1
|
Marly A, Yazdjian A, Soto-Faraco S. The role of conflict processing in multisensory perception: behavioural and electroencephalography evidence. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220346. [PMID: 37545310 PMCID: PMC10404919 DOI: 10.1098/rstb.2022.0346] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 07/04/2023] [Indexed: 08/08/2023] Open
Abstract
To form coherent multisensory perceptual representations, the brain must solve a causal inference problem: to decide if two sensory cues originated from the same event and should be combined, or if they came from different events and should be processed independently. According to current models of multisensory integration, during this process, the integrated (common cause) and segregated (different causes) internal perceptual models are entertained. In the present study, we propose that the causal inference process involves competition between these alternative perceptual models that engages the brain mechanisms of conflict processing. To test this hypothesis, we conducted two experiments, measuring reaction times (RTs) and electroencephalography, using an audiovisual ventriloquist illusion paradigm with varying degrees of intersensory disparities. Consistent with our hypotheses, incongruent trials led to slower RTs and higher fronto-medial theta power, both indicative of conflict. We also predicted that intermediate disparities would yield slower RTs and higher theta power when compared to congruent stimuli and to large disparities, owing to the steeper competition between causal models. Although this prediction was only validated in the RT study, both experiments displayed the anticipated trend. In conclusion, our findings suggest a potential involvement of the conflict mechanisms in multisensory integration of spatial information. This article is part of the theme issue 'Decision and control processes in multisensory perception'.
Collapse
Affiliation(s)
- Adrià Marly
- Center for Brain and Cognition, Universitat Pompeu Fabra, 08005 Barcelona, Spain
| | - Arek Yazdjian
- Center for Brain and Cognition, Universitat Pompeu Fabra, 08005 Barcelona, Spain
| | - Salvador Soto-Faraco
- Center for Brain and Cognition, Universitat Pompeu Fabra, 08005 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| |
Collapse
|
2
|
Hatamimajoumerd E, Ratan Murty NA, Pitts M, Cohen MA. Decoding perceptual awareness across the brain with a no-report fMRI masking paradigm. Curr Biol 2022; 32:4139-4149.e4. [PMID: 35981538 DOI: 10.1016/j.cub.2022.07.068] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/16/2022] [Accepted: 07/26/2022] [Indexed: 12/14/2022]
Abstract
Does perceptual awareness arise within the sensory regions of the brain or within higher-level regions (e.g., the frontal lobe)? To answer this question, researchers traditionally compare neural activity when observers report being aware versus being unaware of a stimulus. However, it is unclear whether the resulting activations are associated with the conscious perception of the stimulus or the post-perceptual processes associated with reporting that stimulus. To address this limitation, we used both report and no-report conditions in a visual masking paradigm while participants were scanned using functional MRI (fMRI). We found that the overall univariate response to visible stimuli in the frontal lobe was robust in the report condition but disappeared in the no-report condition. However, using multivariate patterns, we could still decode in both conditions whether a stimulus reached conscious awareness across the brain, including in the frontal lobe. These results help reconcile key discrepancies in the recent literature and provide a path forward for identifying the neural mechanisms associated with perceptual awareness.
Collapse
Affiliation(s)
- Elaheh Hatamimajoumerd
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Department of Psychology and Program in Neuroscience, Amherst College, 220 South Pleasant Street, Amherst, MA, USA
| | - N Apurva Ratan Murty
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Center for Brains, Minds, and Machines, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Michael Pitts
- Department of Psychology, Reed College, 3203 Southeast Woodstock Blvd, Portland, OR, USA
| | - Michael A Cohen
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Department of Psychology and Program in Neuroscience, Amherst College, 220 South Pleasant Street, Amherst, MA, USA.
| |
Collapse
|
3
|
Safavi S, Dayan P. Multistability, perceptual value, and internal foraging. Neuron 2022; 110:3076-3090. [PMID: 36041434 DOI: 10.1016/j.neuron.2022.07.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/03/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022]
Abstract
Substantial experimental, theoretical, and computational insights into sensory processing have been derived from the phenomena of perceptual multistability-when two or more percepts alternate or switch in response to a single sensory input. Here, we review a range of findings suggesting that alternations can be seen as internal choices by the brain responding to values. We discuss how elements of external, experimenter-controlled values and internal, uncertainty- and aesthetics-dependent values influence multistability. We then consider the implications for the involvement in switching of regions, such as the anterior cingulate cortex, which are more conventionally tied to value-dependent operations such as cognitive control and foraging.
