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Maffei A, Gambarota F, Liotti M, Dell'Acqua R, Tsuchiya N, Sessa P. Conscious perception of fear in faces: Insights from high-density EEG and perceptual awareness scale with threshold stimuli. Cortex 2024; 174:93-109. [PMID: 38493568 DOI: 10.1016/j.cortex.2024.02.010] [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: 05/25/2023] [Revised: 10/12/2023] [Accepted: 02/08/2024] [Indexed: 03/19/2024]
Abstract
Contrary to the extensive research on processing subliminal and/or unattended emotional facial expressions, only a minority of studies have investigated the neural correlates of consciousness (NCCs) of emotions conveyed by faces. In the present high-density electroencephalography (EEG) study, we first employed a staircase procedure to identify each participant's perceptual threshold of the emotion expressed by the face and then compared the EEG signals elicited in trials where the participants were aware with the activity elicited in trials where participants were unaware of the emotions expressed by these, otherwise identical, faces. Drawing on existing knowledge of the neural mechanisms of face processing and NCCs, we hypothesized that activity in frontal electrodes would be modulated in relation to participants' awareness of facial emotional content. More specifically, we hypothesized that the NCC of fear seen on someone else's face could be detected as a modulation of a later and more anterior (i.e., at frontal sites) event-related potential (ERP) than the face-sensitive N170. By adopting a data-driven approach and cluster-based statistics to the analysis of EEG signals, the results were clear-cut in showing that visual awareness of fear was associated with the modulation of a frontal ERP component in a 150-300 msec interval. These insights are dissected and contextualized in relation to prevailing theories of visual consciousness and their proposed NCC benchmarks.
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Affiliation(s)
- Antonio Maffei
- Department of Developmental and Social Psychology (DPSS), University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Filippo Gambarota
- Department of Developmental and Social Psychology (DPSS), University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Mario Liotti
- Department of Developmental and Social Psychology (DPSS), University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Roberto Dell'Acqua
- Department of Developmental and Social Psychology (DPSS), University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Naotsugu Tsuchiya
- Turner Institute for Brain and Mental Health & School of Psychological Sciences, Faculty of Medicine, Nursing, and Health Sciences, Monash University, Melbourne, Victoria, Australia; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita-shi, Osaka, Japan; Laboratory Head, Laboratory of Qualia Structure, ATR Computational Neuroscience Laboratories, Seika-cho, Soraku-gun, Kyoto, Japan.
| | - Paola Sessa
- Department of Developmental and Social Psychology (DPSS), University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
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2
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Munoz Musat E, Rohaut B, Sangare A, Benhaiem JM, Naccache L. Hypnotic Induction of Deafness to Elementary Sounds: An Electroencephalography Case-Study and a Proposed Cognitive and Neural Scenario. Front Neurosci 2022; 16:756651. [PMID: 35368254 PMCID: PMC8969744 DOI: 10.3389/fnins.2022.756651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Hypnosis can be conceived as a unique opportunity to explore how top-down effects can influence various conscious and non-conscious processes. In the field of perception, such modulatory effects have been described in distinct sensory modalities. In the present study we focused on the auditory channel and aimed at creating a radical deafness to elementary sounds by a specific hypnotic suggestion. We report here a single case-study in a highly suggestible healthy volunteer who reported a total hypnotically suggested deafness. We recorded high-density scalp EEG during an auditory odd-ball paradigm before and after hypnotic deafness suggestion. While both early auditory event-related potentials to sounds (P1) and mismatch negativity component were not affected by hypnotic deafness, we observed a total disappearance of the late P3 complex component when the subject reported being deaf. Moreover, a centro-mesial positivity was present exclusively during the hypnotic condition prior to the P3 complex. Interestingly, source localization suggested an anterior cingulate cortex (ACC) origin of this neural event. Multivariate decoding analyses confirmed and specified these findings. Resting state analyses confirmed a similar level of conscious state in both conditions, and suggested a functional disconnection between auditory areas and other cortical areas. Taken together these results suggest the following plausible scenario: (i) preserved early processing of auditory information unaffected by hypnotic suggestion, (ii) conscious setting of an inhibitory process (ACC) preventing conscious access to sounds, (iii) functional disconnection between the modular and unconscious representations of sounds and global neuronal workspace. This single subject study presents several limits that are discussed and remains open to alternative interpretations. This original proof-of-concept paves the way to a larger study that will test the predictions stemming from our theoretical model and from this first report.
