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Colombari E, Parisi G, Tafuro A, Mele S, Mazzi C, Savazzi S. Beyond primary visual cortex: The leading role of lateral occipital complex in early conscious visual processing. Neuroimage 2024; 298:120805. [PMID: 39173692 DOI: 10.1016/j.neuroimage.2024.120805] [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: 03/01/2024] [Revised: 08/16/2024] [Accepted: 08/20/2024] [Indexed: 08/24/2024] Open
Abstract
The study of the neural substrates that serve conscious vision is one of the unsolved questions of cognitive neuroscience. So far, consciousness literature has endeavoured to disentangle which brain areas and in what order are involved in giving rise to visual awareness, but the problem of consciousness still remains unsolved. Availing of two different but complementary sources of data (i.e., Fast Optical Imaging and EEG), we sought to unravel the neural dynamics responsible for the emergence of a conscious visual experience. Our results revealed that conscious vision is characterized by a significant increase of activation in extra-striate visual areas, specifically in the Lateral Occipital Complex (LOC), and that, more interestingly, such activity occurred in the temporal window of the ERP component commonly thought to represent the electrophysiological signature of visual awareness, i.e., the Visual Awareness Negativity (VAN). Furthermore, Granger causality analysis, performed to further investigate the flow of activity occurring in the investigated areas, unveiled that neural processes relating to conscious perception mainly originated in LOC and subsequently spread towards visual and motor areas. In general, the results of the present study seem to advocate for an early contribution of LOC in conscious vision, thus suggesting that it could represent a reliable neural correlate of visual awareness. Conversely, striate visual areas, showing awareness-related activity only in later stages of stimulus processing, could be part of the cascade of neural events following awareness emergence.
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Affiliation(s)
- Elisabetta Colombari
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy
| | - Giorgia Parisi
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy
| | - Alessandra Tafuro
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy
| | - Sonia Mele
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy
| | - Chiara Mazzi
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy.
| | - Silvia Savazzi
- Perception and Awareness (PandA) Laboratory, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, Verona, Italy
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Kim S, Dalboni da Rocha JL, Birbaumer N, Sitaram R. Self-Regulation of the Posterior-Frontal Brain Activity with Real-Time fMRI Neurofeedback to Influence Perceptual Discrimination. Brain Sci 2024; 14:713. [PMID: 39061453 PMCID: PMC11274452 DOI: 10.3390/brainsci14070713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 07/06/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The Global Neuronal Workspace (GNW) hypothesis states that the visual percept is available to conscious awareness only if recurrent long-distance interactions among distributed brain regions activate neural circuitry extending from the posterior areas to prefrontal regions above a certain excitation threshold. To directly test this hypothesis, we trained 14 human participants to increase blood oxygenation level-dependent (BOLD) signals with real-time functional magnetic resonance imaging (rtfMRI)-based neurofeedback simultaneously in four specific regions of the occipital, temporal, insular and prefrontal parts of the brain. Specifically, we hypothesized that the up-regulation of the mean BOLD activity in the posterior-frontal brain regions lowers the perceptual threshold for visual stimuli, while down-regulation raises the threshold. Our results showed that participants could perform up-regulation (Wilcoxon test, session 1: p = 0.022; session 4: p = 0.041) of the posterior-frontal brain activity, but not down-regulation. Furthermore, the up-regulation training led to a significant reduction in the visual perceptual threshold, but no substantial change in perceptual threshold was observed after the down-regulation training. These findings show that the up-regulation of the posterior-frontal regions improves the perceptual discrimination of the stimuli. However, further questions as to whether the posterior-frontal regions can be down-regulated at all, and whether down-regulation raises the perceptual threshold, remain unanswered.
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Affiliation(s)
- Sunjung Kim
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tuebingen, 72076 Tuebingen, Germany
| | | | - Niels Birbaumer
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tuebingen, 72076 Tuebingen, Germany
| | - Ranganatha Sitaram
- St. Jude Children’s Research Hospital, Memphis, TN 38111, USA; (J.L.D.d.R.)
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3
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Knight RS, Chen T, Center EG, Gratton G, Fabiani M, Savazzi S, Mazzi C, Beck DM. Bypassing input to V1 in visual awareness: A TMS-EROS investigation. Neuropsychologia 2024; 198:108864. [PMID: 38521150 PMCID: PMC11194103 DOI: 10.1016/j.neuropsychologia.2024.108864] [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: 10/16/2023] [Revised: 02/07/2024] [Accepted: 03/18/2024] [Indexed: 03/25/2024]
Abstract
Early visual cortex (V1-V3) is believed to be critical for normal visual awareness by providing the necessary feedforward input. However, it remains unclear whether visual awareness can occur without further involvement of early visual cortex, such as re-entrant feedback. It has been challenging to determine the importance of feedback activity to these areas because of the difficulties in dissociating this activity from the initial feedforward activity. Here, we applied single-pulse transcranial magnetic stimulation (TMS) over the left posterior parietal cortex to elicit phosphenes in the absence of direct visual input to early visual cortex. Immediate neural activity after the TMS pulse was assessed using the event-related optical signal (EROS), which can measure activity under the TMS coil without artifacts. Our results show that: 1) The activity in posterior parietal cortex 50 ms after TMS was related to phosphene awareness, and 2) Activity related to awareness was observed in a small portion of V1 140 ms after TMS, but in contrast (3) Activity in V2 was a more robust correlate of awareness. Together, these results are consistent with interactive models proposing that sustained and recurrent loops of activity between cortical areas are necessary for visual awareness to emerge. In addition, we observed phosphene-related activations of the anteromedial cuneus and lateral occipital cortex, suggesting a functional network subserving awareness comprising these regions, the parietal cortex and early visual cortex.
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Affiliation(s)
- Ramisha S Knight
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Aptima, Inc. 2555 University Blvd, Fairborn, OH, USA
| | - Tao Chen
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Department of Psychology, University of Illinois. 601 E John Street, Champaign, IL, USA.
| | - Evan G Center
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Department of Psychology, University of Illinois. 601 E John Street, Champaign, IL, USA; Center for Ubiquitous Computing, University of Oulu, Oulu, Finland
| | - Gabriele Gratton
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Department of Psychology, University of Illinois. 601 E John Street, Champaign, IL, USA
| | - Monica Fabiani
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Department of Psychology, University of Illinois. 601 E John Street, Champaign, IL, USA
| | - Silvia Savazzi
- Perception and Awareness (PandA) Lab, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Chiara Mazzi
- Perception and Awareness (PandA) Lab, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Diane M Beck
- Beckman Institute, University of Illinois.405 N Mathews Avenue, Urbana, IL, USA; Department of Psychology, University of Illinois. 601 E John Street, Champaign, IL, USA.
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Naccache L, Munoz-Musat E. A global neuronal workspace model of functional neurological disorders. DIALOGUES IN CLINICAL NEUROSCIENCE 2024; 26:1-23. [PMID: 38767966 PMCID: PMC11107854 DOI: 10.1080/19585969.2024.2340131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 04/03/2024] [Indexed: 05/22/2024]
Abstract
We introduce here a general model of Functional Neurological Disorders based on the following hypothesis: a Functional Neurological Disorder could correspond to a consciously initiated voluntary top-down process causing involuntary lasting consequences that are consciously experienced and subjectively interpreted by the patient as involuntary. We develop this central hypothesis according to Global Neuronal Workspace theory of consciousness, that is particularly suited to describe interactions between conscious and non-conscious cognitive processes. We then present a list of predictions defining a research program aimed at empirically testing their validity. Finally, this general model leads us to reinterpret the long-debated links between hypnotic suggestion and functional neurological disorders. Driven by both scientific and therapeutic goals, this theoretical paper aims at bringing closer the psychiatric and neurological worlds of functional neurological disorders with the latest developments of cognitive neuroscience of consciousness.
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Affiliation(s)
- Lionel Naccache
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France- Sorbonne Université, UPMC Univ Paris 06, Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
- Department of Neurology, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, DMU Neurosciences, Paris, France
- Department of Clinical Neurophysiology, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, DMU Neurosciences, Paris, France
| | - Esteban Munoz-Musat
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France- Sorbonne Université, UPMC Univ Paris 06, Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
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5
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Mashour GA. Anesthesia and the neurobiology of consciousness. Neuron 2024; 112:1553-1567. [PMID: 38579714 PMCID: PMC11098701 DOI: 10.1016/j.neuron.2024.03.002] [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: 02/02/2024] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 04/07/2024]
Abstract
In the 19th century, the discovery of general anesthesia revolutionized medical care. In the 21st century, anesthetics have become indispensable tools to study consciousness. Here, I review key aspects of the relationship between anesthesia and the neurobiology of consciousness, including interfaces of sleep and anesthetic mechanisms, anesthesia and primary sensory processing, the effects of anesthetics on large-scale functional brain networks, and mechanisms of arousal from anesthesia. I discuss the implications of the data derived from the anesthetized state for the science of consciousness and then conclude with outstanding questions, reflections, and future directions.
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Affiliation(s)
- George A Mashour
- Center for Consciousness Science, Department of Anesthesiology, Department of Pharmacology, Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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Hauw F, Sangaré A, Munoz-Musat E, Meyniel C, Di Donato N, Chokron S, Bozon F, Naccache L. Are we aware of neural activity in primary visual cortex? A neuropsychological case study. Ann Clin Transl Neurol 2024; 11:1365-1370. [PMID: 38509632 DOI: 10.1002/acn3.52038] [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: 10/02/2023] [Revised: 02/20/2024] [Accepted: 02/24/2024] [Indexed: 03/22/2024] Open
Abstract
OBJECTIVE According to a seminal hypothesis stated by Crick and Koch in 1995, one is not aware of neural activity in primary visual cortex (V1) because this region lacks reciprocal connections with prefrontal cortex (PFC). METHODS We provide here a neuropsychological illustration of this hypothesis in a patient with a very rare form of cortical blindness: ventral and dorsal cortical pathways were lesioned bilaterally while V1 areas were partially preserved. RESULTS Visual stimuli escaped conscious perception but still activated V1 regions that were functionally disconnected from PFC. INTERPRETATION These results are consistent with the hypothesis of a causal role of PFC in visual awareness.