Collapse
Affiliation(s)
- Shervin Safavi
- University of Tübingen, Tübingen, Germany; Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
| | - Peter Dayan
- University of Tübingen, Tübingen, Germany; Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| |
Collapse
|
4
|
Kapoor V, Dwarakanath A, Safavi S, Werner J, Besserve M, Panagiotaropoulos TI, Logothetis NK. Decoding internally generated transitions of conscious contents in the prefrontal cortex without subjective reports. Nat Commun 2022; 13:1535. [PMID: 35318323 PMCID: PMC8940963 DOI: 10.1038/s41467-022-28897-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/17/2022] [Indexed: 11/30/2022] Open
Abstract
A major debate about the neural correlates of conscious perception concerns its cortical organization, namely, whether it includes the prefrontal cortex (PFC), which mediates executive functions, or it is constrained within posterior cortices. It has been suggested that PFC activity during paradigms investigating conscious perception is conflated with post-perceptual processes associated with reporting the contents of consciousness or feedforward signals originating from exogenous stimulus manipulations and relayed via posterior cortical areas. We addressed this debate by simultaneously probing neuronal populations in the rhesus macaque (Macaca mulatta) PFC during a no-report paradigm, capable of instigating internally generated transitions in conscious perception, without changes in visual stimulation. We find that feature-selective prefrontal neurons are modulated concomitantly with subjective perception and perceptual suppression of their preferred stimulus during both externally induced and internally generated changes in conscious perception. Importantly, this enables reliable single-trial, population decoding of conscious contents. Control experiments confirm significant decoding of stimulus contents, even when oculomotor responses, used for inferring perception, are suppressed. These findings suggest that internally generated changes in the contents of conscious visual perception are reliably reflected within the activity of prefrontal populations in the absence of volitional reports or changes in sensory input. The role of the prefrontal cortex in conscious perception is debated because of its involvement in task relevant behaviour, such as subjective perceptual reports. Here, the authors show that prefrontal activity in rhesus macaques correlates with subjective perception and the contents of consciousness can be decoded from prefrontal population activity even without reports.
Collapse
Affiliation(s)
- Vishal Kapoor
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany. .,International Center for Primate Brain Research, Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Institute of Neuroscience (ION), Chinese Academy of Sciences, Shanghai, China.
| | - Abhilash Dwarakanath
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany
| | - Shervin Safavi
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany.,International Max Planck Research School, Tübingen, 72076, Germany
| | - Joachim Werner
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany
| | - Michel Besserve
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany.,Department of Empirical Inference, Max Planck Institute for Intelligent Systems, 72076, Tübingen, Germany
| | - Theofanis I Panagiotaropoulos
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany. .,Cognitive Neuroimaging Unit, CEA, DSV/I2BM, INSERM, Universite Paris-Sud, Universite Paris-Saclay, Neurospin Center, 91191, Gif/Yvette, France.
| | - Nikos K Logothetis
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, 72076, Germany.,International Center for Primate Brain Research, Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Institute of Neuroscience (ION), Chinese Academy of Sciences, Shanghai, China.,Division of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, M13 9PT, UK
| |
Collapse
|
5
|
Does the Prefrontal Cortex Play an Essential Role in Consciousness? Insights from Intracranial Electrical Stimulation of the Human Brain. J Neurosci 2021; 41:2076-2087. [PMID: 33692142 DOI: 10.1523/jneurosci.1141-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022] Open
Abstract
A central debate in philosophy and neuroscience pertains to whether PFC activity plays an essential role in the neural basis of consciousness. Neuroimaging and electrophysiology studies have revealed that the contents of conscious perceptual experience can be successfully decoded from PFC activity, but these findings might be confounded by postperceptual cognitive processes, such as thinking, reasoning, and decision-making, that are not necessary for consciousness. To clarify the involvement of the PFC in consciousness, we present a synthesis of research that has used intracranial electrical stimulation (iES) for the causal modulation of neural activity in the human PFC. This research provides compelling evidence that iES of only certain prefrontal regions (i.e., orbitofrontal cortex and anterior cingulate cortex) reliably perturbs conscious experience. Conversely, stimulation of anterolateral prefrontal sites, often considered crucial in higher-order and global workspace theories of consciousness, seldom elicits any reportable alterations in consciousness. Furthermore, the wide variety of iES-elicited effects in the PFC (e.g., emotions, thoughts, and olfactory and visual hallucinations) exhibits no clear relation to the immediate environment. Therefore, there is no evidence for the kinds of alterations in ongoing perceptual experience that would be predicted by higher-order or global workspace theories. Nevertheless, effects in the orbitofrontal and anterior cingulate cortices suggest a specific role for these PFC subregions in supporting emotional aspects of conscious experience. Overall, this evidence presents a challenge for higher-order and global workspace theories, which commonly point to the PFC as the basis for conscious perception based on correlative and possibly confounded information.