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Affiliation(s)
- Esteban Munoz Musat
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- *Correspondence: Esteban Munoz Musat, ,
| | - Benjamin Rohaut
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique–Hôpitaux de Paris, Paris, France
| | - Aude Sangare
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
| | | | - Lionel Naccache
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- Department of Neurophysiology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique–Hôpitaux de Paris, Paris, France
- Lionel Naccache,
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3
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Walter J. Consciousness as a multidimensional phenomenon: implications for the assessment of disorders of consciousness. Neurosci Conscious 2021; 2021:niab047. [PMID: 34992792 PMCID: PMC8716840 DOI: 10.1093/nc/niab047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 10/19/2021] [Accepted: 12/10/2021] [Indexed: 01/10/2023] Open
Abstract
Disorders of consciousness (DoCs) pose a significant clinical and ethical challenge because they allow for complex forms of conscious experience in patients where intentional behaviour and communication are highly limited or non-existent. There is a pressing need for brain-based assessments that can precisely and accurately characterize the conscious state of individual DoC patients. There has been an ongoing research effort to develop neural measures of consciousness. However, these measures are challenging to validate not only due to our lack of ground truth about consciousness in many DoC patients but also because there is an open ontological question about consciousness. There is a growing, well-supported view that consciousness is a multidimensional phenomenon that cannot be fully described in terms of the theoretical construct of hierarchical, easily ordered conscious levels. The multidimensional view of consciousness challenges the utility of levels-based neural measures in the context of DoC assessment. To examine how these measures may map onto consciousness as a multidimensional phenomenon, this article will investigate a range of studies where they have been applied in states other than DoC and where more is known about conscious experience. This comparative evidence suggests that measures of conscious level are more sensitive to some dimensions of consciousness than others and cannot be assumed to provide a straightforward hierarchical characterization of conscious states. Elevated levels of brain complexity, for example, are associated with conscious states characterized by a high degree of sensory richness and minimal attentional constraints, but are suboptimal for goal-directed behaviour and external responsiveness. Overall, this comparative analysis indicates that there are currently limitations to the use of these measures as tools to evaluate consciousness as a multidimensional phenomenon and that the relationship between these neural signatures and phenomenology requires closer scrutiny.
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Affiliation(s)
- Jasmine Walter
- Cognition and Philosophy Lab, 21 Chancellor’s Walk, Monash University, Melbourne, VIC 3800, Australia
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4
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Kern L, Niedeggen M. ERP signatures of auditory awareness in cross-modal distractor-induced deafness. Conscious Cogn 2021; 96:103241. [PMID: 34823076 DOI: 10.1016/j.concog.2021.103241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/15/2021] [Accepted: 11/05/2021] [Indexed: 10/19/2022]
Abstract
Previous research showed that dual-task processes such as the attentional blink are not always transferable from unimodal to cross-modal settings. This study investigated whether such a transfer can be stated for a distractor-induced impairment of target detection established in vision (distractor-induced blindness, DIB) and recently observed in the auditory modality (distractor-induced deafness, DID). A cross-modal DID effect was confirmed: The detection of an auditory target indicated by a visual cue was impaired if multiple auditory distractors preceded the target. Event-related potentials (ERPs) were used to identify psychophysiological correlates of target detection. A frontal negativity about 200 ms succeeded by a sustained, widespread negativity was associated with auditory target awareness. In contrast to unimodal findings, P3 amplitude was not enhanced for hits. The results support the notion that early frontal attentional processes are linked to auditory awareness, whereas the P3 does not seem to be a reliable indicator of target access.
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Affiliation(s)
- Lea Kern
- Freie Universität Berlin, Department of Education and Psychology, Division General Psychology and Neuropsychology, Habelschwerdter Allee 45, 14195 Berlin, Germany.
| | - Michael Niedeggen
- Freie Universität Berlin, Department of Education and Psychology, Division General Psychology and Neuropsychology, Habelschwerdter Allee 45, 14195 Berlin, Germany.
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5
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Eliciting and Recording Event Related Potentials (ERPs) in Behaviourally Unresponsive Populations: A Retrospective Commentary on Critical Factors. Brain Sci 2021; 11:brainsci11070835. [PMID: 34202435 PMCID: PMC8301772 DOI: 10.3390/brainsci11070835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/19/2021] [Accepted: 06/19/2021] [Indexed: 12/05/2022] Open
Abstract
A consistent limitation when designing event-related potential paradigms and interpreting results is a lack of consideration of the multivariate factors that affect their elicitation and detection in behaviorally unresponsive individuals. This paper provides a retrospective commentary on three factors that influence the presence and morphology of long-latency event-related potentials—the P3b and N400. We analyze event-related potentials derived from electroencephalographic (EEG) data collected from small groups of healthy youth and healthy elderly to illustrate the effect of paradigm strength and subject age; we analyze ERPs collected from an individual with severe traumatic brain injury to illustrate the effect of stimulus presentation speed. Based on these critical factors, we support that: (1) the strongest paradigms should be used to elicit event-related potentials in unresponsive populations; (2) interpretation of event-related potential results should account for participant age; and (3) speed of stimulus presentation should be slower in unresponsive individuals. The application of these practices when eliciting and recording event-related potentials in unresponsive individuals will help to minimize result interpretation ambiguity, increase confidence in conclusions, and advance the understanding of the relationship between long-latency event-related potentials and states of consciousness.
