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Doll L, Dykstra AR, Gutschalk A. Perceptual awareness of near-threshold tones scales gradually with auditory cortex activity and pupil dilation. iScience 2024; 27:110530. [PMID: 39175766 PMCID: PMC11338958 DOI: 10.1016/j.isci.2024.110530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 04/16/2024] [Accepted: 07/15/2024] [Indexed: 08/24/2024] Open
Abstract
Negative-going responses in sensory cortex co-vary with perceptual awareness of sensory stimuli. Given that this awareness negativity has also been observed for undetected stimuli, some have challenged its role for perception. To address this question, we combined magnetoencephalography, electroencephalography, and pupillometry to study how sustained attention and response criterion affect the auditory awareness negativity. Participants first detected distractor sounds and denied hearing task-irrelevant near-threshold tones, which evoked neither awareness negativity nor pupil dilation. These same tones evoked both responses when task-relevant, stronger for hit but also present for miss trials. Participants then rated their perception on a six-point scale to test whether response criterion explains the presence of these responses for miss trials. Decreasing perception ratings were associated with gradually reduced evoked responses, consistent with signal detection theory. These results support the concept of an awareness negativity that is modulated by attention but does not require a non-linear threshold mechanism.
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Affiliation(s)
- Laura Doll
- Department of Neurology, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany
| | - Andrew R. Dykstra
- School of Communication Sciences and Disorders, University of Central Florida, Orlando, FL, USA
| | - Alexander Gutschalk
- Department of Neurology, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany
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2
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Rowe EG, Garrido MI, Tsuchiya N. Feedforward connectivity patterns from visual areas to the front of the brain contain information about sensory stimuli regardless of awareness or report. Cortex 2024; 172:284-300. [PMID: 38142179 DOI: 10.1016/j.cortex.2023.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/11/2023] [Accepted: 11/21/2023] [Indexed: 12/25/2023]
Abstract
Current theories of consciousness can be categorized to some extent by their predictions about the putative role of the prefrontal cortex (PFC) in conscious perception. One family of the theories proposes that the PFC is necessary for conscious perception. The other postulates that the PFC is not necessary and that other areas (e.g., posterior cortical areas) are more important for conscious perception. No-report paradigms could potentially arbitrate the debate as they disentangle task reporting from conscious perception. While previous no-report paradigms tend to point to a reduction in PFC activity, they have not examined the critical role of the PFC in "monitoring" or "reading out" the patterns of activity in the sensory cortex to generate conscious perception. To address this, we reanalysed electroencephalography (EEG) data from a no-report inattentional blindness paradigm (Shafto & Pitts, 2015). We examined the role of feedforward input patterns to the PFC from sensory cortices. We employed nonparametric spectral Granger causality and quantified the amount of information that reflected the contents of consciousness using multivariate classifiers. Unexpectedly, regardless of whether the stimulus was consciously seen or not, we found that information relating to the current sensory stimulus was present in the pattern of inputs from visual areas to the PFC. In light of these findings, we suggest various theories of consciousness need to be revised to accommodate the fact that the contents of consciousness are decodable from the input patterns from posterior sensory regions to the PFC, regardless of awareness (or report).
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Affiliation(s)
- Elise G Rowe
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia; Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia.
| | - Marta I Garrido
- Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Victoria, Australia; ARC Centre of Excellence for Integrative Brain Function, Victoria, Australia
| | - Naotsugu Tsuchiya
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia; Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita, Osaka, Japan; Department of Qualia Structure, ATR Computational Neuroscience Laboratories, Seika-cho, Soraku-gun, Kyoto, Japan; ARC Centre of Excellence for Integrative Brain Function, Victoria, Australia
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3
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Veyrié A, Noreña A, Sarrazin JC, Pezard L. Information-Theoretic Approaches in EEG Correlates of Auditory Perceptual Awareness under Informational Masking. BIOLOGY 2023; 12:967. [PMID: 37508397 PMCID: PMC10376775 DOI: 10.3390/biology12070967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023]
Abstract
In informational masking paradigms, the successful segregation between the target and masker creates auditory perceptual awareness. The dynamics of the build-up of auditory perception is based on a set of interactions between bottom-up and top-down processes that generate neuronal modifications within the brain network activity. These neural changes are studied here using event-related potentials (ERPs), entropy, and integrated information, leading to several measures applied to electroencephalogram signals. The main findings show that the auditory perceptual awareness stimulated functional activation in the fronto-temporo-parietal brain network through (i) negative temporal and positive centro-parietal ERP components; (ii) an enhanced processing of multi-information in the temporal cortex; and (iii) an increase in informational content in the fronto-central cortex. These different results provide information-based experimental evidence about the functional activation of the fronto-temporo-parietal brain network during auditory perceptual awareness.