Collapse
|
6
|
Hesse JK, Tsao DY. A new no-report paradigm reveals that face cells encode both consciously perceived and suppressed stimuli. eLife 2020; 9:58360. [PMID: 33174836 PMCID: PMC7676863 DOI: 10.7554/elife.58360] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 11/09/2020] [Indexed: 11/17/2022] Open
Abstract
A powerful paradigm to identify neural correlates of consciousness is binocular rivalry, wherein a constant visual stimulus evokes a varying conscious percept. It has recently been suggested that activity modulations observed during rivalry may represent the act of report rather than the conscious percept itself. Here, we performed single-unit recordings from face patches in macaque inferotemporal (IT) cortex using a no-report paradigm in which the animal’s conscious percept was inferred from eye movements. We found that large proportions of IT neurons represented the conscious percept even without active report. Furthermore, on single trials we could decode both the conscious percept and the suppressed stimulus. Together, these findings indicate that (1) IT cortex possesses a true neural correlate of consciousness and (2) this correlate consists of a population code wherein single cells multiplex representation of the conscious percept and veridical physical stimulus, rather than a subset of cells perfectly reflecting consciousness.
Collapse
Affiliation(s)
- Janis Karan Hesse
- Division of Biology and Biological Engineering, Computation and Neural Systems, Pasadena, United States.,Howard Hughes Medical Institute, Pasadena, United States
| | - Doris Y Tsao
- Division of Biology and Biological Engineering, Computation and Neural Systems, Pasadena, United States.,Howard Hughes Medical Institute, Pasadena, United States
| |
Collapse
|
7
|
Förster J, Koivisto M, Revonsuo A. ERP and MEG correlates of visual consciousness: The second decade. Conscious Cogn 2020; 80:102917. [PMID: 32193077 DOI: 10.1016/j.concog.2020.102917] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/14/2020] [Accepted: 03/07/2020] [Indexed: 01/04/2023]
Abstract
The first decade of event-related potential (ERP) research had established that the most consistent correlates of the onset of visual consciousness are the early visual awareness negativity (VAN), a posterior negative component in the N2 time range, and the late positivity (LP), an anterior positive component in the P3 time range. Two earlier extensive reviews ten years ago had concluded that VAN is the earliest and most reliable correlate of visual phenomenal consciousness, whereas LP probably reflects later processes associated with reflective/access consciousness. This article provides an update to those earlier reviews. ERP and MEG studies that have appeared since 2010 and directly compared ERPs between aware and unaware conditions are reviewed, and important new developments in the field are discussed. The result corroborates VAN as the earliest and most consistent signature of visual phenomenal consciousness, and casts further doubt on LP as an ERP correlate of phenomenal consciousness.
Collapse
Affiliation(s)
- Jona Förster
- Division of Cognitive Neuroscience and Philosophy, University of Skövde, Sweden.
| | - Mika Koivisto
- Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
| | - Antti Revonsuo
- Division of Cognitive Neuroscience and Philosophy, University of Skövde, Sweden; Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
| |
Collapse
|
8
|
Finessing the Bored Monkey Problem. Trends Cogn Sci 2020; 24:167-168. [DOI: 10.1016/j.tics.2019.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 11/23/2022]
|
9
|
Block N. What Is Wrong with the No-Report Paradigm and How to Fix It. Trends Cogn Sci 2019; 23:1003-1013. [PMID: 31676213 DOI: 10.1016/j.tics.2019.10.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/18/2019] [Accepted: 10/06/2019] [Indexed: 11/29/2022]
Abstract
Is consciousness based in prefrontal circuits involved in cognitive processes like thought, reasoning, and memory or is it based in sensory areas in the back of the neocortex? The no-report paradigm has been crucial to this debate because it aims to separate the neural basis of the cognitive processes underlying post-perceptual decision and report from the neural basis of conscious perception itself. However, the no-report paradigm is problematic because, even in the absence of report, subjects might engage in post-perceptual cognitive processing. Therefore, to isolate the neural basis of consciousness, a no-cognition paradigm is needed. Here, I describe a no-cognition approach to binocular rivalry and outline how this approach can help to resolve debates about the neural basis of consciousness.