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6
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Perceptual awareness negativity: a physiological correlate of sensory consciousness. Trends Cogn Sci 2021; 25:660-670. [PMID: 34172384 DOI: 10.1016/j.tics.2021.05.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 11/21/2022]
Abstract
Much research on the neural correlates of consciousness (NCC) has focused on two evoked potentials, the P3b and the visual or auditory awareness negativity (VAN, AAN). Surveying a broad range of recent experimental evidence, we find that repeated failures to observe the P3b during conscious perception eliminate it as a putative NCC. Neither the VAN nor the AAN have been dissociated from consciousness; furthermore, a similar neural signal correlates with tactile consciousness. These awareness negativities can be maximal contralateral to the evoking stimulus, are likely generated in underlying sensory cortices, and point to the existence of a generalized perceptual awareness negativity (PAN) reflecting the onset of sensory consciousness.
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7
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Schröder P, Nierhaus T, Blankenburg F. Dissociating Perceptual Awareness and Postperceptual Processing: The P300 Is Not a Reliable Marker of Somatosensory Target Detection. J Neurosci 2021; 41:4686-4696. [PMID: 33849946 PMCID: PMC8260252 DOI: 10.1523/jneurosci.2950-20.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/26/2021] [Accepted: 03/13/2021] [Indexed: 11/21/2022] Open
Abstract
A central challenge in the study of conscious perception lies in dissociating the neural correlates of perceptual awareness from those reflecting its precursors and consequences. No-report paradigms have been instrumental in this endeavor, demonstrating that the event-related potential P300, recorded from the human scalp, reflects reports rather than awareness. However, these paradigms cannot probe the degree to which stimuli are consciously processed from trial to trial and, thus, leave open the possibility that the P300 is a genuine correlate of conscious access enabling reports. Here, instead of removing report requirements, we took the opposite approach and equated postperceptual task demands across conscious and unconscious trials by orthogonalizing target detection and overt reports in a somatosensory detection task. We used Bayesian model selection to track the transformation from physical to perceptual processing stages in the EEG data of 24 male and female participants and show that the early P50 component scaled with physical stimulus intensity, whereas the N140 component was the first correlate of target detection. The late P300 component was elicited for both perceived and unperceived stimuli and was not substantially modulated by target detection. This was in stark contrast to a control experiment using a classical direct report task, which replicated the P50 and N140 effects but additionally showed a strong effect of target detection in the P300 time range. Our results demonstrate the task dependence of the P300 in the somatosensory modality and show that late cortical potentials dissociate from perceptual awareness even when stimuli are always reported.SIGNIFICANCE STATEMENT The time it takes for sensory information to enter our conscious experience can be an indicator of the neural processing stages that lead to perceptual awareness. However, because many cognitive processes routinely correlate with perception, isolating those signals that uniquely reflect perceptual awareness is not a trivial task. Here, we show that late electroencephalography signals cease to correlate with somatosensory awareness when common task confounds are controlled. Importantly, by balancing report requirements instead of abolishing them, we show that the lack of late effects cannot be explained by a lack of conscious access. Instead, we propose that conscious access occurs earlier, at ∼150 ms, supporting the view that early activity in sensory cortices is a neural correlate of conscious perception.
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Affiliation(s)
- Pia Schröder
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, 14195 Berlin, Germany
| | - Till Nierhaus
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, 14195 Berlin, Germany
| | - Felix Blankenburg
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, 14195 Berlin, Germany
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8
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Drane DL, Pedersen NP, Sabsevitz DS, Block C, Dickey AS, Alwaki A, Kheder A. Cognitive and Emotional Mapping With SEEG. Front Neurol 2021; 12:627981. [PMID: 33912122 PMCID: PMC8072290 DOI: 10.3389/fneur.2021.627981] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/04/2021] [Indexed: 02/05/2023] Open
Abstract
Mapping of cortical functions is critical for the best clinical care of patients undergoing epilepsy and tumor surgery, but also to better understand human brain function and connectivity. The purpose of this review is to explore existing and potential means of mapping higher cortical functions, including stimulation mapping, passive mapping, and connectivity analyses. We examine the history of mapping, differences between subdural and stereoelectroencephalographic approaches, and some risks and safety aspects, before examining different types of functional mapping. Much of this review explores the prospects for new mapping approaches to better understand other components of language, memory, spatial skills, executive, and socio-emotional functions. We also touch on brain-machine interfaces, philosophical aspects of aligning tasks to brain circuits, and the study of consciousness. We end by discussing multi-modal testing and virtual reality approaches to mapping higher cortical functions.