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Affiliation(s)
- Alexandre Veyrié
- Centre National de la Recherche Scientifique (UMR 7291), Laboratoire de Neurosciences Cognitives, Aix-Marseille Université, 13331 Marseille, France
- ONERA, The French Aerospace Lab, 13300 Salon de Provence, France
| | - Arnaud Noreña
- Centre National de la Recherche Scientifique (UMR 7291), Laboratoire de Neurosciences Cognitives, Aix-Marseille Université, 13331 Marseille, France
| | | | - Laurent Pezard
- Centre National de la Recherche Scientifique (UMR 7291), Laboratoire de Neurosciences Cognitives, Aix-Marseille Université, 13331 Marseille, France
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4
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Kronemer SI, Aksen M, Ding JZ, Ryu JH, Xin Q, Ding Z, Prince JS, Kwon H, Khalaf A, Forman S, Jin DS, Wang K, Chen K, Hu C, Agarwal A, Saberski E, Wafa SMA, Morgan OP, Wu J, Christison-Lagay KL, Hasulak N, Morrell M, Urban A, Todd Constable R, Pitts M, Mark Richardson R, Crowley MJ, Blumenfeld H. Human visual consciousness involves large scale cortical and subcortical networks independent of task report and eye movement activity. Nat Commun 2022; 13:7342. [PMID: 36446792 PMCID: PMC9707162 DOI: 10.1038/s41467-022-35117-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022] Open
Abstract
The full neural circuits of conscious perception remain unknown. Using a visual perception task, we directly recorded a subcortical thalamic awareness potential (TAP). We also developed a unique paradigm to classify perceived versus not perceived stimuli using eye measurements to remove confounding signals related to reporting on conscious experiences. Using fMRI, we discovered three major brain networks driving conscious visual perception independent of report: first, increases in signal detection regions in visual, fusiform cortex, and frontal eye fields; and in arousal/salience networks involving midbrain, thalamus, nucleus accumbens, anterior cingulate, and anterior insula; second, increases in frontoparietal attention and executive control networks and in the cerebellum; finally, decreases in the default mode network. These results were largely maintained after excluding eye movement-based fMRI changes. Our findings provide evidence that the neurophysiology of consciousness is complex even without overt report, involving multiple cortical and subcortical networks overlapping in space and time.
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Affiliation(s)
- Sharif I Kronemer
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Mark Aksen
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Julia Z Ding
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jun Hwan Ryu
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Qilong Xin
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Zhaoxiong Ding
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jacob S Prince
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Hunki Kwon
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Aya Khalaf
- Department of Neurology, Yale University, New Haven, CT, USA
- Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Giza, Egypt
| | - Sarit Forman
- Department of Neurology, Yale University, New Haven, CT, USA
| | - David S Jin
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Kevin Wang
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Kaylie Chen
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Claire Hu
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Akshar Agarwal
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Erik Saberski
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Syed Mohammad Adil Wafa
- Department of Neurology, Yale University, New Haven, CT, USA
- Child Study Center, Yale University, New Haven, CT, USA
- Division of Psychology and Language Sciences, University College London, London, UK
| | - Owen P Morgan
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jia Wu
- Child Study Center, Yale University, New Haven, CT, USA
| | | | | | | | | | - R Todd Constable
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
- Department of Neurosurgery, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | | | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | | | - Hal Blumenfeld
- Department of Neurology, Yale University, New Haven, CT, USA.
