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Arnold DH, Clendinen M, Johnston A, Lee ALF, Yarrow K. The precision test of metacognitive sensitivity and confidence criteria. Conscious Cogn 2024; 123:103728. [PMID: 39018832 DOI: 10.1016/j.concog.2024.103728] [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: 10/16/2023] [Revised: 06/24/2024] [Accepted: 07/02/2024] [Indexed: 07/19/2024]
Abstract
Humans experience feelings of confidence in their decisions. In perception, these feelings are typically accurate - we tend to feel more confident about correct decisions. The degree of insight people have into the accuracy of their decisions is known as metacognitive sensitivity. Currently popular methods of estimating metacognitive sensitivity are subject to interpretive ambiguities because they assume people have normally shaped distributions of different experiences when they are repeatedly exposed to a single input. If this normality assumption is violated, calculations can erroneously underestimate metacognitive sensitivity. Here, we describe a means of estimating metacognitive sensitivity that is more robust to violations of the normality assumption. This improved method can easily be added to standard behavioral experiments, and the authors provide Matlab code to help researchers implement these analyses and experimental procedures.
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Affiliation(s)
- Derek H Arnold
- School of Psychology, The University of Queensland, Australia.
| | | | - Alan Johnston
- School of Psychology, The University of Nottingham, United Kingdom
| | - Alan L F Lee
- Department of Psychology, Lingnan University, Hong Kong
| | - Kielan Yarrow
- School of Psychology, City University London, United Kingdom
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2
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Kiefer M, Kammer T. The Relation Between Subjective and Objective Measures of Visual Awareness: Current Evidence, Attempt of a Synthesis and Future Research Directions. J Cogn 2024; 7:59. [PMID: 39035071 PMCID: PMC11259121 DOI: 10.5334/joc.381] [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: 03/28/2024] [Accepted: 06/23/2024] [Indexed: 07/23/2024] Open
Abstract
Within the realm of consciousness research, different methods of measuring the content of visual awareness are used: On the one hand, subjective measures require a report of sensory experiences related to a stimulus. On the other hand, objective measures rely on the observer's performance to accurately detect or discriminate the stimulus. The most appropriate measure of awareness is currently debated. To contribute to this debate, we review findings on the relation between subjective and objective measures of awareness. Although subjective measures sometimes lag behind objective measures, a substantial number of studies demonstrates a convergence of measures. Based on the reviewed studies, we identify five aspects relevant for achieving a convergence of measures. Future research could then identify and empirically test the boundary conditions, under which a convergence or divergence of subjective and measures of awareness is observed.
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3
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Wu YH, Podvalny E, Levinson M, He BJ. Network mechanisms of ongoing brain activity's influence on conscious visual perception. Nat Commun 2024; 15:5720. [PMID: 38977709 PMCID: PMC11231278 DOI: 10.1038/s41467-024-50102-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 06/28/2024] [Indexed: 07/10/2024] Open
Abstract
Sensory inputs enter a constantly active brain, whose state is always changing from one moment to the next. Currently, little is known about how ongoing, spontaneous brain activity participates in online task processing. We employed 7 Tesla fMRI and a threshold-level visual perception task to probe the effects of prestimulus ongoing brain activity on perceptual decision-making and conscious recognition. Prestimulus activity originating from distributed brain regions, including visual cortices and regions of the default-mode and cingulo-opercular networks, exerted a diverse set of effects on the sensitivity and criterion of conscious recognition, and categorization performance. We further elucidate the mechanisms underlying these behavioral effects, revealing how prestimulus activity modulates multiple aspects of stimulus processing in highly specific and network-dependent manners. These findings reveal heretofore unknown network mechanisms underlying ongoing brain activity's influence on conscious perception, and may hold implications for understanding the precise roles of spontaneous activity in other brain functions.
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Affiliation(s)
- Yuan-Hao Wu
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Ella Podvalny
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, 10016, USA
- The Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Max Levinson
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Biyu J He
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, 10016, USA.
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
- Department of Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
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4
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Northoff G, Zilio F, Zhang J. Beyond task response-Pre-stimulus activity modulates contents of consciousness. Phys Life Rev 2024; 49:19-37. [PMID: 38492473 DOI: 10.1016/j.plrev.2024.03.002] [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: 02/28/2024] [Accepted: 03/03/2024] [Indexed: 03/18/2024]
Abstract
The current discussion on the neural correlates of the contents of consciousness (NCCc) focuses mainly on the post-stimulus period of task-related activity. This neglects the substantial impact of the spontaneous or ongoing activity of the brain as manifest in pre-stimulus activity. Does the interaction of pre- and post-stimulus activity shape the contents of consciousness? Addressing this gap in our knowledge, we review and converge two recent lines of findings, that is, pre-stimulus alpha power and pre- and post-stimulus alpha trial-to-trial variability (TTV). The data show that pre-stimulus alpha power modulates post-stimulus activity including specifically the subjective features of conscious contents like confidence and vividness. At the same time, alpha pre-stimulus variability shapes post-stimulus TTV reduction including the associated contents of consciousness. We propose that non-additive rather than merely additive interaction of the internal pre-stimulus activity with the external stimulus in the alpha band is key for contents to become conscious. This is mediated by mechanisms on different levels including neurophysiological, neurocomputational, neurodynamic, neuropsychological and neurophenomenal levels. Overall, considering the interplay of pre-stimulus intrinsic and post-stimulus extrinsic activity across wider timescales, not just evoked responses in the post-stimulus period, is critical for identifying neural correlates of consciousness. This is well in line with both processing and especially the Temporo-spatial theory of consciousness (TTC).
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Affiliation(s)
- Georg Northoff
- University of Ottawa, Institute of Mental Health Research at the Royal Ottawa Hospital, Ottawa, Canada.
| | - Federico Zilio
- Department of Philosophy, Sociology, Education and Applied Psychology, University of Padua, Padua, Italy
| | - Jianfeng Zhang
- Center for Brain Disorders and Cognitive Sciences, School of Psychology, Shenzhen University, Shenzhen, China.
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5
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Shi D, Yu Q. Distinct neural signatures underlying information maintenance and manipulation in working memory. Cereb Cortex 2024; 34:bhae063. [PMID: 38436467 DOI: 10.1093/cercor/bhae063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/04/2024] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Previous working memory research has demonstrated robust stimulus representations during memory maintenance in both voltage and alpha-band activity in electroencephalography. However, the exact functions of these 2 neural signatures have remained controversial. Here we systematically investigated their respective contributions to memory manipulation. Human participants either maintained a previously seen spatial location, or manipulated the location following a mental rotation cue over a delay. Using multivariate decoding, we observed robust location representations in low-frequency voltage and alpha-band oscillatory activity with distinct spatiotemporal dynamics: location representations were most evident in posterior channels in alpha-band activity, but were most prominent in the more anterior, central channels in voltage signals. Moreover, the temporal emergence of manipulated representation in central voltage preceded that in posterior alpha-band activity, suggesting that voltage might carry stimulus-specific source signals originated internally from anterior cortex, whereas alpha-band activity might reflect feedback signals in posterior cortex received from higher-order cortex. Lastly, while location representations in both signals were coded in a low-dimensional neural subspace, location representation in central voltage was higher-dimensional and underwent a representational transformation that exclusively predicted memory behavior. Together, these results highlight the crucial role of central voltage in working memory, and support functional distinctions between voltage and alpha-band activity.
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Affiliation(s)
- Dongping Shi
- Institute of Neuroscience, Key Laboratory of Brain Cognition and Brain-inspired Intelligence Technology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qing Yu
- Institute of Neuroscience, Key Laboratory of Brain Cognition and Brain-inspired Intelligence Technology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
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Shen L, Wu Z, Yue Z, Li B, Chen Q, Han B. Prior Knowledge Uses Prestimulus Alpha Band Oscillations and Persistent Poststimulus Neural Templates for Conscious Perception. J Neurosci 2023; 43:6164-6175. [PMID: 37536980 PMCID: PMC10476639 DOI: 10.1523/jneurosci.0263-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/05/2023] Open
Abstract
Prior knowledge has a profound impact on the way we perceive the world. However, it remains unclear how the prior knowledge is maintained in our brains and thereby influences the subsequent conscious perception. The Dalmatian dog illusion is a perfect tool to study prior knowledge, where the picture is initially perceived as noise. Once the prior knowledge was introduced, a Dalmatian dog could be consciously seen, and the picture immediately became meaningful. Using pictures with hidden objects as standard stimuli and similar pictures without hidden objects as deviant stimuli, we investigated the neural representation of prior knowledge and its impact on conscious perception in an oddball paradigm using electroencephalogram (EEG) in both male and female human subjects. We found that the neural patterns between the prestimulus alpha band oscillations and poststimulus EEG activity were significantly more similar for the standard stimuli than for the deviant stimuli after prior knowledge was provided. Furthermore, decoding analysis revealed that persistent neural templates were evoked after the introduction of prior knowledge, similar to that evoked in the early stages of visual processing. In conclusion, the current study suggests that prior knowledge uses alpha band oscillations in a multivariate manner in the prestimulus period and induces specific persistent neural templates in the poststimulus period, enabling the conscious perception of the hidden objects.SIGNIFICANCE STATEMENT The visual world we live in is not always optimal. In dark or noisy environments, prior knowledge can help us interpret imperfect sensory signals and enable us to consciously perceive hidden objects. However, we still know very little about how prior knowledge works at the neural level. Using the Dalmatian dog illusion and multivariate methods, we found that prior knowledge uses prestimulus alpha band oscillations to carry information about the hidden object and exerts a persistent influence in the poststimulus period by inducing specific neural templates. Our findings provide a window into the neural underpinnings of prior knowledge and offer new insights into the role of alpha band oscillations and neural templates associated with conscious perception.