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Affiliation(s)
- Daniel L. Drane
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Emory Epilepsy Center, Atlanta, GA, United States
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, United States
| | - Nigel P. Pedersen
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Emory Epilepsy Center, Atlanta, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - David S. Sabsevitz
- Department of Psychology and Psychiatry, Mayo Clinic, Jacksonville, FL, United States
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, United States
| | - Cady Block
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Adam S. Dickey
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Abdulrahman Alwaki
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Ammar Kheder
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
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9
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Fu Y, Yan W, Shen M, Chen H. Does consciousness overflow cognitive access? Novel insights from the new phenomenon of attribute amnesia. SCIENCE CHINA-LIFE SCIENCES 2021; 64:847-860. [DOI: 10.1007/s11427-020-1831-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 10/09/2020] [Indexed: 01/01/2023]
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10
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Perez P, Valente M, Hermann B, Sitt J, Faugeras F, Demeret S, Rohaut B, Naccache L. Auditory Event-Related "Global Effect" Predicts Recovery of Overt Consciousness. Front Neurol 2021; 11:588233. [PMID: 33488494 PMCID: PMC7819971 DOI: 10.3389/fneur.2020.588233] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/03/2020] [Indexed: 01/23/2023] Open
Abstract
Objective: To explore whether the presence of an event-related potential (ERP) "global effect" (GE+)-that corresponds to a correlate of conscious processing in the local-global auditory task-predicts behaviorally overt consciousness recovery in a large cohort of patients suffering from disorders of consciousness (DOC). Methods: We conducted a prospective study on all DOC patients evaluated during the 2009-2018 period. Behavioral examination included Coma Recovery Scale-Revised (CRS-R) scores and bedside high-density EEG recordings. Consciousness recovery was evaluated at 6 months by a structured phone interview. The predictive value of a GE+ was calculated both on survivors and on all patients. Results: A total of 236 patients with a documented outcome and technically valid EEG recordings could be included. Among them, 66 patients had a GE+ status (28%). Presence of GE+ predicted behaviorally overt consciousness recovery in survivors with high specificity (Sp = 84%) and high positive predictive value (PPV = 80%) but with low sensitivity (Se = 35%) and low negative predictive value (NPV = 42%). Positive likelihood ratio (LR+) of GE+ was superior to LR+ of initial clinical status and of ERP effect indexing unconscious auditory processing [local effect (LE)]. Interpretation: Our results demonstrate that the presence of a bedside ERP GE+ is highly predictive of behaviorally overt consciousness recovery in DOC patients, regardless of the delay, of behavioral status, and of the etiology of brain dysfunction. However, the absence of this effect is not a reliable predictor of negative outcome. This study provides Class III evidence that the presence of an ERP "global effect" predicts consciousness recovery in DOC patients.
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Affiliation(s)
- Pauline Perez
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France
| | - Mélanie Valente
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France.,Assistance Publique Hôpitaux de Paris (APHP), Hôpital Pitié-Salpêtrière, Department of Clinical Neurophysiology, Paris, France
| | - Bertrand Hermann
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France
| | - Jacobo Sitt
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France
| | - Frédéric Faugeras
- Assistance Publique Hôpitaux de Paris (APHP), Hôpital Henri-Mondor, Department of Neurology, Créteil, France
| | - Sophie Demeret
- Assistance Publique Hôpitaux de Paris (APHP), Hôpital Pitié-Salpêtrière, Department of Neurology, Paris, France
| | - Benjamin Rohaut
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France.,Assistance Publique Hôpitaux de Paris (APHP), Hôpital Pitié-Salpêtrière, Department of Neurology, Paris, France.,Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - Lionel Naccache
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France.,Assistance Publique Hôpitaux de Paris (APHP), Hôpital Pitié-Salpêtrière, Department of Neurology, Paris, France.,Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
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11
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Hermann B, Salah AB, Perlbarg V, Valente M, Pyatigorskaya N, Habert MO, Raimondo F, Stender J, Galanaud D, Kas A, Puybasset L, Perez P, Sitt JD, Rohaut B, Naccache L. Habituation of auditory startle reflex is a new sign of minimally conscious state. Brain 2020; 143:2154-2172. [PMID: 32582938 PMCID: PMC7364741 DOI: 10.1093/brain/awaa159] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 03/05/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