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA.
- Department of Neurosurgery, Yale University, New Haven, CT, USA.
- Department of Neuroscience, Yale University, New Haven, CT, USA.
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5
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Hatamimajoumerd E, Ratan Murty NA, Pitts M, Cohen MA. Decoding perceptual awareness across the brain with a no-report fMRI masking paradigm. Curr Biol 2022; 32:4139-4149.e4. [PMID: 35981538 DOI: 10.1016/j.cub.2022.07.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/16/2022] [Accepted: 07/26/2022] [Indexed: 12/14/2022]
Abstract
Does perceptual awareness arise within the sensory regions of the brain or within higher-level regions (e.g., the frontal lobe)? To answer this question, researchers traditionally compare neural activity when observers report being aware versus being unaware of a stimulus. However, it is unclear whether the resulting activations are associated with the conscious perception of the stimulus or the post-perceptual processes associated with reporting that stimulus. To address this limitation, we used both report and no-report conditions in a visual masking paradigm while participants were scanned using functional MRI (fMRI). We found that the overall univariate response to visible stimuli in the frontal lobe was robust in the report condition but disappeared in the no-report condition. However, using multivariate patterns, we could still decode in both conditions whether a stimulus reached conscious awareness across the brain, including in the frontal lobe. These results help reconcile key discrepancies in the recent literature and provide a path forward for identifying the neural mechanisms associated with perceptual awareness.
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Affiliation(s)
- Elaheh Hatamimajoumerd
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Department of Psychology and Program in Neuroscience, Amherst College, 220 South Pleasant Street, Amherst, MA, USA
| | - N Apurva Ratan Murty
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Center for Brains, Minds, and Machines, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Michael Pitts
- Department of Psychology, Reed College, 3203 Southeast Woodstock Blvd, Portland, OR, USA
| | - Michael A Cohen
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Department of Psychology and Program in Neuroscience, Amherst College, 220 South Pleasant Street, Amherst, MA, USA.
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6
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Lee SY, Chang M, Kwon B, Choi BY, Koo JW, Moon T, De Ridder D, Vanneste S, Song JJ. Is the posterior cingulate cortex an on-off switch for tinnitus?: A comparison between hearing loss subjects with and without tinnitus. Hear Res 2021; 411:108356. [PMID: 34600166 DOI: 10.1016/j.heares.2021.108356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 08/14/2021] [Accepted: 09/20/2021] [Indexed: 12/29/2022]
Abstract
As the human brain works in a Bayesian manner to minimize uncertainty toward external stimuli, the deafferented brain may generate tinnitus in an attempt to fill in missing auditory information, e.g. due to hearing loss. However, not everybody with hearing loss develops tinnitus. Understanding the differences between people with hearing loss who develop tinnitus versus those who do not offers a unique opportunity to unravel critical brain areas involved in the generation of a phantom sound. In this study, we compared resting-state quantitative electroencephalography between hearing loss patients with (HL-T) and without tinnitus (HL-NT) to identify cortical oscillatory signatures that may reveal prerequisites for the selective development of tinnitus in subjects with hearing loss. We enrolled 65 subjects with HL-NT and 65 subjects with HL-T whose tinnitus handicap inventory scores were <16 (grade 1) to minimize the bias induced by distress-induced cortical activity changes. Subjects in the HL-T and HL-NT groups were matched in terms of the bilateral hearing threshold (0.25-8 kHz) using nearest neighbor method. Compared to the HL-NT group, the HL-T group showed significantly higher activity in the right parahippocampus for the beta 1 frequency band, in the left inferior parietal lobule (IPL) for the beta 2 frequency band, and in the right IPL for the beta 3- and gamma frequency bands. Functional connectivity analyses revealed that the HL-T group had significantly higher connectivity than the HL-NT group between both parahippocampal gyri and the right IPL for the delta frequency band, and between the left posterior cingulate cortex (PCC) and right IPL for the beta 2 frequency band. These results suggest that tinnitus may be perceived only if auditory memory stored in the parahippocampus is actively linked to the IPL-based "circuit breaker" system and the circuit breaker signal is connected to the PCC-based default mode network (DMN). Thus, when the circuit breaker system regards tinnitus secondary to peripheral deafferentation as a salient event and then the DMN regards tinnitus as a norm, subjects with hearing loss may consciously perceive tinnitus. The results of this study further refine the recently proposed Bayesian model and decipher the neurobiological mechanism of the selective development of tinnitus in subjects with hearing loss.