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Affiliation(s)
- Lu Shen
- Center for Studies of Psychological Application, South China Normal University, Guangzhou 510631, China
- School of Psychology, South China Normal University, Guangzhou 510631, China
| | - Zehua Wu
- Department of Psychology, Guangdong Provincial Key Laboratory of Social Cognitive Neuroscience and Mental Health, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhenzhu Yue
- Department of Psychology, Guangdong Provincial Key Laboratory of Social Cognitive Neuroscience and Mental Health, Sun Yat-sen University, Guangzhou 510275, China
| | - Bing Li
- Department of Psychology, Jilin University, Changchun 130012, China
| | - Qi Chen
- Center for Studies of Psychological Application, South China Normal University, Guangzhou 510631, China
- School of Psychology, South China Normal University, Guangzhou 510631, China
| | - Biao Han
- Center for Studies of Psychological Application, South China Normal University, Guangzhou 510631, China
- School of Psychology, South China Normal University, Guangzhou 510631, China
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7
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Arnold DH, Johnston A, Adie J, Yarrow K. On why we lack confidence in some signal-detection-based analyses of confidence. Conscious Cogn 2023; 113:103532. [PMID: 37295196 DOI: 10.1016/j.concog.2023.103532] [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: 11/08/2022] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
Signal-detection theory (SDT) is one of the most popular frameworks for analyzing data from studies of human behavior - including investigations of confidence. SDT-based analyses of confidence deliver both standard estimates of sensitivity (d'), and a second estimate informed by high-confidence decisions - meta d'. The extent to which meta d' estimates fall short of d' estimates is regarded as a measure of metacognitive inefficiency, quantifying the contamination of confidence by additional noise. These analyses rely on a key but questionable assumption - that repeated exposures to an input will evoke a normally-shaped distribution of perceptual experiences (the normality assumption). Here we show, via analyses inspired by an experiment and modelling, that when distributions of experience do not conform with the normality assumption, meta d' can be systematically underestimated relative to d'. Our data highlight that SDT-based analyses of confidence do not provide a ground truth measure of human metacognitive inefficiency. We explain why deviance from the normality assumption is especially a problem for some popular SDT-based analyses of confidence, in contrast to other analyses inspired by the SDT framework, which are more robust to violations of the normality assumption.
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Affiliation(s)
- Derek H Arnold
- School of Psychology, The University of Queensland, Australia.
| | - Alan Johnston
- School of Psychology, The University of Nottingham, United Kingdom
| | - Joshua Adie
- Research Institute for Sport & Exercise, University of Canberra, Australia
| | - Kielan Yarrow
- Department of Psychology, City University London, United Kingdom
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8
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Wu YH, Podvalny E, He BJ. Spatiotemporal neural dynamics of object recognition under uncertainty in humans. eLife 2023; 12:e84797. [PMID: 37184213 PMCID: PMC10231926 DOI: 10.7554/elife.84797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 05/12/2023] [Indexed: 05/16/2023] Open
Abstract
While there is a wealth of knowledge about core object recognition-our ability to recognize clear, high-contrast object images-how the brain accomplishes object recognition tasks under increased uncertainty remains poorly understood. We investigated the spatiotemporal neural dynamics underlying object recognition under increased uncertainty by combining MEG and 7 Tesla (7T) fMRI in humans during a threshold-level object recognition task. We observed an early, parallel rise of recognition-related signals across ventral visual and frontoparietal regions that preceded the emergence of category-related information. Recognition-related signals in ventral visual regions were best explained by a two-state representational format whereby brain activity bifurcated for recognized and unrecognized images. By contrast, recognition-related signals in frontoparietal regions exhibited a reduced representational space for recognized images, yet with sharper category information. These results provide a spatiotemporally resolved view of neural activity supporting object recognition under uncertainty, revealing a pattern distinct from that underlying core object recognition.
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Affiliation(s)
- Yuan-hao Wu
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Ella Podvalny
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Biyu J He
- Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
- Department of Neurology, New York University Grossman School of MedicineNew YorkUnited States
- Department of Neuroscience & Physiology, New York University Grossman School of MedicineNew YorkUnited States
- Department of Radiology, New York University Grossman School of MedicineNew YorkUnited States
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9
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Bruno A, Sudkamp J, Souto D. A metacognitive approach to the study of motion-induced duration biases reveals inter-individual differences in forming confidence judgments. J Vis 2023; 23:15. [PMID: 36971682 PMCID: PMC10064922 DOI: 10.1167/jov.23.3.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Our ability to estimate the duration of subsecond visual events is prone to distortions, which depend on both sensory and decisional factors. To disambiguate between these two influences, we can look at the alignment between discrimination estimates of duration at the point of subjective equality and confidence estimates when the confidence about decisions is minimal, because observers should be maximally uncertain when two stimuli are perceptually the same. Here, we used this approach to investigate the relationship between the speed of a visual stimulus and its perceived duration. Participants were required to compare two intervals, report which had the longer duration, and then rate their confidence in that judgment. One of the intervals contained a stimulus drifting at a constant speed, whereas the stimulus embedded in the other interval could be stationary, linearly accelerating or decelerating, or drifting at the same speed. Discrimination estimates revealed duration compression for the stationary stimuli and, to a lesser degree, for the accelerating and decelerating stimuli. Confidence showed a similar pattern, but, overall, the confidence estimates were shifted more toward higher durations, pointing to a small contribution of decisional processes. A simple observer model, which assumes that both judgments are based on the same sensory information, captured well inter-individual differences in the criterion used to form a confidence judgment.
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Affiliation(s)
- Aurelio Bruno
- Department of Psychology, University of York, York, UK
- School of Psychology and Vision Sciences, College of Life Sciences, University of Leicester, Leicester, UK
| | - Jennifer Sudkamp
- School of Psychology and Vision Sciences, College of Life Sciences, University of Leicester, Leicester, UK
| | - David Souto
- School of Psychology and Vision Sciences, College of Life Sciences, University of Leicester, Leicester, UK
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10
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Conscious interpretation: A distinct aspect for the neural markers of the contents of consciousness. Conscious Cogn 2023; 108:103471. [PMID: 36736210 DOI: 10.1016/j.concog.2023.103471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 12/22/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023]
Abstract
Progress in the science of consciousness depends on the experimental paradigms and varieties of contrastive analysis available to researchers. Here we highlight paradigms where the object is represented in consciousness as a set of its features but the interpretation of this set alternates in consciousness. We group experimental paradigms with this property under the label "conscious interpretation". We compare the paradigms studying conscious interpretation of the already consciously perceived objects with other types of experimental paradigms. We review previous and recent studies investigating this interpretative aspect of consciousness and propose future directions. We put forward the hypothesis that there are types of stimuli with a hierarchy of interpretations for which the rule applies: conscious experience is drawn towards higher-level interpretation and reverting back to the lower level of interpretation is impossible. We discuss how theories of consciousness might incorporate knowledge and constraints arising from the characteristics of conscious interpretation.
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11
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Romand R, Ehret G. Neuro-functional modeling of near-death experiences in contexts of altered states of consciousness. Front Psychol 2023; 13:846159. [PMID: 36743633 PMCID: PMC9891231 DOI: 10.3389/fpsyg.2022.846159] [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: 01/10/2022] [Accepted: 11/23/2022] [Indexed: 01/19/2023] Open
Abstract
Near-death experiences (NDEs) including out-of-body experiences (OBEs) have been fascinating phenomena of perception both for affected persons and for communities in science and medicine. Modern progress in the recording of changing brain functions during the time between clinical death and brain death opened the perspective to address and understand the generation of NDEs in brain states of altered consciousness. Changes of consciousness can experimentally be induced in well-controlled clinical or laboratory settings. Reports of the persons having experienced the changes can inform about the similarity of the experiences with those from original NDEs. Thus, we collected neuro-functional models of NDEs including OBEs with experimental backgrounds of drug consumption, epilepsy, brain stimulation, and ischemic stress, and included so far largely unappreciated data from fighter pilot tests under gravitational stress generating cephalic nervous system ischemia. Since we found a large overlap of NDE themes or topics from original NDE reports with those from neuro-functional NDE models, we can state that, collectively, the models offer scientifically appropriate causal explanations for the occurrence of NDEs. The generation of OBEs, one of the NDE themes, can be localized in the temporo-parietal junction (TPJ) of the brain, a multimodal association area. The evaluated literature suggests that NDEs may emerge as hallucination-like phenomena from a brain in altered states of consciousness (ASCs).
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Affiliation(s)
- Raymond Romand
- Faculty of Medicine, University of Strasbourg, Strasbourg, France
| | - Günter Ehret
- Institute of Neurobiology, University of Ulm, Ulm, Germany
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12
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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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13
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Gusso MM, Christison-Lagay KL, Zuckerman D, Chandrasekaran G, Kronemer SI, Ding JZ, Freedman NC, Nohama P, Blumenfeld H. More than a feeling: Scalp EEG and eye signals in conscious tactile perception. Conscious Cogn 2022; 105:103411. [PMID: 36156359 DOI: 10.1016/j.concog.2022.103411] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 08/22/2022] [Accepted: 08/28/2022] [Indexed: 01/27/2023]
Abstract
Understanding the neural basis of consciousness is a fundamental goal of neuroscience, and sensory perception is often used as a proxy for consciousness in empirical studies. However, most studies rely on reported perception of visual stimuli. Here we present behavior, high density scalp EEG and eye metric recordings collected simultaneously during a novel tactile threshold perception task. We found significant N80, N140 and P300 event related potentials in perceived trials and in perceived versus not perceived trials. Significance was limited to a P100 and P300 in not perceived trials. We also found an increase in pupil diameter and blink rate and a decrease in microsaccade rate following perceived relative to not perceived tactile stimuli. These findings support the use of eye metrics as a measure of physiological arousal associated with conscious perception. Eye metrics may also represent a novel path toward the creation of tactile no-report tasks in the future.