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Affiliation(s)
- Fabien Hauw
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, UPMC Univ Paris 06, Sorbonne Université, Paris, France
- Department of Neurology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
| | - Aude Sangaré
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, UPMC Univ Paris 06, Sorbonne Université, Paris, France
- Department of Neurology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
| | - Esteban Munoz-Musat
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, UPMC Univ Paris 06, Sorbonne Université, Paris, France
| | - Claire Meyniel
- Department of Clinical Neurophysiology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
| | - Nina Di Donato
- Institut de Neuropsychologie, Neurovision, NeuroCognition, Fondation Ophtalmologique Rothschild, Paris, 75019, France
| | - Sylvie Chokron
- Institut de Neuropsychologie, Neurovision, NeuroCognition, Fondation Ophtalmologique Rothschild, Paris, 75019, France
- Integrative Neuroscience and Cognition Center, UMR 8002, CNRS & Université de Paris, Paris, 75006, France
| | - Frédérique Bozon
- Department of Neurology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
| | - Lionel Naccache
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Faculté de Médecine Pitié-Salpêtrière, UPMC Univ Paris 06, Sorbonne Université, Paris, France
- Department of Neurology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
- Department of Clinical Neurophysiology, DMU Neurosciences, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, Paris, France
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Lewis CM, Wunderle T, Fries P. Top-down modulation of visual cortical stimulus encoding and gamma independent of firing rates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.11.589006. [PMID: 38645050 PMCID: PMC11030389 DOI: 10.1101/2024.04.11.589006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Neurons in primary visual cortex integrate sensory input with signals reflecting the animal's internal state to support flexible behavior. Internal variables, such as expectation, attention, or current goals, are imposed in a top-down manner via extensive feedback projections from higher-order areas. We optogenetically activated a high-order visual area, area 21a, in the lightly anesthetized cat (OptoTD), while recording from neuronal populations in V1. OptoTD induced strong, up to several fold, changes in gamma-band synchronization together with much smaller changes in firing rate, and the two effects showed no correlation. OptoTD effects showed specificity for the features of the simultaneously presented visual stimuli. OptoTD-induced changes in gamma synchronization, but not firing rates, were predictive of simultaneous changes in the amount of encoded stimulus information. Our findings suggest that one important role of top-down signals is to modulate synchronization and the information encoded by populations of sensory neurons.
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Joshi SD, Ruffini G, Nuttall HE, Watson DG, Braithwaite JJ. Optimised Multi-Channel Transcranial Direct Current Stimulation (MtDCS) Reveals Differential Involvement of the Right-Ventrolateral Prefrontal Cortex (rVLPFC) and Insular Complex in those Predisposed to Aberrant Experiences. Conscious Cogn 2024; 117:103610. [PMID: 38056338 DOI: 10.1016/j.concog.2023.103610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/08/2023]
Abstract
Research has shown a prominent role for cortical hyperexcitability underlying aberrant perceptions, hallucinations, and distortions in human conscious experience - even in neurotypical groups. The rVLPFC has been identified as an important structure in mediating cognitive affective states / feeling conscious states. The current study examined the involvement of the rVLPFC in mediating cognitive affective states in those predisposed to aberrant experiences in the neurotypical population. Participants completed two trait-based measures: (i) the Cortical Hyperexcitability Index_II (CHi_II, a proxy measure of cortical hyperexcitability) and (ii) two factors from the Cambridge Depersonalisation Scale (CDS). An optimised 7-channel MtDCS montage for stimulation conditions (Anodal, Cathodal and Sham) was created targeting the rVLPFC in a single-blind study. At the end of each stimulation session, participants completed a body-threat task (BTAB) while skin conductance responses (SCRs) and psychological responses were recorded. Participants with signs of increasing cortical hyperexcitability showed significant suppression of SCRs in the Cathodal stimulation relative to the Anodal and sSham conditions. Those high on the trait-based measures of depersonalisation-like experiences failed to show reliable effects. Collectively, the findings suggest that baseline brain states can mediate the effects of neurostimulation which would be missed via sample level averaging and without appropriate measures for stratifying individual differences.
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9
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Ciobanu MM, Manoliu DR, Ciobotaru MC, Anchidin BG, Matei M, Munteanu M, Frunză G, Murariu OC, Flocea EI, Boișteanu PC. The Influence of Sensory Characteristics of Game Meat on Consumer Neuroperception: A Narrative Review. Foods 2023; 12:foods12061341. [PMID: 36981266 PMCID: PMC10048761 DOI: 10.3390/foods12061341] [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: 02/20/2023] [Revised: 03/11/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Game meat contains bioactive compounds that directly influence the formation of a rich reservoir of flavor precursors that produce specific sensory properties. Quality is considered one of the most influential determinants of consumer behavior, but the interpretation of this concept differs between consumers. Although recognized for its quality, its unique sensory characteristics (smell, taste, aroma) may have a major impact on consumer perception. The aim of this review is to describe the consumer behavior regarding game meat through elements of neuroperception, using methods of analysis, observation, and interpretation of scientific information from the literature. Following the analysis of published papers on this topic, it was shown that external factors influencing the biological basis of behavior could provide explanations for the acceptance or rejection of this type of meat and solutions. Neuroperception can explain the mechanism behind consumer decision-making. The influence of extrinsic factors (environment, mood, emotions, stress) shapes the perception of the quality attributes of game meat, the unique sensory characteristics of game meat passing through a primary filter of sensory receptors (eyes, nose, tongue, etc). Game meat is darker and tougher (compared to meat from domestic animals), and the taste and smell have the power to trigger memories and change the mood, influencing consumer behavior. Understanding consumer attitudes towards game meat in relation to quality attributes and the physiology of sensory perception can provide important insights for food industry professionals, processors, sensory evaluators, and researchers.
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Affiliation(s)
- Marius-Mihai Ciobanu
- Faculty of Agriculture, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 3, 700490 Iasi, Romania
| | - Diana-Remina Manoliu
- Faculty of Animal and Food Resources Engineering, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 8, 700490 Iasi, Romania
| | - Mihai-Cătălin Ciobotaru
- Faculty of Agriculture, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 3, 700490 Iasi, Romania
| | - Bianca-Georgiana Anchidin
- Faculty of Animal and Food Resources Engineering, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 8, 700490 Iasi, Romania
| | - Mădălina Matei
- Faculty of Animal and Food Resources Engineering, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 8, 700490 Iasi, Romania
| | - Mugurel Munteanu
- Faculty of Animal and Food Resources Engineering, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 8, 700490 Iasi, Romania
| | - Gabriela Frunză
- Faculty of Agriculture, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 3, 700490 Iasi, Romania
| | - Otilia Cristina Murariu
- Faculty of Agriculture, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 3, 700490 Iasi, Romania
| | - Elena-Iuliana Flocea
- Faculty of Agriculture, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 3, 700490 Iasi, Romania
| | - Paul-Corneliu Boișteanu
- Faculty of Animal and Food Resources Engineering, "Ion Ionescu de la Brad" University of Life Sciences, M. Sadoveanu Alley, No. 8, 700490 Iasi, Romania
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10
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Higgins NC, Scurry AN, Jiang F, Little DF, Alain C, Elhilali M, Snyder JS. Adaptation in the sensory cortex drives bistable switching during auditory stream segregation. Neurosci Conscious 2023; 2023:niac019. [PMID: 36751309 PMCID: PMC9899071 DOI: 10.1093/nc/niac019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/17/2022] [Accepted: 12/26/2022] [Indexed: 02/06/2023] Open
Abstract
Current theories of perception emphasize the role of neural adaptation, inhibitory competition, and noise as key components that lead to switches in perception. Supporting evidence comes from neurophysiological findings of specific neural signatures in modality-specific and supramodal brain areas that appear to be critical to switches in perception. We used functional magnetic resonance imaging to study brain activity around the time of switches in perception while participants listened to a bistable auditory stream segregation stimulus, which can be heard as one integrated stream of tones or two segregated streams of tones. The auditory thalamus showed more activity around the time of a switch from segregated to integrated compared to time periods of stable perception of integrated; in contrast, the rostral anterior cingulate cortex and the inferior parietal lobule showed more activity around the time of a switch from integrated to segregated compared to time periods of stable perception of segregated streams, consistent with prior findings of asymmetries in brain activity depending on the switch direction. In sound-responsive areas in the auditory cortex, neural activity increased in strength preceding switches in perception and declined in strength over time following switches in perception. Such dynamics in the auditory cortex are consistent with the role of adaptation proposed by computational models of visual and auditory bistable switching, whereby the strength of neural activity decreases following a switch in perception, which eventually destabilizes the current percept enough to lead to a switch to an alternative percept.