Collapse
Affiliation(s)
- Ned Block
- New York University, New York, NY, USA.
| |
Collapse
|
10
|
Phillips I. The methodological puzzle of phenomenal consciousness. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0347. [PMID: 30061461 DOI: 10.1098/rstb.2017.0347] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2018] [Indexed: 11/12/2022] Open
Abstract
Is phenomenal consciousness constitutively related to cognitive access? Despite being a fundamental issue for any science of consciousness, its empirical study faces a severe methodological puzzle. Recent years have seen numerous attempts to address this puzzle, either in practice, by offering evidence for a positive or negative answer, or in principle, by proposing a framework for eventual resolution. The present paper critically considers these endeavours, including partial-report, metacognitive and no-report paradigms, as well as the theoretical proposal that we can make progress by studying phenomenal consciousness as a natural kind. It is argued that the methodological puzzle remains obdurately with us and that, for now, we must adopt an attitude of humility towards the phenomenal.This article is part of the theme issue 'Perceptual consciousness and cognitive access'.
Collapse
Affiliation(s)
- Ian Phillips
- Department of Philosophy, Birmingham University, Birmingham, West Midlands, UK .,Cognitive Science, University of Princeton, Princeton, NJ, USA
| |
Collapse
|
11
|
Kapoor V, Besserve M, Logothetis NK, Panagiotaropoulos TI. Parallel and functionally segregated processing of task phase and conscious content in the prefrontal cortex. Commun Biol 2018; 1:215. [PMID: 30534607 PMCID: PMC6281663 DOI: 10.1038/s42003-018-0225-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 11/08/2018] [Indexed: 11/30/2022] Open
Abstract
The role of lateral prefrontal cortex (LPFC) in mediating conscious perception has been recently questioned due to potential confounds resulting from the parallel operation of task related processes. We have previously demonstrated encoding of contents of visual consciousness in LPFC neurons during a no-report task involving perceptual suppression. Here, we report a separate LPFC population that exhibits task-phase related activity during the same task. The activity profile of these neurons could be captured as canonical response patterns (CRPs), with their peak amplitudes sequentially distributed across different task phases. Perceptually suppressed visual input had a negligible impact on sequential firing and functional connectivity structure. Importantly, task-phase related neurons were functionally segregated from the neuronal population, which encoded conscious perception. These results suggest that neurons exhibiting task-phase related activity operate in the LPFC concurrently with, but segregated from neurons representing conscious content during a no-report task involving perceptual suppression. Vishal Kapoor et al. identify a population of cells in the lateral prefrontal cortex that exhibits task phase-related activity during a no-report task. This cell population is functionally segregated from the population encoding conscious perception, although the two operate in parallel.