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Affiliation(s)
- Mariana M Gusso
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, R. Imaculada Conceição, 1155, Prado Velho, Curitiba, Paraná 80215-901, Brazil
| | - Kate L Christison-Lagay
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - David Zuckerman
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Ganesh Chandrasekaran
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Sharif I Kronemer
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Departments of Interdepartmental Neuroscience Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Julia Z Ding
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Noah C Freedman
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Percy Nohama
- Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, R. Imaculada Conceição, 1155, Prado Velho, Curitiba, Paraná 80215-901, Brazil
| | - Hal Blumenfeld
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Departments of Interdepartmental Neuroscience Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Departments of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA; Departments of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
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14
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Ehret G, Romand R. Awareness and consciousness in humans and animals – neural and behavioral correlates in an evolutionary perspective. Front Syst Neurosci 2022; 16:941534. [PMID: 35910003 PMCID: PMC9331465 DOI: 10.3389/fnsys.2022.941534] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/29/2022] [Indexed: 11/29/2022] Open
Abstract
Awareness or consciousness in the context of stimulus perception can directly be assessed in well controlled test situations with humans via the persons’ reports about their subjective experiences with the stimuli. Since we have no direct access to subjective experiences in animals, their possible awareness or consciousness in stimulus perception tasks has often been inferred from behavior and cognitive abilities previously observed in aware and conscious humans. Here, we analyze published human data primarily on event-related potentials and brain-wave generation during perception and responding to sensory stimuli and extract neural markers (mainly latencies of evoked-potential peaks and of gamma-wave occurrence) indicating that a person became aware or conscious of the perceived stimulus. These neural correlates of consciousness were then applied to sets of corresponding data from various animals including several species of mammals, and one species each of birds, fish, cephalopods, and insects. We found that the neural markers from studies in humans could also successfully be applied to the mammal and bird data suggesting that species in these animal groups can become subjectively aware of and conscious about perceived stimuli. Fish, cephalopod and insect data remained inconclusive. In an evolutionary perspective we have to consider that both awareness of and consciousness about perceived stimuli appear as evolved, attention-dependent options added to the ongoing neural activities of stimulus processing and action generation. Since gamma-wave generation for functional coupling of brain areas in aware/conscious states is energetically highly cost-intensive, it remains to be shown which animal species under which conditions of lifestyle and ecological niche may achieve significant advantages in reproductive fitness by drawing upon these options. Hence, we started our discussion about awareness and consciousness in animals with the question in how far these expressions of brain activity are necessary attributes for perceiving stimuli and responding in an adaptive way.
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Affiliation(s)
- Günter Ehret
- Institute of Neurobiology, University of Ulm, Ulm, Germany
- *Correspondence: Günter Ehret,
| | - Raymond Romand
- Faculty of Medicine, Institute de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), University of Strasbourg and Centre National de la Recherche Scientifique (CNRS), Strasbourg, France
- Raymond Romand,
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15
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Bellet J, Gay M, Dwarakanath A, Jarraya B, van Kerkoerle T, Dehaene S, Panagiotaropoulos TI. Decoding rapidly presented visual stimuli from prefrontal ensembles without report nor post-perceptual processing. Neurosci Conscious 2022; 2022:niac005. [PMID: 35223085 PMCID: PMC8868130 DOI: 10.1093/nc/niac005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 12/09/2021] [Accepted: 01/27/2022] [Indexed: 11/14/2022] Open
Abstract
The role of the primate prefrontal cortex (PFC) in conscious perception is debated. The global neuronal workspace theory of consciousness predicts that PFC neurons should contain a detailed code of the current conscious contents. Previous research showed that PFC is indeed activated in paradigms of conscious visual perception, including no-report paradigms where no voluntary behavioral report of the percept is given, thus avoiding a conflation of signals related to visual consciousness with signals related to the report. Still, it has been argued that prefrontal modulation could reflect post-perceptual processes that may be present even in the absence of report, such as thinking about the perceived stimulus, therefore reflecting a consequence rather than a direct correlate of conscious experience. Here, we investigate these issues by recording neuronal ensemble activity from the macaque ventrolateral PFC during briefly presented visual stimuli, either in isolated trials in which stimuli were clearly perceived or in sequences of rapid serial visual presentation (RSVP) in which perception and post-perceptual processing were challenged. We report that the identity of each stimulus could be decoded from PFC population activity even in the RSVP condition. The first visual signals could be detected at 60 ms after stimulus onset and information was maximal at 150 ms. However, in the RSVP condition, 200 ms after the onset of a stimulus, the decoding accuracy quickly dropped to chance level and the next stimulus started to be decodable. Interestingly, decoding in the ventrolateral PFC was stronger compared to posterior parietal cortex for both isolated and RSVP stimuli. These results indicate that neuronal populations in the macaque PFC reliably encode visual stimuli even under conditions that have been shown to challenge conscious perception and/or substantially reduce the probability of post-perceptual processing in humans. We discuss whether the observed activation reflects conscious access, phenomenal consciousness, or merely a preconscious bottom-up wave.
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Affiliation(s)
- Joachim Bellet
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Marion Gay
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Abhilash Dwarakanath
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Bechir Jarraya
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Timo van Kerkoerle
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Stanislas Dehaene
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
| | - Theofanis I Panagiotaropoulos
- Cognitive Neuroimaging Unit, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, INSERM, Université Paris-Saclay, NeuroSpin, Gif-Sur-Yvette 91191, France
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16
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Martin CG, He BJ, Chang C. State-related neural influences on fMRI connectivity estimation. Neuroimage 2021; 244:118590. [PMID: 34560268 PMCID: PMC8815005 DOI: 10.1016/j.neuroimage.2021.118590] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/11/2021] [Accepted: 09/16/2021] [Indexed: 12/01/2022] Open
Abstract
The spatiotemporal structure of functional magnetic resonance imaging (fMRI) signals has provided a valuable window into the network underpinnings of human brain function and dysfunction. Although some cross-regional temporal correlation patterns (functional connectivity; FC) exhibit a high degree of stability across individuals and species, there is growing acknowledgment that measures of FC can exhibit marked changes over a range of temporal scales. Further, FC can covary with experimental task demands and ongoing neural processes linked to arousal, consciousness and perception, cognitive and affective state, and brain-body interactions. The increased recognition that such interrelated neural processes modulate FC measurements has raised both challenges and new opportunities in using FC to investigate brain function. Here, we review recent advances in the quantification of neural effects that shape fMRI FC and discuss the broad implications of these findings in the design and analysis of fMRI studies. We also discuss how a more complete understanding of the neural factors that shape FC measurements can resolve apparent inconsistencies in the literature and lead to more interpretable conclusions from fMRI studies.
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Affiliation(s)
- Caroline G Martin
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, USA
| | - Biyu J He
- Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Departments of Neurology, Neuroscience & Physiology, and Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Catie Chang
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
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17
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Arnold DH, Saurels BW, Anderson NL, Johnston A. An observer model of tilt perception, sensitivity and confidence. Proc Biol Sci 2021; 288:20211276. [PMID: 34344185 PMCID: PMC8334841 DOI: 10.1098/rspb.2021.1276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/14/2021] [Indexed: 11/12/2022] Open
Abstract
Humans experience levels of confidence in perceptual decisions that tend to scale with the precision of their judgements; but not always. Sometimes precision can be held constant while confidence changes-leading researchers to assume precision and confidence are shaped by different types of information (e.g. perceptual and decisional). To assess this, we examined how visual adaptation to oriented inputs changes tilt perception, perceptual sensitivity and confidence. Some adaptors had a greater detrimental impact on measures of confidence than on precision. We could account for this using an observer model, where precision and confidence rely on different magnitudes of sensory information. These data show that differences in perceptual sensitivity and confidence can therefore emerge, not because these factors rely on different types of information, but because they rely on different magnitudes of sensory information.
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Affiliation(s)
- Derek H. Arnold
- Perception Lab, School of Psychology, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Blake W. Saurels
- Perception Lab, School of Psychology, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Natasha L. Anderson
- Perception Lab, School of Psychology, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Alan Johnston
- School of Psychology, University of Nottingham, Nottingham NG7 2RD, UK
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18
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Pereira M, Megevand P, Tan MX, Chang W, Wang S, Rezai A, Seeck M, Corniola M, Momjian S, Bernasconi F, Blanke O, Faivre N. Evidence accumulation relates to perceptual consciousness and monitoring. Nat Commun 2021; 12:3261. [PMID: 34059682 PMCID: PMC8166835 DOI: 10.1038/s41467-021-23540-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 05/04/2021] [Indexed: 11/29/2022] Open
Abstract
A fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.
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Affiliation(s)
- Michael Pereira
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
- University Grenoble Alpes, University Savoie Mont Blanc, CNRS, LPNC, Grenoble, France
- Rockefeller Neuroscience Institute (RNI), West Virginia University, Morgantown, USA
| | - Pierre Megevand
- Neurology Division, Department of Clinical Neuroscience, Geneva University Hospitals, Geneva, Switzerland
- Department of Fundamental Neuroscience, University of Geneva, Geneva, Switzerland
- Wyss Center for Bio and Neuroengineering, Geneva, Switzerland
| | - Mi Xue Tan
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
| | - Wenwen Chang
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
| | - Shuo Wang
- Rockefeller Neuroscience Institute (RNI), West Virginia University, Morgantown, USA
- Department of Chemical and Biomedical Engineering, West Virginia University, Morgantown, USA
| | - Ali Rezai
- Rockefeller Neuroscience Institute (RNI), West Virginia University, Morgantown, USA
| | - Margitta Seeck
- Neurology Division, Department of Clinical Neuroscience, Geneva University Hospitals, Geneva, Switzerland
| | - Marco Corniola
- Neurosurgery Division, Department of Clinical Neuroscience, University of Geneva University Hospitals, Geneva, Switzerland
- Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland
| | - Shahan Momjian
- Neurosurgery Division, Department of Clinical Neuroscience, University of Geneva University Hospitals, Geneva, Switzerland
- Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland
| | - Fosco Bernasconi
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
| | - Olaf Blanke
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
- Faculty of Medicine, University Hospital Geneva, Geneva, Switzerland
| | - Nathan Faivre
- Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Faculty of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.
