this strategy.


Assuntos
Eletrodos Implantados , Eletrofisiologia/métodos , Espaço Extracelular/fisiologia , Silício/química , Potenciais de Ação , Animais , Encéfalo/fisiologia , Eletrofisiologia/instrumentação , Desenho de Equipamento , Camundongos , Rede Nervosa/fisiologia , Neurônios/fisiologia , Processamento de Sinais Assistido por Computador
8.
J Cogn Neurosci ; 33(7): 1230-1252, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34496395

RESUMO

Human time perception is malleable and subject to many biases. For example, it has repeatedly been shown that stimuli that are physically intense or that are unexpected seem to last longer. Two competing hypotheses have been proposed to account for such biases: One states that these temporal illusions are the result of increased levels of arousal that speeds up neural clock dynamics, whereas the alternative "magnitude coding" account states that the magnitude of sensory responses causally modulates perceived durations. Common experimental paradigms used to study temporal biases cannot dissociate between these accounts, as arousal and sensory magnitude covary and modulate each other. Here, we present two temporal discrimination experiments where two flashing stimuli demarcated the start and end of a to-be-timed interval. These stimuli could be either in the same or a different location, which led to different sensory responses because of neural repetition suppression. Crucially, changes and repetitions were fully predictable, which allowed us to explore effects of sensory response magnitude without changes in arousal or surprise. Intervals with changing markers were perceived as lasting longer than those with repeating markers. We measured EEG (Experiment 1) and pupil size (Experiment 2) and found that temporal perception was related to changes in ERPs (P2) and pupil constriction, both of which have been related to responses in the sensory cortex. Conversely, correlates of surprise and arousal (P3 amplitude and pupil dilation) were unaffected by stimulus repetitions and changes. These results demonstrate, for the first time, that sensory magnitude affects time perception even under constant levels of arousal.


Assuntos
Percepção do Tempo , Nível de Alerta , Atenção , Eletrofisiologia , Potenciais Evocados , Humanos
10.
Nat Commun ; 12(1): 4880, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385444

RESUMO

Accurate and imperceptible monitoring of electrophysiological signals is of primary importance for wearable healthcare. Stiff and bulky pregelled electrodes are now commonly used in clinical diagnosis, causing severe discomfort to users for long-time using as well as artifact signals in motion. Here, we report a ~100 nm ultra-thin dry epidermal electrode that is able to conformably adhere to skin and accurately measure electrophysiological signals. It showed low sheet resistance (~24 Ω/sq, 4142 S/cm), high transparency, and mechano-electrical stability. The enhanced optoelectronic performance was due to the synergistic effect between graphene and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which induced a high degree of molecular ordering on PEDOT and charge transfer on graphene by strong π-π interaction. Together with ultra-thin nature, this dry epidermal electrode is able to accurately monitor electrophysiological signals such as facial skin and brain activity with low-motion artifact, enabling human-machine interfacing and long-time mental/physical health monitoring.


Assuntos
Eletrodos , Eletrofisiologia/métodos , Epiderme/fisiologia , Desenho de Equipamento/métodos , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Artefatos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Condutividade Elétrica , Eletrofisiologia/instrumentação , Eletrofisiologia/normas , Desenho de Equipamento/normas , Grafite/química , Humanos , Estrutura Molecular , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/normas , Movimento (Física) , Polímeros/química , Poliestirenos/química , Pele
12.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203369

RESUMO

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disorder affecting one in 500 of the general population. Atrial fibrillation (AF) is the most common arrhythmia in patients with HCM. We sought to characterize the atrial electrophysiological and structural substrate in young and aging Gly203Ser cardiac troponin-I transgenic (HCM) mice. At 30 weeks and 50 weeks of age (n = 6 per strain each group), the left atrium was excised and placed on a multi-electrode array (MEA) for electrophysiological study; subsequent histological analyses and plasma samples were analyzed for biomarkers of extracellular matrix remodeling and cell adhesion and inflammation. Wild-type mice of matched ages were included as controls. Young HCM mice demonstrated significantly shortened atrial action potential duration (APD), increased conduction heterogeneity index (CHI), increased myocyte size, and increased interstitial fibrosis without changes in effective refractory periods (ERP), conduction velocity (CV), inflammatory infiltrates, or circulating markers of extracellular matrix remodeling and inflammation. Aging HCM mice demonstrated aggravated changes in atria electrophysiology and structural remodeling as well as increased circulating matrix metalloproteinases (MMP)-2, MMP-3, and VCAM-1 levels. This model of HCM demonstrates an underlying atrial substrate that progresses with age and may in part be responsible for the greater propensity for AF in HCM.