Neurological examination of non-communicating patients relies on a few decisive items that enable the crucial distinction between vegetative state (VS)-also coined unresponsive wakefulness syndrome (UWS)-and minimally conscious state. Over the past 10 years, this distinction has proven its diagnostic value as well as its important prognostic value on consciousness recovery. However, clinicians are currently limited by three factors: (i) the current behavioural repertoire of minimally conscious state items is limited and restricted to a few cognitive domains in the goldstandard revised version of the Coma Recovery Scale; (ii) a proportion of ∼15-20% clinically VS/UWS patients are actually in a richer state than VS/UWS as evidenced by functional brain imaging; and (iii) the neurophysiological and cognitive interpretation of each minimally conscious state item is still unclear and debated. In the current study we demonstrate that habituation of the auditory startle reflex (hASR) tested at bedside constitutes a novel, simple and powerful behavioural sign that can accurately distinguish minimally conscious state from VS/UWS. In addition to enlarging the minimally conscious state items repertoire, and therefore decreasing the low sensitivity of current behavioural measures, we also provide an original and rigorous description of the neurophysiological basis of hASR through a combination of functional (high density EEG and 18F-fluorodeoxyglucose PET imaging) and structural (diffusion tensor imaging MRI) measures. We show that preservation of hASR is associated with the functional and structural integrity of a brain-scale fronto-parietal network, including prefrontal regions related to control of action and inhibition, and meso-parietal areas associated with minimally conscious and conscious states. Lastly, we show that hASR predicts 6-month improvement of consciousness. Taken together, our results show that hASR is a cortically-mediated behaviour, and suggest that it could be a new clinical item to clearly and accurately identify non-communicating patients who are in the minimally conscious state.
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Affiliation(s)
- Bertrand Hermann
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Department of Neurology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
| | - Amina Ben Salah
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Vincent Perlbarg
- Sorbonne Université, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, LIB, F-75006, Paris, France
- BrainTale SAS, F-75013, Paris, France
| | - Mélanie Valente
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Department of Clinical Neurophysiology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Nadya Pyatigorskaya
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
- Department of Neuroradiology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Marie-Odile Habert
- Sorbonne Université, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, LIB, F-75006, Paris, France
- Department of Nuclear Medicine, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Federico Raimondo
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Coma Science Group, GIGA Consciousness, University of Liège, Belgium
- Centre du Cerveau, University Hospital of Liège, Belgium
| | - Johan Stender
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Damien Galanaud
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
- Department of Neuroradiology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Aurélie Kas
- Sorbonne Université, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, LIB, F-75006, Paris, France
- Department of Nuclear Medicine, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Louis Puybasset
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
- Sorbonne Université, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, LIB, F-75006, Paris, France
- Department of Anesthesia and Critical Care, Multidisciplinary Intensive Care Unit, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
| | - Pauline Perez
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Jacobo D Sitt
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
| | - Benjamin Rohaut
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Department of Neurology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
- Department of Neurology, Columbia University, New York, NY 10027, USA
| | - Lionel Naccache
- Institut du Cerveau et de la Moelle épinière - ICM, Inserm U1127, CNRS UMR 7225, F-75013, Paris, France
- Department of Neurology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, Sorbonne Universités, UPMC Université Paris 06, Paris, France
- Department of Clinical Neurophysiology, Groupe hospitalier Pitié-Salpêtrière, AP-HP, F-75013, Paris, France
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12
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Blundon EG, Gallagher RE, Ward LM. Electrophysiological evidence of preserved hearing at the end of life. Sci Rep 2020; 10:10336. [PMID: 32587364 PMCID: PMC7316981 DOI: 10.1038/s41598-020-67234-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 06/04/2020] [Indexed: 11/17/2022] Open
Abstract
This study attempts to answer the question: “Is hearing the last to go?” We present evidence of hearing among unresponsive actively dying hospice patients. Individual ERP (MMN, P3a, and P3b) responses to deviations in auditory patterns are reported for conscious young, healthy control participants, as well as for hospice patients, both when the latter were conscious, and again when they became unresponsive to their environment. Whereas the MMN (and perhaps too the P3a) is considered an automatic response to auditory irregularities, the P3b is associated with conscious detection of oddball targets. All control participants, and most responsive hospice patients, evidenced a “local” effect (either a MMN, a P3a, or both) and some a “global” effect (P3b) to deviations in tone, or deviations in auditory pattern. Importantly, most unresponsive patients showed evidence of MMN responses to tone changes, and some showed a P3a or P3b response to either tone or pattern changes. Thus, their auditory systems were responding similarly to those of young, healthy controls just hours from end of life. Hearing may indeed be one of the last senses to lose function as humans die.