- University Grenoble Alpes, University Savoie Mont Blanc, CNRS, LPNC, Grenoble, France.
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19
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Levinson M, Podvalny E, Baete SH, He BJ. Cortical and subcortical signatures of conscious object recognition. Nat Commun 2021; 12:2930. [PMID: 34006884 PMCID: PMC8131711 DOI: 10.1038/s41467-021-23266-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/12/2021] [Indexed: 11/29/2022] Open
Abstract
The neural mechanisms underlying conscious recognition remain unclear, particularly the roles played by the prefrontal cortex, deactivated brain areas and subcortical regions. We investigated neural activity during conscious object recognition using 7 Tesla fMRI while human participants viewed object images presented at liminal contrasts. Here, we show both recognized and unrecognized images recruit widely distributed cortical and subcortical regions; however, recognized images elicit enhanced activation of visual, frontoparietal, and subcortical networks and stronger deactivation of the default-mode network. For recognized images, object category information can be decoded from all of the involved cortical networks but not from subcortical regions. Phase-scrambled images trigger strong involvement of inferior frontal junction, anterior cingulate cortex and default-mode network, implicating these regions in inferential processing under increased uncertainty. Our results indicate that content-specific activity in both activated and deactivated cortical networks and non-content-specific subcortical activity support conscious recognition. Cortical and subcortical neural activity supporting conscious object recognition has not yet been well defined. Here, the authors describe these networks and show recognition-related category information can be decoded from widespread cortical activity but not subcortical activity.
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Affiliation(s)
- Max Levinson
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Ella Podvalny
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Steven H Baete
- Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Biyu J He
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA. .,Department of Radiology, New York University School of Medicine, New York, NY, USA. .,Department of Neurology, New York University School of Medicine, New York, NY, USA. .,Department of Neuroscience & Physiology, New York University School of Medicine, New York, NY, USA.
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20
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Anterior insula regulates brain network transitions that gate conscious access. Cell Rep 2021; 35:109081. [PMID: 33951427 PMCID: PMC8157795 DOI: 10.1016/j.celrep.2021.109081] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/19/2021] [Accepted: 04/13/2021] [Indexed: 12/20/2022] Open
Abstract
Conscious access to sensory information is likely gated at an intermediate site between primary sensory and transmodal association cortices, but the structure responsible remains unknown. We perform functional neuroimaging to determine the neural correlates of conscious access using a volitional mental imagery task, a report paradigm not confounded by motor behavior. Titrating propofol to loss of behavioral responsiveness in healthy volunteers creates dysfunction of the anterior insular cortex (AIC) in association with an impairment of dynamic transitions of default-mode and dorsal attention networks. Candidate subcortical regions mediating sensory gating or arousal (thalamus, basal forebrain) fail to show this association. The gating role of the AIC is consistent with findings in awake participants, whose conscious access is predicted by pre-stimulus AIC activity near perceptual threshold. These data support the hypothesis that AIC, situated at an intermediate position of the cortical hierarchy, regulates brain network transitions that gate conscious access. In a human neuroimaging study, Huang et al. manipulate the level and content of consciousness using independent experimental protocols to demonstrate that the anterior insula, situated between unimodal and transmodal cortical areas along the brain’s functional hierarchy, serves as a gate for conscious access of sensory information.
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21
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Faramarzi M, Kasten FH, Altaş G, Aleman A, Ćurčić-Blake B, Herrmann CS. Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions. Front Neurosci 2021; 15:602437. [PMID: 33867913 PMCID: PMC8047478 DOI: 10.3389/fnins.2021.602437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 03/12/2021] [Indexed: 12/31/2022] Open
Abstract
Hallucinations and illusions are two instances of perceptual experiences illustrating how perception might diverge from external sensory stimulations and be generated or altered based on internal brain states. The occurrence of these phenomena is not constrained to patient populations. Similar experiences can be elicited in healthy subjects by means of suitable experimental procedures. Studying the neural mechanisms underlying these experiences not only has the potential to expand our understanding of the brain's perceptual machinery but also of how it might get impaired. In the current study, we employed an auditory signal detection task to induce auditory illusions by presenting speech snippets at near detection threshold intensity embedded in noise. We investigated the neural correlates of auditory false perceptions by examining the EEG activity preceding the responses in speech absent (false alarm, FA) trials and comparing them to speech present (hit) trials. The results of the comparison of event-related potentials (ERPs) in the activation period vs. baseline revealed the presence of an early negativity (EN) and a late positivity (LP) similar in both hits and FAs, which were absent in misses, correct rejections (CR) and control button presses (BPs). We postulate that the EN and the LP might represent the auditory awareness negativity (AAN) and centro-parietal positivity (CPP) or P300, respectively. The event-related spectral perturbations (ERSPs) exhibited a common power enhancement in low frequencies (<4 Hz) in hits and FAs. The low-frequency power enhancement has been frequently shown to be accompanied with P300 as well as separately being a marker of perceptual awareness, referred to as slow cortical potentials (SCP). Furthermore, the comparison of hits vs. FAs showed a significantly higher LP amplitude and low frequency power in hits compared to FAs. Generally, the observed patterns in the present results resembled some of the major neural correlates associated with perceptual awareness in previous studies. Our findings provide evidence that the neural correlates associated with conscious perception, can be elicited in similar ways in both presence and absence of externally presented sensory stimuli. The present findings did not reveal any pre-stimulus alpha and beta modulations distinguishing conscious vs. unconscious perceptions.
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Affiliation(s)
- Maryam Faramarzi
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence “Hearing4All,” Carl von Ossietzky University, Oldenburg, Germany
- Department of Biomedical Sciences of Cells and Systems, Cognitive Neuroscience Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Florian H. Kasten
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence “Hearing4All,” Carl von Ossietzky University, Oldenburg, Germany
- Neuroimaging Unit, European Medical School, Carl von Ossietzky University, Oldenburg, Germany
| | - Gamze Altaş
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence “Hearing4All,” Carl von Ossietzky University, Oldenburg, Germany
| | - André Aleman
- Department of Biomedical Sciences of Cells and Systems, Cognitive Neuroscience Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Branislava Ćurčić-Blake
- Department of Biomedical Sciences of Cells and Systems, Cognitive Neuroscience Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Christoph S. Herrmann
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence “Hearing4All,” Carl von Ossietzky University, Oldenburg, Germany
- Neuroimaging Unit, European Medical School, Carl von Ossietzky University, Oldenburg, Germany
- Research Center Neurosensory Science, Carl von Ossietzky University, Oldenburg, Germany
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22
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Gusso MDM, Serur G, Nohama P. Pupil Reactions to Tactile Stimulation: A Systematic Review. Front Neurosci 2021; 15:610841. [PMID: 33692668 PMCID: PMC7937793 DOI: 10.3389/fnins.2021.610841] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/12/2021] [Indexed: 11/20/2022] Open
Abstract
Pupil dynamics can represent an indirect measure of perception; thus, it has been broadly explored in the auditory and visual fields. Although it is crucial for experiencing the outside world, tactile perception is not well-explored. Considering that, we sought to answer the following question via a systematic review: does normal tactile perception processing modulate pupil dilation in mammals (human or not)? The review process was conducted according to PRISMA Statement. We searched on Periódicos CAPES (Brazil) for the following terms: [(touch) OR (cutaneous stimulation) OR (tactile perception) OR (somatosensory) AND (pupil OR pupillary) NOT blind NOT reflex NOT pain NOT fear NOT noxious NOT autism NOT nerve NOT (pupillary block) NOT glaucoma NOT cataract NOT aneurysm NOT syndrome NOT treatment NOT special education]. From the 6,488 papers found, 4,568 were duplicates, and nine fulfilled the inclusion criteria. All papers found a positive relationship between pupil diameter and tactile perception. We found that the pupil is a reliable indirect measure of brain states and can evaluate norepinephrine (NE)/locus coeruleus (LC) action, stimulus inhibition, arousal, cognitive processes, and affection independently of the stimuli category (visual, auditory, or tactile). We also found that the perceptual tactile processing occurs in similar ways as the other perceptual modalities. We verified that more studies should be done, mostly avoiding low sampling rate recording systems, confounders as cue signs, not automated stimulation, and concurrent stimulus and using more reliable equipment.
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Affiliation(s)
- Mariana de Mello Gusso
- Laboratório de Engenharia de Reabilitação, Programa de Pós-Graduação em Tecnologia em Saúde, Escola Politécnica, Pontifícia Universidade Católica Do Paraná, Curitiba, Brazil
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23
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Dowdle LT, Ghose G, Ugurbil K, Yacoub E, Vizioli L. Clarifying the role of higher-level cortices in resolving perceptual ambiguity using ultra high field fMRI. Neuroimage 2021; 227:117654. [PMID: 33333319 PMCID: PMC10614695 DOI: 10.1016/j.neuroimage.2020.117654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/17/2020] [Accepted: 12/05/2020] [Indexed: 12/17/2022] Open
Abstract
The brain is organized into distinct, flexible networks. Within these networks, cognitive variables such as attention can modulate sensory representations in accordance with moment-to-moment behavioral requirements. These modulations can be studied by varying task demands; however, the tasks employed are often incongruent with the postulated functions of a sensory system, limiting the characterization of the system in relation to natural behaviors. Here we combine domain-specific task manipulations and ultra-high field fMRI to study the nature of top-down modulations. We exploited faces, a visual category underpinned by a complex cortical network, and instructed participants to perform either a stimulus-relevant/domain-specific or a stimulus-irrelevant task in the scanner. We found that 1. perceptual ambiguity (i.e. difficulty of achieving a stable percept) is encoded in top-down modulations from higher-level cortices; 2. the right inferior-temporal lobe is active under challenging conditions and uniquely encodes trial-by-trial variability in face perception.