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Affiliation(s)
- Nathan C Higgins
- Department of Communication Sciences and Disorders, University of South Florida, 4202 E. Fowler Avenue, PCD1017, Tampa, FL 33620, USA
| | - Alexandra N Scurry
- Department of Psychology, University of Nevada, 1664 N. Virginia Street Mail Stop 0296, Reno, NV 89557, USA
| | - Fang Jiang
- Department of Psychology, University of Nevada, 1664 N. Virginia Street Mail Stop 0296, Reno, NV 89557, USA
| | - David F Little
- Department of Electrical and Computer Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Claude Alain
- Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, ON M6A 2E1, Canada
| | - Mounya Elhilali
- Department of Electrical and Computer Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Joel S Snyder
- Department of Psychology, University of Nevada, 4505 Maryland Parkway Mail Stop 5030, Las Vegas, NV 89154, USA
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11
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Sheehan TC, Serences JT. Attractive serial dependence overcomes repulsive neuronal adaptation. PLoS Biol 2022; 20:e3001711. [PMID: 36067148 PMCID: PMC9447932 DOI: 10.1371/journal.pbio.3001711] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 06/14/2022] [Indexed: 01/12/2023] Open
Abstract
Sensory responses and behavior are strongly shaped by stimulus history. For example, perceptual reports are sometimes biased toward previously viewed stimuli (serial dependence). While behavioral studies have pointed to both perceptual and postperceptual origins of this phenomenon, neural data that could elucidate where these biases emerge is limited. We recorded functional magnetic resonance imaging (fMRI) responses while human participants (male and female) performed a delayed orientation discrimination task. While behavioral reports were attracted to the previous stimulus, response patterns in visual cortex were repelled. We reconciled these opposing neural and behavioral biases using a model where both sensory encoding and readout are shaped by stimulus history. First, neural adaptation reduces redundancy at encoding and leads to the repulsive biases that we observed in visual cortex. Second, our modeling work suggest that serial dependence is induced by readout mechanisms that account for adaptation in visual cortex. According to this account, the visual system can simultaneously improve efficiency via adaptation while still optimizing behavior based on the temporal structure of natural stimuli.
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Affiliation(s)
- Timothy C. Sheehan
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - John T. Serences
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
- Department of Psychology, University of California San Diego, La Jolla, California, United States of America
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, California, United States of America
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12
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Francken JC, Beerendonk L, Molenaar D, Fahrenfort JJ, Kiverstein JD, Seth AK, van Gaal S. An academic survey on theoretical foundations, common assumptions and the current state of consciousness science. Neurosci Conscious 2022; 2022:niac011. [PMID: 35975240 PMCID: PMC9374479 DOI: 10.1093/nc/niac011] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 05/13/2022] [Accepted: 07/27/2022] [Indexed: 11/24/2022] Open
Abstract
We report the results of an academic survey into the theoretical and methodological foundations, common assumptions, and the current state of the field of consciousness research. The survey consisted of 22 questions and was distributed on two different occasions of the annual meeting of the Association of the Scientific Study of Consciousness (2018 and 2019). We examined responses from 166 consciousness researchers with different backgrounds (e.g. philosophy, neuroscience, psychology, and computer science) and at various stages of their careers (e.g. junior/senior faculty and graduate/undergraduate students). The results reveal that there remains considerable discussion and debate between the surveyed researchers about the definition of consciousness and the way it should be studied. To highlight a few observations, a majority of respondents believe that machines could have consciousness, that consciousness is a gradual phenomenon in the animal kingdom, and that unconscious processing is extensive, encompassing both low-level and high-level cognitive functions. Further, we show which theories of consciousness are currently considered most promising by respondents and how supposedly different theories cluster together, which dependent measures are considered best to index the presence or absence of consciousness, and which neural measures are thought to be the most likely signatures of consciousness. These findings provide us with a snapshot of the current views of researchers in the field and may therefore help prioritize research and theoretical approaches to foster progress.
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Affiliation(s)
- Jolien C Francken
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Institute for Interdisciplinary Studies, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
- Faculty of Philosophy, Theology and Religious Sciences, Radboud University, Erasmusplein 1, 6525 HT, Nijmegen, the Netherlands
| | - Lola Beerendonk
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
| | - Dylan Molenaar
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
| | - Johannes J Fahrenfort
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Department of Experimental and Applied Psychology, Vrije Universiteit, Van der Boechorststraat 7, 1081 BT, Amsterdam, the Netherlands
| | - Julian D Kiverstein
- Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - Anil K Seth
- Department of Informatics, University of Sussex, Sussex House, Falmer, Brighton BN1 9RH, UK
- Sackler Centre for Consciousness Science, University of Sussex, Sussex House, Falmer, Brighton BN1 9RH, UK
- Canadian Institute for Advanced Research (CIFAR) Program on Brain, Mind, and Consciousness, MaRS Centre, West Tower, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Simon van Gaal
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
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13
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DiNuzzo M, Mangia S, Moraschi M, Mascali D, Hagberg GE, Giove F. Perception is associated with the brain's metabolic response to sensory stimulation. eLife 2022; 11:71016. [PMID: 35225790 PMCID: PMC9038191 DOI: 10.7554/elife.71016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
Processing of incoming sensory stimulation triggers an increase of cerebral perfusion and blood oxygenation (neurovascular response) as well as an alteration of the metabolic neurochemical profile (neurometabolic response). Here we show in human primary visual cortex (V1) that perceived and unperceived isoluminant chromatic flickering stimuli designed to have similar neurovascular responses as measured by blood oxygenation level dependent functional MRI (BOLD-fMRI) have markedly different neurometabolic responses as measured by functional MRS. In particular, a significant regional buildup of lactate, an index of aerobic glycolysis, and glutamate, an index of malate-aspartate shuttle, occurred in V1 only when the flickering was perceived, without any relation with behavioral or physiological variables. Whereas the BOLD-fMRI signal in V1, a proxy for input to V1, was insensitive to flickering perception by design, the BOLD-fMRI signal in secondary visual areas was larger during perceived than unperceived flickering, indicating increased output from V1. These results demonstrate that the upregulation of energy metabolism induced by visual stimulation depends on the type of information processing taking place in V1, and that 1H-fMRS provides unique information about local input/output balance that is not measured by BOLD fMRI.
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Affiliation(s)
- Mauro DiNuzzo
- Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome, Italy
| | - Silvia Mangia
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, United States
| | - Marta Moraschi
- Department of Radiation Oncology, University of Rome, Rome, Italy
| | - Daniele Mascali
- Dipartimento di Neuroscienze, Università Gabriele D'Annunzio, Chieti, Italy
| | - Gisela E Hagberg
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics and Biomedical Magnetic Resonance, Tübingen, Germany
| | - Federico Giove
- Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome, Italy
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14
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Ding J, Ye Z, Xu F, Hu X, Yu H, Zhang S, Tu Y, Zhang Q, Sun Q, Hua T, Lu ZL. Effects of top-down influence suppression on behavioral and V1 neuronal contrast sensitivity functions in cats. iScience 2022; 25:103683. [PMID: 35059603 PMCID: PMC8760559 DOI: 10.1016/j.isci.2021.103683] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/16/2021] [Accepted: 12/20/2021] [Indexed: 02/09/2023] Open
Abstract
To explore the relative contributions of higher-order and primary visual cortex (V1) to visual perception, we compared cats' behavioral and V1 neuronal contrast sensitivity functions (CSF) and threshold versus external noise contrast (TvC) functions before and after top-down influence of area 7 (A7) was modulated with transcranial direct current stimulation (tDCS). We found that suppressing top-down influence of A7 with cathode-tDCS, but not sham-tDCS, reduced behavioral and neuronal contrast sensitivity in the same range of spatial frequencies and increased behavioral and neuronal contrast thresholds in the same range of external noise levels. The neuronal CSF and TvC functions were highly correlated with their behavioral counterparts both before and after the top-down suppression. Analysis of TvC functions using the Perceptual Template Model (PTM) indicated that top-down influence of A7 increased both behavioral and V1 neuronal contrast sensitivity by reducing internal additive noise and the impact of external noise. Top-down suppression lowers both behavioral and V1 neuronal CSF functions Top-down suppression raises both behavioral and V1 neuronal TvC functions The neuronal CSFs and TvCs are highly correlated with their behavioral counterparts Top-down influence lowers internal additive noise and impact of external noise in V1
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Affiliation(s)
- Jian Ding
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Zheng Ye
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Fei Xu
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xiangmei Hu
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Hao Yu
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Shen Zhang
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yanni Tu
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Qiuyu Zhang
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Qingyan Sun
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Tianmiao Hua
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Zhong-Lin Lu
- Divison of Arts and Sciences, NYU Shanghai, Shanghai 200122, China.,Center for Neural Science and Department of Psychology, New York University, New York, NY 10003, USA.,NYU-ECNU Institute of Brain and Cognitive Science, NYU Shanghai, Shanghai 200062, China
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15
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Yook J, Lee L, Vossel S, Weidner R, Hogendoorn H. Motion extrapolation in the flash-lag effect depends on perceived, rather than physical speed. Vision Res 2021; 193:107978. [PMID: 34942429 DOI: 10.1016/j.visres.2021.107978] [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: 03/09/2021] [Revised: 11/11/2021] [Accepted: 11/29/2021] [Indexed: 11/26/2022]
Abstract
In the flash-lag effect (FLE), a flash in spatiotemporal alignment with a moving object is misperceived as lagging behind the moving object. One proposed explanation for this illusion is based on predictive motion extrapolation of trajectories. In this interpretation, the diverging effects of velocity on the perceived position of the moving object suggest that FLE might be based on the neural representation of perceived, rather than physical, velocity. By contrast, alternative explanations based on differential latency or temporal averaging would predict that the FLE does not rely on such a representation of perceived velocity. Here we examined whether the FLE is sensitive to illusory changes in perceived speed that result in changes to perceived velocity, while physical speed is constant. The perceived speed of the moving object was manipulated using revolving wedge stimuli with variable pattern textures (Experiment 1) and luminance contrast (Experiment 2). The motion extrapolation interpretation would predict that the changes in FLE magnitude should correspond to the changes in the perceived speed of the moving object. In the current study, two experiments demonstrated that perceived speed and FLE magnitude increased in the dynamic pattern relative to the static pattern conditions, and that the same effect was found in the low contrast compared to the high contrast conditions. These results showed that manipulations of texture and contrast that are known to alter judgments of perceived speed also modulate perceived position. We interpret this as a consequence of motion extrapolation mechanisms and discuss possible explanations for why we observed no cross-effect correlation.