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Affiliation(s)
| | - Romayne E Gallagher
- Department of Family Medicine, Vancouver, Canada.,Department of Family and Community Medicine, Providence Health Care, Vancouver, Canada
| | - Lawrence M Ward
- Department of Psychology, Vancouver, Canada. .,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.
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13
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Lack of awareness despite complex visual processing: Evidence from event-related potentials in a case of selective metamorphopsia. Proc Natl Acad Sci U S A 2020; 117:16055-16064. [PMID: 32571942 DOI: 10.1073/pnas.2000424117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Visual awareness is thought to result from integration of low- and high-level processing; instances of integration failure provide a crucial window into the cognitive and neural bases of awareness. We present neurophysiological evidence of complex cognitive processing in the absence of awareness, raising questions about the conditions necessary for visual awareness. We describe an individual with a neurodegenerative disease who exhibits impaired visual awareness for the digits 2 to 9, and stimuli presented in close proximity to these digits, due to perceptual distortion. We identified robust event-related potential responses indicating 1) face detection with the N170 component and 2) task-dependent target-word detection with the P3b component, despite no awareness of the presence of faces or target words. These data force us to reconsider the relationship between neural processing and visual awareness; even stimuli processed by a workspace-like cognitive system can remain inaccessible to awareness. We discuss how this finding challenges and constrains theories of visual awareness.
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14
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Förster J, Koivisto M, Revonsuo A. ERP and MEG correlates of visual consciousness: The second decade. Conscious Cogn 2020; 80:102917. [PMID: 32193077 DOI: 10.1016/j.concog.2020.102917] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/14/2020] [Accepted: 03/07/2020] [Indexed: 01/04/2023]
Abstract
The first decade of event-related potential (ERP) research had established that the most consistent correlates of the onset of visual consciousness are the early visual awareness negativity (VAN), a posterior negative component in the N2 time range, and the late positivity (LP), an anterior positive component in the P3 time range. Two earlier extensive reviews ten years ago had concluded that VAN is the earliest and most reliable correlate of visual phenomenal consciousness, whereas LP probably reflects later processes associated with reflective/access consciousness. This article provides an update to those earlier reviews. ERP and MEG studies that have appeared since 2010 and directly compared ERPs between aware and unaware conditions are reviewed, and important new developments in the field are discussed. The result corroborates VAN as the earliest and most consistent signature of visual phenomenal consciousness, and casts further doubt on LP as an ERP correlate of phenomenal consciousness.
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Affiliation(s)
- Jona Förster
- Division of Cognitive Neuroscience and Philosophy, University of Skövde, Sweden.
| | - Mika Koivisto
- Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
| | - Antti Revonsuo
- Division of Cognitive Neuroscience and Philosophy, University of Skövde, Sweden; Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
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15
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Combined behavioral and electrophysiological evidence for a direct cortical effect of prefrontal tDCS on disorders of consciousness. Sci Rep 2020; 10:4323. [PMID: 32152347 PMCID: PMC7062738 DOI: 10.1038/s41598-020-61180-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 02/19/2020] [Indexed: 12/11/2022] Open
Abstract
Severe brain injuries can lead to long-lasting disorders of consciousness (DoC) such as vegetative state/unresponsive wakefulness syndrome (VS/UWS) or minimally conscious state (MCS). While behavioral assessment remains the gold standard to determine conscious state, EEG has proven to be a promising complementary tool to monitor the effect of new therapeutics. Encouraging results have been obtained with invasive electrical stimulation of the brain, and recent studies identified transcranial direct current stimulation (tDCS) as an effective approach in randomized controlled trials. This non-invasive and inexpensive tool may turn out to be the preferred treatment option. However, its mechanisms of action and physiological effects on brain activity remain unclear and debated. Here, we stimulated 60 DoC patients with the anode placed over left-dorsolateral prefrontal cortex in a prospective open-label study. Clinical behavioral assessment improved in twelve patients (20%) and none deteriorated. This behavioral response after tDCS coincided with an enhancement of putative EEG markers of consciousness: in comparison with non-responders, responders showed increases of power and long-range cortico-cortical functional connectivity in the theta-alpha band, and a larger and more sustained P300 suggesting improved conscious access to auditory novelty. The EEG changes correlated with electric fields strengths in prefrontal cortices, and no correlation was found on the scalp. Taken together, this prospective intervention in a large cohort of DoC patients strengthens the validity of the proposed EEG signatures of consciousness, and is suggestive of a direct causal effect of tDCS on consciousness.
