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Marvan T, Phillips WA. Cellular mechanisms of cooperative context-sensitive predictive inference. CURRENT RESEARCH IN NEUROBIOLOGY 2024; 6:100129. [PMID: 38665363 PMCID: PMC11043869 DOI: 10.1016/j.crneur.2024.100129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 02/14/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
We argue that prediction success maximization is a basic objective of cognition and cortex, that it is compatible with but distinct from prediction error minimization, that neither objective requires subtractive coding, that there is clear neurobiological evidence for the amplification of predicted signals, and that we are unconvinced by evidence proposed in support of subtractive coding. We outline recent discoveries showing that pyramidal cells on which our cognitive capabilities depend usually transmit information about input to their basal dendrites and amplify that transmission when input to their distal apical dendrites provides a context that agrees with the feedforward basal input in that both are depolarizing, i.e., both are excitatory rather than inhibitory. Though these intracellular discoveries require a level of technical expertise that is beyond the current abilities of most neuroscience labs, they are not controversial and acclaimed as groundbreaking. We note that this cellular cooperative context-sensitivity greatly enhances the cognitive capabilities of the mammalian neocortex, and that much remains to be discovered concerning its evolution, development, and pathology.
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Affiliation(s)
- Tomáš Marvan
- Institute of Philosophy, Czech Academy of Sciences (CAS), Czech Republic
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2
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Schmid D, Jarvers C, Neumann H. Canonical circuit computations for computer vision. BIOLOGICAL CYBERNETICS 2023; 117:299-329. [PMID: 37306782 PMCID: PMC10600314 DOI: 10.1007/s00422-023-00966-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/18/2023] [Indexed: 06/13/2023]
Abstract
Advanced computer vision mechanisms have been inspired by neuroscientific findings. However, with the focus on improving benchmark achievements, technical solutions have been shaped by application and engineering constraints. This includes the training of neural networks which led to the development of feature detectors optimally suited to the application domain. However, the limitations of such approaches motivate the need to identify computational principles, or motifs, in biological vision that can enable further foundational advances in machine vision. We propose to utilize structural and functional principles of neural systems that have been largely overlooked. They potentially provide new inspirations for computer vision mechanisms and models. Recurrent feedforward, lateral, and feedback interactions characterize general principles underlying processing in mammals. We derive a formal specification of core computational motifs that utilize these principles. These are combined to define model mechanisms for visual shape and motion processing. We demonstrate how such a framework can be adopted to run on neuromorphic brain-inspired hardware platforms and can be extended to automatically adapt to environment statistics. We argue that the identified principles and their formalization inspires sophisticated computational mechanisms with improved explanatory scope. These and other elaborated, biologically inspired models can be employed to design computer vision solutions for different tasks and they can be used to advance neural network architectures of learning.
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Affiliation(s)
- Daniel Schmid
- Institute for Neural Information Processing, Ulm University, James-Franck-Ring, Ulm, 89081 Germany
| | - Christian Jarvers
- Institute for Neural Information Processing, Ulm University, James-Franck-Ring, Ulm, 89081 Germany
| | - Heiko Neumann
- Institute for Neural Information Processing, Ulm University, James-Franck-Ring, Ulm, 89081 Germany
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3
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Giersch A, Laprévote V. Perceptual Functioning. Curr Top Behav Neurosci 2023; 63:79-113. [PMID: 36306053 DOI: 10.1007/7854_2022_393] [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] [Indexed: 06/16/2023]
Abstract
Perceptual disorders are not part of the diagnosis criteria for schizophrenia. Yet, a considerable amount of work has been conducted, especially on visual perception abnormalities, and there is little doubt that visual perception is altered in patients. There are several reasons why such perturbations are of interest in this pathology. They are observed during the prodromal phase of psychosis, they are related to the pathophysiology (clinical disorganization, disorders of the sense of self), and they are associated with neuronal connectivity disorders. Perturbations occur at different levels of processing and likely affect how patients interact and adapt to their surroundings. The literature has become very large, and here we try to summarize different models that have guided the exploration of perception in patients. We also illustrate several lines of research by showing how perception has been investigated and by discussing the interpretation of the results. In addition to discussing domains such as contrast sensitivity, masking, and visual grouping, we develop more recent fields like processing at the level of the retina, and the timing of perception.
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Affiliation(s)
- Anne Giersch
- University of Strasbourg, INSERM U1114, Centre Hospitalier Régional Universitaire de Strasbourg, Strasbourg, France.
| | - Vincent Laprévote
- University of Strasbourg, INSERM U1114, Centre Hospitalier Régional Universitaire de Strasbourg, Strasbourg, France
- CLIP Centre de Liaison et d'Intervention Précoce, Centre Psychothérapique de Nancy, Laxou, France
- Faculté de Médecine, Université de Lorraine, Vandoeuvre-lès-Nancy, France
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4
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Iyer A, Grewal K, Velu A, Souza LO, Forest J, Ahmad S. Avoiding Catastrophe: Active Dendrites Enable Multi-Task Learning in Dynamic Environments. Front Neurorobot 2022; 16:846219. [PMID: 35574225 PMCID: PMC9100780 DOI: 10.3389/fnbot.2022.846219] [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: 12/30/2021] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
A key challenge for AI is to build embodied systems that operate in dynamically changing environments. Such systems must adapt to changing task contexts and learn continuously. Although standard deep learning systems achieve state of the art results on static benchmarks, they often struggle in dynamic scenarios. In these settings, error signals from multiple contexts can interfere with one another, ultimately leading to a phenomenon known as catastrophic forgetting. In this article we investigate biologically inspired architectures as solutions to these problems. Specifically, we show that the biophysical properties of dendrites and local inhibitory systems enable networks to dynamically restrict and route information in a context-specific manner. Our key contributions are as follows: first, we propose a novel artificial neural network architecture that incorporates active dendrites and sparse representations into the standard deep learning framework. Next, we study the performance of this architecture on two separate benchmarks requiring task-based adaptation: Meta-World, a multi-task reinforcement learning environment where a robotic agent must learn to solve a variety of manipulation tasks simultaneously; and a continual learning benchmark in which the model's prediction task changes throughout training. Analysis on both benchmarks demonstrates the emergence of overlapping but distinct and sparse subnetworks, allowing the system to fluidly learn multiple tasks with minimal forgetting. Our neural implementation marks the first time a single architecture has achieved competitive results in both multi-task and continual learning settings. Our research sheds light on how biological properties of neurons can inform deep learning systems to address dynamic scenarios that are typically impossible for traditional ANNs to solve.
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Affiliation(s)
- Abhiram Iyer
- Numenta, Redwood City, CA, United States
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
| | | | - Akash Velu
- Department of Computer Science, Stanford University, Stanford, CA, United States
| | | | - Jeremy Forest
- Department of Psychology, Cornell University, Ithaca, NY, United States
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5
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Marvan T, Polák M, Bachmann T, Phillips WA. Apical amplification-a cellular mechanism of conscious perception? Neurosci Conscious 2021; 2021:niab036. [PMID: 34650815 PMCID: PMC8511476 DOI: 10.1093/nc/niab036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 07/09/2021] [Accepted: 09/23/2021] [Indexed: 11/25/2022] Open
Abstract
We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant. We argue that apical amplification enables conscious perceptual experience and makes it more flexible, and thus more adaptive, by being sensitive to context. Apical amplification provides a possible mechanism for recurrent processing theory that avoids strong loops. It makes the broadcasting hypothesized by global neuronal workspace theories feasible while preserving the distinct contributions of the individual cells receiving the broadcast. It also provides mechanisms that contribute to the holistic aspects of integrated information theory. As apical amplification is highly dependent on cholinergic, aminergic, and other neuromodulators, it relates the specific contents of conscious experience to global mental states and to fluctuations in arousal when awake. We conclude that apical dendrites provide a cellular mechanism for the context-sensitive selective amplification that is a cardinal prerequisite of conscious perception.
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Affiliation(s)
- Tomáš Marvan
- Department of Analytic Philosophy, Institute of Philosophy, Czech Academy of Sciences, Jilská 1, Prague 110 00, Czech Republic
| | - Michal Polák
- Department of Philosophy, University of West Bohemia, Sedláčkova 19, Pilsen 306 14, Czech Republic
| | - Talis Bachmann
- School of Law and Cognitive Neuroscience Laboratory, University of Tartu (Tallinn branch), Kaarli pst 3, Tallinn 10119, Estonia
| | - William A Phillips
- Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK
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6
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Silverstein SM, Thompson JL, Gold JM, Schiffman J, Waltz JA, Williams TF, Zinbarg RE, Mittal VA, Ellman LM, Strauss GP, Walker EF, Woods SW, Levin JA, Kafadar E, Kenney J, Smith D, Powers AR, Corlett PR. Increased face detection responses on the mooney faces test in people at clinical high risk for psychosis. NPJ SCHIZOPHRENIA 2021; 7:26. [PMID: 34001909 PMCID: PMC8129098 DOI: 10.1038/s41537-021-00156-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/19/2021] [Indexed: 02/03/2023]
Abstract
Identifying state-sensitive measures of perceptual and cognitive processes implicated in psychosis may allow for objective, earlier, and better monitoring of changes in mental status that are predictive of an impending psychotic episode, relative to traditional self-report-based clinical measures. To determine whether a measure of visual perception that has demonstrated sensitivity to the clinical state of schizophrenia in multiple prior studies is sensitive to features of the at-risk mental state, we examined differences between young people identified as being at clinical high risk for psychosis (CHR; n = 37) and non-psychiatric matched controls (n = 29) on the Mooney Faces Test (MFT). On each trial of the MFT, participants report whether they perceive a face in a degraded face image. The CHR group reported perceiving a greater number of faces in both upright and inverted MFT stimuli. Consistent with prior work, males reported more faces on the MFT than females in both conditions. However, the finding of greater reported face perception among CHR subjects was robustly observed in the female CHR group relative to the female control group. Among male CHR participants, greater reported face perception was related to increased perceptual abnormalities. These preliminary results are consistent with a small but growing literature suggesting that heightened perceptual sensitivity may characterize individuals at increased clinical risk for psychosis. Further studies are needed to determine the contributions of specific perceptual, cognitive, and motivational mechanisms to the findings.
