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1.
Clin Neurophysiol ; 130(7): 1135-1143, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31085447

RESUMO

OBJECTIVE: A recent neurocomputational model proposed that anxious hypervigilance impedes perceptual learning. This view is supported by the observed modulation of the mismatch negativity (MMN), a biomarker of implicit perceptual learning processes, in anxiety disorders. However, other studies found that anxious states sensitize brain responses with no impact on perceptual learning. The present research aimed to elucidate the impact of anticipatory anxiety on early stimulus processing in the healthy population. METHODS: We used electroencephalography to investigate the impact of unpredictable threat on the amplitude of the MMN and other components of the auditory evoked response in healthy participants during a passive auditory oddball task. RESULTS: We found a general sensitization of early components of the auditory evoked response and changes in subjective and autonomic measures of anxiety during threat periods. The MMN amplitude did not differ during threat, compared to safe periods. However, this difference was modulated by the level of state or trait anxiety. CONCLUSION: We propose that anxiety sensitizes early brain responses to unspecific environmental stimuli but affects implicit perceptual learning processes only when an individual is located at the higher end of the anxiety spectrum. SIGNIFICANCE: This view might distinguish between an adaptive role of anxiety on processing efficiency and its detrimental impact on implicit perceptual learning observed in psychiatric conditions.


Assuntos
Ansiedade/fisiopatologia , Percepção Auditiva/fisiologia , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Aprendizagem/fisiologia , Ansiedade/psicologia , Estimulação Elétrica/métodos , Potenciais Evocados P300/fisiologia , Feminino , Resposta Galvânica da Pele/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Autorrelato
2.
Neuropsychologia ; 119: 92-100, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30040956

RESUMO

Non-dual meditation aims to undo maladaptive cognitive and affective patterns by recognizing their constructed and transient nature. We previously found high-amplitude spontaneous gamma (25-40 Hz) oscillatory activity during such practice. Nonetheless, it is unclear how this meditation state differs from other practices, in terms of perceptual information processing. Here, we hypothesized that non-dual meditation can downregulate the automatic formation of perceptual habits. To investigate this hypothesis, we recorded EEG from expert Buddhist meditation practitioners and matched novices to measure two components of the auditory evoked response: the Mismatch Negativity (MMN) and the Late Frontal Negativity (LFN), a potential observed at a latency sensitive to attentional engagement to the auditory environment, during the practices of Open Presence (OP) and Focused Attention (FA), as well as during a control state, in the context of a passive oddball paradigm. We found an increase in gamma oscillatory power during both meditation states in expert practitioners and an interaction between states and groups in the amplitude of the MMN. A further investigation identified the specific interplay between the MMN and the LFN as a possible marker to differentiate the two meditation states as a function of expertise. In experts, the MMN increased during FA, compared to OP, while the opposite pattern was observed at the LFN latency. We propose that the state of OP in experts is characterized by increased sensory monitoring and reduced perceptual inferences compared to FA. This study represents a first attempt to describe the impact of non-dual meditation states on the regulation of automatic brain predictive processes.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Hábitos , Meditação , Adulto , Ritmo alfa/fisiologia , Potenciais Evocados Auditivos , Feminino , Ritmo Gama/fisiologia , Humanos , Masculino , Prática Psicológica , Competência Profissional
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