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16
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Ye M, Lyu Y, Sclodnick B, Sun HJ. The P3 Reflects Awareness and Can Be Modulated by Confidence. Front Neurosci 2019; 13:510. [PMID: 31156381 PMCID: PMC6533851 DOI: 10.3389/fnins.2019.00510] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 05/02/2019] [Indexed: 12/30/2022] Open
Abstract
An important question in neural correlate of consciousness (NCC) studies is whether event-related potential (ERP) component P3 reflects visual awareness or the confidence with which one reports a visual experience. In the present study, participants detected visual stimuli presented at threshold-level contrast, then rated their subjective confidence with respect to their response on a four-point scale (very confident, quite confident, slightly confident, and not confident at all). Because awareness responses in trials with rating of “not confident at all” were likely noise, we analyzed the data excluding those trials. The ERP results revealed a significant positive difference in P3 amplitude between “aware” and “unaware” trials. P3 amplitude was more positive in aware trials compared to unaware trials. Importantly, this pattern was observed for trials with combined confidence ratings of “very confident” and “quite confident,” and for trials with confidence ratings of “slightly confident,” suggesting that awareness alone can modulate P3. A significant interaction between awareness and confidence is reported, suggesting that confidence influences P3 as well. In addition, ERP results revealed that visual awareness negativity (VAN) was observed over posterior temporal and occipital electrodes and largely not influenced by confidence. This result indicated that VAN is an early neural correlate of visual awareness.
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Affiliation(s)
- Muwang Ye
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Yong Lyu
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Ben Sclodnick
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
| | - Hong-Jin Sun
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
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17
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Competitive Frontoparietal Interactions Mediate Implicit Inferences. J Neurosci 2019; 39:5183-5194. [PMID: 31015338 DOI: 10.1523/jneurosci.2551-18.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 04/16/2019] [Accepted: 04/18/2019] [Indexed: 01/17/2023] Open
Abstract
Frequent experience with regularities in our environment allows us to use predictive information to guide our decision process. However, contingencies in our environment are not always explicitly present and sometimes need to be inferred. Heretofore, it remained unknown how predictive information guides decision-making when explicit knowledge is absent and how the brain shapes such implicit inferences. In the present experiment, 17 human participants (9 females) performed a discrimination task in which a target stimulus was preceded by a predictive cue. Critically, participants had no explicit knowledge that some of the cues signaled an upcoming target, allowing us to investigate how implicit inferences emerge and guide decision-making. Despite unawareness of the cue-target contingencies, participants were able to use implicit information to improve performance. Concurrent EEG recordings demonstrate that implicit inferences rely upon interactions between internally and externally oriented networks, whereby prefrontal regions inhibit parietal cortex under internal implicit control.SIGNIFICANCE STATEMENT Regularities in our environment can guide our behavior providing information about upcoming events. Interestingly, such predictive information does not need to be explicitly represented to effectively guide our decision process. Here, we show how the brain engages in such real-world "data mining" and how implicit inferences emerge. We used a contingency cueing task and demonstrated that implicit inferences influenced responses to subsequent targets despite a lack of awareness of cue-target contingencies. Further, we show that these implicit inferences emerge through interactions between internally and externally oriented neural networks. The current results highlight the importance of prefrontal processes in transforming external events into predictive internalized models of the world.
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18
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Ye M, Lyu Y. Later Positivity Reflects Post-perceptual Processes: Evidence From Immediate Detection and Delayed Detection Tasks. Front Psychol 2019; 10:82. [PMID: 30766499 PMCID: PMC6365435 DOI: 10.3389/fpsyg.2019.00082] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/11/2019] [Indexed: 11/24/2022] Open
Abstract
Electrophysiological recordings are usually used to study neural correlates of consciousness (NCCs). The aim of our present study was to use two detection tasks to dissociate the electrophysiological correlates of visual awareness from the post-perceptual processes. In immediate detection task, participants had to quickly report whether the stimulus was presented after stimulus, whereas in delayed detection task, participants had to put off reporting whether the stimulus was presented after stimulus. The results showed that two previously frequently observed electrophysiological NCCs were observed: visual awareness negativity (VAN) and later positivity (LP). Importantly, the amplitude of VAN over posterior temporal and occipital areas was not influenced by the task manipulation. However, the amplitude of LP over parietal, posterior temporal and occipital areas was influenced by the task manipulation during 650–850 ms. These data suggest that VAN is an early electrophysiological correlates of visual awareness, and LP reflects post-perceptual processes required in reporting perceptual awareness.