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Affiliation(s)
- Steven M. Silverstein
- grid.412750.50000 0004 1936 9166University of Rochester Medical Center, New York, NY USA
| | - Judy L. Thompson
- grid.412750.50000 0004 1936 9166University of Rochester Medical Center, New York, NY USA
| | - James M. Gold
- grid.411024.20000 0001 2175 4264University of Maryland School of Medicine, Baltimore, MD USA
| | - Jason Schiffman
- grid.411024.20000 0001 2175 4264University of Maryland School of Medicine, Baltimore, MD USA ,grid.266093.80000 0001 0668 7243Present Address: University of California, Irvine, CA USA
| | - James A. Waltz
- grid.411024.20000 0001 2175 4264University of Maryland School of Medicine, Baltimore, MD USA
| | - Trevor F. Williams
- grid.16753.360000 0001 2299 3507Northwestern University, Evanston, IL USA
| | - Richard E. Zinbarg
- grid.16753.360000 0001 2299 3507Northwestern University, Evanston, IL USA
| | - Vijay A. Mittal
- grid.16753.360000 0001 2299 3507Northwestern University, Evanston, IL USA
| | - Lauren M. Ellman
- grid.264727.20000 0001 2248 3398Temple University, Philadelphia, PA USA
| | | | - Elaine F. Walker
- grid.189967.80000 0001 0941 6502Emory University, Atlanta, GA USA
| | - Scott W. Woods
- grid.47100.320000000419368710Yale University, New Haven, CT USA
| | - Jason A. Levin
- grid.213876.90000 0004 1936 738XUniversity of Georgia, Athens, GA USA
| | - Eren Kafadar
- grid.47100.320000000419368710Yale University, New Haven, CT USA
| | - Joshua Kenney
- grid.47100.320000000419368710Yale University, New Haven, CT USA
| | - Dillon Smith
- grid.16750.350000 0001 2097 5006Princeton University, Princeton, NJ USA
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7
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Silverstein SM, Lai A. The Phenomenology and Neurobiology of Visual Distortions and Hallucinations in Schizophrenia: An Update. Front Psychiatry 2021; 12:684720. [PMID: 34177665 PMCID: PMC8226016 DOI: 10.3389/fpsyt.2021.684720] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/14/2021] [Indexed: 12/15/2022] Open
Abstract
Schizophrenia is characterized by visual distortions in ~60% of cases, and visual hallucinations (VH) in ~25-50% of cases, depending on the sample. These symptoms have received relatively little attention in the literature, perhaps due to the higher rate of auditory vs. visual hallucinations in psychotic disorders, which is the reverse of what is found in other neuropsychiatric conditions. Given the clinical significance of these perceptual disturbances, our aim is to help address this gap by updating and expanding upon prior reviews. Specifically, we: (1) present findings on the nature and frequency of VH and distortions in schizophrenia; (2) review proposed syndromes of VH in neuro-ophthalmology and neuropsychiatry, and discuss the extent to which these characterize VH in schizophrenia; (3) review potential cortical mechanisms of VH in schizophrenia; (4) review retinal changes that could contribute to VH in schizophrenia; (5) discuss relationships between findings from laboratory measures of visual processing and VH in schizophrenia; and (6) integrate findings across biological and psychological levels to propose an updated model of VH mechanisms, including how their content is determined, and how they may reflect vulnerabilities in the maintenance of a sense of self. In particular, we emphasize the potential role of alterations at multiple points in the visual pathway, including the retina, the roles of multiple neurotransmitters, and the role of a combination of disinhibited default mode network activity and enhanced state-related apical/contextual drive in determining the onset and content of VH. In short, our goal is to cast a fresh light on the under-studied symptoms of VH and visual distortions in schizophrenia for the purposes of informing future work on mechanisms and the development of targeted therapeutic interventions.
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Affiliation(s)
- Steven M Silverstein
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, United States.,Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, United States.,Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, United States.,Center for Visual Science, University of Rochester Medical Center, Rochester, NY, United States
| | - Adriann Lai
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, United States
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8
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Aru J, Siclari F, Phillips WA, Storm JF. Apical drive-A cellular mechanism of dreaming? Neurosci Biobehav Rev 2020; 119:440-455. [PMID: 33002561 DOI: 10.1016/j.neubiorev.2020.09.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/08/2020] [Accepted: 09/13/2020] [Indexed: 11/17/2022]
Abstract
Dreams are internally generated experiences that occur independently of current sensory input. Here we argue, based on cortical anatomy and function, that dream experiences are tightly related to the workings of a specific part of cortical pyramidal neurons, the apical integration zone (AIZ). The AIZ receives and processes contextual information from diverse sources and could constitute a major switch point for transitioning from externally to internally generated experiences such as dreams. We propose that during dreams the output of certain pyramidal neurons is mainly driven by input into the AIZ. We call this mode of functioning "apical drive". Our hypothesis is based on the evidence that the cholinergic and adrenergic arousal systems, which show different dynamics between waking, slow wave sleep, and rapid eye movement sleep, have specific effects on the AIZ. We suggest that apical drive may also contribute to waking experiences, such as mental imagery. Future studies, investigating the different modes of apical function and their regulation during sleep and wakefulness are likely to be richly rewarded.
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Affiliation(s)
- Jaan Aru
- Institute of Computer Science, University of Tartu, Estonia; Institute of Biology, Humboldt University Berlin, Germany.
| | - Francesca Siclari
- Center for Investigation and Research on Sleep, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom.
| | - William A Phillips
- Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom.
| | - Johan F Storm
- Brain Signalling Group, Section for Physiology, Faculty of Medicine, Domus Medica, University of Oslo, PB 1104 Blindern, 0317 Oslo, Norway.
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9
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Abstract
It is now well documented that schizophrenia is associated with impairments in visual processing at all levels of vision, and that these disturbances are related to deficits in multiple higher-level cognitive and social cognitive functions. Visual remediation methods have been slow to appear in the literature as a potential treatment strategy to target these impairments, however, in contrast to interventions that aim to improve auditory and higher cognitive functions in schizophrenia. In this report, we describe a National Institute of Mental Health (NIMH)-funded R61/R33 grant that uses a phased approach to optimize and evaluate a novel visual remediation intervention for people with schizophrenia. The goals of this project are: (1) in the R61 phase, to establish the optimal components and dose (number of sessions) of a visual remediation intervention from among two specific visual training strategies (and their combination) for improving low and mid-level visual functions in schizophrenia; and (2) in the R33 phase, to determine the extent to which the optimal intervention improves not only visual processing but also higher-level cognitive and role functions. Here we present the scientific background for and innovation of the study, along with our methods, hypotheses, and preliminary data. The results of this study will help determine the utility of this novel intervention approach for targeting visual perceptual, cognitive, and functional impairments in schizophrenia.
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10
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Adeel A. Conscious Multisensory Integration: Introducing a Universal Contextual Field in Biological and Deep Artificial Neural Networks. Front Comput Neurosci 2020; 14:15. [PMID: 32508610 PMCID: PMC7248356 DOI: 10.3389/fncom.2020.00015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/07/2020] [Indexed: 11/24/2022] Open
Abstract
Conscious awareness plays a major role in human cognition and adaptive behavior, though its function in multisensory integration is not yet fully understood, hence, questions remain: How does the brain integrate the incoming multisensory signals with respect to different external environments? How are the roles of these multisensory signals defined to adhere to the anticipated behavioral-constraint of the environment? This work seeks to articulate a novel theory on conscious multisensory integration (CMI) that addresses the aforementioned research challenges. Specifically, the well-established contextual field (CF) in pyramidal cells and coherent infomax theory (Kay et al., 1998; Kay and Phillips, 2011) is split into two functionally distinctive integrated input fields: local contextual field (LCF) and universal contextual field (UCF). LCF defines the modulatory sensory signal coming from some other parts of the brain (in principle from anywhere in space-time) and UCF defines the outside environment and anticipated behavior (based on past learning and reasoning). Both LCF and UCF are integrated with the receptive field (RF) to develop a new class of contextually-adaptive neuron (CAN), which adapts to changing environments. The proposed theory is evaluated using human contextual audio-visual (AV) speech modeling. Simulation results provide new insights into contextual modulation and selective multisensory information amplification/suppression. The central hypothesis reviewed here suggests that the pyramidal cell, in addition to the classical excitatory and inhibitory signals, receives LCF and UCF inputs. The UCF (as a steering force or tuner) plays a decisive role in precisely selecting whether to amplify/suppress the transmission of relevant/irrelevant feedforward signals, without changing the content e.g., which information is worth paying more attention to? This, as opposed to, unconditional excitatory and inhibitory activity in existing deep neural networks (DNNs), is called conditional amplification/suppression.
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Affiliation(s)
- Ahsan Adeel
- Oxford Computational Neuroscience, Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- School of Mathematics and Computer Science, University of Wolverhampton, Wolverhampton, United Kingdom
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11
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Abstract
Neural systems are composed of many local processors that generate an output given their many inputs as specified by a transfer function. This paper studies a transfer function that is fundamentally asymmetric and builds on multi-site intracellular recordings indicating that some neocortical pyramidal cells can function as context-sensitive two-point processors in which some inputs modulate the strength with which they transmit information about other inputs. Learning and processing at the level of the local processor can then be guided by the context of activity in the system as a whole without corrupting the message that the local processor transmits. We use a recent advance in the foundations of information theory to compare the properties of this modulatory transfer function with that of the simple arithmetic operators. This advance enables the information transmitted by processors with two distinct inputs to be decomposed into those components unique to each input, that shared between the two inputs, and that which depends on both though it is in neither, i.e., synergy. We show that contextual modulation is fundamentally asymmetric, contrasts with all four simple arithmetic operators, can take various forms, and can occur together with the anatomical asymmetry that defines pyramidal neurons in mammalian neocortex.
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12
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Bosker HR, Sjerps MJ, Reinisch E. Temporal contrast effects in human speech perception are immune to selective attention. Sci Rep 2020; 10:5607. [PMID: 32221376 PMCID: PMC7101381 DOI: 10.1038/s41598-020-62613-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/16/2020] [Indexed: 11/09/2022] Open
Abstract
Two fundamental properties of perception are selective attention and perceptual contrast, but how these two processes interact remains unknown. Does an attended stimulus history exert a larger contrastive influence on the perception of a following target than unattended stimuli? Dutch listeners categorized target sounds with a reduced prefix "ge-" marking tense (e.g., ambiguous between gegaan-gaan "gone-go"). In 'single talker' Experiments 1-2, participants perceived the reduced syllable (reporting gegaan) when the target was heard after a fast sentence, but not after a slow sentence (reporting gaan). In 'selective attention' Experiments 3-5, participants listened to two simultaneous sentences from two different talkers, followed by the same target sounds, with instructions to attend only one of the two talkers. Critically, the speech rates of attended and unattended talkers were found to equally influence target perception - even when participants could watch the attended talker speak. In fact, participants' target perception in 'selective attention' Experiments 3-5 did not differ from participants who were explicitly instructed to divide their attention equally across the two talkers (Experiment 6). This suggests that contrast effects of speech rate are immune to selective attention, largely operating prior to attentional stream segregation in the auditory processing hierarchy.