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Affiliation(s)
- Sang-Yeon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, 13620, Korea
| | - Munyoung Chang
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Chung-Ang University, Seoul, Korea
| | | | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, 13620, Korea
| | - Ja-Won Koo
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, 13620, Korea
| | - Taesup Moon
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Dirk De Ridder
- Unit of Neurosurgery, Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Sven Vanneste
- Lab for Clinical & Integrative Neuroscience, Trinity College of Neuroscience, Trinity College Dublin, Ireland
| | - Jae-Jin Song
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, 13620, Korea..
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7
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Dellert T, Müller-Bardorff M, Schlossmacher I, Pitts M, Hofmann D, Bruchmann M, Straube T. Dissociating the Neural Correlates of Consciousness and Task Relevance in Face Perception Using Simultaneous EEG-fMRI. J Neurosci 2021; 41:7864-7875. [PMID: 34301829 PMCID: PMC8445054 DOI: 10.1523/jneurosci.2799-20.2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 05/31/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022] Open
Abstract
Current theories of visual consciousness disagree about whether it emerges during early stages of processing in sensory brain regions or later when a widespread frontoparietal network becomes involved. Moreover, disentangling conscious perception from task-related postperceptual processes (e.g., report) and integrating results across different neuroscientific methods remain ongoing challenges. The present study addressed these problems using simultaneous EEG-fMRI and a specific inattentional blindness paradigm with three physically identical phases in female and male human participants. In phase 1, participants performed a distractor task during which line drawings of faces and control stimuli were presented centrally. While some participants spontaneously noticed the faces in phase 1, others remained inattentionally blind. In phase 2, all participants were made aware of the task-irrelevant faces but continued the distractor task. In phase 3, the faces became task-relevant. Bayesian analysis of brain responses demonstrated that conscious face perception was most strongly associated with activation in fusiform gyrus (fMRI) as well as the N170 and visual awareness negativity (EEG). Smaller awareness effects were revealed in the occipital and prefrontal cortex (fMRI). Task-relevant face processing, on the other hand, led to strong, extensive activation of occipitotemporal, frontoparietal, and attentional networks (fMRI). In EEG, it enhanced early negativities and elicited a pronounced P3b component. Overall, we provide evidence that conscious visual perception is linked with early processing in stimulus-specific sensory brain areas but may additionally involve prefrontal cortex. In contrast, the strong activation of widespread brain networks and the P3b are more likely associated with task-related processes.SIGNIFICANCE STATEMENT How does our brain generate visual consciousness-the subjective experience of what it is like to see, for example, a face? To date, it is hotly debated whether it emerges early in sensory brain regions or later when a widespread frontoparietal network is activated. Here, we use simultaneous fMRI and EEG for high spatial and temporal resolution and demonstrate that conscious face perception is predominantly linked to early and occipitotemporal processes, but also prefrontal activity. Task-related processes (e.g., decision-making), on the other hand, elicit brain-wide activations including late and strong frontoparietal activity. These findings challenge numerous previous studies and highlight the importance of investigating the neural correlates of consciousness in the absence of task relevance.