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Affiliation(s)
- Logan T Dowdle
- Center for Magnetic Resonance Research, University of Minnesota 2021 6th St SE, Minneapolis, MN 55455, United States; Department of Neuroscience, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455.
| | - Geoffrey Ghose
- Center for Magnetic Resonance Research, University of Minnesota 2021 6th St SE, Minneapolis, MN 55455, United States; Department of Neuroscience, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455
| | - Kamil Ugurbil
- Center for Magnetic Resonance Research, University of Minnesota 2021 6th St SE, Minneapolis, MN 55455, United States
| | - Essa Yacoub
- Center for Magnetic Resonance Research, University of Minnesota 2021 6th St SE, Minneapolis, MN 55455, United States
| | - Luca Vizioli
- Center for Magnetic Resonance Research, University of Minnesota 2021 6th St SE, Minneapolis, MN 55455, United States; Department of Neurosurgery, University of Minnesota, 500 SE Harvard St, Minneapolis, MN 55455.
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24
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Imbir KK, Pastwa M, Jankowska M, Kosman M, Modzelewska A, Wielgopolan A. Valence and arousal of words in visual and conceptual interference control efficiency. PLoS One 2020; 15:e0241694. [PMID: 33211720 PMCID: PMC7676691 DOI: 10.1371/journal.pone.0241694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/20/2020] [Indexed: 11/18/2022] Open
Abstract
Cognitive control efficiency is susceptible to the emotional state of an individual. The aim of the current experiment was to search for the role of valence and arousal of emotion-laden words in a performance efficiency of a modified emotional Stroop task (EST) combined with the flanker task. Both paradigms allow for the measurement of the interference control, but interference appears on different stages of stimulus processing. In the flanker task, the interference is perceptual, while in EST, it is based on the emotional meaning of stimuli. We expected to find the effects of emotionality of words, that is, arousal and valence levels, for interference measured with EST. In a series of two experiments, the results confirmed that a high arousal level enlarges the reaction latencies to the EST. We also identified interaction between valence and arousal in shaping reaction latencies. We found the flanker congruency effect. We did not find interactions between emotional factors and flanker congruency. This suggests that interference measured with the EST and flanker task are in fact different from one another, and while using the modified EST combined with the flanker task, the word-meaning effects do not interfere with pure perceptual interferences.
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Affiliation(s)
- Kamil K. Imbir
- Faculty of Psychology, University of Warsaw, Warsaw, Poland
| | - Maciej Pastwa
- Faculty of Psychology, University of Warsaw, Warsaw, Poland
| | | | - Marcin Kosman
- Faculty of Polish Studies, Institute of Applied Polish Studies, Warsaw, Poland
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25
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Bourdillon P, Hermann B, Guénot M, Bastuji H, Isnard J, King JR, Sitt J, Naccache L. Brain-scale cortico-cortical functional connectivity in the delta-theta band is a robust signature of conscious states: an intracranial and scalp EEG study. Sci Rep 2020; 10:14037. [PMID: 32820188 PMCID: PMC7441406 DOI: 10.1038/s41598-020-70447-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/22/2020] [Indexed: 11/17/2022] Open
Abstract
Long-range cortico-cortical functional connectivity has long been theorized to be necessary for conscious states. In the present work, we estimate long-range cortical connectivity in a series of intracranial and scalp EEG recordings experiments. In the two first experiments intracranial-EEG (iEEG) was recorded during four distinct states within the same individuals: conscious wakefulness (CW), rapid-eye-movement sleep (REM), stable periods of slow-wave sleep (SWS) and deep propofol anaesthesia (PA). We estimated functional connectivity using the following two methods: weighted Symbolic-Mutual-Information (wSMI) and phase-locked value (PLV). Our results showed that long-range functional connectivity in the delta-theta frequency band specifically discriminated CW and REM from SWS and PA. In the third experiment, we generalized this original finding on a large cohort of brain-injured patients. FC in the delta-theta band was significantly higher in patients being in a minimally conscious state (MCS) than in those being in a vegetative state (or unresponsive wakefulness syndrome). Taken together the present results suggest that FC of cortical activity in this slow frequency band is a new and robust signature of conscious states.
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Affiliation(s)
- Pierre Bourdillon
- Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Hospices Civils de Lyon, Lyon, France.
- Faculté de médecine Claude Bernard, Université de Lyon, Lyon, France.
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France.
- Sorbonne Université, Paris, France.
| | - Bertrand Hermann
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
- Sorbonne Université, Paris, France
- Neuro Intensive Care Unit, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Marc Guénot
- Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Hospices Civils de Lyon, Lyon, France
- Faculté de médecine Claude Bernard, Université de Lyon, Lyon, France
- Neuropain Team, Centre de Recherche en Neurosciences de Lyon, INSERM U1028, Lyon, France
| | - Hélène Bastuji
- Neuropain Team, Centre de Recherche en Neurosciences de Lyon, INSERM U1028, Lyon, France
- Functional Neurology Department and Sleep Center, Hospices Civils de Lyon, Lyon, France
| | - Jean Isnard
- Functional Neurology Department and Sleep Center, Hospices Civils de Lyon, Lyon, France
| | - Jean-Rémi King
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
| | - Jacobo Sitt
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
| | - Lionel Naccache
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France.
- Sorbonne Université, Paris, France.
- Department of Neurophysiology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Paris, France.
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26
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Glim S, Ries A, Sorg C, Wohlschläger AM. The temporal evolution of pre-stimulus slow cortical potentials is associated with an upcoming stimulus' access to visual consciousness. Conscious Cogn 2020; 84:102993. [PMID: 32771954 DOI: 10.1016/j.concog.2020.102993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 01/21/2023]
Abstract
Slow cortical potentials (SCPs) have been proposed to be essential for the formation of conscious experience. To examine their temporal characteristics, we recorded electroencephalography during a visual backward-masking task, which required participants to localize the missing part of a target stimulus. A subsequent confidence rating was used as a proxy for the target's access to consciousness. Event-related potentials (ERPs) of all correct trials were determined relative to a brief period immediately before the target and then compared among consciousness levels. In an interval ranging from 2 s prior to target presentation up to this period, a negative relationship between slowly fluctuating ERP values and the level of consciousness became evident. After target presentation, high conscious awareness was characterized by an enhanced visual awareness negativity, an increased P3 component, and associated positive SCPs. Together, these findings add new evidence to the proposed role of SCPs in the emergence of visual consciousness.
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Affiliation(s)
- Sarah Glim
- Department of Neuroradiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Graduate School of Systemic Neurosciences, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Anja Ries
- Department of Neuroradiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Christian Sorg
- Department of Neuroradiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Department of Psychiatry, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Afra M Wohlschläger
- Department of Neuroradiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Graduate School of Systemic Neurosciences, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany.
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27
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Avramiea AE, Hardstone R, Lueckmann JM, Bím J, Mansvelder HD, Linkenkaer-Hansen K. Pre-stimulus phase and amplitude regulation of phase-locked responses are maximized in the critical state. eLife 2020; 9:e53016. [PMID: 32324137 PMCID: PMC7217696 DOI: 10.7554/elife.53016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/20/2020] [Indexed: 01/23/2023] Open
Abstract
Understanding why identical stimuli give differing neuronal responses and percepts is a central challenge in research on attention and consciousness. Ongoing oscillations reflect functional states that bias processing of incoming signals through amplitude and phase. It is not known, however, whether the effect of phase or amplitude on stimulus processing depends on the long-term global dynamics of the networks generating the oscillations. Here, we show, using a computational model, that the ability of networks to regulate stimulus response based on pre-stimulus activity requires near-critical dynamics-a dynamical state that emerges from networks with balanced excitation and inhibition, and that is characterized by scale-free fluctuations. We also find that networks exhibiting critical oscillations produce differing responses to the largest range of stimulus intensities. Thus, the brain may bring its dynamics close to the critical state whenever such network versatility is required.
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Affiliation(s)
- Arthur-Ervin Avramiea
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
| | - Richard Hardstone
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
- Neuroscience Institute, New York University School of MedicineNew YorkUnited States
| | - Jan-Matthis Lueckmann
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
- Technical University of MunichMunichGermany
| | - Jan Bím
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
- Czech Technical University in PraguePragueCzech Republic
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
| | - Klaus Linkenkaer-Hansen
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam NeuroscienceAmsterdamNetherlands
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28
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Herman WX, Smith RE, Kronemer SI, Watsky RE, Chen WC, Gober LM, Touloumes GJ, Khosla M, Raja A, Horien CL, Morse EC, Botta KL, Hirsch LJ, Alkawadri R, Gerrard JL, Spencer DD, Blumenfeld H. A Switch and Wave of Neuronal Activity in the Cerebral Cortex During the First Second of Conscious Perception. Cereb Cortex 2020; 29:461-474. [PMID: 29194517 DOI: 10.1093/cercor/bhx327] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Indexed: 12/17/2022] Open
Abstract
Conscious perception occurs within less than 1 s. To study events on this time scale we used direct electrical recordings from the human cerebral cortex during a conscious visual perception task. Faces were presented at individually titrated visual threshold for 9 subjects while measuring broadband 40-115 Hz gamma power in a total of 1621 intracranial electrodes widely distributed in both hemispheres. Surface maps and k-means clustering analysis showed initial activation of visual cortex for both perceived and non-perceived stimuli. However, only stimuli reported as perceived then elicited a forward-sweeping wave of activity throughout the cerebral cortex accompanied by large-scale network switching. Specifically, a monophasic wave of broadband gamma activation moves through bilateral association cortex at a rate of approximately 150 mm/s and eventually reenters visual cortex for perceived but not for non-perceived stimuli. Meanwhile, the default mode network and the initial visual cortex and higher association cortex networks are switched off for the duration of conscious stimulus processing. Based on these findings, we propose a new "switch-and-wave" model for the processing of consciously perceived stimuli. These findings are important for understanding normal conscious perception and may also shed light on its vulnerability to disruption by brain disorders.