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Affiliation(s)
- Hans Rutger Bosker
- Max Planck Institute for Psycholinguistics, PO Box 310, 6500 AH, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
| | - Matthias J Sjerps
- Max Planck Institute for Psycholinguistics, PO Box 310, 6500 AH, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Eva Reinisch
- Institute of Phonetics and Speech Processing, Ludwig Maximilian University Munich, Munich, Germany
- Acoustics Research Institute, Austrian Academy of Sciences, Vienna, Austria
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13
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Zhuo C, Ji F, Xiao B, Lin X, Chen C, Jiang D, Ma X, Li R, Liu S, Xu Y, Wang W. Antipsychotic agent-induced deterioration of the visual system in first-episode untreated patients with schizophrenia maybe self-limited: Findings from a secondary small sample follow-up study based on a pilot follow-up study. Psychiatry Res 2020; 286:112906. [PMID: 32151847 DOI: 10.1016/j.psychres.2020.112906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/29/2020] [Accepted: 02/29/2020] [Indexed: 12/15/2022]
Abstract
Define changes in the visual cortex and retina in first-episode schizophrenia patients with visual disturbance (FUSCHVD) accompanied by antipsychotic agent treatment is important for guiding treatment. We examined the visual system prior to and after 3 years of antipsychotic-agent treatment in 48 patients with FUSCHVD and 50 healthy controls, and after 3.5 years of antipsychotic-agent treatment in 12 patients with FUSCHVD and 12 healthy subjects who came from the cohort with 3 years of follow up. Reduction of the visual cortex gray matter volume (GMV) was observed in patients compared to healthy controls, and impairments deteriorated accompanied with 3 years' treatment with antipsychotic agents. Total retinal thickness was also reduced in patients but did not deteriorated with treatment with antipsychotic agents. However, in the 12 patients who performed the additional 6-month follow-up, GMV and total retinal thickness reductions did not demonstrate any further trend in deterioration. These findings indicate that the reductions of GMV and retinal thickness may be self-limited. Although these findings were consistent with previous reports, it was only observed in a small number of patients. Therefore, clinicians should remain pay greater attention to visual system impairment in FUSCHVD.
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Affiliation(s)
- Chuanjun Zhuo
- School of Mental Health, Jining Medical University, Jining, Shandong 272119, China; Psychiatric-Neuroimaging-Genetics Laboratory, Wenzhou Seventh People's Hospital, Wenzhou, Zhejiang 325000, China; Psychiatric-Neuroimaging-Genetics-Comorbidity Laboratory, Tianjin Mental Health Centre, Mental Health Teaching Hospital of Tianjin Medical University, Tianjin Anding Hospital, Tianjin 300222, China; Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China; MDT Center for Cognitive Impairment and Sleep Disorders, First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China; Co-collaboration Laboratory of China and Canada, Xiamen Xianyue Hospital and University of Alberta, Xiamen, Fujian 361000, China.
| | - Feng Ji
- School of Mental Health, Jining Medical University, Jining, Shandong 272119, China
| | - Bo Xiao
- Department of OTC center, Tianjin Medical University Affiliated Eye Hospital, Tianjin, 272004, China
| | - Xiaodong Lin
- Psychiatric-Neuroimaging-Genetics Laboratory, Wenzhou Seventh People's Hospital, Wenzhou, Zhejiang 325000, China
| | - Ce Chen
- Psychiatric-Neuroimaging-Genetics Laboratory, Wenzhou Seventh People's Hospital, Wenzhou, Zhejiang 325000, China
| | - Deguo Jiang
- Psychiatric-Neuroimaging-Genetics Laboratory, Wenzhou Seventh People's Hospital, Wenzhou, Zhejiang 325000, China
| | - Xiaoyan Ma
- Psychiatric-Neuroimaging-Genetics-Comorbidity Laboratory, Tianjin Mental Health Centre, Mental Health Teaching Hospital of Tianjin Medical University, Tianjin Anding Hospital, Tianjin 300222, China
| | - Ranli Li
- Psychiatric-Neuroimaging-Genetics-Comorbidity Laboratory, Tianjin Mental Health Centre, Mental Health Teaching Hospital of Tianjin Medical University, Tianjin Anding Hospital, Tianjin 300222, China
| | - Sha Liu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China; MDT Center for Cognitive Impairment and Sleep Disorders, First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Yong Xu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China; MDT Center for Cognitive Impairment and Sleep Disorders, First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Wenqiang Wang
- Co-collaboration Laboratory of China and Canada, Xiamen Xianyue Hospital and University of Alberta, Xiamen, Fujian 361000, China
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14
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Kerlin A, Mohar B, Flickinger D, MacLennan BJ, Dean MB, Davis C, Spruston N, Svoboda K. Functional clustering of dendritic activity during decision-making. eLife 2019; 8:46966. [PMID: 31663507 PMCID: PMC6821494 DOI: 10.7554/elife.46966] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 09/26/2019] [Indexed: 01/08/2023] Open
Abstract
The active properties of dendrites can support local nonlinear operations, but previous imaging and electrophysiological measurements have produced conflicting views regarding the prevalence and selectivity of local nonlinearities in vivo. We imaged calcium signals in pyramidal cell dendrites in the motor cortex of mice performing a tactile decision task. A custom microscope allowed us to image the soma and up to 300 μm of contiguous dendrite at 15 Hz, while resolving individual spines. New analysis methods were used to estimate the frequency and spatial scales of activity in dendritic branches and spines. The majority of dendritic calcium transients were coincident with global events. However, task-associated calcium signals in dendrites and spines were compartmentalized by dendritic branching and clustered within branches over approximately 10 μm. Diverse behavior-related signals were intermingled and distributed throughout the dendritic arbor, potentially supporting a large learning capacity in individual neurons.
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Affiliation(s)
- Aaron Kerlin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Boaz Mohar
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Daniel Flickinger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Bryan J MacLennan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Matthew B Dean
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Courtney Davis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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15
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Scene Representations Conveyed by Cortical Feedback to Early Visual Cortex Can Be Described by Line Drawings. J Neurosci 2019; 39:9410-9423. [PMID: 31611306 PMCID: PMC6867807 DOI: 10.1523/jneurosci.0852-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 08/27/2019] [Accepted: 09/23/2019] [Indexed: 11/25/2022] Open
Abstract
Human behavior is dependent on the ability of neuronal circuits to predict the outside world. Neuronal circuits in early visual areas make these predictions based on internal models that are delivered via non-feedforward connections. Despite our extensive knowledge of the feedforward sensory features that drive cortical neurons, we have a limited grasp on the structure of the brain's internal models. Progress in neuroscience therefore depends on our ability to replicate the models that the brain creates internally. Here we record human fMRI data while presenting partially occluded visual scenes. Visual occlusion allows us to experimentally control sensory input to subregions of visual cortex while internal models continue to influence activity in these regions. Because the observed activity is dependent on internal models, but not on sensory input, we have the opportunity to map visual features conveyed by the brain's internal models. Our results show that activity related to internal models in early visual cortex are more related to scene-specific features than to categorical or depth features. We further demonstrate that behavioral line drawings provide a good description of internal model structure representing scene-specific features. These findings extend our understanding of internal models, showing that line drawings provide a window into our brains' internal models of vision. SIGNIFICANCE STATEMENT We find that fMRI activity patterns corresponding to occluded visual information in early visual cortex fill in scene-specific features. Line drawings of the missing scene information correlate with our recorded activity patterns, and thus to internal models. Despite our extensive knowledge of the sensory features that drive cortical neurons, we have a limited grasp on the structure of our brains' internal models. These results therefore constitute an advance to the field of neuroscience by extending our knowledge about the models that our brains construct to efficiently represent and predict the world. Moreover, they link a behavioral measure to these internal models, which play an active role in many components of human behavior, including visual predictions, action planning, and decision making.
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16
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Mäki-Marttunen T, Devor A, Phillips WA, Dale AM, Andreassen OA, Einevoll GT. Computational Modeling of Genetic Contributions to Excitability and Neural Coding in Layer V Pyramidal Cells: Applications to Schizophrenia Pathology. Front Comput Neurosci 2019; 13:66. [PMID: 31616272 PMCID: PMC6775251 DOI: 10.3389/fncom.2019.00066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 09/09/2019] [Indexed: 11/13/2022] Open
Abstract
Pyramidal cells in layer V of the neocortex are one of the most widely studied neuron types in the mammalian brain. Due to their role as integrators of feedforward and cortical feedback inputs, they are well-positioned to contribute to the symptoms and pathology in mental disorders-such as schizophrenia-that are characterized by a mismatch between the internal perception and external inputs. In this modeling study, we analyze the input/output properties of layer V pyramidal cells and their sensitivity to modeled genetic variants in schizophrenia-associated genes. We show that the excitability of layer V pyramidal cells and the way they integrate inputs in space and time are altered by many types of variants in ion-channel and Ca2+ transporter-encoding genes that have been identified as risk genes by recent genome-wide association studies. We also show that the variability in the output patterns of spiking and Ca2+ transients in layer V pyramidal cells is altered by these model variants. Importantly, we show that many of the predicted effects are robust to noise and qualitatively similar across different computational models of layer V pyramidal cells. Our modeling framework reveals several aspects of single-neuron excitability that can be linked to known schizophrenia-related phenotypes and existing hypotheses on disease mechanisms. In particular, our models predict that single-cell steady-state firing rate is positively correlated with the coding capacity of the neuron and negatively correlated with the amplitude of a prepulse-mediated adaptation and sensitivity to coincidence of stimuli in the apical dendrite and the perisomatic region of a layer V pyramidal cell. These results help to uncover the voltage-gated ion-channel and Ca2+ transporter-associated genetic underpinnings of schizophrenia phenotypes and biomarkers.
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Affiliation(s)
| | - Anna Devor
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States.,Department of Radiology, University of California San Diego, La Jolla, CA, United States.,Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States
| | - William A Phillips
- Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Anders M Dale
- Department of Neurosciences, University of California San Diego, La Jolla, CA, United States.,Department of Radiology, University of California San Diego, La Jolla, CA, United States
| | - Ole A Andreassen
- NORMENT, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Gaute T Einevoll
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway.,Department of Physics, University of Oslo, Oslo, Norway
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17
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Yi HG, Leonard MK, Chang EF. The Encoding of Speech Sounds in the Superior Temporal Gyrus. Neuron 2019; 102:1096-1110. [PMID: 31220442 PMCID: PMC6602075 DOI: 10.1016/j.neuron.2019.04.023] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/08/2019] [Accepted: 04/16/2019] [Indexed: 01/02/2023]
Abstract
The human superior temporal gyrus (STG) is critical for extracting meaningful linguistic features from speech input. Local neural populations are tuned to acoustic-phonetic features of all consonants and vowels and to dynamic cues for intonational pitch. These populations are embedded throughout broader functional zones that are sensitive to amplitude-based temporal cues. Beyond speech features, STG representations are strongly modulated by learned knowledge and perceptual goals. Currently, a major challenge is to understand how these features are integrated across space and time in the brain during natural speech comprehension. We present a theory that temporally recurrent connections within STG generate context-dependent phonological representations, spanning longer temporal sequences relevant for coherent percepts of syllables, words, and phrases.