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Affiliation(s)
- Torge Dellert
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
| | - Miriam Müller-Bardorff
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
| | - Insa Schlossmacher
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
| | - Michael Pitts
- Department of Psychology, Reed College, Portland, Oregon 97202
| | - David Hofmann
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
| | - Maximilian Bruchmann
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
| | - Thomas Straube
- Institute of Medical Psychology and Systems Neuroscience, University of Münster, 48149 Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
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8
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Gärtner K, Gutschalk A. Auditory cortex activity related to perceptual awareness versus masking of tone sequences. Neuroimage 2021; 228:117681. [PMID: 33359346 DOI: 10.1016/j.neuroimage.2020.117681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/24/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022] Open
Abstract
Sequences of repeating tones can be masked by other tones of different frequency. When these tone sequences are perceived, nevertheless, a prominent neural response in the auditory cortex is evoked by each tone of the sequence. When the targets are detected based on their isochrony, participants know that they are listening to the target once they detected it. To explore if the neural activity is more closely related to this detection task or to perceptual awareness, this magnetoencephalography (MEG) study used targets that could only be identified with cues provided after or before the masked target. In experiment 1, multiple mono-tone streams with jittered inter-stimulus interval were used, and the tone frequency of the target was indicated by a cue. Results showed no differential auditory cortex activity between hit and miss trials with post-stimulus cues. A late negative response for hit trials was only observed for pre-stimulus cues, suggesting a task-related component. Since experiment 1 provided no evidence for a link of a difference response with tone awareness, experiment 2 was planned to probe if detection of tone streams was linked to a difference response in auditory cortex. Random-tone sequences were presented in the presence of a multi-tone masker, and the sequence was repeated without masker thereafter. Results showed a prominent difference wave for hit compared to miss trials in experiment 2 evoked by targets in the presence of the masker. These results suggest that perceptual awareness of tone streams is linked to neural activity in auditory cortex.
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Affiliation(s)
- Kai Gärtner
- Department of Neurology, Heidelberg University, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Alexander Gutschalk
- Department of Neurology, Heidelberg University, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
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9
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Distinguishing the Neural Correlates of Perceptual Awareness and Postperceptual Processing. J Neurosci 2020; 40:4925-4935. [PMID: 32409620 DOI: 10.1523/jneurosci.0120-20.2020] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/10/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
To identify the neural correlates of perceptual awareness, researchers often compare the differences in neural activation between conditions in which an observer is or is not aware of a stimulus. While intuitive, this approach often contains a critical limitation: to link brain activity with perceptual awareness, observers traditionally report the contents of their perceptual experience. However, relying on observers' reports is problematic because it is difficult to know whether the neural responses being measured are associated with conscious perception or with postperceptual processes involved in the reporting task (e.g., working memory, decision-making). To address this issue, we combined a standard visual masking paradigm with a recently developed "no-report" paradigm in male/female human participants. In the visual masking paradigm, observers saw images of animals and objects that were visible or invisible, depending on their proximity to masks. Meanwhile, on half of the trials, observers reported the contents of their perceptual experience (i.e., report condition), while on the other half of trials they refrained from reporting about their experiences (i.e., no-report condition). We used electroencephalography to examine how visibility interacts with reporting by measuring the P3b event-related potential, one of the proposed canonical "signatures" of conscious processing. Overall, we found a robust P3b in the report condition, but no P3b whatsoever in the no-report condition. This finding suggests that the P3b itself is not a neural signature of conscious processing and highlights the importance of carefully distinguishing the neural correlates of perceptual awareness from postperceptual processing.SIGNIFICANCE STATEMENT What are the neural signatures that differentiate conscious and unconscious processing in the brain? Perhaps the most well established candidate signature is the P3b event-related potential, a late slow wave that appears when observers are aware of a stimulus, but disappears when a stimulus fails to reach awareness. Here, however, we found that the P3b does not track what observers are perceiving, but instead tracks what observers are reporting. When observers are aware of simple visual stimuli, the P3b is nowhere to be found unless observers are reporting the contents of their experience. These results challenge the well established notion of the P3b as a neural marker of awareness and highlight the need for new approaches to the neuroscience of consciousness.