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Affiliation(s)
- Jane Yook
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Australia; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Forschungszentrum Jülich, Jülich, Germany; Department of Psychology, Faculty of Human Sciences, University of Cologne, Cologne, Germany.
| | - Lysha Lee
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Australia
| | - Simone Vossel
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Forschungszentrum Jülich, Jülich, Germany; Department of Psychology, Faculty of Human Sciences, University of Cologne, Cologne, Germany
| | - Ralph Weidner
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Forschungszentrum Jülich, Jülich, Germany
| | - Hinze Hogendoorn
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Australia
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16
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Sun ED, Dekel R. ImageNet-trained deep neural networks exhibit illusion-like response to the Scintillating grid. J Vis 2021; 21:15. [PMID: 34677575 PMCID: PMC8543405 DOI: 10.1167/jov.21.11.15] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Deep neural network (DNN) models for computer vision are capable of human-level object recognition. Consequently, similarities between DNN and human vision are of interest. Here, we characterize DNN representations of Scintillating grid visual illusion images in which white disks are perceived to be partially black. Specifically, we use VGG-19 and ResNet-101 DNN models that were trained for image classification and consider the representational dissimilarity (\(L^1\) distance in the penultimate layer) between pairs of images: one with white Scintillating grid disks and the other with disks of decreasing luminance levels. Results showed a nonmonotonic relation, such that decreasing disk luminance led to an increase and subsequently a decrease in representational dissimilarity. That is, the Scintillating grid image with white disks was closer, in terms of the representation, to images with black disks than images with gray disks. In control nonillusion images, such nonmonotonicity was rare. These results suggest that nonmonotonicity in a deep computational representation is a potential test for illusion-like response geometry in DNN models.
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Affiliation(s)
- Eric D Sun
- Mather House, Harvard University, Cambridge, MA, USA.,
| | - Ron Dekel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, PA, Israel.,
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17
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Zhaoping L. Contrast-reversed binocular dot-pairs in random-dot stereograms for depth perception in central visual field: Probing the dynamics of feedforward-feedback processes in visual inference. Vision Res 2021; 186:124-139. [PMID: 34091397 DOI: 10.1016/j.visres.2021.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/04/2021] [Accepted: 03/02/2021] [Indexed: 10/21/2022]
Abstract
In a random-dot stereogram (RDS), the spatial disparities between the interocularly corresponding black and white random dots determine the depths of object surfaces. If a black dot in one monocular image corresponds to a white dot in the other, disparity-tuned neurons in primary visual cortex (V1) respond as if their preferred disparities become non-preferred and vice versa, reversing the disparity sign reported to higher visual areas. Reversed depth is perceptible in the peripheral but not the central visual field. This study demonstrates that, in central vision, adding contrast-reversed dots to a noisy RDS (containing the normal contrast-matched dots) can augment or degrade depth perception. Augmentation occurs when the reversed depth signals are congruent with the normal depth signals to report the same disparity sign, and occurs regardless of the viewing duration. Degradation occurs when the reversed and normal depth signals are incongruent with each other and when the RDS is viewed briefly. These phenomena reflect the Feedforward-Feedback-Verify-and-reWeight (FFVW) process for visual inference in central vision, and are consistent with the central-peripheral dichotomy that central vision has a stronger top-down feedback from higher to lower brain areas to disambiguate noisy and ambiguous inputs from V1. When a RDS is viewed too briefly for feedback, augmentation and degradation work by adding the reversed depth signals from contrast-reversed dots to the feedforward, normal, depth signals. With a sufficiently long viewing duration, the feedback vetoes incongruent reversed depth signals and amends or completes the imperfect, but congruent, reversed depth signals by analysis-by-synthesis computation.
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Affiliation(s)
- Li Zhaoping
- University of Tübingen, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
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18
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Mulkey M, Everhart DE, Gencarelli A, Sorrell A, Kim S. A Review of Neuronal Pathways Associated With Consciousness. J Neurosci Nurs 2021; 53:39-43. [PMID: 33252410 PMCID: PMC8127025 DOI: 10.1097/jnn.0000000000000559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ABSTRACT INTRODUCTION: Accurate communication of information regarding fluctuations in level of consciousness is critical. It is, important for nurses to understand terms related to consciousness to appropriately assess and implement plans of care. CONTENT: Although the neurobiology of consciousness is complex and multifaceted, consciousness can be conceptualized as having 2 distinct but interrelated dimensions: arousal and awareness. The different levels of consciousness are thought to fall on a continuum ranging from being fully awake to coma. CONCLUSION: This article focuses on the terms of consciousness, awareness, and arousal along with nursing implications where appropriate.
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19
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Zooming-in on higher-level vision: High-resolution fMRI for understanding visual perception and awareness. Prog Neurobiol 2021; 207:101998. [PMID: 33497652 DOI: 10.1016/j.pneurobio.2021.101998] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 11/11/2020] [Accepted: 01/16/2021] [Indexed: 12/24/2022]
Abstract
One of the central questions in visual neuroscience is how the sparse retinal signals leaving our eyes are transformed into a rich subjective visual experience of the world. Invasive physiology studies, which offers the highest spatial resolution, have revealed many facts about the processing of simple visual features like contrast, color, and orientation, focusing on the early visual areas. At the same time, standard human fMRI studies with comparably coarser spatial resolution have revealed more complex, functionally specialized, and category-selective responses in higher visual areas. Although the visual system is the best understood among the sensory modalities, these two areas of research remain largely segregated. High-resolution fMRI opens up a possibility for linking them. On the one hand, it allows studying how the higher-level visual functions affect the fine-scale activity in early visual areas. On the other hand, it allows discovering the fine-scale functional organization of higher visual areas and exploring their functional connectivity with visual areas lower in the hierarchy. In this review, I will discuss examples of successful work undertaken in these directions using high-resolution fMRI and discuss where this method could be applied in the future to advance our understanding of the complexity of higher-level visual processing.
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20
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Abstract
We begin with the functions of the striate cortex (area V1 of the visual cortex) and end with a review of the effects of damage to striate cortex or its inputs; namely, homonymous hemifield defects. Clinical and anatomical studies accrued over the past 25 years have modified our understanding of the role of V1 in vision. We discuss the evidence that V1 is not the sole recipient of visual signals; is not the earliest recipient of visual signals; and is not essential for conscious vision. In the second section, we give a brief history of how the visual field was found to be represented in striate cortex, then cover the work that has demonstrated the overrepresentation of the central region of vision in humans. The common patterns of visual field disturbance caused by damage to the retrochiasmal visual system are discussed, with some less common examples shown as brief case studies.
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Affiliation(s)
- Semir Zeki
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Alexander Leff
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.
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21
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Abstract
The pathophysiological mechanisms that underlie the generation and maintenance of tinnitus are being unraveled progressively. Based on this knowledge, a large variety of different neuromodulatory interventions have been developed and are still being designed, adapting to the progressive mechanistic insights in the pathophysiology of tinnitus. rTMS targeting the temporal, temporoparietal, and the frontal cortex has been the mainstay of non-invasive neuromodulation. Yet, the evidence is still unclear, and therefore systematic meta-analyses are needed for drawing conclusions on the effectiveness of rTMS in chronic tinnitus. Different forms of transcranial electrical stimulation (tDCS, tACS, tRNS), applied over the frontal and temporal cortex, have been investigated in tinnitus patients, also without robust evidence for universal efficacy. Cortex and deep brain stimulation with implanted electrodes have shown benefit, yet there is insufficient data to support their routine clinical use. Recently, bimodal stimulation approaches have revealed promising results and it appears that targeting different sensory modalities in temporally combined manners may be more promising than single target approaches.While most neuromodulatory approaches seem promising, further research is required to help translating the scientific outcomes into routine clinical practice.
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22
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Bareham CA, Oxner M, Gastrell T, Carmel D. Beyond the neural correlates of consciousness: using brain stimulation to elucidate causal mechanisms underlying conscious states and contents. J R Soc N Z 2020. [DOI: 10.1080/03036758.2020.1840405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Corinne A. Bareham
- School of Psychology, Victoria University of Wellington, Wellington, New Zealand
| | - Matt Oxner
- School of Psychology, Victoria University of Wellington, Wellington, New Zealand
| | - Tim Gastrell
- School of Psychology, Victoria University of Wellington, Wellington, New Zealand
| | - David Carmel
- School of Psychology, Victoria University of Wellington, Wellington, New Zealand
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23
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Sattin D, Rossi Sebastiano D, D’Incerti L, Guido D, Marotta G, Benti R, Tirelli S, Magnani FG, Bersano A, Duran D, Ferraro S, Minati L, Nigri A, Rosazza C, Bianchi Marzoli S, Leonardi M. Visual behaviors in disorders of consciousness: Disentangling conscious visual processing by a multimodal approach. Eur J Neurosci 2020; 52:4345-4355. [DOI: 10.1111/ejn.14875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Davide Sattin
- Neurology, Public health, Disability Unit / Coma Research Centre Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Davide Rossi Sebastiano
- Neurophysiology and Diagnostic Epileptology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Ludovico D’Incerti
- Neuroradiology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Davide Guido
- Neurology, Public health, Disability Unit / Coma Research Centre Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Giorgio Marotta
- Department of Nuclear Medicine Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico Milan Italy
| | - Riccardo Benti
- Department of Nuclear Medicine Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico Milan Italy
| | - Simone Tirelli
- Neurology, Public health, Disability Unit / Coma Research Centre Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Francesca Giulia Magnani
- Neurology, Public health, Disability Unit / Coma Research Centre Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Anna Bersano
- Neurology Unit UCV Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Dunja Duran
- Neurophysiology and Diagnostic Epileptology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Stefania Ferraro
- Neuroradiology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Ludovico Minati
- Direzione Scientifica Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Anna Nigri
- Neuroradiology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
| | - Cristina Rosazza
- Neuroradiology Unit Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
- Dipartimento di Studi Umanistici (DISTUM) Università degli Studi di Urbino Carlo Bo Urbino PU Italy
| | - Stefania Bianchi Marzoli
- Neuro‐Ophthalmology Center IRCCS Istituto Auxologico Italiano, Scientific Institute Capitanio Hospital Milan Italy
| | - Matilde Leonardi
- Neurology, Public health, Disability Unit / Coma Research Centre Fondazione IRCCS Istituto Neurologico Carlo Besta Milan Italy
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24
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LeDoux JE, Michel M, Lau H. A little history goes a long way toward understanding why we study consciousness the way we do today. Proc Natl Acad Sci U S A 2020; 117:6976-6984. [PMID: 32170012 PMCID: PMC7132279 DOI: 10.1073/pnas.1921623117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Consciousness is currently a thriving area of research in psychology and neuroscience. While this is often attributed to events that took place in the early 1990s, consciousness studies today are a continuation of research that started in the late 19th century and that continued throughout the 20th century. From the beginning, the effort built on studies of animals to reveal basic principles of brain organization and function, and of human patients to gain clues about consciousness itself. Particularly important and our focus here is research in the 1950s, 1960s, and 1970s involving three groups of patients-amnesia, split brain, and blindsight. Across all three groups, a similar pattern of results was found-the patients could respond appropriately to stimuli that they denied seeing (or in the case of amnesiacs, having seen before). These studies paved the way for the current wave of research on consciousness. The field is, in fact, still grappling with the implications of the findings showing that the ability to consciously know and report the identity of a visual stimulus can be dissociated in the brain from the mechanisms that underlie the ability to behave in a meaningful way to the same stimulus.