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Affiliation(s)
- Han Gyol Yi
- Department of Neurological Surgery, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA 94158, USA
| | - Matthew K Leonard
- Department of Neurological Surgery, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA 94158, USA
| | - Edward F Chang
- Department of Neurological Surgery, University of California, San Francisco, 675 Nelson Rising Lane, San Francisco, CA 94158, USA.
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18
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Li Q, Meso AI, Logothetis NK, Keliris GA. Scene Regularity Interacts With Individual Biases to Modulate Perceptual Stability. Front Neurosci 2019; 13:523. [PMID: 31191225 PMCID: PMC6546877 DOI: 10.3389/fnins.2019.00523] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/06/2019] [Indexed: 11/16/2022] Open
Abstract
Sensory input is inherently ambiguous but our brains achieve remarkable perceptual stability. Prior experience and knowledge of the statistical properties of the world are thought to play a key role in the stabilization process. Individual differences in responses to ambiguous input and biases toward one or the other interpretation could modulate the decision mechanism for perception. However, the role of perceptual bias and its interaction with stimulus spatial properties such as regularity and element density remain to be understood. To this end, we developed novel bi-stable moving visual stimuli in which perception could be parametrically manipulated between two possible mutually exclusive interpretations: transparently or coherently moving. We probed perceptual stability across three composite stimulus element density levels with normal or degraded regularity using a factorial design. We found that increased density led to the amplification of individual biases and consequently to a stabilization of one interpretation over the alternative. This effect was reduced for degraded regularity, demonstrating an interaction between density and regularity. To understand how prior knowledge could be used by the brain in this task, we compared the data with simulations coming from four different hierarchical models of causal inference. These models made different assumptions about the use of prior information by including conditional priors that either facilitated or inhibited motion direction integration. An architecture that included a prior inhibiting motion direction integration consistently outperformed the others. Our results support the hypothesis that direction integration based on sensory likelihoods maybe the default processing mode with conditional priors inhibiting integration employed in order to help motion segmentation and transparency perception.
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Affiliation(s)
- Qinglin Li
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,IMPRS for Cognitive and Systems Neuroscience, University Tuebingen, Tübingen, Germany.,Bernstein Center for Computational Neuroscience, Tübingen, Germany.,Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Andrew Isaac Meso
- Psychology and Interdisciplinary Neurosciences Research Group, Faculty of Science and Technology, Bournemouth University, Poole, United Kingdom
| | - Nikos K Logothetis
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Division of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom
| | - Georgios A Keliris
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Bernstein Center for Computational Neuroscience, Tübingen, Germany.,Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
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19
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Contextual effects on binocular matching are evident in primary visual cortex. Vision Res 2019; 159:76-85. [PMID: 30980834 PMCID: PMC6597948 DOI: 10.1016/j.visres.2019.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 04/02/2019] [Accepted: 04/06/2019] [Indexed: 11/20/2022]
Abstract
Global context can dramatically influence local visual perception. This phenomenon is well-documented for monocular features, e.g., the Kanizsa triangle. It has been demonstrated for binocular matching: the disambiguation of the Wallpaper Illusion via the luminance of the background. For monocular features, there is evidence that global context can influence neuronal responses as early as V1. However, for binocular matching, the activity in this area of the visual cortex is thought to represent local processing, suggesting that the influence of global context may occur at later stages of cortical processing. Here we sought to test if binocular matching is influenced by contextual effects in V1, using fMRI to measure brain activity while participants viewed perceptually ambiguous “wallpaper” stereograms whose depth was disambiguated by the luminance of the surrounding region. We localized voxels in V1 corresponding to the ambiguous region of the pattern, i.e., where the signal received from the eyes was not predictive of depth, and despite the ambiguity of the input signal, using multi-voxel pattern analysis we were able to reliably decode perceived (near/far) depth from the activity of these voxels. These findings indicate that stereoscopic related neural activity is influenced by global context as early as V1.
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20
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Thakkar KN, Silverstein SM, Brascamp JW. A review of visual aftereffects in schizophrenia. Neurosci Biobehav Rev 2019; 101:68-77. [PMID: 30940436 DOI: 10.1016/j.neubiorev.2019.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 03/13/2019] [Accepted: 03/24/2019] [Indexed: 12/11/2022]
Abstract
Psychosis-a cardinal symptom of schizophrenia-has been associated with a failure to appropriately create or use stored regularities about past states of the world to guide the interpretation of incoming information, which leads to abnormal perceptions and beliefs. The visual system provides a test bed for investigating the role of prior experience and prediction, as accumulated knowledge of the world informs our current perception. More specifically, the strength of visual aftereffects, illusory percepts that arise after prolonged viewing of a visual stimulus, can serve as a valuable measure of the influence of prior experience on current visual processing. In this paper, we review findings from a largely older body of work on visual aftereffects in schizophrenia, attempt to reconcile discrepant findings, highlight the role of antipsychotic medication, consider mechanistic interpretations for behavioral effects, and propose directions for future research.
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Affiliation(s)
- Katharine N Thakkar
- Department of Psychology, Michigan State University, East Lansing, MI, United States; Division of Psychiatry and Behavioral Medicine, Michigan State University, East Lansing, MI, United States.
| | - Steven M Silverstein
- Departments of Psychiatry and Ophthalmology, Rutgers University, Piscataway, NJ, United States
| | - Jan W Brascamp
- Department of Psychology, Michigan State University, East Lansing, MI, United States
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21
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Abe K, Yawo H. Quantitative study of the somatosensory sensitization underlying cross-modal plasticity. PLoS One 2018; 13:e0208089. [PMID: 30517160 PMCID: PMC6281227 DOI: 10.1371/journal.pone.0208089] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 11/12/2018] [Indexed: 11/18/2022] Open
Abstract
Loss of one sensory modality can cause other types to become more perceptive (cross-modal plasticity). To test the hypothesis that the loss of vision changes the perceptual threshold in the somatosensory system, we applied optogenetics to directly manipulate the afferent inputs involved in the whisker-barrel system using a transgenic rat (W-TChR2V4) that expresses channelrhodopsin-2 (ChR2) selectively in the large mechanoreceptive neurons in the trigeminal ganglion (TG) and their peripheral nerve terminals. The licking behavior of W-TChR2V4 rat was conditioned to a blue LED light cue on the whisker area while the magnitude and duration of light pulses were varied. The perceptual threshold was thus quantitatively determined for each rat according to the relationship between the magnitude/duration of light and the reaction time between the LED light cue and the first licking event after it. We found that the perceptual threshold was more significantly reduced than the control non-deprived rats when the rats were visually deprived at postnatal 26-30 days (P26-30, early VD group), but not at P58-66 (late VD group). However, the sensory threshold of a late VD animal was similar to that of a control. Our results suggest the presence of cross-modal plasticity by which the loss of vision at the juvenile period increased the sensitivity of the somatosensory system involved in the touch of whiskers.
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Affiliation(s)
- Kenta Abe
- Department of Development Biology and Neuroscience, Tohoku University Graduate School of Life Science, Sendai, Japan
| | - Hiromu Yawo
- Department of Development Biology and Neuroscience, Tohoku University Graduate School of Life Science, Sendai, Japan.,Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
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22
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Beck AT, Himelstein R, Bredemeier K, Silverstein SM, Grant P. What accounts for poor functioning in people with schizophrenia: a re-evaluation of the contributions of neurocognitive v. attitudinal and motivational factors. Psychol Med 2018; 48:2776-2785. [PMID: 29501072 DOI: 10.1017/s0033291718000442] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Neurocognitive deficits are often seen as core features of schizophrenia, and as primary determinants of poor functioning. Yet, our clinical observations suggest that individuals who score within the impaired range on standardized tests can reliably perform better in complex real-world situations, especially when performance is embedded within a positive socio-affective context. METHODS We analyzed literature on the influence of non-neurocognitive factors on test performance in order to clarify their contributions. RESULTS We identified seven non-neurocognitive factors that significantly contribute to neurocognitive test performance: avolition, dysfunctional attitudes, effort, stress, negative emotions, asociality, and disorganized symptoms. We then proposed an alternative model based on dysfunctional (e.g. defeatist) attitudes and their consequences for motivation and sustained task engagement. We demonstrated that these factors account for substantial variance in negative symptoms, neurocognitive test performance, and functional outcomes. We then demonstrated that recovery-oriented cognitive therapy - which is derived from this alternative model and primarily targets dysfunctional beliefs - has been successful in the treatment of low functioning individuals with schizophrenia. CONCLUSION The contributions of neurocognitive impairments to poor real-world functioning in people with schizophrenia may be overstated in the literature, and may even be limited relative to non-neurocognitive factors. We offer suggestions for further research to more precisely quantify the contributions of attitudinal/motivation v. neurocognitive factors in schizophrenia.
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Affiliation(s)
- Aaron T Beck
- Department of Psychiatry,University of Pennsylvania,Philadelphia,Pennsylvania,USA
| | - Robyn Himelstein
- Department of Psychiatry,University of Pennsylvania,Philadelphia,Pennsylvania,USA
| | - Keith Bredemeier
- Center for Assessment Research and Translation,University of Delaware,Newark,Delaware,USA
| | - Steven M Silverstein
- Department of Psychiatry,Rutgers - Robert Wood Johnson Medical School,Piscataway Township,New Jersey,USA
| | - Paul Grant
- Department of Psychiatry,University of Pennsylvania,Philadelphia,Pennsylvania,USA
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23
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Sterzer P, Adams RA, Fletcher P, Frith C, Lawrie SM, Muckli L, Petrovic P, Uhlhaas P, Voss M, Corlett PR. The Predictive Coding Account of Psychosis. Biol Psychiatry 2018; 84:634-643. [PMID: 30007575 PMCID: PMC6169400 DOI: 10.1016/j.biopsych.2018.05.015] [Citation(s) in RCA: 370] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 01/12/2023]
Abstract
Fueled by developments in computational neuroscience, there has been increasing interest in the underlying neurocomputational mechanisms of psychosis. One successful approach involves predictive coding and Bayesian inference. Here, inferences regarding the current state of the world are made by combining prior beliefs with incoming sensory signals. Mismatches between prior beliefs and incoming signals constitute prediction errors that drive new learning. Psychosis has been suggested to result from a decreased precision in the encoding of prior beliefs relative to the sensory data, thereby garnering maladaptive inferences. Here, we review the current evidence for aberrant predictive coding and discuss challenges for this canonical predictive coding account of psychosis. For example, hallucinations and delusions may relate to distinct alterations in predictive coding, despite their common co-occurrence. More broadly, some studies implicate weakened prior beliefs in psychosis, and others find stronger priors. These challenges might be answered with a more nuanced view of predictive coding. Different priors may be specified for different sensory modalities and their integration, and deficits in each modality need not be uniform. Furthermore, hierarchical organization may be critical. Altered processes at lower levels of a hierarchy need not be linearly related to processes at higher levels (and vice versa). Finally, canonical theories do not highlight active inference-the process through which the effects of our actions on our sensations are anticipated and minimized. It is possible that conflicting findings might be reconciled by considering these complexities, portending a framework for psychosis more equipped to deal with its many manifestations.
