1
|
Nieder A. In search for consciousness in animals: Using working memory and voluntary attention as behavioral indicators. Neurosci Biobehav Rev 2022; 142:104865. [PMID: 36096205 DOI: 10.1016/j.neubiorev.2022.104865] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/17/2022] [Accepted: 09/05/2022] [Indexed: 10/31/2022]
Abstract
Whether animals have subjective experiences about the content of their sensory input, i.e., whether they are aware of stimuli, is a notoriously difficult question to answer. If consciousness is present in animals, it must share fundamental characteristics with human awareness. Working memory and voluntary/endogenous attention are suggested as diagnostic features of conscious awareness. Behavioral evidence shows clear signatures of both working memory and voluntary attention as minimal criterium for sensory consciousness in mammals and birds. In contrast, reptiles and amphibians show no sign of either working memory or volitional attention. Surprisingly, some species of teleost fishes exhibit elementary working memory and voluntary attention effects suggestive of possibly rudimentary forms of subjective experience. With the potential exception of honeybees, evidence for conscious processing is lacking in invertebrates. These findings suggest that consciousness is not ubiquitous in the animal kingdom but also not exclusive to humans. The phylogenetic gap between animal taxa argues that evolution does not rely on specific neural substrates to endow distantly related species with basic forms of consciousness.
Collapse
Affiliation(s)
- Andreas Nieder
- Animal Physiology Unit, Institute of Neurobiology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.
| |
Collapse
|
2
|
Müller CP. Serotonin and Consciousness-A Reappraisal. Behav Brain Res 2022; 432:113970. [PMID: 35716774 DOI: 10.1016/j.bbr.2022.113970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 11/02/2022]
Abstract
The serotonergic system of the brain is a major modulator of behaviour. Here we describe a re-appraisal of its function for consciousness based on anatomical, functional and pharmacological data. For a better understanding, the current model of consciousness is expanded. Two parallel streams of conscious flow are distinguished. A flow of conscious content and an affective consciousness flow. While conscious content flow has its functional equivalent in the activity of higher cortico-cortical and cortico-thalamic networks, affective conscious flow originates in segregated deeper brain structures for single emotions. It is hypothesized that single emotional networks converge on serotonergic and other modulatory transmitter neurons in the brainstem where a bound percept of an affective conscious flow is formed. This is then dispersed to cortical and thalamic networks, where it is time locked with conscious content flow at the level of these networks. Serotonin acts in concert with other modulatory systems of the brain stem with some possible specialization on single emotions. Together, these systems signal a bound percept of affective conscious flow. Dysfunctions in the serotonergic system may not only give rise to behavioural and somatic symptoms, but also essentially affect the coupling of conscious affective flow with conscious content flow, leading to the affect-stained subjective side of mental disorders like anxiety, depression, or schizophrenia. The present model is an attempt to integrate the growing insights into serotonergic system function. However, it is acknowledged, that several key claims are still at a heuristic level that need further empirical support.
Collapse
Affiliation(s)
- Christian P Müller
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054, Erlangen, Germany; Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
| |
Collapse
|
3
|
Zlomuzica A, Dere E. Towards an animal model of consciousness based on the platform theory. Behav Brain Res 2022; 419:113695. [PMID: 34856300 DOI: 10.1016/j.bbr.2021.113695] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/21/2021] [Accepted: 11/26/2021] [Indexed: 11/02/2022]
Abstract
The evolution of intellectual capacities has brought forth a continuum of consciousness levels subserved by neuronal networks of varying complexity. Brain pathologies, neurodegenerative, and mental diseases affect conscious cognition and behavior. Although impairments in consciousness are among the most devastating consequences of neurological and mental diseases, valid and reliable animal models of consciousness, that could be used for preclinical research are missing. The platform theory holds that the brain enters a conscious operation mode, whenever mental representations of stimuli, associations, concepts, memories, and experiences are effortfully maintained (in working memory) and actively manipulated. We used the platform theory as a framework and evaluation standard to categorize behavioral paradigms with respect to the level of consciousness involved in task performance. According to the platform theory, a behavioral paradigm involves conscious cognitive operations, when the problem posed is unexpected, novel or requires the maintenance and manipulation of a large amount of information to perform cognitive operations on them. Conscious cognitive operations are associated with a relocation of processing resources and the redirection of attentional focus. A consciousness behavioral test battery is proposed that is composed of tests which are assumed to require higher levels of consciousness as compared to other tasks and paradigms. The consciousness test battery for rodents includes the following tests: Working memory in the radial arm maze, episodic-like memory, prospective memory, detour test, and operant conditioning with concurrent variable-interval variable-ratio schedules. Performance in this test battery can be contrasted with the performance in paradigms and tests that require lower levels of consciousness. Additionally, a second more comprehensive behavioral test battery is proposed to control for behavioral phenotypes not related to consciousness. Our theory could serve as a guidance for the decryption of the neurobiological basis of consciousness.