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Affiliation(s)
- Joseph E LeDoux
- Center for Neural Science, New York University, New York, NY 10003;
- Department of Psychology, New York University, New York, NY 10003
- Department of Psychiatry, New York University Langone Medical School, New York, NY 10003
- Department of Child and Adolescent Psychiatry, New York University Langone Medical School, New York, NY 10003
- Emotional Brain Institute, Nathan Kline Institute, Orangeburg, NY 10962
| | - Matthias Michel
- Consciousness, Cognition & Computation Group, Université Libre de Bruxelles, B1050 Bruxelles, Belgium
- Center for Mind, Brain and Consciousness, New York University, New York, NY 10003
| | - Hakwan Lau
- Department of Psychology, University of California, Los Angeles, CA 90095
- Brain Research Institute, University of California, Los Angeles, CA 90095
- Department of Psychology, University of Hong Kong, Hong Kong
- State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Hong Kong
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25
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Horwitz GD. Temporal information loss in the macaque early visual system. PLoS Biol 2020; 18:e3000570. [PMID: 31971946 PMCID: PMC6977937 DOI: 10.1371/journal.pbio.3000570] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/05/2019] [Indexed: 01/09/2023] Open
Abstract
Stimuli that modulate neuronal activity are not always detectable, indicating a loss of information between the modulated neurons and perception. To identify where in the macaque visual system information about periodic light modulations is lost, signal-to-noise ratios were compared across simulated cone photoreceptors, lateral geniculate nucleus (LGN) neurons, and perceptual judgements. Stimuli were drifting, threshold-contrast Gabor patterns on a photopic background. The sensitivity of LGN neurons, extrapolated to populations, was similar to the monkeys' at low temporal frequencies. At high temporal frequencies, LGN sensitivity exceeded the monkeys' and approached the upper bound set by cone photocurrents. These results confirm a loss of high-frequency information downstream of the LGN. However, this loss accounted for only about 5% of the total. Phototransduction accounted for essentially all of the rest. Together, these results show that low temporal frequency information is lost primarily between the cones and the LGN, whereas high-frequency information is lost primarily within the cones, with a small additional loss downstream of the LGN.
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Affiliation(s)
- Gregory D. Horwitz
- Department of Physiology and Biophysics, Washington National Primate Research Center, University of Washington, Seattle, Washington, United States of America
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26
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Kanai R, Chang A, Yu Y, Magrans de Abril I, Biehl M, Guttenberg N. Information generation as a functional basis of consciousness. Neurosci Conscious 2019; 2019:niz016. [PMID: 31798969 PMCID: PMC6884095 DOI: 10.1093/nc/niz016] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 10/14/2019] [Accepted: 10/22/2019] [Indexed: 01/27/2023] Open
Abstract
What is the biological advantage of having consciousness? Functions of consciousness have been elusive due to the subjective nature of consciousness and ample empirical evidence showing the presence of many nonconscious cognitive performances in the human brain. Drawing upon empirical literature, here, we propose that a core function of consciousness be the ability to internally generate representations of events possibly detached from the current sensory input. Such representations are constructed by generative models learned through sensory-motor interactions with the environment. We argue that the ability to generate information underlies a variety of cognitive functions associated with consciousness such as intention, imagination, planning, short-term memory, attention, curiosity, and creativity, all of which contribute to non-reflexive behavior. According to this view, consciousness emerged in evolution when organisms gained the ability to perform internal simulations using internal models, which endowed them with flexible intelligent behavior. To illustrate the notion of information generation, we take variational autoencoders (VAEs) as an analogy and show that information generation corresponds the decoding (or decompression) part of VAEs. In biological brains, we propose that information generation corresponds to top-down predictions in the predictive coding framework. This is compatible with empirical observations that recurrent feedback activations are linked with consciousness whereas feedforward processing alone seems to occur without evoking conscious experience. Taken together, the information generation hypothesis captures many aspects of existing ideas about potential functions of consciousness and provides new perspectives on the functional roles of consciousness.
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Affiliation(s)
- Ryota Kanai
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
| | - Acer Chang
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
| | - Yen Yu
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
| | - Ildefons Magrans de Abril
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
| | - Martin Biehl
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
| | - Nicholas Guttenberg
- Basic Research Group, Araya, Inc., P.O. Box 577 ARK Mori Building 24 F, 1-12-32 Akasaka, Minato-ku, Tokyo, 107-6024, Japan
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Haun A, Tononi G. Why Does Space Feel the Way it Does? Towards a Principled Account of Spatial Experience. ENTROPY 2019. [PMCID: PMC7514505 DOI: 10.3390/e21121160] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
There must be a reason why an experience feels the way it does. A good place to begin addressing this question is spatial experience, because it may be more penetrable by introspection than other qualities of consciousness such as color or pain. Moreover, much of experience is spatial, from that of our body to the visual world, which appears as if painted on an extended canvas in front of our eyes. Because it is ‘right there’, we usually take space for granted and overlook its qualitative properties. However, we should realize that a great number of phenomenal distinctions and relations are required for the canvas of space to feel ‘extended’. Here we argue that, to be experienced as extended, the canvas of space must be composed of countless spots, here and there, small and large, and these spots must be related to each other in a characteristic manner through connection, fusion, and inclusion. Other aspects of the structure of spatial experience follow from extendedness: every spot can be experienced as enclosing a particular region, with its particular location, size, boundary, and distance from other spots. We then propose an account of the phenomenal properties of spatial experiences based on integrated information theory (IIT). The theory provides a principled approach for characterizing both the quantity and quality of experience by unfolding the cause-effect structure of a physical substrate. Specifically, we show that a simple simulated substrate of units connected in a grid-like manner yields a cause-effect structure whose properties can account for the main properties of spatial experience. These results uphold the hypothesis that our experience of space is supported by brain areas whose units are linked by a grid-like connectivity. They also predict that changes in connectivity, even in the absence of changes in activity, should lead to a warping of experienced space. To the extent that this approach provides an initial account of phenomenal space, it may also serve as a starting point for investigating other aspects of the quality of experience and their physical correspondents.
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Caruana N, Inkley C, Zein ME, Seymour K. No influence of eye gaze on emotional face processing in the absence of conscious awareness. Sci Rep 2019; 9:16198. [PMID: 31700080 PMCID: PMC6838103 DOI: 10.1038/s41598-019-52728-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/22/2019] [Indexed: 11/30/2022] Open
Abstract
The human brain has evolved specialised mechanisms to enable the rapid detection of threat cues, including emotional face expressions (e.g., fear and anger). However, contextual cues - such as gaze direction - influence the ability to recognise emotional expressions. For instance, anger paired with direct gaze, and fear paired with averted gaze are more accurately recognised compared to alternate conjunctions of these features. It is argued that this is because gaze direction conveys the relevance and locus of the threat to the observer. Here, we used continuous flash suppression (CFS) to assess whether the modulatory effect of gaze direction on emotional face processing occurs outside of conscious awareness. Previous research using CFS has demonstrated that fearful facial expressions are prioritised by the visual system and gain privileged access to awareness over other expressed emotions. We hypothesised that if the modulatory effects of gaze on emotional face processing occur also at this level, then the gaze-emotion conjunctions signalling self-relevant threat will reach awareness faster than those that do not. We report that fearful faces gain privileged access to awareness over angry faces, but that gaze direction does not modulate this effect. Thus, our findings suggest that previously reported effects of gaze direction on emotional face processing are likely to occur once the face is detected, where the self-relevance and locus of the threat can be consciously appraised.
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Affiliation(s)
- Nathan Caruana
- Perception in Action Research Centre, Macquarie University, Sydney, Australia.
- Department of Cognitive Science, Macquarie University, Sydney, Australia.
| | - Christine Inkley
- Department of Cognitive Science, Macquarie University, Sydney, Australia
| | - Marwa El Zein
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - Kiley Seymour
- School of Psychology, Western Sydney University, Sydney, Australia
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, Australia
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29
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Lawrence SJ, Formisano E, Muckli L, de Lange FP. Laminar fMRI: Applications for cognitive neuroscience. Neuroimage 2019; 197:785-791. [DOI: 10.1016/j.neuroimage.2017.07.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/04/2017] [Accepted: 07/03/2017] [Indexed: 11/30/2022] Open
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30
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Prefrontal neural dynamics in consciousness. Neuropsychologia 2019; 131:25-41. [DOI: 10.1016/j.neuropsychologia.2019.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 12/11/2022]
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31
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Zhaoping L. A new framework for understanding vision from the perspective of the primary visual cortex. Curr Opin Neurobiol 2019; 58:1-10. [PMID: 31271931 DOI: 10.1016/j.conb.2019.06.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 06/02/2019] [Accepted: 06/10/2019] [Indexed: 11/25/2022]
Abstract
Visual attention selects only a tiny fraction of visual input information for further processing. Selection starts in the primary visual cortex (V1), which creates a bottom-up saliency map to guide the fovea to selected visual locations via gaze shifts. This motivates a new framework that views vision as consisting of encoding, selection, and decoding stages, placing selection on center stage. It suggests a massive loss of non-selected information from V1 downstream along the visual pathway. Hence, feedback from downstream visual cortical areas to V1 for better decoding (recognition), through analysis-by-synthesis, should query for additional information and be mainly directed at the foveal region. Accordingly, non-foveal vision is not only poorer in spatial resolution, but also more susceptible to many illusions.