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Affiliation(s)
- Philipp Sterzer
- Department of Psychiatry, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rick A Adams
- Division of Psychiatry, University College London, London, United Kingdom
| | - Paul Fletcher
- Department of Psychiatry, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom; Wellcome-MRC Behavioral and Clinical Neuroscience Institute, Cambridge and Peterborough Foundation Trust, Cambridge, United Kingdom
| | - Chris Frith
- Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom
| | - Stephen M Lawrie
- Center for Clinical and Brain Sciences, Division of Psychiatry, Royal Edinburgh Hospital, University of Edinburgh, Edinburgh, United Kingdom
| | - Lars Muckli
- Centre for Cognitive Neuroimaging, Institute of Neuroscience & Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Peter Uhlhaas
- Centre for Cognitive Neuroimaging, Institute of Neuroscience & Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Martin Voss
- Department of Psychiatry and Psychotherapy, Charité University Medicine and St. Hedwig Hospital, Berlin Center for Advanced Neuroimaging, Humboldt University Berlin, Berlin, Germany
| | - Philip R Corlett
- Department of Psychiatry, Yale University, New Haven, Connecticut.
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24
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Abstract
We summarize evidence that input to the apical tufts of neocortical pyramidal cells modulates their response to basal input. Because this apical amplification and disamplification provide intracortical mechanisms for prioritization, Mather and colleagues' arguments suggest that their effects are enhanced by noradrenergic arousal. Though that is likely, it has not yet been adequately studied. Their article shows that it should be.
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25
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Layher G, Neumann H. Points and Stripes: A Novel Technique for Masking Biological Motion Point-Light Stimuli. Front Psychol 2018; 9:1455. [PMID: 30210382 PMCID: PMC6121090 DOI: 10.3389/fpsyg.2018.01455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 07/24/2018] [Indexed: 12/02/2022] Open
Abstract
Human articulated motion can be readily recognized robustly even from impoverished so-called point-light displays. Such sequence information is processed by separate visual processing channels recruiting different stages at low and intermediate levels of the cortical visual processing hierarchy. The different contributions that motion and form information make to form articulated, or biological, motion perception are still under investigation. Here we investigate experimentally whether and how specific spatio-temporal features, such as extrema in the motion energy or maximum limb expansion, indicated by the lateral and longitudinal extension, constrain the formation of the representations of articulated body motion. In order to isolate the relevant stimulus properties we suggest a novel masking technique, which allows to selectively impair the ankle information of the body configuration while keeping the motion of the point-light locations intact. Our results provide evidence that maxima in feature channel representations, e.g., the lateral or longitudinal extension, define elemental features to specify key poses of biological motion patterns. These findings provide support for models which aim at automatically building visual representations for the cortical processing of articulated motion by identifying temporally localized events in a continuous input stream.
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Affiliation(s)
- Georg Layher
- Institute of Neural Information Processing, Ulm University, Ulm, Germany
| | - Heiko Neumann
- Institute of Neural Information Processing, Ulm University, Ulm, Germany
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26
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Panton KR, Badcock JC, Dickinson JE, Badcock DR. Poorer Search Efficiency in Healthy Young Adults With High Schizotypal Personality Traits. Front Psychiatry 2018; 9:285. [PMID: 30050472 PMCID: PMC6052133 DOI: 10.3389/fpsyt.2018.00285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/12/2018] [Indexed: 11/13/2022] Open
Abstract
Perceptual organization (PO) difficulties have repeatedly been reported in people with schizophrenia, and in healthy individuals with high levels of schizotypy traits, who are at increased risk for schizophrenia. In particular, poor performance on the Embedded Figures Test (EFT) has been interpreted as an atypically strong preference for global over local processing, even though these processes cannot be clearly disambiguated on this test. Here we use two separate versions of the Radial Frequency Search Task (RFST), a new index of PO abilities, to selectively investigate global and local processing of shape information in trait schizotypy. Schizotypy traits were assessed using the Wisconsin Schizotypy Scales-Brief. Individuals selected for high and low levels of positive schizotypy [assessed with the Wisconsin Schizotypy Scales-Brief Perceptual Aberration (PAb) scale] completed the EFT, along with the Global RFST and the Local RFST, all of which require participants to find a target shape amongst distractor elements. The High PAb group (n = 83) were less efficient (i.e., reactions times slowed more as the set size increased) than the Low PAb group (n = 146) on the Global RFST (significant group differences for Target Absent conditions only), but not the Local RFST. High and Low PAb groups also differed on other schizotypy traits, so the specificity of the results to positive schizotypy cannot be assured. Unexpectedly, no group differences were observed on the EFT; however, there was a small, but significant, positive correlation between RFST search efficiency and EFT performance, indicating that they shared some common processes. Overall, the pattern of results suggests that global (but not local) processing difficulties may be contributing to the poorer perceptual organization observed in groups with high levels of schizotypy traits. In addition, the confinement of this result to the Target Absent condition suggests that the underlying mechanism involves differences in decisional processes on the RFST between high and low schizotypy groups. The RFST shows promise as a useful tool for measuring specific perceptual organization abilities in non-clinical, and potentially clinical, samples.
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Affiliation(s)
- Kirsten R. Panton
- Human Vision Laboratory, School of Psychological Science, University of Western Australia, Perth, WA, Australia
| | - Johanna C. Badcock
- Division of Psychiatry, Faculty of Health and Medical Sciences, Centre for Clinical Research in Neuropsychiatry, University of Western Australia, Perth, WA, Australia
- Cooperative Research Centre - Mental Health, Carlton, VIC, Australia
| | - J. Edwin Dickinson
- Human Vision Laboratory, School of Psychological Science, University of Western Australia, Perth, WA, Australia
| | - David R. Badcock
- Human Vision Laboratory, School of Psychological Science, University of Western Australia, Perth, WA, Australia
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27
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Phillips WA, Bachmann T, Storm JF. Apical Function in Neocortical Pyramidal Cells: A Common Pathway by Which General Anesthetics Can Affect Mental State. Front Neural Circuits 2018; 12:50. [PMID: 30013465 PMCID: PMC6036169 DOI: 10.3389/fncir.2018.00050] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 06/05/2018] [Indexed: 11/27/2022] Open
Abstract
It has been argued that general anesthetics suppress the level of consciousness, or the contents of consciousness, or both. The distinction between level and content is important because, in addition to clarifying the mechanisms of anesthesia, it may help clarify the neural bases of consciousness. We assess these arguments in the light of evidence that both the level and the content of consciousness depend upon the contribution of apical input to the information processing capabilities of neocortical pyramidal cells which selectively amplify relevant signals. We summarize research suggesting that what neocortical pyramidal cells transmit information about can be distinguished from levels of arousal controlled by sub-cortical nuclei and from levels of prioritization specified by interactions within the thalamocortical system. Put simply, on the basis of the observations reviewed, we hypothesize that when conscious we have particular, directly experienced, percepts, thoughts, feelings and intentions, and that general anesthetics affect consciousness by interfering with the subcellular processes by which particular activities are selectively amplified when relevant to the current context.
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Affiliation(s)
- William A. Phillips
- Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom
| | - Talis Bachmann
- Department of Penal Law, University of Tartu, Tartu, Estonia
| | - Johan F. Storm
- IBMS Department of Physiology, University of Oslo, Oslo, Norway
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28
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Ciullo V, Vecchio D, Gili T, Spalletta G, Piras F. Segregation of Brain Structural Networks Supports Spatio-Temporal Predictive Processing. Front Hum Neurosci 2018; 12:212. [PMID: 29881338 PMCID: PMC5978278 DOI: 10.3389/fnhum.2018.00212] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/08/2018] [Indexed: 01/21/2023] Open
Abstract
The ability to generate probabilistic expectancies regarding when and where sensory stimuli will occur, is critical to derive timely and accurate inferences about updating contexts. However, the existence of specialized neural networks for inferring predictive relationships between events is still debated. Using graph theoretical analysis applied to structural connectivity data, we tested the extent of brain connectivity properties associated with spatio-temporal predictive performance across 29 healthy subjects. Participants detected visual targets appearing at one out of three locations after one out of three intervals; expectations about stimulus location (spatial condition) or onset (temporal condition) were induced by valid or invalid symbolic cues. Connectivity matrices and centrality/segregation measures, expressing the relative importance of, and the local interactions among specific cerebral areas respect to the behavior under investigation, were calculated from whole-brain tractography and cortico-subcortical parcellation. Results: Response preparedness to cued stimuli relied on different structural connectivity networks for the temporal and spatial domains. Significant covariance was observed between centrality measures of regions within a subcortical-fronto-parietal-occipital network -comprising the left putamen, the right caudate nucleus, the left frontal operculum, the right inferior parietal cortex, the right paracentral lobule and the right superior occipital cortex-, and the ability to respond after a short cue-target delay suggesting that the local connectedness of such nodes plays a central role when the source of temporal expectation is explicit. When the potential for functional segregation was tested, we found highly clustered structural connectivity across the right superior, the left middle inferior frontal gyrus and the left caudate nucleus as related to explicit temporal orienting. Conversely, when the interaction between explicit and implicit temporal orienting processes was considered at the long interval, we found that explicit processes were related to centrality measures of the bilateral inferior parietal lobule. Degree centrality of the same region in the left hemisphere covaried with behavioral measures indexing the process of attentional re-orienting. These results represent a crucial step forward the ordinary predictive processing description, as we identified the patterns of connectivity characterizing the brain organization associated with the ability to generate and update temporal expectancies in case of contextual violations.