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Affiliation(s)
- Wendy X Herman
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Rachel E Smith
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Sharif I Kronemer
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Rebecca E Watsky
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - William C Chen
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Leah M Gober
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - George J Touloumes
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Meenakshi Khosla
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Anusha Raja
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Corey L Horien
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Elliot C Morse
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Katherine L Botta
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Lawrence J Hirsch
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Rafeed Alkawadri
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Jason L Gerrard
- Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Dennis D Spencer
- Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
- Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
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29
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Podvalny E, Flounders MW, King LE, Holroyd T, He BJ. A dual role of prestimulus spontaneous neural activity in visual object recognition. Nat Commun 2019; 10:3910. [PMID: 31477706 PMCID: PMC6718405 DOI: 10.1038/s41467-019-11877-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 08/08/2019] [Indexed: 12/17/2022] Open
Abstract
Vision relies on both specific knowledge of visual attributes, such as object categories, and general brain states, such as those reflecting arousal. We hypothesized that these phenomena independently influence recognition of forthcoming stimuli through distinct processes reflected in spontaneous neural activity. Here, we recorded magnetoencephalographic (MEG) activity in participants (N = 24) who viewed images of objects presented at recognition threshold. Using multivariate analysis applied to sensor-level activity patterns recorded before stimulus presentation, we identified two neural processes influencing subsequent subjective recognition: a general process, which disregards stimulus category and correlates with pupil size, and a specific process, which facilitates category-specific recognition. The two processes are doubly-dissociable: the general process correlates with changes in criterion but not in sensitivity, whereas the specific process correlates with changes in sensitivity but not in criterion. Our findings reveal distinct mechanisms of how spontaneous neural activity influences perception and provide a framework to integrate previous findings. The effect of spontaneous variations in prestimulus neural activity on subsequent perception is incompletely understood. Here, using MEG, the authors identify two distinct neural processes that can influence object recognition in different ways.
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Affiliation(s)
- Ella Podvalny
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA.
| | - Matthew W Flounders
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA
| | - Leana E King
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA
| | - Tom Holroyd
- Magnetoencephalography Core Facility, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Biyu J He
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA. .,Departments of Neurology, Neuroscience & Physiology, and Radiology, New York University School of Medicine, New York, NY, 10016, USA.
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30
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State-aware detection of sensory stimuli in the cortex of the awake mouse. PLoS Comput Biol 2019; 15:e1006716. [PMID: 31150385 PMCID: PMC6561583 DOI: 10.1371/journal.pcbi.1006716] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/12/2019] [Accepted: 05/15/2019] [Indexed: 11/19/2022] Open
Abstract
Cortical responses to sensory inputs vary across repeated presentations of identical stimuli, but how this trial-to-trial variability impacts detection of sensory inputs is not fully understood. Using multi-channel local field potential (LFP) recordings in primary somatosensory cortex (S1) of the awake mouse, we optimized a data-driven cortical state classifier to predict single-trial sensory-evoked responses, based on features of the spontaneous, ongoing LFP recorded across cortical layers. Our findings show that, by utilizing an ongoing prediction of the sensory response generated by this state classifier, an ideal observer improves overall detection accuracy and generates robust detection of sensory inputs across various states of ongoing cortical activity in the awake brain, which could have implications for variability in the performance of detection tasks across brain states. Establishing the link between neural activity and behavior is a central goal of neuroscience. One context in which to examine this link is in a sensory detection task, in which an animal is trained to report the presence of a barely perceptible sensory stimulus. In such tasks, both sensory responses in the brain and behavioral responses are highly variable. A simple hypothesis, originating in signal detection theory, is that perceived inputs generate neural activity that cross some threshold for detection. According to this hypothesis, sensory response variability would predict behavioral variability, but previous studies have not born out this prediction. Further complicating the picture, sensory response variability is partially dependent on the ongoing state of cortical activity, and we wondered whether this could resolve the mismatch between response variability and behavioral variability. Here, we use a computational approach to study an adaptive observer that utilizes an ongoing prediction of sensory responsiveness to detect sensory inputs. This observer has higher overall accuracy than the standard ideal observer. Moreover, because of the adaptation, the observer breaks the direct link between neural and behavioral variability, which could resolve discrepancies arising in past studies. We suggest new experiments to test our theory.
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31
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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: 18] [Impact Index Per Article: 3.6] [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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32
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Flounders MW, González-García C, Hardstone R, He BJ. Neural dynamics of visual ambiguity resolution by perceptual prior. eLife 2019; 8:41861. [PMID: 30843519 PMCID: PMC6415935 DOI: 10.7554/elife.41861] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 02/25/2019] [Indexed: 11/30/2022] Open
Abstract
Past experiences have enormous power in shaping our daily perception. Currently, dynamical neural mechanisms underlying this process remain mysterious. Exploiting a dramatic visual phenomenon, where a single experience of viewing a clear image allows instant recognition of a related degraded image, we investigated this question using MEG and 7 Tesla fMRI in humans. We observed that following the acquisition of perceptual priors, different degraded images are represented much more distinctly in neural dynamics starting from ~500 ms after stimulus onset. Content-specific neural activity related to stimulus-feature processing dominated within 300 ms after stimulus onset, while content-specific neural activity related to recognition processing dominated from 500 ms onward. Model-driven MEG-fMRI data fusion revealed the spatiotemporal evolution of neural activities involved in stimulus, attentional, and recognition processing. Together, these findings shed light on how experience shapes perceptual processing across space and time in the brain.
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Affiliation(s)
- Matthew W Flounders
- Neuroscience Institute, New York University Langone Medical Center, New York, United States
| | | | - Richard Hardstone
- Neuroscience Institute, New York University Langone Medical Center, New York, United States
| | - Biyu J He
- Neuroscience Institute, New York University Langone Medical Center, New York, United States.,Department of Neurology, New York University Langone Medical Center, New York, United States.,Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, United States.,Department of Radiology, New York University Langone Medical Center, New York, United States
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33
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Huk A, Bonnen K, He BJ. Beyond Trial-Based Paradigms: Continuous Behavior, Ongoing Neural Activity, and Natural Stimuli. J Neurosci 2018; 38:7551-7558. [PMID: 30037835 PMCID: PMC6113904 DOI: 10.1523/jneurosci.1920-17.2018] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/02/2018] [Accepted: 07/07/2018] [Indexed: 11/21/2022] Open
Abstract
The vast majority of experiments examining perception and behavior are conducted using experimental paradigms that adhere to a rigid trial structure: each trial consists of a brief and discrete series of events and is regarded as independent from all other trials. The assumptions underlying this structure ignore the reality that natural behavior is rarely discrete, brain activity follows multiple time courses that do not necessarily conform to the trial structure, and the natural environment has statistical structure and dynamics that exhibit long-range temporal correlation. Modern advances in statistical modeling and analysis offer tools that make it feasible for experiments to move beyond rigid independent and identically distributed trial structures. Here we review literature that serves as evidence for the feasibility and advantages of moving beyond trial-based paradigms to understand the neural basis of perception and cognition. Furthermore, we propose a synthesis of these efforts, integrating the characterization of natural stimulus properties with measurements of continuous neural activity and behavioral outputs within the framework of sensory-cognitive-motor loops. Such a framework provides a basis for the study of natural statistics, naturalistic tasks, and/or slow fluctuations in brain activity, which should provide starting points for important generalizations of analytical tools in neuroscience and subsequent progress in understanding the neural basis of perception and cognition.
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Affiliation(s)
- Alexander Huk
- Center for Perceptual Systems,
- Institute for Neuroscience
- Departments of Psychology and Neuroscience, The University of Texas at Austin, Austin 78712, Texas, and
| | | | - Biyu J He
- Departments of Neurology, Neuroscience and Physiology, and Radiology, Neuroscience Institute, New York University Langone Medical Center, New York, New York 10016
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Abstract
It is natural to see conscious perceptions as typically bringing with them a degree of confidence about what is perceived. So one might also expect such confidence not to occur if a perception is not conscious. This has resulted in the use of confidence as a test or measure of consciousness, one that may be more reliable and fine-grained than the traditional appeal to subjective report as a test for a perception's being conscious. The following describes theoretical difficulties for the use of confidence as a reliable test for consciousness, which show that confidence is less reliable than subjective report. Difficulties are also presented for the use of confidence ratings in assessing degrees of consciousness, which cast doubt on any advantage confidence might have from being more fine-grained than subjective report. And an explanation is proposed for the wide appeal of using confidence to assess subjective awareness, an explanation that also makes clear why confidence is less reliable than subjective report.