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Affiliation(s)
- Li Zhaoping
- University of Tübingen, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
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32
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Caruana N, Stein T, Watson T, Williams N, Seymour K. Intact prioritisation of unconscious face processing in schizophrenia. Cogn Neuropsychiatry 2019; 24:135-151. [PMID: 30848987 DOI: 10.1080/13546805.2019.1590189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Faces provide a rich source of social information, crucial for the successful navigation of daily social interactions. People with schizophrenia suffer a wide range of social-cognitive deficits, including abnormalities in face perception. However, to date, studies of face perception in schizophrenia have primarily employed tasks that require patients to make judgements about the faces. It is, thus, unclear whether the reported deficits reflect an impairment in encoding visual face information, or biased social-cognitive evaluative processes. METHODS We assess the integrity of early unconscious face processing in 21 out-patients diagnosed with Schizophrenia or Schizoaffective Disorder (15M/6F) and 21 healthy controls (14M/7F). In order to control for any direct influence of higher order cognitive processes, we use a behavioural paradigm known as breaking continuous flash suppression (b-CFS), where participants simply respond to the presence and location of a face. In healthy adults, this method has previously been used to show that upright faces gain rapid and privileged access to conscious awareness over inverted faces and other inanimate objects. RESULTS Here, we report similar effects in patients, suggesting that the early unconscious stages of face processing are intact in schizophrenia. CONCLUSION Our data indicate that face processing deficits reported in the literature must manifest at a conscious stage of processing, where the influence of mentalizing or attribution biases might play a role.
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Affiliation(s)
- Nathan Caruana
- a ARC Centre of Excellence in Cognition and Its Disorders , Sydney , Australia.,b Department of Cognitive Science , Macquarie University , Sydney , Australia
| | - Timo Stein
- c Department of Psychology , University of Amsterdam , Amsterdam , The Netherlands
| | - Tamara Watson
- d School of Social Sciences and Psychology , Western Sydney University , Sydney , Australia
| | - Nikolas Williams
- a ARC Centre of Excellence in Cognition and Its Disorders , Sydney , Australia.,b Department of Cognitive Science , Macquarie University , Sydney , Australia
| | - Kiley Seymour
- a ARC Centre of Excellence in Cognition and Its Disorders , Sydney , Australia.,d School of Social Sciences and Psychology , Western Sydney University , Sydney , Australia
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33
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Bielczyk NZ, Piskała K, Płomecka M, Radziński P, Todorova L, Foryś U. Time-delay model of perceptual decision making in cortical networks. PLoS One 2019; 14:e0211885. [PMID: 30768608 PMCID: PMC6377186 DOI: 10.1371/journal.pone.0211885] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/23/2019] [Indexed: 11/18/2022] Open
Abstract
It is known that cortical networks operate on the edge of instability, in which oscillations can appear. However, the influence of this dynamic regime on performance in decision making, is not well understood. In this work, we propose a population model of decision making based on a winner-take-all mechanism. Using this model, we demonstrate that local slow inhibition within the competing neuronal populations can lead to Hopf bifurcation. At the edge of instability, the system exhibits ambiguity in the decision making, which can account for the perceptual switches observed in human experiments. We further validate this model with fMRI datasets from an experiment on semantic priming in perception of ambivalent (male versus female) faces. We demonstrate that the model can correctly predict the drop in the variance of the BOLD within the Superior Parietal Area and Inferior Parietal Area while watching ambiguous visual stimuli.
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Affiliation(s)
| | | | - Martyna Płomecka
- Methods of Plasticity Research, Department of Psychology, University of Zürich, Zürich, Switzerland
- Laboratory of Brain Imaging, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Radziński
- Faculty of Mathematics, University of Warsaw, Warsaw, Poland
| | - Lara Todorova
- Faculty of Social Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
- Donders Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Urszula Foryś
- Faculty of Mathematics, University of Warsaw, Warsaw, Poland
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34
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Meijer GT, Mertens PEC, Pennartz CMA, Olcese U, Lansink CS. The circuit architecture of cortical multisensory processing: Distinct functions jointly operating within a common anatomical network. Prog Neurobiol 2019; 174:1-15. [PMID: 30677428 DOI: 10.1016/j.pneurobio.2019.01.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 12/21/2018] [Accepted: 01/21/2019] [Indexed: 12/16/2022]
Abstract
Our perceptual systems continuously process sensory inputs from different modalities and organize these streams of information such that our subjective representation of the outside world is a unified experience. By doing so, they also enable further cognitive processing and behavioral action. While cortical multisensory processing has been extensively investigated in terms of psychophysics and mesoscale neural correlates, an in depth understanding of the underlying circuit-level mechanisms is lacking. Previous studies on circuit-level mechanisms of multisensory processing have predominantly focused on cue integration, i.e. the mechanism by which sensory features from different modalities are combined to yield more reliable stimulus estimates than those obtained by using single sensory modalities. In this review, we expand the framework on the circuit-level mechanisms of cortical multisensory processing by highlighting that multisensory processing is a family of functions - rather than a single operation - which involves not only the integration but also the segregation of modalities. In addition, multisensory processing not only depends on stimulus features, but also on cognitive resources, such as attention and memory, as well as behavioral context, to determine the behavioral outcome. We focus on rodent models as a powerful instrument to study the circuit-level bases of multisensory processes, because they enable combining cell-type-specific recording and interventional techniques with complex behavioral paradigms. We conclude that distinct multisensory processes share overlapping anatomical substrates, are implemented by diverse neuronal micro-circuitries that operate in parallel, and are flexibly recruited based on factors such as stimulus features and behavioral constraints.
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Affiliation(s)
- Guido T Meijer
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands.
| | - Paul E C Mertens
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands.
| | - Cyriel M A Pennartz
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands.
| | - Umberto Olcese
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands.
| | - Carien S Lansink
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands.
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35
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Singh A, Chandrasekhar Pammi VS, Guleria A, Srinivasan N. Concentrative (Sahaj Samadhi) meditation training and visual awareness: An fMRI study on color afterimages. PROGRESS IN BRAIN RESEARCH 2019; 244:185-206. [PMID: 30732837 DOI: 10.1016/bs.pbr.2018.10.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
All of us consciously experience the world around us through our sensory modalities. Empirical studies on the relationship between attention and awareness have shown that attention does influence perceptual experience or appearance in addition to better performance in perceptual tasks. The practice of meditation also changes perceptual experience in addition to better perceptual performance. For example, a study with Sahaj Samadhi meditators utilizing negative color afterimages had shown that concentrative meditation influences visual experience. However the brain regions that are modified by meditation practice leading to such changes in visual experience or awareness are still not known. Here using negative color afterimages in a functional MRI study, we investigated the brain mechanisms underlying the changes in visual awareness as a function of attentional enhancement achieved through long-term concentrative meditation practice. We found increased activity in right lateralized inferior occipital and inferior frontal cortex, which suggests the importance of attentional control in modulating visual awareness. The results of this study indicate that the link between attention and conscious experience is possibly changed by meditation practices.
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Affiliation(s)
- Amrendra Singh
- Centre of Behavioural and Cognitive Sciences, University of Allahabad, Allahabad, India
| | | | | | - Narayanan Srinivasan
- Centre of Behavioural and Cognitive Sciences, University of Allahabad, Allahabad, India.
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36
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Prettyman A. Perceptual learning. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2018; 10:e1489. [PMID: 30570213 DOI: 10.1002/wcs.1489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 09/07/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022]
Abstract
Perceptual learning involves long-term changes to perception due to practice or experience. While perceptual learning has been studied for over a century in philosophy and psychology, research into the cognitive and neural mechanisms underlying perceptual learning remains an area of ongoing development. This review explores what perceptual learning is and how it occurs, with a focus on areas of controversy. It then turns to several current debates. First, it explores the debate as to whether such learning involves genuine perceptual change at all, rather than a change in action, attention, or decision-making. Second, it questions the role that higher-cognitive mechanisms, like attention, might play in perceptual learning. Does perceptual learning require attention, or can it occur through mere exposure in the absence of attention? Third, it examines a debate about what perceptual learning means for the perception-cognition divide. Does it blur the divide or preserve it? This article is categorized under: Philosophy > Psychological Capacities Psychology > Perception and Psychophysics Psychology > Learning.
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37
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Lee ALF. The contribution of local and global motion adaptation in the repulsive direction aftereffect. J Vis 2018; 18:2. [PMID: 30458510 DOI: 10.1167/18.12.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
After adapting to a certain motion direction, our perception of a similar direction will be repelled away from the adapting direction, a phenomenon known as the direction aftereffect (DAE). As the motion system consists of local and global processing stages, it remains unclear how the adaptation of the two stages contributes in producing the DAE. The present study addresses this question by independently inducing adaptation at local and global motion-processing levels. Local adaptation was manipulated by presenting test stimuli at either adapted or nonadapted locations. Global adaptation was manipulated by embedding one or five global motion directions in the adapting motion. Repulsive DAE, when measured using a multiple-element test pattern, was stronger when it was produced by global adaptation than when produced by local adaptation. Specifically, the DAE resulting from local adaptation (a) decreased when test orientations differed from adapting orientation, (b) decreased when local directions were disambiguated using plaid stimuli, (c) remained the same even when attention was focused at specific test locations during adaptation, and (d) increased when tested with a single element. Overall, these findings suggest that the strength of repulsive DAE depends on both the motion-processing level at which adaptation occurs and the level at which the DAE was tested. Furthermore, the repulsive DAE arising from local adaptation alone can be explained by the propagation of local speed repulsion instead of local direction repulsion. Findings are discussed in the context of how motion aftereffects arise from the adaptation of a hierarchical motion system.