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Affiliation(s)
- Valentina Ciullo
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
- Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Daniela Vecchio
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Tommaso Gili
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
- IMT School for Advanced Studies, Lucca, Italy
| | - Gianfranco Spalletta
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States
| | - Federica Piras
- Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
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29
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Enhanced mental imagery and intact perceptual organization in schizotypal personality disorder. Psychiatry Res 2018; 259:433-438. [PMID: 29131991 DOI: 10.1016/j.psychres.2017.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/01/2017] [Accepted: 11/04/2017] [Indexed: 11/21/2022]
Abstract
According to a widely held view, psychotic disorders such as schizophrenia are characterized by a vague boundary between the perception of the external world and the inner imagery of persons, objects, and events. In this study, we addressed the perception-imagery debate in schizotypal personality disorder (SPD). Thirty individuals with SPD and 30 matched healthy subjects completed a lateral masking task. Participants were asked to detect a low-contrast Gabor patch flanked by two collinear Gabor masks. In the perceptual task, the masks were physically present, whereas in the imagery task, participants only imagined the masks. By applying a binocular rivalry paradigm, we also measured the imagery priming effect. Results revealed that, in the perceptual task, collinear masks similarly decreased contrast threshold in SPD and controls. In the imagery task, contrast threshold reduction (facilitation by the imagined masks) was more pronounced in SPD relative to the controls. In the binocular rivalry paradigm, individuals with SPD showed higher imagery priming effects as compared to healthy controls. Enhanced imagery was not related to schizotypal traits. These results indicate intact early visual perception and heightened imagery in SPD, which may be a trait marker of unusual experiences without psychotic disorganization.
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30
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Silverstein SM, Demmin DL, Bednar JA. Computational Modeling of Contrast Sensitivity and Orientation Tuning in First-Episode and Chronic Schizophrenia. COMPUTATIONAL PSYCHIATRY (CAMBRIDGE, MASS.) 2017; 1:102-131. [PMID: 30090855 PMCID: PMC6067832 DOI: 10.1162/cpsy_a_00005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/16/2017] [Indexed: 12/11/2022]
Abstract
Computational modeling is a useful method for generating hypotheses about the contributions of impaired neurobiological mechanisms, and their interactions, to psychopathology. Modeling is being increasingly used to further our understanding of schizophrenia, but to date, it has not been applied to questions regarding the common perceptual disturbances in the disorder. In this article, we model aspects of low-level visual processing and demonstrate how this can lead to testable hypotheses about both the nature of visual abnormalities in schizophrenia and the relationships between the mechanisms underlying these disturbances and psychotic symptoms. Using a model that incorporates retinal, lateral geniculate nucleus (LGN), and V1 activity, as well as gain control in the LGN, homeostatic adaptation in V1, lateral excitation and inhibition in V1, and self-organization of synaptic weights based on Hebbian learning and divisive normalization, we show that (a) prior data indicating increased contrast sensitivity for low-spatial-frequency stimuli in first-episode schizophrenia can be successfully modeled as a function of reduced retinal and LGN efferent activity, leading to overamplification at the cortical level, and (b) prior data on reduced contrast sensitivity and broadened orientation tuning in chronic schizophrenia can be successfully modeled by a combination of reduced V1 lateral inhibition and an increase in the Hebbian learning rate at V1 synapses for LGN input. These models are consistent with many current findings, and they predict several relationships that have not yet been demonstrated. They also have implications for understanding changes in brain and visual function from the first psychotic episode to the chronic stage of illness.
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Affiliation(s)
- Steven M. Silverstein
- Rutgers University Behavioral Health Care, Piscataway, New Jersey, USA
- Robert Wood Johnson Medical School Department of Psychiatry, Rutgers University, Piscataway, New Jersey, USA
| | - Docia L. Demmin
- Rutgers University Behavioral Health Care, Piscataway, New Jersey, USA
- Department of Psychology, Rutgers University, Piscataway, New Jersey, USA
| | - James A. Bednar
- School of Informatics, University of Edinburgh, Edinburgh, Scotland
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31
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Normalized value coding explains dynamic adaptation in the human valuation process. Proc Natl Acad Sci U S A 2017; 114:12696-12701. [PMID: 29133418 DOI: 10.1073/pnas.1715293114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The notion of subjective value is central to choice theories in ecology, economics, and psychology, serving as an integrated decision variable by which options are compared. Subjective value is often assumed to be an absolute quantity, determined in a static manner by the properties of an individual option. Recent neurobiological studies, however, have shown that neural value coding dynamically adapts to the statistics of the recent reward environment, introducing an intrinsic temporal context dependence into the neural representation of value. Whether valuation exhibits this kind of dynamic adaptation at the behavioral level is unknown. Here, we show that the valuation process in human subjects adapts to the history of previous values, with current valuations varying inversely with the average value of recently observed items. The dynamics of this adaptive valuation are captured by divisive normalization, linking these temporal context effects to spatial context effects in decision making as well as spatial and temporal context effects in perception. These findings suggest that adaptation is a universal feature of neural information processing and offer a unifying explanation for contextual phenomena in fields ranging from visual psychophysics to economic choice.
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32
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Partial and Entropic Information Decompositions of a Neuronal Modulatory Interaction. ENTROPY 2017. [DOI: 10.3390/e19110560] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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33
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Silverstein SM, Wibral M, Phillips WA. Implications of Information Theory for Computational Modeling of Schizophrenia. COMPUTATIONAL PSYCHIATRY 2017; 1:82-101. [PMID: 29601053 PMCID: PMC5774180 DOI: 10.1162/cpsy_a_00004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 03/28/2016] [Accepted: 04/11/2017] [Indexed: 02/01/2023]
Abstract
Information theory provides a formal framework within which information processing and its disorders can be described. However, information theory has rarely been applied to modeling aspects of the cognitive neuroscience of schizophrenia. The goal of this article is to highlight the benefits of an approach based on information theory, including its recent extensions, for understanding several disrupted neural goal functions as well as related cognitive and symptomatic phenomena in schizophrenia. We begin by demonstrating that foundational concepts from information theory—such as Shannon information, entropy, data compression, block coding, and strategies to increase the signal-to-noise ratio—can be used to provide novel understandings of cognitive impairments in schizophrenia and metrics to evaluate their integrity. We then describe more recent developments in information theory, including the concepts of infomax, coherent infomax, and coding with synergy, to demonstrate how these can be used to develop computational models of schizophrenia-related failures in the tuning of sensory neurons, gain control, perceptual organization, thought organization, selective attention, context processing, predictive coding, and cognitive control. Throughout, we demonstrate how disordered mechanisms may explain both perceptual/cognitive changes and symptom emergence in schizophrenia. Finally, we demonstrate that there is consistency between some information-theoretic concepts and recent discoveries in neurobiology, especially involving the existence of distinct sites for the accumulation of driving input and contextual information prior to their interaction. This convergence can be used to guide future theory, experiment, and treatment development.
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Affiliation(s)
| | - Michael Wibral
- MEG Unit, Brain Imaging Center, Goethe University, Frankfurt, Germany
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34
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van Schalkwyk GI, Volkmar FR, Corlett PR. A Predictive Coding Account of Psychotic Symptoms in Autism Spectrum Disorder. J Autism Dev Disord 2017; 47:1323-1340. [PMID: 28185044 DOI: 10.1007/s10803-017-3065-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The co-occurrence of psychotic and autism spectrum disorder (ASD) symptoms represents an important clinical challenge. Here we consider this problem in the context of a computational psychiatry approach that has been applied to both conditions-predictive coding. Some symptoms of schizophrenia have been explained in terms of a failure of top-down predictions or an enhanced weighting of bottom-up prediction errors. Likewise, autism has been explained in terms of similar perturbations. We suggest that this theoretical overlap may explain overlapping symptomatology. Experimental evidence highlights meaningful distinctions and consistencies between these disorders. We hypothesize individuals with ASD may experience some degree of delusions without the presence of any additional impairment, but that hallucinations are likely indicative of a distinct process.
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Affiliation(s)
| | - Fred R Volkmar
- Child Study Center, Yale University School of Medicine, New Haven, CT, USA
| | - Philip R Corlett
- Department of Psychiatry, Clinical Neuroscience Research Unit, Connecticut Mental Health Center, Yale University School of Medicine, 230 South Frontage Road, New Haven, CT, 06510, USA
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35
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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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36
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Juxtaposing the real-time unfolding of subjective experience and ERP neuromarker dynamics. Conscious Cogn 2017; 54:3-19. [DOI: 10.1016/j.concog.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 01/08/2023]
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37
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Takahashi N, Oertner TG, Hegemann P, Larkum ME. Active cortical dendrites modulate perception. Science 2017; 354:1587-1590. [PMID: 28008068 DOI: 10.1126/science.aah6066] [Citation(s) in RCA: 219] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 11/23/2016] [Indexed: 11/02/2022]
Abstract
There is as yet no consensus concerning the neural basis of perception and how it operates at a mechanistic level. We found that Ca2+ activity in the apical dendrites of a subset of layer 5 (L5) pyramidal neurons in primary somatosensory cortex (S1) in mice is correlated with the threshold for perceptual detection of whisker deflections. Manipulating the activity of apical dendrites shifted the perceptual threshold, demonstrating that an active dendritic mechanism is causally linked to perceptual detection.
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Affiliation(s)
- Naoya Takahashi
- Institute for Biology, Neuronal Plasticity, Humboldt Universität zu Berlin, D-10117, Berlin, Germany
| | - Thomas G Oertner
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, D-20251, Hamburg, Germany
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt Universität zu Berlin, D-10115, Berlin, Germany
| | - Matthew E Larkum
- Institute for Biology, Neuronal Plasticity, Humboldt Universität zu Berlin, D-10117, Berlin, Germany.
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38
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Visual Population Receptive Fields in People with Schizophrenia Have Reduced Inhibitory Surrounds. J Neurosci 2016; 37:1546-1556. [PMID: 28025253 PMCID: PMC5299570 DOI: 10.1523/jneurosci.3620-15.2016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/22/2016] [Accepted: 11/15/2016] [Indexed: 11/21/2022] Open
Abstract
People with schizophrenia (SZ) experience abnormal visual perception on a range of visual tasks, which have been linked to abnormal synaptic transmission and an imbalance between cortical excitation and inhibition. However, differences in the underlying architecture of visual cortex neurons, which might explain these visual anomalies, have yet to be reported in vivo Here, we probed the neural basis of these deficits using fMRI and population receptive field (pRF) mapping to infer properties of visually responsive neurons in people with SZ. We employed a difference-of-Gaussian model to capture the center-surround configuration of the pRF, providing critical information about the spatial scale of the pRFs inhibitory surround. Our analysis reveals that SZ is associated with reduced pRF size in early retinotopic visual cortex, as well as a reduction in size and depth of the inhibitory surround in V1, V2, and V4. We consider how reduced inhibition might explain the diverse range of visual deficits reported in SZ.SIGNIFICANCE STATEMENT People with schizophrenia (SZ) experience abnormal perception on a range of visual tasks, which has been linked to abnormal synaptic transmission and an imbalance between cortical excitation/inhibition. However, associated differences in the functional architecture of visual cortex neurons have yet to be reported in vivo We used fMRI and population receptive field (pRF) mapping to demonstrate that the fine-grained functional architecture of visual cortex in people with SZ differs from unaffected controls. SZ is associated with reduced pRF size in early retinotopic visual cortex largely due to reduced inhibitory surrounds. An imbalance between cortical excitation and inhibition could drive such a change in the center-surround pRF configuration and ultimately explain the range of visual deficits experienced in SZ.