Collapse
Affiliation(s)
- Vishal Kapoor
- 1Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,2Graduate School of Neural and Behavioral Sciences, International Max Planck Research School, Eberhard-Karls University of Tübingen, 72074 Tübingen, Germany
| | - Michel Besserve
- 1Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,Department of Empirical Inference, Max Planck Institute for Intelligent Systems and Max Planck ETH Center for Learning Systems, 72076 Tübingen, Germany
| | - Nikos K Logothetis
- 1Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,4Imaging Science and Biomedical Engineering, University of Manchester, Manchester, M13 9PL UK
| | - Theofanis I Panagiotaropoulos
- 1Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,5Cognitive Neuroimaging Unit, CEA, DSV/I2BM, INSERM, Universite Paris-Sud, Universite Paris-Saclay, Neurospin Center, 91191 Gif/Yvette, France
| |
Collapse
|
12
|
Key B, Brown D. Designing Brains for Pain: Human to Mollusc. Front Physiol 2018; 9:1027. [PMID: 30127750 PMCID: PMC6088194 DOI: 10.3389/fphys.2018.01027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/11/2018] [Indexed: 12/16/2022] Open
Abstract
There is compelling evidence that the "what it feels like" subjective experience of sensory stimuli arises in the cerebral cortex in both humans as well as mammalian experimental animal models. Humans are alone in their ability to verbally communicate their experience of the external environment. In other species, sensory awareness is extrapolated on the basis of behavioral indicators. For instance, cephalopods have been claimed to be sentient on the basis of their complex behavior and anecdotal reports of human-like intelligence. We have interrogated the findings of avoidance learning behavioral paradigms and classical brain lesion studies and conclude that there is no evidence for cephalopods feeling pain. This analysis highlighted the questionable nature of anthropometric assumptions about sensory experience with increased phylogenetic distance from humans. We contend that understanding whether invertebrates such as molluscs are sentient should first begin with defining the computational processes and neural circuitries underpinning subjective awareness. Using fundamental design principles, we advance the notion that subjective awareness is dependent on observer neural networks (networks that in some sense introspect the neural processing generating neural representations of sensory stimuli). This introspective process allows the observer network to create an internal model that predicts the neural processing taking place in the network being surveyed. Predictions arising from the internal model form the basis of a rudimentary form of awareness. We develop an algorithm built on parallel observer networks that generates multiple levels of sensory awareness. A network of cortical regions in the human brain has the appropriate functional properties and neural interconnectivity that is consistent with the predicted circuitry of the algorithm generating pain awareness. By contrast, the cephalopod brain lacks the necessary neural circuitry to implement such an algorithm. In conclusion, we find no compelling behavioral, functional, or neuroanatomical evidence to indicate that cephalopods feel pain.
Collapse
Affiliation(s)
- Brian Key
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Deborah Brown
- School of Historical and Philosophical Inquiry, University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
13
|
Gelbard-Sagiv H, Mudrik L, Hill MR, Koch C, Fried I. Human single neuron activity precedes emergence of conscious perception. Nat Commun 2018; 9:2057. [PMID: 29802308 PMCID: PMC5970215 DOI: 10.1038/s41467-018-03749-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 03/06/2018] [Indexed: 11/09/2022] Open
Abstract
Identifying the neuronal basis of spontaneous changes in conscious experience in the absence of changes in the external environment is a major challenge. Binocular rivalry, in which two stationary monocular images lead to continuously changing perception, provides a unique opportunity to address this issue. We studied the activity of human single neurons in the medial temporal and frontal lobes while patients were engaged in binocular rivalry. Here we report that internal changes in the content of perception are signaled by very early (~-2000 ms) nonselective medial frontal activity, followed by selective activity of medial temporal lobe neurons that precedes the perceptual change by ~1000 ms. Such early activations are not found for externally driven perceptual changes. These results suggest that a medial fronto-temporal network may be involved in the preconscious internal generation of perceptual transitions.
Collapse
Affiliation(s)
- Hagar Gelbard-Sagiv
- Division of Biology, California Institute of Technology, Pasadena, 91126, CA, USA. .,Department of Neurosurgery, David Geffen School of Medicine and Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, 90095, CA, USA. .,Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel. .,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.