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Affiliation(s)
- Muwang Ye
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Yong Lyu
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
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19
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Garcia-Larrea L, Hagiwara K. Electrophysiology in diagnosis and management of neuropathic pain. Rev Neurol (Paris) 2019; 175:26-37. [DOI: 10.1016/j.neurol.2018.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/24/2018] [Indexed: 12/30/2022]
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20
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Naccache L. Why and how access consciousness can account for phenomenal consciousness. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170357. [PMID: 30061470 PMCID: PMC6074081 DOI: 10.1098/rstb.2017.0357] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2018] [Indexed: 11/12/2022] Open
Abstract
According to a popular distinction proposed by the philosopher Ned Block in 1995, our conscious experience would overflow the very limited set of what we can consciously report to ourselves and to others. He proposed to coin this limited consciousness 'Access Consciousness' (A-Cs) and to define 'Phenomenal Consciousness' as a much richer subjective experience that is not accessed but that would still delineate the extent of consciousness. In this article, I review and develop five major problems raised by this theory, and show how a strict A-Cs theory can account for our conscious experience. I illustrate such an A-Cs account within the global workspace (GW) theoretical framework, and revisit some seminal empirical findings and neuropsychological syndromes. In this strict A-Cs perspective, subjective reports are not conceived as the mere passive broadcasting of information to the GW, but as resulting from a dynamic and active chain of internal processes that notably include interpretative and belief attribution stages. Finally, I list a set of testable predictions, of unsolved questions and of some counterintuitive hypotheses.This article is part of the theme issue 'Perceptual consciousness and cognitive access'.
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Affiliation(s)
- Lionel Naccache
- Department of Neurology, AP-HP, Groupe hospitalier Pitié-Salpêtrière, 75013 Paris, France
- Department of Neurophysiology, AP-HP, Groupe hospitalier Pitié-Salpêtrière, 75013 Paris, France
- Sorbonne Université, INSERM, U 1127, 75013 Paris, France
- Institut du Cerveau et de la Moelle épinière, ICM, PICNIC Lab, 75013 Paris, France
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21
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Cubelli R, Della Sala S. Looking back to go forward: Promoting single case studies. Cortex 2017; 97:A1-A3. [PMID: 29110884 DOI: 10.1016/j.cortex.2017.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 09/29/2017] [Indexed: 11/25/2022]
Affiliation(s)
- Roberto Cubelli
- Department of Psychology and Cognitive Sciences, University of Trento, Italy.
| | - Sergio Della Sala
- Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK
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22
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Juxtaposing the real-time unfolding of subjective experience and ERP neuromarker dynamics. Conscious Cogn 2017; 54:3-19. [DOI: 10.1016/j.concog.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 01/08/2023]
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23
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Fu Q, Liu YJ, Dienes Z, Wu J, Chen W, Fu X. Neural Correlates of Subjective Awareness for Natural Scene Categorization of Color Photographs and Line-Drawings. Front Psychol 2017; 8:210. [PMID: 28261141 PMCID: PMC5309232 DOI: 10.3389/fpsyg.2017.00210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 02/01/2017] [Indexed: 11/25/2022] Open
Abstract
It remains controversial whether visual awareness is correlated with early activation indicated by VAN (visual awareness negativity), as the recurrent process hypothesis theory proposes, or with later activation indicated by P3 or LP (late positive), as suggested by global workspace theories. To address this issue, a backward masking task was adopted, in which participants were first asked to categorize natural scenes of color photographs and line-drawings and then to rate the clarity of their visual experience on a Perceptual Awareness Scale (PAS). The interstimulus interval between the scene and the mask was manipulated. The behavioral results showed that categorization accuracy increased with PAS ratings for both color photographs and line-drawings, with no difference in accuracy between the two types of images for each rating, indicating that the experience rating reflected visibility. Importantly, the event-related potential (ERP) results revealed that for correct trials, the early posterior N1 and anterior P2 components changed with the PAS ratings for color photographs, but did not vary with the PAS ratings for line-drawings, indicating that the N1 and P2 do not always correlate with subjective visual awareness. Moreover, for both types of images, the anterior N2 and posterior VAN changed with the PAS ratings in a linear way, while the LP changed with the PAS ratings in a non-linear way, suggesting that these components relate to different types of subjective awareness. The results reconcile the apparently contradictory predictions of different theories and help to resolve the current debate on neural correlates of visual awareness.
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Affiliation(s)
- Qiufang Fu
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Yong-Jin Liu
- Tsinghua National Laboratory for Information Science and Technology, Department of Computer Science and Technology, Tsinghua UniversityBeijing, China
| | - Zoltan Dienes
- Sackler Centre for Consciousness Science, School of Psychology, University of SussexBrighton, UK
| | - Jianhui Wu
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of SciencesBeijing, China
- College of Psychology and Sociology, Shenzhen UniversityShenzhen, China
| | - Wenfeng Chen
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of SciencesBeijing, China
| | - Xiaolan Fu
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
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24
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Unconscious P3b and complex unconscious processing: Reply to Naccache et al., 2016. Cortex 2016; 85:129-132. [DOI: 10.1016/j.cortex.2016.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/07/2016] [Indexed: 11/18/2022]
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