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39
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Sterzer P, Mishara AL, Voss M, Heinz A. Thought Insertion as a Self-Disturbance: An Integration of Predictive Coding and Phenomenological Approaches. Front Hum Neurosci 2016; 10:502. [PMID: 27785123 PMCID: PMC5060939 DOI: 10.3389/fnhum.2016.00502] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/23/2016] [Indexed: 01/30/2023] Open
Abstract
Current theories in the framework of hierarchical predictive coding propose that positive symptoms of schizophrenia, such as delusions and hallucinations, arise from an alteration in Bayesian inference, the term inference referring to a process by which learned predictions are used to infer probable causes of sensory data. However, for one particularly striking and frequent symptom of schizophrenia, thought insertion, no plausible account has been proposed in terms of the predictive-coding framework. Here we propose that thought insertion is due to an altered experience of thoughts as coming from “nowhere”, as is already indicated by the early 20th century phenomenological accounts by the early Heidelberg School of psychiatry. These accounts identified thought insertion as one of the self-disturbances (from German: “Ichstörungen”) of schizophrenia and used mescaline as a model-psychosis in healthy individuals to explore the possible mechanisms. The early Heidelberg School (Gruhle, Mayer-Gross, Beringer) first named and defined the self-disturbances, and proposed that thought insertion involves a disruption of the inner connectedness of thoughts and experiences, and a “becoming sensory” of those thoughts experienced as inserted. This account offers a novel way to integrate the phenomenology of thought insertion with the predictive coding framework. We argue that the altered experience of thoughts may be caused by a reduced precision of context-dependent predictions, relative to sensory precision. According to the principles of Bayesian inference, this reduced precision leads to increased prediction-error signals evoked by the neural activity that encodes thoughts. Thus, in analogy with the prediction-error related aberrant salience of external events that has been proposed previously, “internal” events such as thoughts (including volitions, emotions and memories) can also be associated with increased prediction-error signaling and are thus imbued with aberrant salience. We suggest that the individual’s attempt to explain the aberrant salience of thoughts results in their interpretation as being inserted by an alien agent, similarly to the emergence of delusions in response to the aberrant salience of sensory stimuli.
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Affiliation(s)
- Philipp Sterzer
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Germany
| | - Aaron L Mishara
- Department of Clinical Psychology, Chicago School of Professional Psychology, Southern California Campus Los Angeles, CA, USA
| | - Martin Voss
- Department of Psychiatry and Psychotherapy, Charité University Hospital and St. Hedwig Hospital Berlin, Germany
| | - Andreas Heinz
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité - Universitätsmedizin Berlin, Germany
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40
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Wieser MJ, Miskovic V, Keil A. Steady-state visual evoked potentials as a research tool in social affective neuroscience. Psychophysiology 2016; 53:1763-1775. [PMID: 27699794 DOI: 10.1111/psyp.12768] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 09/06/2016] [Indexed: 11/29/2022]
Abstract
Like many other primates, humans place a high premium on social information transmission and processing. One important aspect of this information concerns the emotional state of other individuals, conveyed by distinct visual cues such as facial expressions, overt actions, or by cues extracted from the situational context. A rich body of theoretical and empirical work has demonstrated that these socioemotional cues are processed by the human visual system in a prioritized fashion, in the service of optimizing social behavior. Furthermore, socioemotional perception is highly dependent on situational contexts and previous experience. Here, we review current issues in this area of research and discuss the utility of the steady-state visual evoked potential (ssVEP) technique for addressing key empirical questions. Methodological advantages and caveats are discussed with particular regard to quantifying time-varying competition among multiple perceptual objects, trial-by-trial analysis of visual cortical activation, functional connectivity, and the control of low-level stimulus features. Studies on facial expression and emotional scene processing are summarized, with an emphasis on viewing faces and other social cues in emotional contexts, or when competing with each other. Further, because the ssVEP technique can be readily accommodated to studying the viewing of complex scenes with multiple elements, it enables researchers to advance theoretical models of socioemotional perception, based on complex, quasinaturalistic viewing situations.
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Affiliation(s)
- Matthias J Wieser
- Institute of Psychology, Erasmus University Rotterdam, Rotterdam, Netherlands.,Department of Psychology, University of Würzburg, Würzburg, Germany
| | - Vladimir Miskovic
- Department of Psychology, State University of New York at Binghamton, Binghamton, New York, USA
| | - Andreas Keil
- Department of Psychology, University of Florida, Gainesville, Florida, USA
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41
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Disruptions in neural connectivity associated with reduced susceptibility to a depth inversion illusion in youth at ultra high risk for psychosis. NEUROIMAGE-CLINICAL 2016; 12:681-690. [PMID: 27761399 PMCID: PMC5065045 DOI: 10.1016/j.nicl.2016.09.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 12/24/2022]
Abstract
Patients with psychosis exhibit a reduced susceptibility to depth inversion illusions (DII) in which a physically concave surface is perceived as convex (e.g., the hollow mask illusion). Here, we examined the extent to which lessened susceptibility to DII characterized youth at ultra high risk (UHR) for psychosis. In this study, 44 UHR participants and 29 healthy controls judged the apparent convexity of face-like human masks, two of which were concave and the other convex. One of the concave masks was painted with realistic texture to enhance the illusion; the other was shown without such texture. Networks involved with top-down and bottom-up processing were evaluated with resting state functional connectivity magnetic resonance imaging (fcMRI). We examined regions associated with the fronto-parietal network and the visual system and their relations with susceptibility to DII. Consistent with prior studies, the UHR group was less susceptible to DII (i.e., they were characterized by more veridical perception of the stimuli) than the healthy control group. Veridical responses were related to weaker connectivity within the fronto-parietal network, and this relationship was stronger in the UHR group, suggesting possible abnormalities of top-down modulation of sensory signals. This could serve as a vulnerability marker and a further clue to the pathogenesis of psychosis.
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42
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Phillips WA, Larkum ME, Harley CW, Silverstein SM. The effects of arousal on apical amplification and conscious state. Neurosci Conscious 2016; 2016:niw015. [PMID: 29877512 PMCID: PMC5934888 DOI: 10.1093/nc/niw015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/28/2016] [Accepted: 08/08/2016] [Indexed: 01/19/2023] Open
Abstract
Neocortical pyramidal cells can integrate two classes of input separately and use one to modulate response to the other. Their tuft dendrites are electrotonically separated from basal dendrites and soma by the apical dendrite, and apical hyperpolarization-activated currents (Ih) further isolate subthreshold integration of tuft inputs. When apical depolarization exceeds a threshold, however, it can enhance response to the basal inputs that specify the cell's selective sensitivity. This process is referred to as apical amplification (AA). We review evidence suggesting that, by regulating Ih in the apical compartments, adrenergic arousal controls the coupling between apical and somatic integration zones thus modifying cognitive capabilities closely associated with consciousness. Evidence relating AA to schizophrenia, sleep, and anesthesia is reviewed, and we assess theories that emphasize the relevance of AA to consciousness. Implications for theories of neocortical computation that emphasize context-sensitive modulation are summarized. We conclude that the findings concerning AA and its regulation by arousal offer a new perspective on states of consciousness, the function and evolution of neocortex, and psychopathology. Many issues worthy of closer examination arise.
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Affiliation(s)
- W. A. Phillips
- School of Natural Sciences, University of Stirling, Scotland FK9 4LA, UK
| | - M. E. Larkum
- Neurocure Cluster of Excellence, Department of Biology, Humboldt University,
Charitéplatz 1, Berlin 10117, Germany
| | - C. W. Harley
- Psychology Department, Memorial University of Newfoundland, St. John's, NL A1C 5S7,
P.O. Box 4200, Canada
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43
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Powers AR, Kelley M, Corlett PR. Hallucinations as top-down effects on perception. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2016. [PMID: 28626813 DOI: 10.1016/j.bpsc.2016.04.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The problem of whether and how information is integrated across hierarchical brain networks embodies a fundamental tension in contemporary cognitive neuroscience, and by extension, cognitive neuropsychiatry. Indeed, the penetrability of perceptual processes in a 'top-down' manner by higher-level cognition-a natural extension of hierarchical models of perception-may contradict a strictly modular view of mental organization. Furthermore, some in the cognitive science community have challenged cognitive penetration as an unlikely, if not impossible, process. We review the evidence for and against top-down influences in perception, informed by a predictive coding model of perception and drawing heavily upon the literature of computational neuroimaging. We extend these findings to propose a way in which these processes may be altered in mental illness. We propose that hallucinations - perceptions without stimulus - can be understood as top-down effects on perception, mediated by inappropriate perceptual priors.
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44
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Silverstein SM. Visual Perception Disturbances in Schizophrenia: A Unified Model. NEBRASKA SYMPOSIUM ON MOTIVATION. NEBRASKA SYMPOSIUM ON MOTIVATION 2016; 63:77-132. [PMID: 27627825 DOI: 10.1007/978-3-319-30596-7_4] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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45
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Wibral M, Priesemann V, Kay JW, Lizier JT, Phillips WA. Partial information decomposition as a unified approach to the specification of neural goal functions. Brain Cogn 2015; 112:25-38. [PMID: 26475739 DOI: 10.1016/j.bandc.2015.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/15/2015] [Accepted: 09/16/2015] [Indexed: 11/15/2022]
Abstract
In many neural systems anatomical motifs are present repeatedly, but despite their structural similarity they can serve very different tasks. A prime example for such a motif is the canonical microcircuit of six-layered neo-cortex, which is repeated across cortical areas, and is involved in a number of different tasks (e.g. sensory, cognitive, or motor tasks). This observation has spawned interest in finding a common underlying principle, a 'goal function', of information processing implemented in this structure. By definition such a goal function, if universal, cannot be cast in processing-domain specific language (e.g. 'edge filtering', 'working memory'). Thus, to formulate such a principle, we have to use a domain-independent framework. Information theory offers such a framework. However, while the classical framework of information theory focuses on the relation between one input and one output (Shannon's mutual information), we argue that neural information processing crucially depends on the combination of multiple inputs to create the output of a processor. To account for this, we use a very recent extension of Shannon Information theory, called partial information decomposition (PID). PID allows to quantify the information that several inputs provide individually (unique information), redundantly (shared information) or only jointly (synergistic information) about the output. First, we review the framework of PID. Then we apply it to reevaluate and analyze several earlier proposals of information theoretic neural goal functions (predictive coding, infomax and coherent infomax, efficient coding). We find that PID allows to compare these goal functions in a common framework, and also provides a versatile approach to design new goal functions from first principles. Building on this, we design and analyze a novel goal function, called 'coding with synergy', which builds on combining external input and prior knowledge in a synergistic manner. We suggest that this novel goal function may be highly useful in neural information processing.
