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Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions

Hallucinations and illusions are two instances of perceptual experiences illustrating how perception might diverge from external sensory stimulations and be generated or altered based on internal brain states. The occurrence of these phenomena is not constrained to patient populations. Similar exper...

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Autores principales: Faramarzi, Maryam, Kasten, Florian H., Altaş, Gamze, Aleman, André, Ćurčić-Blake, Branislava, Herrmann, Christoph S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047478/
https://www.ncbi.nlm.nih.gov/pubmed/33867913
http://dx.doi.org/10.3389/fnins.2021.602437
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author Faramarzi, Maryam
Kasten, Florian H.
Altaş, Gamze
Aleman, André
Ćurčić-Blake, Branislava
Herrmann, Christoph S.
author_facet Faramarzi, Maryam
Kasten, Florian H.
Altaş, Gamze
Aleman, André
Ćurčić-Blake, Branislava
Herrmann, Christoph S.
author_sort Faramarzi, Maryam
collection PubMed
description Hallucinations and illusions are two instances of perceptual experiences illustrating how perception might diverge from external sensory stimulations and be generated or altered based on internal brain states. The occurrence of these phenomena is not constrained to patient populations. Similar experiences can be elicited in healthy subjects by means of suitable experimental procedures. Studying the neural mechanisms underlying these experiences not only has the potential to expand our understanding of the brain’s perceptual machinery but also of how it might get impaired. In the current study, we employed an auditory signal detection task to induce auditory illusions by presenting speech snippets at near detection threshold intensity embedded in noise. We investigated the neural correlates of auditory false perceptions by examining the EEG activity preceding the responses in speech absent (false alarm, FA) trials and comparing them to speech present (hit) trials. The results of the comparison of event-related potentials (ERPs) in the activation period vs. baseline revealed the presence of an early negativity (EN) and a late positivity (LP) similar in both hits and FAs, which were absent in misses, correct rejections (CR) and control button presses (BPs). We postulate that the EN and the LP might represent the auditory awareness negativity (AAN) and centro-parietal positivity (CPP) or P300, respectively. The event-related spectral perturbations (ERSPs) exhibited a common power enhancement in low frequencies (<4 Hz) in hits and FAs. The low-frequency power enhancement has been frequently shown to be accompanied with P300 as well as separately being a marker of perceptual awareness, referred to as slow cortical potentials (SCP). Furthermore, the comparison of hits vs. FAs showed a significantly higher LP amplitude and low frequency power in hits compared to FAs. Generally, the observed patterns in the present results resembled some of the major neural correlates associated with perceptual awareness in previous studies. Our findings provide evidence that the neural correlates associated with conscious perception, can be elicited in similar ways in both presence and absence of externally presented sensory stimuli. The present findings did not reveal any pre-stimulus alpha and beta modulations distinguishing conscious vs. unconscious perceptions.
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spelling pubmed-80474782021-04-16 Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions Faramarzi, Maryam Kasten, Florian H. Altaş, Gamze Aleman, André Ćurčić-Blake, Branislava Herrmann, Christoph S. Front Neurosci Neuroscience Hallucinations and illusions are two instances of perceptual experiences illustrating how perception might diverge from external sensory stimulations and be generated or altered based on internal brain states. The occurrence of these phenomena is not constrained to patient populations. Similar experiences can be elicited in healthy subjects by means of suitable experimental procedures. Studying the neural mechanisms underlying these experiences not only has the potential to expand our understanding of the brain’s perceptual machinery but also of how it might get impaired. In the current study, we employed an auditory signal detection task to induce auditory illusions by presenting speech snippets at near detection threshold intensity embedded in noise. We investigated the neural correlates of auditory false perceptions by examining the EEG activity preceding the responses in speech absent (false alarm, FA) trials and comparing them to speech present (hit) trials. The results of the comparison of event-related potentials (ERPs) in the activation period vs. baseline revealed the presence of an early negativity (EN) and a late positivity (LP) similar in both hits and FAs, which were absent in misses, correct rejections (CR) and control button presses (BPs). We postulate that the EN and the LP might represent the auditory awareness negativity (AAN) and centro-parietal positivity (CPP) or P300, respectively. The event-related spectral perturbations (ERSPs) exhibited a common power enhancement in low frequencies (<4 Hz) in hits and FAs. The low-frequency power enhancement has been frequently shown to be accompanied with P300 as well as separately being a marker of perceptual awareness, referred to as slow cortical potentials (SCP). Furthermore, the comparison of hits vs. FAs showed a significantly higher LP amplitude and low frequency power in hits compared to FAs. Generally, the observed patterns in the present results resembled some of the major neural correlates associated with perceptual awareness in previous studies. Our findings provide evidence that the neural correlates associated with conscious perception, can be elicited in similar ways in both presence and absence of externally presented sensory stimuli. The present findings did not reveal any pre-stimulus alpha and beta modulations distinguishing conscious vs. unconscious perceptions. Frontiers Media S.A. 2021-04-01 /pmc/articles/PMC8047478/ /pubmed/33867913 http://dx.doi.org/10.3389/fnins.2021.602437 Text en Copyright © 2021 Faramarzi, Kasten, Altaş, Aleman, Ćurčić-Blake and Herrmann. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Faramarzi, Maryam
Kasten, Florian H.
Altaş, Gamze
Aleman, André
Ćurčić-Blake, Branislava
Herrmann, Christoph S.
Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title_full Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title_fullStr Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title_full_unstemmed Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title_short Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions
title_sort similar eeg activity patterns during experimentally-induced auditory illusions and veridical perceptions
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047478/
https://www.ncbi.nlm.nih.gov/pubmed/33867913
http://dx.doi.org/10.3389/fnins.2021.602437
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