Assuntos
Fibrilação Atrial/metabolismo , Cardiomiopatia Hipertrófica/metabolismo , Átrios do Coração/metabolismo , Troponina I/metabolismo , Potenciais de Ação/fisiologia , Animais , Fibrilação Atrial/genética , Remodelamento Atrial/genética , Remodelamento Atrial/fisiologia , Pressão Sanguínea/fisiologia , Eletrofisiologia Cardíaca , Cardiomiopatia Hipertrófica/genética , Modelos Animais de Doenças , Eletrofisiologia , Feminino , Átrios do Coração/patologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Mutação , Troponina I/genética
13.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203489

RESUMO

The most common type of spinal cord injury is the contusion of the spinal cord, which causes progressive secondary tissue degeneration. In this study, we applied genetically modified human neural stem cells overexpressing BDNF (brain-derived neurotrophic factor) (F3.BDNF) to determine whether they can promote functional recovery in the spinal cord injury (SCI) model in rats. We transplanted F3.BDNF cells via intrathecal catheter delivery after a contusion of the thoracic spinal cord and found that they were migrated toward the injured spinal cord area by MR imaging. Transplanted F3.BDNF cells expressed neural lineage markers, such as NeuN, MBP, and GFAP and were functionally connected to the host neurons. The F3.BDNF-transplanted rats exhibited significantly improved locomotor functions compared with the sham group. This functional recovery was accompanied by an increased volume of spared myelination and decreased area of cystic cavity in the F3.BDNF group. We also observed that the F3.BDNF-transplanted rats showed reduced numbers of Iba1- and iNOS-positive inflammatory cells as well as GFAP-positive astrocytes. These results strongly suggest the transplantation of F3.BDNF cells can modulate inflammatory cells and glia activation and also improve the hyperalgesia following SCI.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Células-Tronco Neurais/metabolismo , Animais , Eletrofisiologia , Humanos , Imuno-Histoquímica , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/metabolismo
14.
Cortex ; 142: 296-316, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34332197

RESUMO

There is an apparent disparity between the fields of cognitive audiology and cognitive electrophysiology as to how linguistic context is used when listening to perceptually challenging speech. To gain a clearer picture of how listening effort impacts context use, we conducted a pre-registered study to simultaneously examine electrophysiological, pupillometric, and behavioral responses when listening to sentences varying in contextual constraint and acoustic challenge in the same sample. Participants (N = 44) listened to sentences that were highly constraining and completed with expected or unexpected sentence-final words ("The prisoners were planning their escape/party") or were low-constraint sentences with unexpected sentence-final words ("All day she thought about the party"). Sentences were presented either in quiet or with +3 dB SNR background noise. Pupillometry and EEG were simultaneously recorded and subsequent sentence recognition and word recall were measured. While the N400 expectancy effect was diminished by noise, suggesting impaired real-time context use, we simultaneously observed a beneficial effect of constraint on subsequent recognition memory for degraded speech. Importantly, analyses of trial-to-trial coupling between pupil dilation and N400 amplitude showed that when participants' showed increased listening effort (i.e., greater pupil dilation), there was a subsequent recovery of the N400 effect, but at the same time, higher effort was related to poorer subsequent sentence recognition and word recall. Collectively, these findings suggest divergent effects of acoustic challenge and listening effort on context use: while noise impairs the rapid use of context to facilitate lexical semantic processing in general, this negative effect is attenuated when listeners show increased effort in response to noise. However, this effort-induced reliance on context for online word processing comes at the cost of poorer subsequent memory.


Assuntos
Eletroencefalografia , Percepção da Fala , Eletrofisiologia , Potenciais Evocados , Feminino , Humanos , Masculino , Ruído
15.
16.
Eye (Lond) ; 35(9): 2344-2353, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34290445

RESUMO

Visual disturbance or visual failure due to toxicity of an ingested substance or a severe nutritional deficiency can present significant challenges for diagnosis and management, for instance, where an adverse reaction to a prescribed medicine is suspected. Objective assessment of visual function is important, particularly where structural changes in the retina or optic nerve have not yet occurred, as there may be a window of opportunity to mitigate or reverse visual loss. This paper reviews a number of clinical presentations where visual electrophysiological assessment has an important role in early diagnosis or management alongside clinical assessment and ocular imaging modalities. We highlight the importance of vitamin A deficiency as an easily detected marker for severe combined micronutrient deficiency.


Assuntos
Eletrorretinografia , Doenças do Nervo Óptico , Eletrofisiologia , Humanos , Doenças do Nervo Óptico/diagnóstico , Retina/diagnóstico por imagem , Transtornos da Visão/diagnóstico , Transtornos da Visão/etiologia
17.
J Electrocardiol ; 68: 44-45, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34325103

RESUMO

In modern Medicine, team working has become crucial to guarantee favorable outcomes in most therapeutical procedures. Electrophysiology (EP) represents an exemplary paradigm of it. Herein, the role of the EP staff members and the importance of cooperation before, during and after the procedure is highlighted. Moreover, the strategies and the future challenges for developing a strong and efficient teamwork through a continuous process of improvement (the so-called "Kaizen Methodology") are widely discussed.