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Affiliation(s)
- Michael Wibral
- MEG Unit, Brain Imaging Center, Goethe University, Heinrich Hoffmann Straße 10, 60528 Frankfurt am Main, Germany.
| | - Viola Priesemann
- Department of Non-linear Dynamics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Jim W Kay
- Department of Statistics, University of Glasgow, Glasgow G12 8QQ, UK
| | - Joseph T Lizier
- Complex Systems Research Group, School of Civil Engineering, The University of Sydney, NSW, Australia
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Muckli L, De Martino F, Vizioli L, Petro LS, Smith FW, Ugurbil K, Goebel R, Yacoub E. Contextual Feedback to Superficial Layers of V1. Curr Biol 2015; 25:2690-5. [PMID: 26441356 PMCID: PMC4612466 DOI: 10.1016/j.cub.2015.08.057] [Citation(s) in RCA: 219] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/27/2015] [Accepted: 08/25/2015] [Indexed: 11/17/2022]
Abstract
Neuronal cortical circuitry comprises feedforward, lateral, and feedback projections, each of which terminates in distinct cortical layers [1–3]. In sensory systems, feedforward processing transmits signals from the external world into the cortex, whereas feedback pathways signal the brain’s inference of the world [4–11]. However, the integration of feedforward, lateral, and feedback inputs within each cortical area impedes the investigation of feedback, and to date, no technique has isolated the feedback of visual scene information in distinct layers of healthy human cortex. We masked feedforward input to a region of V1 cortex and studied the remaining internal processing. Using high-resolution functional brain imaging (0.8 mm3) and multivoxel pattern information techniques, we demonstrate that during normal visual stimulation scene information peaks in mid-layers. Conversely, we found that contextual feedback information peaks in outer, superficial layers. Further, we found that shifting the position of the visual scene surrounding the mask parametrically modulates feedback in superficial layers of V1. Our results reveal the layered cortical organization of external versus internal visual processing streams during perception in healthy human subjects. We provide empirical support for theoretical feedback models such as predictive coding [10, 12] and coherent infomax [13] and reveal the potential of high-resolution fMRI to access internal processing in sub-millimeter human cortex. High-resolution MRI shows functional information patterns in non-stimulated V1 Non-stimulated V1 receives cortical feedback information to superficial layers Feedback to non-stimulated V1 superficial layers is predictive of visual context
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Affiliation(s)
- Lars Muckli
- Centre for Cognitive Neuroimaging (CCNi), Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, 58 Hillhead Street, G12 8QB Scotland, UK.
| | - Federico De Martino
- Faculty of Psychology and Neuroscience, Department of Cognitive Neurosciences, Maastricht University, Oxfordlaan 55, 6229 EV Maastricht, the Netherlands; Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, 2021 Sixth Street SE, Minneapolis, MN 55455, USA
| | - Luca Vizioli
- Centre for Cognitive Neuroimaging (CCNi), Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, 58 Hillhead Street, G12 8QB Scotland, UK
| | - Lucy S Petro
- Centre for Cognitive Neuroimaging (CCNi), Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, 58 Hillhead Street, G12 8QB Scotland, UK
| | - Fraser W Smith
- School of Psychology, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Kamil Ugurbil
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, 2021 Sixth Street SE, Minneapolis, MN 55455, USA
| | - Rainer Goebel
- Faculty of Psychology and Neuroscience, Department of Cognitive Neurosciences, Maastricht University, Oxfordlaan 55, 6229 EV Maastricht, the Netherlands; Department of Neuroimaging and Neuromodeling, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Essa Yacoub
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, 2021 Sixth Street SE, Minneapolis, MN 55455, USA
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Phillips WA. Cognitive functions of intracellular mechanisms for contextual amplification. Brain Cogn 2015; 112:39-53. [PMID: 26428863 DOI: 10.1016/j.bandc.2015.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/16/2015] [Accepted: 09/18/2015] [Indexed: 01/31/2023]
Abstract
Evidence for the hypothesis that input to the apical tufts of neocortical pyramidal cells plays a central role in cognition by amplifying their responses to feedforward input is reviewed. Apical tufts are electrically remote from the soma, and their inputs come from diverse sources including direct feedback from higher cortical regions, indirect feedback via the thalamus, and long-range lateral connections both within and between cortical regions. This suggests that input to tuft dendrites may amplify the cell's response to basal inputs that they receive via layer 4 and which have synapses closer to the soma. ERP data supporting this inference is noted. Intracellular studies of apical amplification (AA) and of disamplification by inhibitory interneurons targeted only at tufts are reviewed. Cognitive processes that have been related to them by computational, electrophysiological, and psychopathological studies are then outlined. These processes include: figure-ground segregation and Gestalt grouping; contextual disambiguation in perception and sentence comprehension; priming; winner-take-all competition; attention and working memory; setting the level of consciousness; cognitive control; and learning. It is argued that theories in cognitive neuroscience should not assume that all neurons function as integrate-and-fire point processors, but should use the capabilities of cells with distinct sites of integration for driving and modulatory inputs. Potentially 'unifying' theories that depend upon these capabilities are reviewed. It is concluded that evolution of the primitives of AA and disamplification in neocortex may have extended cognitive capabilities beyond those built from the long-established primitives of excitation, inhibition, and disinhibition.
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Affiliation(s)
- William A Phillips
- School of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK.
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Joseph J, Gara MA, Silverstein SM. Hierarchical Classes Analysis (HICLAS): A novel data reduction method to examine associations between biallelic SNPs and perceptual organization phenotypes in schizophrenia. Schizophr Res Cogn 2015; 2:56-63. [PMID: 26346124 PMCID: PMC4559868 DOI: 10.1016/j.scog.2015.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The power of SNP association studies to detect valid relationships with clinical phenotypes in schizophrenia is largely limited by the number of SNPs selected and non-specificity of phenotypes. To address this, we first assessed performance on two visual perceptual organization tasks designed to avoid many generalized deficit confounds, Kanizsa shape perception and contour integration, in a schizophrenia patient sample. Then, to reduce the total number of candidate SNPs analyzed in association with perceptual organization phenotypes, we employed a two-stage strategy: first a priori SNPs from three candidate genes were selected (GAD1, NRG1 and DTNBP1); then a Hierarchical Classes Analysis (HICLAS) was performed to reduce the total number of SNPs, based on statistically related SNP clusters. HICLAS reduced the total number of candidate SNPs for subsequent phenotype association analyses from 6 to 3. MANCOVAs indicated that rs10503929 and rs1978340 were associated with the Kanizsa shape perception filling in metric but not the global shape detection metric. rs10503929 was also associated with altered contour integration performance. SNPs not selected by the HICLAS model were unrelated to perceptual phenotype indices. While the contribution of candidate SNPs to perceptual impairments requires further clarification, this study reports the first application of HICLAS as a hypothesis-independent mathematical method for SNP data reduction. HICLAS may be useful for future larger scale genotype-phenotype association studies.
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Affiliation(s)
- Jamie Joseph
- Rutgers University Graduate School of Biomedical Sciences, 675 Hoes Lane, Piscataway, NJ 08854, USA
- Rutgers University Behavioral Health Care, 151 Centennial Ave, Piscataway, NJ 08854, USA
| | - Michael A. Gara
- Rutgers University Behavioral Health Care, 151 Centennial Ave, Piscataway, NJ 08854, USA
- Rutgers–Robert Wood Johnson Medical School, 671 Hoes Lane, Piscataway, NJ 08854, USA
| | - Steven M. Silverstein
- Rutgers University Behavioral Health Care, 151 Centennial Ave, Piscataway, NJ 08854, USA
- Rutgers–Robert Wood Johnson Medical School, 671 Hoes Lane, Piscataway, NJ 08854, USA
- Corresponding author at: Department of Psychiatry, Rutgers University Behavioral Health Care and Robert Wood Johnson Medical School, 671 Hoes Lane, Piscataway, NJ 08854, USA.
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Javitt DC. Meeting overview: Sensory perception and schizophrenia, Lausanne, Switzerland June 31-July 1, 2014. SCHIZOPHRENIA RESEARCH-COGNITION 2015; 2:42-45. [PMID: 29114453 PMCID: PMC5609646 DOI: 10.1016/j.scog.2015.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/20/2015] [Indexed: 11/07/2022]
Abstract
Schizophrenia is increasingly being viewed as a “whole brain” disorder with deficits affecting widespread cortical and subcortical networks. Within this context, studies of visual cortical function may be particularly important both because visual processing deficits directly affect social and occupational function and because these systems are well characterized at the basic science level, permitting informative translational research. This article summarizes a conference on visual processing dysfunction in schizophrenia held in Lausanne, Switzerland from June 30 to July 1, 2014 and introduces this special issue. Speakers focused on multiple aspects of visual dysfunction in schizophrenia using behavioral, neurophysiological and fMRI-based approaches. Four main themes emerged. First was a focus on response disturbances within the early visual system, using paradigms such as sensory EEG and MEG-based responses. Second, behavioral deficits were noted in processing related to local interaction within visual regions, using paradigms such as Vernier acuity or contour integration. These deficits provided potential model systems to understand impaired connectivity within the brain in schizophrenia more generally. Third, several visual measures were found to correlate highly with symptoms and/or neurocognitive processing. Deficits in contour integration, for example, correlated highly with conceptual disorganization, whereas perceptual instability correlated with delusion formation. These findings highlight links between perceptual-level disturbance and clinical manifestation. Finally, the potential involvement of specific neurotransmitter receptors, including N-methyl-D-aspartate (NMDA)-type glutamate receptors and alpha7 nicotinic receptors were discussed as potential etiological mechanisms. Overall, the meeting highlighted the contributions of visual pathway dysfunction to the etiopathogenesis of neurocognitive dysfunction in schizophrenia.
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Affiliation(s)
- Daniel C Javitt
- Division of Experimental Therapeutics Columbia University Medical Center, Schizophrenia Research Nathan Kline Institute for Psychiatric Research, 1051 Riverside Drive, Unit 21, New York, NY 10032 USA
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