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35
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Baria AT, Maniscalco B, He BJ. Initial-state-dependent, robust, transient neural dynamics encode conscious visual perception. PLoS Comput Biol 2017; 13:e1005806. [PMID: 29176808 PMCID: PMC5720802 DOI: 10.1371/journal.pcbi.1005806] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 12/07/2017] [Accepted: 10/01/2017] [Indexed: 01/09/2023] Open
Abstract
Recent research has identified late-latency, long-lasting neural activity as a robust correlate of conscious perception. Yet, the dynamical nature of this activity is poorly understood, and the mechanisms governing its presence or absence and the associated conscious perception remain elusive. We applied dynamic-pattern analysis to whole-brain slow (< 5 Hz) cortical dynamics recorded by magnetoencephalography (MEG) in human subjects performing a threshold-level visual perception task. Up to 1 second before stimulus onset, brain activity pattern across widespread cortices significantly predicted whether a threshold-level visual stimulus was later consciously perceived. This initial state of brain activity interacts nonlinearly with stimulus input to shape the evolving cortical activity trajectory, with seen and unseen trials following well separated trajectories. We observed that cortical activity trajectories during conscious perception are fast evolving and robust to small variations in the initial state. In addition, spontaneous brain activity pattern prior to stimulus onset also influences unconscious perceptual making in unseen trials. Together, these results suggest that brain dynamics underlying conscious visual perception belongs to the class of initial-state-dependent, robust, transient neural dynamics. What brain mechanisms underlie conscious perception? A commonly adopted paradigm for studying this question is to present human subjects with threshold-level stimuli. When shown repeatedly, the same stimulus is sometimes consciously perceived, sometimes not. Using magnetoencephalography, we shed light on the neural mechanisms governing whether the stimulus is consciously perceived in a given trial. We observed that depending on the initial brain state defined by widespread activity pattern in the slow cortical potential (<5 Hz) range, a physically identical, brief (30–60 ms) stimulus input triggers distinct sequences of activity pattern evolution over time that correspond to either consciously perceiving the stimulus or not. Such activity pattern evolution forms a “trajectory” in the state space and affords significant single-trial decoding of perceptual outcome from 1 sec before to 3 sec after stimulus onset. While previous theories on conscious perception have emphasized sustained, high-level activity, we found that brain dynamics underlying conscious perception exhibit fast-changing activity patterns. These results significantly further our understanding on the neural mechanisms governing conscious access of a stimulus and the dynamical nature of distributed neural activity underlying conscious perception.
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Affiliation(s)
- Alexis T. Baria
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian Maniscalco
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- Neuroscience Institute, New York University Langone Medical Center, New York, NY, United States of America
| | - Biyu J. He
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- Neuroscience Institute, New York University Langone Medical Center, New York, NY, United States of America
- Departments of Neurology, Neuroscience and Physiology, and Radiology, New York University Langone Medical Center, New York, NY, United States of America
- * E-mail:
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36
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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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37
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Northoff G. “Paradox of slow frequencies” – Are slow frequencies in upper cortical layers a neural predisposition of the level/state of consciousness (NPC)? Conscious Cogn 2017; 54:20-35. [DOI: 10.1016/j.concog.2017.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/05/2017] [Accepted: 03/13/2017] [Indexed: 01/01/2023]
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38
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Northoff G. Personal Identity and Cortical Midline Structure (CMS): Do Temporal Features of CMS Neural Activity Transform Into “Self-Continuity”? PSYCHOLOGICAL INQUIRY 2017. [DOI: 10.1080/1047840x.2017.1337396] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Georg Northoff
- Mental Health Centre, Zhejiang University School of Medicine, Hangzhou, China
- Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China
- Centre for Brain and Consciousness, Taipei Medical University, Taipei, Taiwan
- College for Humanities and Medicine, Taipei Medical University, Taipei, Taiwan
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Northoff G, Huang Z. How do the brain's time and space mediate consciousness and its different dimensions? Temporo-spatial theory of consciousness (TTC). Neurosci Biobehav Rev 2017; 80:630-645. [PMID: 28760626 DOI: 10.1016/j.neubiorev.2017.07.013] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/10/2017] [Accepted: 07/27/2017] [Indexed: 11/19/2022]
Abstract
Time and space are the basic building blocks of nature. As a unique existent in nature, our brain exists in time and takes up space. The brain's activity itself also constitutes and spreads in its own (intrinsic) time and space that is crucial for consciousness. Consciousness is a complex phenomenon including different dimensions: level/state, content/form, phenomenal aspects, and cognitive features. We propose a Temporo-spatial Theory of Consciousness (TTC) focusing primarily on the temporal and spatial features of the brain activity. We postulate four different neuronal mechanisms accounting for the different dimensions of consciousness: (i) "temporo-spatial nestedness" of the spontaneous activity accounts for the level/state of consciousness as neural predisposition of consciousness (NPC); (ii) "temporo-spatial alignment" of the pre-stimulus activity accounts for the content/form of consciousness as neural prerequisite of consciousness (preNCC); (iii) "temporo-spatial expansion" of early stimulus-induced activity accounts for phenomenal consciousness as neural correlates of consciousness (NCC); (iv) "temporo-spatial globalization" of late stimulus-induced activity accounts for the cognitive features of consciousness as neural consequence of consciousness (NCCcon).
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Affiliation(s)
- Georg Northoff
- Mental Health Centre, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; University of Ottawa, Institute of Mental Health Research, University of Ottawa Brain and Mind Research Institute, Ottawa, Canada; Centre for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China; Centre for Brain and Consciousness, Taipei Medical University (TMU), Taipei, Taiwan; College for Humanities and Medicine, Taipei Medical University (TMU), Taipei, Taiwan; Center for the Study of Language and Cognition, Zhejiang University, Hangzhou 310028, China.
| | - Zirui Huang
- Department of Anesthesiology and Center for Consciousness Science, University of Michigan, Ann Arbor, USA.
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King JR, Pescetelli N, Dehaene S. Brain Mechanisms Underlying the Brief Maintenance of Seen and Unseen Sensory Information. Neuron 2017; 92:1122-1134. [PMID: 27930903 DOI: 10.1016/j.neuron.2016.10.051] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 07/05/2016] [Accepted: 10/21/2016] [Indexed: 01/24/2023]
Abstract
Recent evidence of unconscious working memory challenges the notion that only visible stimuli can be actively maintained over time. In the present study, we investigated the neural dynamics underlying the maintenance of variably visible stimuli using magnetoencephalography. Subjects had to detect and mentally maintain the orientation of a masked grating. We show that the stimulus is fully encoded in early brain activity independently of visibility reports. However, the presence and orientation of the target are actively maintained throughout the brief retention period, even when the stimulus is reported as unseen. Source and decoding analyses revealed that perceptual maintenance recruits a hierarchical network spanning the early visual, temporal, parietal, and frontal cortices. Importantly, the representations coded in the late processing stages of this network specifically predicted visibility reports. These unexpected results challenge several theories of consciousness and suggest that invisible information can be briefly maintained within the higher processing stages of visual perception.
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Affiliation(s)
- Jean-Rémi King
- Department of Psychology, New York University, New York, NY 10003, USA; Neuroscience Department, Frankfurt Institute for Advanced Studies, 60438 Frankfurt, Germany.
| | - Niccolo Pescetelli
- Department of Experimental Psychology, University of Oxford, OX1 3UD Oxford, UK
| | - Stanislas Dehaene
- Cognitive Neuroimaging Unit, CEA DSV/I2BM, INSERM, Université Paris-Sud, Université Paris-Saclay, NeuroSpin Center, 91191 Gif/Yvette, France; Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
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Peters MAK, Thesen T, Ko YD, Maniscalco B, Carlson C, Davidson M, Doyle W, Kuzniecky R, Devinsky O, Halgren E, Lau H. Perceptual confidence neglects decision-incongruent evidence in the brain. Nat Hum Behav 2017; 1:0139. [PMID: 29130070 PMCID: PMC5675133 DOI: 10.1038/s41562-017-0139] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/06/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Megan A. K. Peters
- Department of Psychology, University of California, Los Angeles, Los Angeles, California, USA
| | - Thomas Thesen
- Comprehensive Epilepsy Center, Department of Neurology, New York University Medical Center, New York, New York, USA
- Multimodal Imaging Laboratory, University of California, San Diego, La Jolla, California, USA
- Department of Physiology & Neuroscience, St. George’s University, Grenada, West Indies
| | - Yoshiaki D. Ko
- Department of Psychology, Columbia University, New York, New York, USA
| | - Brian Maniscalco
- Neuroscience Institute, New York University, New York, New York, USA
| | - Chad Carlson
- Comprehensive Epilepsy Center, Department of Neurology, New York University Medical Center, New York, New York, USA
| | - Matt Davidson
- Department of Psychology, Columbia University, New York, New York, USA
| | - Werner Doyle
- Comprehensive Epilepsy Center, Department of Neurology, New York University Medical Center, New York, New York, USA
| | - Ruben Kuzniecky
- Comprehensive Epilepsy Center, Department of Neurology, New York University Medical Center, New York, New York, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, Department of Neurology, New York University Medical Center, New York, New York, USA
| | - Eric Halgren
- Multimodal Imaging Laboratory, University of California, San Diego, La Jolla, California, USA
| | - Hakwan Lau
- Department of Psychology, University of California, Los Angeles, Los Angeles, California, USA
- Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA
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42
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Kononowicz TW, Penney TB. The contingent negative variation (CNV): timing isn’t everything. Curr Opin Behav Sci 2016. [DOI: 10.1016/j.cobeha.2016.02.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Morales J, Chiang J, Lau H. Controlling for performance capacity confounds in neuroimaging studies of conscious awareness. Neurosci Conscious 2015; 2015:niv008. [PMID: 29877506 PMCID: PMC5932880 DOI: 10.1093/nc/niv008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/13/2015] [Accepted: 09/25/2015] [Indexed: 11/13/2022] Open
Abstract
Studying the neural correlates of conscious awareness depends on a reliable comparison
between activations associated with awareness and unawareness. One particularly difficult
confound to remove is task performance capacity, i.e. the difference in performance
between the conditions of interest. While ideally task performance capacity should be
matched across different conditions, this is difficult to achieve experimentally. However,
differences in performance could theoretically be corrected for mathematically. One such
proposal is found in a recent paper by Lamy, Salti and Bar-Haim [Lamy D, Salti M, Bar-Haim
Y. Neural correlates of subjective awareness and unconscious processing: an ERP study.
J Cognitive Neurosci 2009,21:1435-46], who put forward a
corrective method for an electroencephalography experiment. We argue that their analysis
is essentially grounded in a version of High Threshold Theory, which has been shown to be
inferior in general to Signal Detection Theory. We show through a series of computer
simulations that their correction method only partially removes the influence of
performance capacity, which can yield misleading results. We present a mathematical
correction method based on Signal Detection Theory that is theoretically capable of
removing performance capacity confounds. We discuss the limitations of mathematically
correcting for performance capacity confounds in imaging studies and its impact for
theories about consciousness.