| | - Liad Mudrik
- Division of Biology, California Institute of Technology, Pasadena, 91126, CA, USA.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.,School of Psychological Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Michael R Hill
- Division of Biology, California Institute of Technology, Pasadena, 91126, CA, USA.,Department of Neurosurgery, David Geffen School of Medicine and Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, 90095, CA, USA
| | - Christof Koch
- Division of Biology, California Institute of Technology, Pasadena, 91126, CA, USA.,Allen Institute for Brain Science, Seattle, WA, 98109, USA
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine and Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, 90095, CA, USA.,Functional Neurosurgery Unit, Tel-Aviv Medical Center and Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, 6423906, Israel
| |
Collapse
|
14
|
Rosa LA. The High-Order and Conscious Emotion: Assessing the Foundations, Contributions, and Implications of LeDoux’s Model of Conscious and Cognitive Emotion. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s41470-018-0015-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
15
|
Combined fMRI- and eye movement-based decoding of bistable plaid motion perception. Neuroimage 2017; 171:190-198. [PMID: 29294388 DOI: 10.1016/j.neuroimage.2017.12.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/22/2017] [Accepted: 12/29/2017] [Indexed: 11/23/2022] Open
Abstract
The phenomenon of bistable perception, in which perception alternates spontaneously despite constant sensory stimulation, has been particularly useful in probing the neural bases of conscious perception. The study of such bistability requires access to the observer's perceptual dynamics, which is usually achieved via active report. This report, however, constitutes a confounding factor in the study of conscious perception and can also be biased in the context of certain experimental manipulations. One approach to circumvent these problems is to track perceptual alternations using signals from the eyes or the brain instead of observers' reports. Here we aimed to optimize such decoding of perceptual alternations by combining eye and brain signals. Eye-tracking and functional magnetic resonance imaging (fMRI) was performed in twenty participants while they viewed a bistable visual plaid motion stimulus and reported perceptual alternations. Multivoxel pattern analysis (MVPA) for fMRI was combined with eye-tracking in a Support vector machine to decode participants' perceptual time courses from fMRI and eye-movement signals. While both measures individually already yielded high decoding accuracies (on average 86% and 88% correct, respectively) classification based on the two measures together further improved the accuracy (91% correct). These findings show that leveraging on both fMRI and eye movement data may pave the way for optimized no-report paradigms through improved decodability of bistable motion perception and hence for a better understanding of the neural correlates of consciousness.
Collapse
|
16
|
|
17
|
Koch C, Massimini M, Boly M, Tononi G. Neural correlates of consciousness: progress and problems. Nat Rev Neurosci 2016; 17:307-21. [DOI: 10.1038/nrn.2016.22] [Citation(s) in RCA: 731] [Impact Index Per Article: 91.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
18
|
Tsuchiya N, Wilke M, Frässle S, Lamme VA. No-Report Paradigms: Extracting the True Neural Correlates of Consciousness. Trends Cogn Sci 2015; 19:757-770. [DOI: 10.1016/j.tics.2015.10.002] [Citation(s) in RCA: 205] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 10/04/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
|
19
|
Naber M, Brascamp J. Commentary: Is the Frontal Lobe Involved in Conscious Perception? Front Psychol 2015; 6:1736. [PMID: 26617558 PMCID: PMC4641901 DOI: 10.3389/fpsyg.2015.01736] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/28/2015] [Indexed: 12/04/2022] Open
Affiliation(s)
- Marnix Naber
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University Utrecht, Netherlands
| | - Jan Brascamp
- Department of Psychology, Michigan State University, East Lansing MI, USA
| |
Collapse
|
20
|
Brascamp J, Blake R, Knapen T. Negligible fronto-parietal BOLD activity accompanying unreportable switches in bistable perception. Nat Neurosci 2015; 18:1672-8. [PMID: 26436901 PMCID: PMC4603386 DOI: 10.1038/nn.4130] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
The human brain's executive systems play a vital role in deciding and selecting among actions. Selection among alternatives also occurs in the perceptual domain, for instance when perception switches between interpretations during perceptual bistability. Whether executive systems also underlie this functionality remains debated, with known fronto-parietal concomitants of perceptual switches being variously interpreted as reflecting the switches' cause, or as reflecting their consequences. We developed a paradigm where the two eyes receive different inputs and perception demonstrably switches between these inputs, yet where switches themselves are so inconspicuous as to become unreportable, minimizing their executive consequences. Fronto-parietal fMRI BOLD responses that accompany perceptual switches were similarly minimized in this paradigm, indicating that these reflect the switches' consequences rather than their cause. We conclude that perceptual switches do not always rely on executive brain areas, and that processes responsible for selection among alternatives may operate outside of the brain's executive systems.