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Affiliation(s)
- Alan L F Lee
- Department of Applied Psychology, Lingnan University, Hong Kong
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38
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Abstract
Prior functional magnetic resonance imaging (fMRI) results suggest that true memories, but not false memories, activate early sensory cortex. It is thought that false memories, which reflect conscious processing, do not activate early sensory cortex because these regions are associated with nonconscious processing. We posited that false memories may activate the earliest visual cortical processing region (i.e., V1) when task conditions are manipulated to evoke conscious processing in this region. In an fMRI experiment, abstract shapes were presented to the left or right of fixation during encoding. During retrieval, old shapes were presented at fixation and participants characterized each shape as previously on the "left" or "right" followed by an "unsure"-"sure"-"very sure" confidence rating. False memories for spatial location (i.e., "right"/left or "left"/right trials with "sure" or "very sure" confidence ratings) were associated with activity in bilateral early visual regions, including V1. In a follow-up fMRI-guided transcranial magnetic stimulation (TMS) experiment that employed the same paradigm, we assessed whether V1 activity was necessary for false memory construction. Between the encoding phase and the retrieval phase of each run, TMS (1 Hz, 8 min) was used to target the location of false memory activity (identified in the fMRI experiment) in left V1, right V1, or the vertex (control site). Confident false memories for spatial location were significantly reduced following TMS to V1, as compared to vertex. The results of the present experiments provide convergent evidence that early sensory cortex can contribute to false memory construction under particular task conditions.
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Affiliation(s)
- Jessica M Karanian
- a Department of Psychology , John Jay College of Criminal Justice, The City University of New York , New York , NY , USA
| | - Scott D Slotnick
- b Department of Psychology , Boston College , Chestnut Hill , MA , USA
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39
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Hegdé J. Neural Mechanisms of High-Level Vision. Compr Physiol 2018; 8:903-953. [PMID: 29978891 DOI: 10.1002/cphy.c160035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The last three decades have seen major strides in our understanding of neural mechanisms of high-level vision, or visual cognition of the world around us. Vision has also served as a model system for the study of brain function. Several broad insights, as yet incomplete, have recently emerged. First, visual perception is best understood not as an end unto itself, but as a sensory process that subserves the animal's behavioral goal at hand. Visual perception is likely to be simply a side effect that reflects the readout of visual information processing that leads to behavior. Second, the brain is essentially a probabilistic computational system that produces behaviors by collectively evaluating, not necessarily consciously or always optimally, the available information about the outside world received from the senses, the behavioral goals, prior knowledge about the world, and possible risks and benefits of a given behavior. Vision plays a prominent role in the overall functioning of the brain providing the lion's share of information about the outside world. Third, the visual system does not function in isolation, but rather interacts actively and reciprocally with other brain systems, including other sensory faculties. Finally, various regions of the visual system process information not in a strict hierarchical manner, but as parts of various dynamic brain-wide networks, collectively referred to as the "connectome." Thus, a full understanding of vision will ultimately entail understanding, in granular, quantitative detail, various aspects of dynamic brain networks that use visual sensory information to produce behavior under real-world conditions. © 2017 American Physiological Society. Compr Physiol 8:903-953, 2018.
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Affiliation(s)
- Jay Hegdé
- Brain and Behavior Discovery Institute, Augusta University, Augusta, Georgia, USA.,James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, USA.,Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.,The Graduate School, Augusta University, Augusta, Georgia, USA
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40
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Kirschfeld K. How we perceive our own retina. Proc Biol Sci 2018; 284:rspb.2017.1904. [PMID: 29070728 PMCID: PMC5666110 DOI: 10.1098/rspb.2017.1904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 09/28/2017] [Indexed: 11/12/2022] Open
Abstract
Ever since the days of René Descartes, in the seventeenth century, the search for the relationship between subjective perception and neural activity has been an ongoing challenge. In neuroscience, an approach to the problem via the visual system has produced a paradigm using perceptual suppression, changing with time. Cortical areas in which the neural activity was modulated in temporal correlation with this percept could be traced. Although these areas may lead directly to perception, such temporal correlation of neural activity does not suffice as ultimate proof that they actually do so. In this article, I will use a different method to show that, for the perception of our own retina, any brain area leading directly to this perception also needs to represent the retina without distortion. Furthermore, I will demonstrate that the phenomenon of size constancy must be realized in this area.
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Affiliation(s)
- Kuno Kirschfeld
- Max-Planck-Institute for Biological Cybernetics, Spemannstrasse 41, 72076 Tuebingen, Germany
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41
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Pitzalis S, Strappini F, Bultrini A, Di Russo F. Detailed spatiotemporal brain mapping of chromatic vision combining high-resolution VEP with fMRI and retinotopy. Hum Brain Mapp 2018. [PMID: 29536594 DOI: 10.1002/hbm.24046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed-forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto-occipital areas including V1, LOC, V8/VO, and the motion-sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re-entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas.
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Affiliation(s)
- Sabrina Pitzalis
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico,", Rome, Italy.,Santa Lucia Foundation, IRCCS, Rome, Italy
| | | | - Alessandro Bultrini
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico,", Rome, Italy
| | - Francesco Di Russo
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico,", Rome, Italy.,Santa Lucia Foundation, IRCCS, Rome, Italy
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42
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Mashour GA, Hudetz AG. Neural Correlates of Unconsciousness in Large-Scale Brain Networks. Trends Neurosci 2018; 41:150-160. [PMID: 29409683 PMCID: PMC5835202 DOI: 10.1016/j.tins.2018.01.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/12/2017] [Accepted: 01/09/2018] [Indexed: 12/21/2022]
Abstract
The biological basis of consciousness is one of the most challenging and fundamental questions in 21st century science. A related pursuit aims to identify the neural correlates and causes of unconsciousness. We review current trends in the investigation of physiological, pharmacological, and pathological states of unconsciousness at the level of large-scale functional brain networks. We focus on the roles of brain connectivity, repertoire, graph-theoretical techniques, and neural dynamics in understanding the functional brain disconnections and reduced complexity that appear to characterize these states. Persistent questions in the field, such as distinguishing true correlates, linking neural scales, and understanding differential recovery patterns, are also addressed.
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Affiliation(s)
- George A Mashour
- Neuroscience Graduate Program, Center for Consciousness Science, Department of Anesthesiology, University of Michigan Medical School, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Anthony G Hudetz
- Neuroscience Graduate Program, Center for Consciousness Science, Department of Anesthesiology, University of Michigan Medical School, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA
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43
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Gratton G. Brain reflections: A circuit‐based framework for understanding information processing and cognitive control. Psychophysiology 2017; 55. [DOI: 10.1111/psyp.13038] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Gabriele Gratton
- Psychology Department and Beckman InstituteUniversity of Illinois at Urbana‐ChampaignUrbana Illinois USA
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44
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Pennartz CMA. Consciousness, Representation, Action: The Importance of Being Goal-Directed. Trends Cogn Sci 2017; 22:137-153. [PMID: 29233478 DOI: 10.1016/j.tics.2017.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 12/14/2022]
Abstract
Recent years have witnessed fierce debates on the dependence of consciousness on interactions between a subject and the environment. Reviewing neuroscientific, computational, and clinical evidence, I will address three questions. First, does conscious experience necessarily depend on acute interactions between a subject and the environment? Second, does it depend on specific perception-action loops in the longer run? Third, which types of action does consciousness cohere with, if not with all of them? I argue that conscious contents do not necessarily depend on acute or long-term brain-environment interactions. Instead, consciousness is proposed to be specifically associated with, and subserve, deliberate, goal-directed behavior (GDB). Brain systems implied in conscious representation are highly connected to, but distinct from, neural substrates mediating GDB and declarative memory.
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Affiliation(s)
- Cyriel M A Pennartz
- Swammerdam Institute for Life Sciences, Center for Neuroscience, Faculty of Science, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, The Netherlands.
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Mikellidou K, Arrighi R, Aghakhanyan G, Tinelli F, Frijia F, Crespi S, De Masi F, Montanaro D, Morrone MC. Plasticity of the human visual brain after an early cortical lesion. Neuropsychologia 2017; 128:166-177. [PMID: 29100949 DOI: 10.1016/j.neuropsychologia.2017.10.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/16/2017] [Accepted: 10/29/2017] [Indexed: 11/17/2022]
Abstract
In adults, partial damage to V1 or optic radiations abolishes perception in the corresponding part of the visual field, causing a scotoma. However, it is widely accepted that the developing cortex has superior capacities to reorganize following an early lesion to endorse adaptive plasticity. Here we report a single patient case (G.S.) with near normal central field vision despite a massive unilateral lesion to the optic radiations acquired early in life. The patient underwent surgical removal of a right hemisphere parieto-temporal-occipital atypical choroid plexus papilloma of the right lateral ventricle at four months of age, which presumably altered the visual pathways during in utero development. Both the tumor and surgery severely compromised the optic radiations. Residual vision of G.S. was tested psychophysically when the patient was 7 years old. We found a close-to-normal visual acuity and contrast sensitivity within the central 25° and a great impairment in form and contrast vision in the far periphery (40-50°) of the left visual hemifield. BOLD response to full field luminance flicker was recorded from the primary visual cortex (V1) and in a region in the residual temporal-occipital region, presumably corresponding to the middle temporal complex (MT+), of the lesioned (right) hemisphere. A population receptive field analysis of the BOLD responses to contrast modulated stimuli revealed a retinotopic organization just for the MT+ region but not for the calcarine regions. Interestingly, consistent islands of ipsilateral activity were found in MT+ and in the parieto-occipital sulcus (POS) of the intact hemisphere. Probabilistic tractography revealed that optic radiations between LGN and V1 were very sparse in the lesioned hemisphere consistently with the post-surgery cerebral resection, while normal in the intact hemisphere. On the other hand, strong structural connections between MT+ and LGN were found in the lesioned hemisphere, while the equivalent tract in the spared hemisphere showed minimal structural connectivity. These results suggest that during development of the pathological brain, abnormal thalamic projections can lead to functional cortical changes, which may mediate functional recovery of vision.