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Affiliation(s)
- Jorge Morales
- Department of Philosophy, Columbia University, 708 Philosophy Hall Mail Code: 4971 1150 Amsterdam Avenue New York, NY 10027 USA
| | - Jeffrey Chiang
- Department of Psychology, UCLA, 1285 Franz Hall Box 951563 Los Angeles, CA 90095 USA
| | - Hakwan Lau
- Department of Psychology, UCLA, 1285 Franz Hall Box 951563 Los Angeles, CA 90095 USA.,Brain Research Institute, UCLA, 695 Charles E Young Dr. South Los Angeles, CA 90095 USA
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Modulating conscious movement intention by noninvasive brain stimulation and the underlying neural mechanisms. J Neurosci 2015; 35:7239-55. [PMID: 25948272 DOI: 10.1523/jneurosci.4894-14.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Conscious intention is a fundamental aspect of the human experience. Despite long-standing interest in the basis and implications of intention, its underlying neurobiological mechanisms remain poorly understood. Using high-definition transcranial DC stimulation (tDCS), we observed that enhancing spontaneous neuronal excitability in both the angular gyrus and the primary motor cortex caused the reported time of conscious movement intention to be ∼60-70 ms earlier. Slow brain waves recorded ∼2-3 s before movement onset, as well as hundreds of milliseconds after movement onset, independently correlated with the modulation of conscious intention by brain stimulation. These brain activities together accounted for 81% of interindividual variability in the modulation of movement intention by brain stimulation. A computational model using coupled leaky integrator units with biophysically plausible assumptions about the effect of tDCS captured the effects of stimulation on both neural activity and behavior. These results reveal a temporally extended brain process underlying conscious movement intention that spans seconds around movement commencement.
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Markkula G. Answering questions about consciousness by modeling perception as covert behavior. Front Psychol 2015; 6:803. [PMID: 26136704 PMCID: PMC4468364 DOI: 10.3389/fpsyg.2015.00803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 05/27/2015] [Indexed: 11/25/2022] Open
Abstract
Two main open questions in current consciousness research concern (i) the neural correlates of consciousness (NCC) and (ii) the relationship between neural activity and first-person, subjective experience. Here, possible answers are sketched for both of these, by means of a model-based analysis of what is required for one to admit having a conscious experience. To this end, a model is proposed that allows reasoning, albeit necessarily in a simplistic manner, about all of the so called “easy problems” of consciousness, from discrimination of stimuli to control of behavior and language. First, it is argued that current neuroscientific knowledge supports the view of perception and action selection as two examples of the same basic phenomenon, such that one can meaningfully refer to neuronal activations involved in perception as covert behavior. Building on existing neuroscientific and psychological models, a narrative behavior model is proposed, outlining how the brain selects covert (and sometimes overt) behaviors to construct a complex, multi-level narrative about what it is like to be the individual in question. It is hypothesized that we tend to admit a conscious experience of X if, at the time of judging consciousness, we find ourselves acceptably capable of performing narrative behavior describing X. It is argued that the proposed account reconciles seemingly conflicting empirical results, previously presented as evidence for competing theories of consciousness, and suggests that well-defined, experiment-independent NCCs are unlikely to exist. Finally, an analysis is made of what the modeled narrative behavior machinery is and is not capable of. It is discussed how an organism endowed with such a machinery could, from its first-person perspective, come to adopt notions such as “subjective experience,” and of there being “hard problems,” and “explanatory gaps” to be addressed in order to understand consciousness.
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Affiliation(s)
- Gustav Markkula
- Adaptive Systems Group, Division of Vehicle Engineering and Autonomous Systems, Department of Applied Mechanics, Chalmers University of Technology Gothenburg, Sweden
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46
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Cortical activity is more stable when sensory stimuli are consciously perceived. Proc Natl Acad Sci U S A 2015; 112:E2083-92. [PMID: 25847997 DOI: 10.1073/pnas.1418730112] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
According to recent evidence, stimulus-tuned neurons in the cerebral cortex exhibit reduced variability in firing rate across trials, after the onset of a stimulus. However, in order for a reduction in variability to be directly relevant to perception and behavior, it must be realized within trial--the pattern of activity must be relatively stable. Stability is characteristic of decision states in recurrent attractor networks, and its possible relevance to conscious perception has been suggested by theorists. However, it is difficult to measure on the within-trial time scales and broadly distributed spatial scales relevant to perception. We recorded simultaneous magneto- and electroencephalography (MEG and EEG) data while subjects observed threshold-level visual stimuli. Pattern-similarity analyses applied to the data from MEG gradiometers uncovered a pronounced decrease in variability across trials after stimulus onset, consistent with previous single-unit data. This was followed by a significant divergence in variability depending upon subjective report (seen/unseen), with seen trials exhibiting less variability. Applying the same analysis across time, within trial, we found that the latter effect coincided in time with a difference in the stability of the pattern of activity. Stability alone could be used to classify data from individual trials as "seen" or "unseen." The same metric applied to EEG data from patients with disorders of consciousness exposed to auditory stimuli diverged parametrically according to clinically diagnosed level of consciousness. Differences in signal strength could not account for these results. Conscious perception may involve the transient stabilization of distributed cortical networks, corresponding to a global brain-scale decision.
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47
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Navajas J, Rey HG, Quian Quiroga R. Perceptual and contextual awareness: methodological considerations in the search for the neural correlates of consciousness. Front Psychol 2014; 5:959. [PMID: 25221537 PMCID: PMC4148639 DOI: 10.3389/fpsyg.2014.00959] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 08/12/2014] [Indexed: 11/13/2022] Open
Abstract
In the last decades, the neural correlates of consciousness (NCCs) have been explored using both invasive and non-invasive recordings by comparing the brain activity elicited by seen versus unseen visual stimuli (i.e., the contrastive analysis). Here, we review a selection of these studies and discuss a set of considerations to improve the search for the NCCs using the contrastive analysis. In particular, we first argue in favor of implementing paradigms where different perceptual outputs are obtained using identical visual inputs. Second, we propose that the large disagreement in the field -in terms of the dissimilar neural patterns proposed as NCCs- is partially explained by the fact that different studies report the neural correlates of different conscious processes in the brain. More specifically, we distinguish between the perceptual awareness of a visual stimulus, associated to a boost in object-selective neural assemblies, and a more elaborate process (contextual awareness) that we argue is reflected in the firing of concept neurons in the medial temporal lobe, triggering a rich representation of the context, associations, and memories linked to the specific stimulus.
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Affiliation(s)
- Joaquin Navajas
- Centre for Systems Neuroscience, University of Leicester Leicester, UK
| | - Hernan G Rey
- Centre for Systems Neuroscience, University of Leicester Leicester, UK
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49
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Wang M, He BJ. A cross-modal investigation of the neural substrates for ongoing cognition. Front Psychol 2014; 5:945. [PMID: 25206347 PMCID: PMC4143722 DOI: 10.3389/fpsyg.2014.00945] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Accepted: 08/07/2014] [Indexed: 11/17/2022] Open
Abstract
What neural mechanisms underlie the seamless flow of our waking consciousness? A necessary albeit insufficient condition for such neural mechanisms is that they should be consistently modulated across time were a segment of the conscious stream to be repeated twice. In this study, we experimentally manipulated the content of a story followed by subjects during functional magnetic resonance imaging (fMRI) independently from the modality of sensory input (as visual text or auditory speech) as well as attentional focus. We then extracted brain activity patterns consistently modulated across subjects by the evolving content of the story regardless of whether it was presented visually or auditorily. Specifically, in one experiment we presented the same story to different subjects via either auditory or visual modality. In a second experiment, we presented two different stories simultaneously, one auditorily, one visually, and manipulated the subjects' attentional focus. This experimental design allowed us to dissociate brain activities underlying modality-specific sensory processing from modality-independent story processing. We uncovered a network of brain regions consistently modulated by the evolving content of a story regardless of the sensory modality used for stimulus input, including the superior temporal sulcus/gyrus (STS/STG), the inferior frontal gyrus (IFG), the posterior cingulate cortex (PCC), the medial frontal cortex (MFC), the temporal pole (TP), and the temporoparietal junction (TPJ). Many of these regions have previously been implicated in semantic processing. Interestingly, different stories elicited similar brain activity patterns, but with subtle differences potentially attributable to varying degrees of emotional valence and self-relevance.
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Affiliation(s)
- Megan Wang
- National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Biyu J He
- National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
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50
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Bachmann T, Hudetz AG. It is time to combine the two main traditions in the research on the neural correlates of consciousness: C = L × D. Front Psychol 2014; 5:940. [PMID: 25202297 PMCID: PMC4141455 DOI: 10.3389/fpsyg.2014.00940] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 08/06/2014] [Indexed: 01/08/2023] Open
Abstract
Research on neural correlates of consciousness has been conducted and carried out mostly from within two relatively autonomous paradigmatic traditions – studying the specific contents of conscious experience and their brain-process correlates and studying the level of consciousness. In the present paper we offer a theoretical integration suggesting that an emphasis has to be put on understanding the mechanisms of consciousness (and not a mere correlates) and in doing this, the two paradigmatic traditions must be combined. We argue that consciousness emerges as a result of interaction of brain mechanisms specialized for representing the specific contents of perception/cognition – the data – and mechanisms specialized for regulating the level of activity of whatever data the content-carrying specific mechanisms happen to represent. Each of these mechanisms are necessary because without the contents there is no conscious experience and without the required level of activity the processed contents remain unconscious. Together the two mechanisms, when activated up to a necessary degree each, provide conditions sufficient for conscious experience to emerge. This proposal is related to pertinent experimental evidence.
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