Assuntos
Eletrocardiografia , Eletrofisiologia , Humanos
18.
Nat Commun ; 12(1): 4363, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272395

RESUMO

Conformational changes in ion channels lead to gating of an ion-conductive pore. Ion flux has been measured with high temporal resolution by single-channel electrophysiology for decades. However, correlation between functional and conformational dynamics remained difficult, lacking experimental techniques to monitor sub-millisecond conformational changes. Here, we use the outer membrane protein G (OmpG) as a model system where loop-6 opens and closes the ß-barrel pore like a lid in a pH-dependent manner. Functionally, single-channel electrophysiology shows that while closed states are favored at acidic pH and open states are favored at physiological pH, both states coexist and rapidly interchange in all conditions. Using HS-AFM height spectroscopy (HS-AFM-HS), we monitor sub-millisecond loop-6 conformational dynamics, and compare them to the functional dynamics from single-channel recordings, while MD simulations provide atomistic details and energy landscapes of the pH-dependent loop-6 fluctuations. HS-AFM-HS offers new opportunities to analyze conformational dynamics at timescales of domain and loop fluctuations.


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Eletrofisiologia/métodos , Proteínas de Escherichia coli/química , Escherichia coli/metabolismo , Canais Iônicos/metabolismo , Porinas/química , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Escherichia coli/química , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Ativação do Canal Iônico , Bicamadas Lipídicas/química , Microscopia de Força Atômica , Simulação de Dinâmica Molecular , Porinas/genética , Porinas/metabolismo , Conformação Proteica , Conformação Proteica em Folha beta , Proteínas Recombinantes , Análise Espectral , Relação Estrutura-Atividade
19.
J Invasive Cardiol ; 33(7): E522-E530, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34224381

RESUMO

BACKGROUND: The volume of atrial fibrillation (AF) catheter ablation procedures has increased to address the growing patient population with AF; however, the impact of cryoballoon ablation on electrophysiology (EP) lab throughput is under-studied when treating patients with persistent AF (PsAF). OBJECTIVE: To assess EP lab utilization associated with cryoballoon ablation for the treatment of patients with PsAF and to evaluate mechanisms that optimize hospital resources. METHODS: Procedural data derived from the STOP Persistent AF trial were input into a discrete event simulation to assess EP lab utilization during AF ablation procedures. Patient and physician delays and lab occupancy times were modeled in a nominal and efficient EP lab setting over 1000 days. Accounting for variation in procedural times, we evaluated the number of days in which preplanned pulmonary vein isolation (PVI) cases resulted in overtime or excess time for non-ablation EP cases within a given lab day. A sensitivity analysis determined the parameters that most strongly influenced EP lab throughput. RESULTS: Lab occupancy times for the Nominal Use (NU) case included 165 procedures, and the High-Efficiency Use (HEU) case was derived from 69 procedures conducted at sites with faster procedure times than average. The HEU case had shorter lab occupancy times than the NU case (158 ± 32 minutes vs 188 ± 51 minutes, respectively). In the NU case, a total of 2000 procedures were conducted, with 28 lab days (2.8%) extending into overtime and 900 lab days (90%) exhibiting excess time for a non-ablation EP case. In the HEU case, a total of 3000 procedures were conducted, with 87 lab days (8.7%) extending into overtime and 635 lab days (63.5%) exhibiting excess time for a non-ablation EP case. The model was most sensitive to lab occupancy duration and the time of day that overtime started. CONCLUSIONS: Cryoballoon ablation for the treatment of patients with PsAF confers EP lab efficiencies that can support 3 PVI cases in a lab day.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Criocirurgia , Veias Pulmonares , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Eletrofisiologia , Seguimentos , Humanos , Veias Pulmonares/cirurgia , Recidiva , Resultado do Tratamento
20.
J Vis Exp ; (172)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34279498

RESUMO

Controversies have always existed in research related to reading abilities; on whether printed words are perceived in a feedforward manner based on orthographic information after which, other representations, such as phonology and semantics are activated, or whether these are fully interactive and high-level semantic information affects early processing. An interference paradigm was implemented in the presented protocol of phonological and semantic judgment tasks that utilized the same precede-target pairs to explore the relative order of phonological and semantic activation. The high- and low-frequency target words were preceded with three conditions: semantically related, phonological-related (homophones), or unrelated. The results showed that the induced P200 component of low-frequency word pairs was significantly greater than high-frequency words in both the semantic and phonological tasks. In addition, both the homophones in the semantic task and the semantically related pairs in the phonological task caused reduction in N400 when compared to the the control condition, word frequency-independently. It is worth noting that for the low-frequency pairs in the phonological judgment task, the P200 released by the semantically related word pairs was significantly larger than that in the control condition. Overall, semantic processing in phonological tasks and phonological processing in semantic tasks were found in both high- and low-frequency words, suggesting that the interaction between semantics and phonology may operate in a task-independent manner. However, the specific time this interaction occurred may have been affected by the task and frequency.


Assuntos
Eletroencefalografia , Semântica , Eletrofisiologia , Potenciais Evocados , Feminino , Humanos , Masculino , Fonética , Tempo de Reação , Leitura
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