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Affiliation(s)
- K Mikellidou
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - R Arrighi
- Department of Neuroscience, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | - G Aghakhanyan
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - F Tinelli
- Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy
| | - F Frijia
- UOC Bioingegneria e Ingegneria Clinica, Fondazione CNR/Regione Toscana G. Monasterio, Pisa, Italy
| | - S Crespi
- Department of Psychology, Vita-Salute San Raffaele University, Milan, Italy; Unit of Experimental Psychology, Division of Neuroscience, Scientific Institute San Raffaele, Milan, Italy; Neuroradiology Unit - CERMAC, San Raffaele Hospital, Milan, Italy
| | - F De Masi
- Division of Anesthesiology and Intensive Care, University Hospital of Pisa, Italy
| | - D Montanaro
- Unità di Neuroradiologia, Fondazione CNR/Regione Toscana G. Monasterio, Pisa, Italy
| | - M C Morrone
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy; Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
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46
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Giersch A, Mishara AL. Is Schizophrenia a Disorder of Consciousness? Experimental and Phenomenological Support for Anomalous Unconscious Processing. Front Psychol 2017; 8:1659. [PMID: 29033868 PMCID: PMC5625017 DOI: 10.3389/fpsyg.2017.01659] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/08/2017] [Indexed: 12/27/2022] Open
Abstract
Decades ago, several authors have proposed that disorders in automatic processing lead to intrusive symptoms or abnormal contents in the consciousness of people with schizophrenia. However, since then, studies have mainly highlighted difficulties in patients' conscious experiencing and processing but rarely explored how unconscious and conscious mechanisms may interact in producing this experience. We report three lines of research, focusing on the processing of spatial frequencies, unpleasant information, and time-event structure that suggest that impairments occur at both the unconscious and conscious level. We argue that focusing on unconscious, physiological and automatic processing of information in patients, while contrasting that processing with conscious processing, is a first required step before understanding how distortions or other impairments emerge at the conscious level. We then indicate that the phenomenological tradition of psychiatry supports a similar claim and provides a theoretical framework helping to understand the relationship between the impairments and clinical symptoms. We base our argument on the presence of disorders in the minimal self in patients with schizophrenia. The minimal self is tacit and non-verbal and refers to the sense of bodily presence. We argue this sense is shaped by unconscious processes, whose alteration may thus affect the feeling of being a unique individual. This justifies a focus on unconscious mechanisms and a distinction from those associated with consciousness.
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Affiliation(s)
- Anne Giersch
- INSERM U1114, Pôle de Psychiatrie, Fédération de Médecine Translationnelle de Strasbourg, Centre Hospitalier Régional Universitaire of Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Aaron L. Mishara
- Department of Clinical Psychology, The Chicago School of Professional Psychology, Los Angeles, CA, United States
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47
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Karanian JM, Slotnick SD. False memories for shape activate the lateral occipital complex. ACTA ACUST UNITED AC 2017; 24:552-556. [PMID: 28916630 PMCID: PMC5602348 DOI: 10.1101/lm.045765.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/02/2017] [Indexed: 11/25/2022]
Abstract
Previous functional magnetic resonance imaging evidence has shown that false memories arise from higher-level conscious processing regions rather than lower-level sensory processing regions. In the present study, we assessed whether the lateral occipital complex (LOC)—a lower-level conscious shape processing region—was associated with false memories for shape. During encoding, participants viewed intact or scrambled colored abstract shapes. During retrieval, colored disks were presented and participants indicated whether the corresponding item was previously “intact” or “scrambled.” False memories for shape (“intact”/scrambled > “scrambled”/scrambled) activated LOC, which indicates lower-level sensory processing regions can support false memory.
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Affiliation(s)
- Jessica M Karanian
- Department of Psychology, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Scott D Slotnick
- Department of Psychology, Boston College, Chestnut Hill, Massachusetts 02467, USA
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48
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Golan T, Davidesco I, Meshulam M, Groppe DM, Mégevand P, Yeagle EM, Goldfinger MS, Harel M, Melloni L, Schroeder CE, Deouell LY, Mehta AD, Malach R. Increasing suppression of saccade-related transients along the human visual hierarchy. eLife 2017; 6. [PMID: 28850030 PMCID: PMC5576487 DOI: 10.7554/elife.27819] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/08/2017] [Indexed: 11/13/2022] Open
Abstract
A key hallmark of visual perceptual awareness is robustness to instabilities arising from unnoticeable eye and eyelid movements. In previous human intracranial (iEEG) work (Golan et al., 2016) we found that excitatory broadband high-frequency activity transients, driven by eye blinks, are suppressed in higher-level but not early visual cortex. Here, we utilized the broad anatomical coverage of iEEG recordings in 12 eye-tracked neurosurgical patients to test whether a similar stabilizing mechanism operates following small saccades. We compared saccades (1.3°−3.7°) initiated during inspection of large individual visual objects with similarly-sized external stimulus displacements. Early visual cortex sites responded with positive transients to both conditions. In contrast, in both dorsal and ventral higher-level sites the response to saccades (but not to external displacements) was suppressed. These findings indicate that early visual cortex is highly unstable compared to higher-level visual regions which apparently constitute the main target of stabilizing extra-retinal oculomotor influences.
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Affiliation(s)
- Tal Golan
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ido Davidesco
- Department of Psychology, New York University, New York, United States
| | - Meir Meshulam
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - David M Groppe
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States.,The Krembil Neuroscience Centre, Toronto, Canada
| | - Pierre Mégevand
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Erin M Yeagle
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Matthew S Goldfinger
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Michal Harel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Lucia Melloni
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany.,NYU Comprehensive Epilepsy Center, Department of Neurology, School of Medicine, New York University, New York, United States
| | - Charles E Schroeder
- Department of Neurosurgery, Columbia University College of Physicians and Surgeons, New York, United States.,Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute, Orangeburg, United States
| | - Leon Y Deouell
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Psychology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ashesh D Mehta
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Rafael Malach
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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Aston S, Hurlbert A. What #theDress reveals about the role of illumination priors in color perception and color constancy. J Vis 2017; 17:4. [PMID: 28793353 PMCID: PMC5812438 DOI: 10.1167/17.9.4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The disagreement between people who named #theDress (the Internet phenomenon of 2015) "blue and black" versus "white and gold" is thought to be caused by individual differences in color constancy. It is hypothesized that observers infer different incident illuminations, relying on illumination "priors" to overcome the ambiguity of the image. Different experiences may drive the formation of different illumination priors, and these may be indicated by differences in chronotype. We assess this hypothesis, asking whether matches to perceived illumination in the image and/or perceived dress colors relate to scores on the morningness-eveningness questionnaire (a measure of chronotype). We find moderate correlations between chronotype and illumination matches (morning types giving bluer illumination matches than evening types) and chronotype and dress body matches, but these are significant only at the 10% level. Further, although inferred illumination chromaticity in the image explains variation in the color matches to the dress (confirming the color constancy hypothesis), color constancy thresholds obtained using an established illumination discrimination task are not related to dress color perception. We also find achromatic settings depend on luminance, suggesting that subjective white point differences may explain the variation in dress color perception only if settings are made at individually tailored luminance levels. The results of such achromatic settings are inconsistent with their assumed correspondence to perceived illumination. Finally, our results suggest that perception and naming are disconnected, with observers reporting different color names for the dress photograph and their isolated color matches, the latter best capturing the variation in the matches.
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Affiliation(s)
- Stacey Aston
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Anya Hurlbert
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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50
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Metzger BA, Mathewson KE, Tapia E, Fabiani M, Gratton G, Beck DM. Regulating the Access to Awareness: Brain Activity Related to Probe-related and Spontaneous Reversals in Binocular Rivalry. J Cogn Neurosci 2017; 29:1089-1102. [PMID: 28195526 DOI: 10.1162/jocn_a_01104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Research on the neural correlates of consciousness (NCC) has implicated an assortment of brain regions, ERP components, and network properties associated with visual awareness. Recently, the P3b ERP component has emerged as a leading NCC candidate. However, typical P3b paradigms depend on the detection of some stimulus change, making it difficult to separate brain processes elicited by the stimulus itself from those associated with updates or changes in visual awareness. Here we used binocular rivalry to ask whether the P3b is associated with changes in awareness even in the absence of changes in the object of awareness. We recorded ERPs during a probe-mediated binocular rivalry paradigm in which brief probes were presented over the image in either the suppressed or dominant eye to determine whether the elicited P3b activity is probe or reversal related. We found that the timing of P3b (but not its amplitude) was closely related to the timing of the report of a perceptual change rather than to the onset of the probe. This is consistent with the proposal that P3b indexes updates in conscious awareness, rather than being related to stimulus processing per se. Conversely, the probe-related P1 amplitude (but not its latency) was associated with reversal latency, suggesting that the degree to which the probe is processed increases the likelihood of a fast perceptual reversal. Finally, the response-locked P3b amplitude (but not its latency) was associated with the duration of an intermediate stage between reversals in which parts of both percepts coexist (piecemeal period). Together, the data suggest that the P3b reflects an update in consciousness and that the intensity of that process (as indexed by P3b amplitude) predicts how immediate that update is.
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