Collapse
Affiliation(s)
- Jan Brascamp
- Helmholtz Institute and Division of Experimental Psychology, Utrecht University, Utrecht, the Netherlands.,Brain and Cognition, University of Amsterdam, Amsterdam, the Netherlands.,Department of Psychology, Michigan State University, East Lansing, Michigan, USA
| | - Randolph Blake
- Department of Psychology and Vanderbilt Vision Research Center, Vanderbilt University, Nashville, Tennessee, USA.,Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Republic of Korea
| | - Tomas Knapen
- Brain and Cognition, University of Amsterdam, Amsterdam, the Netherlands.,Cognitive Psychology, Department of Behavioral and Movement Sciences, VU Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
21
|
Abstract
What is the primary function of consciousness in the nervous system? The answer to this question remains enigmatic, not so much because of a lack of relevant data, but because of the lack of a conceptual framework with which to interpret the data. To this end, we have developed Passive Frame Theory, an internally coherent framework that, from an action-based perspective, synthesizes empirically supported hypotheses from diverse fields of investigation. The theory proposes that the primary function of consciousness is well-circumscribed, serving the somatic nervous system. For this system, consciousness serves as a frame that constrains and directs skeletal muscle output, thereby yielding adaptive behavior. The mechanism by which consciousness achieves this is more counterintuitive, passive, and "low level" than the kinds of functions that theorists have previously attributed to consciousness. Passive frame theory begins to illuminate (a) what consciousness contributes to nervous function, (b) how consciousness achieves this function, and (c) the neuroanatomical substrates of conscious processes. Our untraditional, action-based perspective focuses on olfaction instead of on vision and is descriptive (describing the products of nature as they evolved to be) rather than normative (construing processes in terms of how they should function). Passive frame theory begins to isolate the neuroanatomical, cognitive-mechanistic, and representational (e.g., conscious contents) processes associated with consciousness.
Collapse
|
22
|
Aru J, Bachmann T. Still wanted-the mechanisms of consciousness! Front Psychol 2015; 6:5. [PMID: 25653636 PMCID: PMC4300864 DOI: 10.3389/fpsyg.2015.00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 01/04/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jaan Aru
- Faculty of Mathematics and Computer Science/Faculty of Law, University of Tartu Tartu, Estonia
| | | |
Collapse
|
23
|
Vidal JR, Perrone-Bertolotti M, Kahane P, Lachaux JP. Intracranial spectral amplitude dynamics of perceptual suppression in fronto-insular, occipito-temporal, and primary visual cortex. Front Psychol 2015; 5:1545. [PMID: 25642199 PMCID: PMC4295601 DOI: 10.3389/fpsyg.2014.01545] [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: 07/07/2014] [Accepted: 12/14/2014] [Indexed: 12/13/2022] Open
Abstract
If conscious perception requires global information integration across active distant brain networks, how does the loss of conscious perception affect neural processing in these distant networks? Pioneering studies on perceptual suppression (PS) described specific local neural network responses in primary visual cortex, thalamus and lateral prefrontal cortex of the macaque brain. Yet the neural effects of PS have rarely been studied with intracerebral recordings outside these cortices and simultaneously across distant brain areas. Here, we combined (1) a novel experimental paradigm in which we produced a similar perceptual disappearance and also re-appearance by using visual adaptation with transient contrast changes, with (2) electrophysiological observations from human intracranial electrodes sampling wide brain areas. We focused on broadband high-frequency (50–150 Hz, i.e., gamma) and low-frequency (8–24 Hz) neural activity amplitude modulations related to target visibility and invisibility. We report that low-frequency amplitude modulations reflected stimulus visibility in a larger ensemble of recording sites as compared to broadband gamma responses, across distinct brain regions including occipital, temporal and frontal cortices. Moreover, the dynamics of the broadband gamma response distinguished stimulus visibility from stimulus invisibility earlier in anterior insula and inferior frontal gyrus than in temporal regions, suggesting a possible role of fronto-insular cortices in top–down processing for conscious perception. Finally, we report that in primary visual cortex only low-frequency amplitude modulations correlated directly with perceptual status. Interestingly, in this sensory area broadband gamma was not modulated during PS but became positively modulated after 300 ms when stimuli were rendered visible again, suggesting that local networks could be ignited by top–down influences during conscious perception.
Collapse
Affiliation(s)
- Juan R Vidal
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon - Université Claude Bernard Lyon 1, Lyon, France ; University Grenoble Alpes, LPNC, F -38040 Grenoble France ; CNRS, LPNC, UMR 5105, F -38040 Grenoble France
| | - Marcela Perrone-Bertolotti
- University Grenoble Alpes, LPNC, F -38040 Grenoble France ; CNRS, LPNC, UMR 5105, F -38040 Grenoble France
| | - Philippe Kahane
- CHU Grenoble and Department of Neurology, INSERM U704, F -38043 Grenoble France
| | - Jean-Philippe Lachaux
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon - Université Claude Bernard Lyon 1, Lyon, France
| |
Collapse
|