scholarly journals Novelty is not enough: laser-evoked potentials are determined by stimulus saliency, not absolute novelty

2013 ◽  
Vol 109 (3) ◽  
pp. 692-701 ◽  
Author(s):  
I. Ronga ◽  
E. Valentini ◽  
A. Mouraux ◽  
G. D. Iannetti
Keyword(s):  
Evoked Potentials ◽  
Stimulus Intensity ◽  
Interstimulus Interval ◽  
Event Related Potentials ◽  
Spatial Location ◽  
Laser Evoked Potentials ◽  
Repeated Stimulus ◽  
Stimulus Saliency ◽  
Related Potentials ◽  
Selective Change

Event-related potentials (ERPs) elicited by transient nociceptive stimuli in humans are largely sensitive to bottom-up novelty induced, for example, by changes in stimulus attributes (e.g., modality or spatial location) within a stream of repeated stimuli. Here we aimed 1) to test the contribution of a selective change of the intensity of a repeated stimulus in determining the magnitude of nociceptive ERPs, and 2) to dissect the effect of this change of intensity in terms of “novelty” and “saliency” (an increase of stimulus intensity is more salient than a decrease of stimulus intensity). Nociceptive ERPs were elicited by trains of three consecutive laser stimuli (S1-S2-S3) delivered to the hand dorsum at a constant 1-s interstimulus interval. Three, equally spaced intensities were used: low (L), medium (M), and high (H). While the intensities of S1 and S2 were always identical (L, M, or H), the intensity of S3 was either identical (e.g., HHH) or different (e.g., MMH) from the intensity of S1 and S2. Introducing a selective change in stimulus intensity elicited significantly larger N1 and N2 waves of the S3-ERP but only when the change consisted in an increase in stimulus intensity. This observation indicates that nociceptive ERPs do not simply reflect processes involved in the detection of novelty but, instead, are mainly determined by stimulus saliency.

scholarly journals Potenciais evocados auditivos corticais no transtorno do espectro do autismo: revisão sistemática

CoDAS ◽  
2021 ◽  
Vol 33 (2) ◽  
Author(s):  
Mariana Keiko Kamita ◽  
Liliane Aparecida Fagundes Silva ◽  
Carla Gentile Matas
Keyword(s):  
Autism Spectrum Disorder ◽  
Evoked Potentials ◽  
Autistic Disorder ◽  
Web Of Science ◽  
Event Related Potentials ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Cochrane Library ◽  
Related Potentials

RESUMO Objetivo Identificar e analisar quais são os achados característicos dos Potenciais Evocados Auditivos Corticais (PEAC) em crianças e/ou adolescentes com Transtorno do Espectro do Autismo (TEA) em comparação do desenvolvimento típico, por meio de uma revisão sistemática da literatura. Estratégia de pesquisa Após formulação da pergunta de pesquisa, foi realizada uma revisão da literatura em sete bases de dados (Web of Science, Pubmed, Cochrane Library, Lilacs, Scielo, Science Direct, e Google acadêmico), com os seguintes descritores: transtorno do espectro autista (autism spectrum disorder), transtorno autístico (autistic disorder), potenciais evocados auditivos (evoked potentials, auditory), potencial evocado P300 (event related potentials, P300) e criança (child). A presente revisão foi cadastrada no Próspero, sob número 118751. Critérios de seleção Foram selecionados estudos publicados na integra, sem limitação de idioma, entre 2007 e 2019. Análise dos dados: Foram analisadas as características de latência e amplitude dos componentes P1, N1, P2, N2 e P3 presentes nos PEAC. Resultados Foram localizados 193 estudos; contudo 15 estudos contemplaram os critérios de inclusão. Embora não tenha sido possível identificar um padrão de resposta para os componentes P1, N1, P2, N2 e P3, os resultados da maioria dos estudos demonstraram que indivíduos com TEA podem apresentar diminuição de amplitude e aumento de latência do componente P3. Conclusão Indivíduos com TEA podem apresentar respostas diversas para os componentes dos PEAC, sendo que a diminuição de amplitude e aumento de latência do componente P3 foram as características mais comuns.

scholarly journals The Potential of Trial-by-Trial Variabilities of Ongoing-EEG, Evoked Potentials, Event Related Potentials and fMRI as Diagnostic Markers for Neuropsychiatric Disorders

2019 ◽  
Vol 12 ◽  
Author(s):  
Carlos Trenado ◽  
Anaí González-Ramírez ◽  
Victoria Lizárraga-Cortés ◽  
Nicole Pedroarena Leal ◽  
Elias Manjarrez ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Event Related Potentials ◽  
Neuropsychiatric Disorders ◽  
Diagnostic Markers ◽  
Related Potentials ◽  
Ongoing Eeg

scholarly journals Single-Trial Evoked Potential Estimating Based on Sparse Coding under Impulsive Noise Environment

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Nannan Yu ◽  
Ying Chen ◽  
Lingling Wu ◽  
Hanbing Lu
Keyword(s):  
Evoked Potentials ◽  
Sparse Coding ◽  
Stable Distribution ◽  
Impulsive Noise ◽  
Event Related Potentials ◽  
Signal Denoising ◽  
Single Trial ◽  
Gaussian Random Process ◽  
Noise Environment ◽  
Related Potentials

Estimating single-trial evoked potentials (EPs) corrupted by the spontaneous electroencephalogram (EEG) can be regarded as signal denoising problem. Sparse coding has significant success in signal denoising and EPs have been proven to have strong sparsity over an appropriate dictionary. In sparse coding, the noise generally is considered to be a Gaussian random process. However, some studies have shown that the background noise in EPs may present an impulsive characteristic which is far from Gaussian but suitable to be modeled by the α-stable distribution 1<α≤2. Consequently, the performances of general sparse coding will degrade or even fail. In view of this, we present a new sparse coding algorithm using p-norm optimization in single-trial EPs estimating. The algorithm can track the underlying EPs corrupted by α-stable distribution noise, trial-by-trial, without the need to estimate the α value. Simulations and experiments on human visual evoked potentials and event-related potentials are carried out to examine the performance of the proposed approach. Experimental results show that the proposed method is effective in estimating single-trial EPs under impulsive noise environment.

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