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10
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Yamamoto AK, Parker Jones O, Hope TMH, Prejawa S, Oberhuber M, Ludersdorfer P, Yousry TA, Green DW, Price CJ. A special role for the right posterior superior temporal sulcus during speech production. Neuroimage 2019; 203:116184. [PMID: 31520744 PMCID: PMC6876272 DOI: 10.1016/j.neuroimage.2019.116184] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 08/19/2019] [Accepted: 09/10/2019] [Indexed: 11/29/2022] Open
Abstract
This fMRI study of 24 healthy human participants investigated whether any part of the auditory cortex was more responsive to self-generated speech sounds compared to hearing another person speak. The results demonstrate a double dissociation in two different parts of the auditory cortex. In the right posterior superior temporal sulcus (RpSTS), activation was higher during speech production than listening to auditory stimuli, whereas in bilateral superior temporal gyri (STG), activation was higher for listening to auditory stimuli than during speech production. In the second part of the study, we investigated the function of the identified regions, by examining how activation changed across a range of listening and speech production tasks that systematically varied the demands on acoustic, semantic, phonological and orthographic processing. In RpSTS, activation during auditory conditions was higher in the absence of semantic cues, plausibly indicating increased attention to the spectral-temporal features of auditory inputs. In addition, RpSTS responded in the absence of any auditory inputs when participants were making one-back matching decisions on visually presented pseudowords. After analysing the influence of visual, phonological, semantic and orthographic processing, we propose that RpSTS (i) contributes to short term memory of speech sounds as well as (ii) spectral-temporal processing of auditory input and (iii) may play a role in integrating auditory expectations with auditory input. In contrast, activation in bilateral STG was sensitive to acoustic input and did not respond in the absence of auditory input. The special role of RpSTS during speech production therefore merits further investigation if we are to fully understand the neural mechanisms supporting speech production during speech acquisition, adult life, hearing loss and after brain injury. In right auditory cortex, a region is more sensitive to own than another’s speech. This region (RpSTS) responds to phonological input in the absence of auditory input. RpSTS may match auditory feedback with internal representations of speech sounds.
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Affiliation(s)
- Adam Kenji Yamamoto
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom; Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.
| | - Oiwi Parker Jones
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom; FMRIB Centre and Wolfson College, University of Oxford, Oxford, United Kingdom.
| | - Thomas M H Hope
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom.
| | - Susan Prejawa
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom; Collaborative Research Centre 1052 "Obesity Mechanisms", Faculty of Medicine, University of Leipzig, Leipzig, Germany; Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
| | - Marion Oberhuber
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom.
| | - Philipp Ludersdorfer
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom.
| | - Tarek A Yousry
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom; Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.
| | - David W Green
- Experimental Psychology, University College London, London, United Kingdom.
| | - Cathy J Price
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, United Kingdom.
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Pitts MA, Lutsyshyna LA, Hillyard SA. The relationship between attention and consciousness: an expanded taxonomy and implications for 'no-report' paradigms. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170348. [PMID: 30061462 PMCID: PMC6074089 DOI: 10.1098/rstb.2017.0348] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2018] [Indexed: 12/19/2022] Open
Abstract
Tensions between global neuronal workspace theory and recurrent processing theory have sparked much debate in the field of consciousness research. Here, we focus on one of the key distinctions between these theories: the proposed relationship between attention and consciousness. By reviewing recent empirical evidence, we argue that both theories contain key insights and that certain aspects of each theory can be reconciled into a novel framework that may help guide future research. Alternative theories are also considered, including attended intermediate-level representations theory, integrated information theory and higher order thought theory. With the aim of offering a fresh and nuanced perspective to current theoretical debates, an updated taxonomy of conscious and non-conscious states is proposed. This framework maps a wider spectrum of conscious states by incorporating contemporary views from cognitive neuroscience regarding the variety of attentional mechanisms that are known to interact with sensory processing. Whether certain types of attention are necessary for phenomenal and access consciousness is considered and incorporated into this extended taxonomy. To navigate this expanded space, we review recent 'no-report' paradigms and address several methodological misunderstandings in order to pave a clear path forward for identifying the neural basis of perceptual awareness.This article is part of the theme issue 'Perceptual consciousness and cognitive access'.
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Affiliation(s)
- Michael A Pitts
- Department of Psychology, Reed College, 3203 SE Woodstock Boulevard, Portland, OR 97202, USA
| | - Lydia A Lutsyshyna
- Department of Psychology, Reed College, 3203 SE Woodstock Boulevard, Portland, OR 97202, USA
| | - Steven A Hillyard
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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