Collapse
Affiliation(s)
- Armin Zlomuzica
- Department of Behavioral and Clinical Neuroscience, Ruhr-University Bochum (RUB), Massenbergstraße 9-13, D-44787 Bochum, Germany.
| | - Ekrem Dere
- Department of Behavioral and Clinical Neuroscience, Ruhr-University Bochum (RUB), Massenbergstraße 9-13, D-44787 Bochum, Germany; Sorbonne Université. Institut de Biologie Paris-Seine, (IBPS), Département UMR 8256: Adaptation Biologique et Vieillissement, UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris, France.
| |
Collapse
|
4
|
NMDAR1 autoantibodies amplify behavioral phenotypes of genetic white matter inflammation: a mild encephalitis model with neuropsychiatric relevance. Mol Psychiatry 2022; 27:4974-4983. [PMID: 34866134 PMCID: PMC9763107 DOI: 10.1038/s41380-021-01392-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/28/2021] [Accepted: 11/12/2021] [Indexed: 02/06/2023]
Abstract
Encephalitis has an estimated prevalence of ≤0.01%. Even with extensive diagnostic work-up, an infectious etiology is identified or suspected in <50% of cases, suggesting a role for etiologically unclear, noninfectious processes. Mild encephalitis runs frequently unnoticed, despite slight neuroinflammation detectable postmortem in many neuropsychiatric illnesses. A widely unexplored field in humans, though clearly documented in rodents, is genetic brain inflammation, particularly that associated with myelin abnormalities, inducing primary white matter encephalitis. We hypothesized that "autoimmune encephalitides" may result from any brain inflammation concurring with the presence of brain antigen-directed autoantibodies, e.g., against N-methyl-D-aspartate-receptor NR1 (NMDAR1-AB), which are not causal of, but may considerably shape the encephalitis phenotype. We therefore immunized young female Cnp-/- mice lacking the structural myelin protein 2'-3'-cyclic nucleotide 3'-phosphodiesterase (Cnp) with a "cocktail" of NMDAR1 peptides. Cnp-/- mice exhibit early low-grade inflammation of white matter tracts and blood-brain barrier disruption. Our novel mental-time-travel test disclosed that Cnp-/- mice are compromised in what-where-when orientation, but this episodic memory readout was not further deteriorated by NMDAR1-AB. In contrast, comparing wild-type and Cnp-/- mice without/with NMDAR1-AB regarding hippocampal learning/memory and motor balance/coordination revealed distinct stair patterns of behavioral pathology. To elucidate a potential contribution of oligodendroglial NMDAR downregulation to NMDAR1-AB effects, we generated conditional NR1 knockout mice. These mice displayed normal Morris water maze and mental-time-travel, but beam balance performance was similar to immunized Cnp-/-. Immunohistochemistry confirmed neuroinflammation/neurodegeneration in Cnp-/- mice, yet without add-on effect of NMDAR1-AB. To conclude, genetic brain inflammation may explain an encephalitic component underlying autoimmune conditions.
Collapse
|
5
|
Manrique HM, Zeidler H, Roberts G, Barclay P, Walker M, Samu F, Fariña A, Bshary R, Raihani N. The psychological foundations of reputation-based cooperation. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200287. [PMID: 34601920 PMCID: PMC8487732 DOI: 10.1098/rstb.2020.0287] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2021] [Indexed: 12/27/2022] Open
Abstract
Humans care about having a positive reputation, which may prompt them to help in scenarios where the return benefits are not obvious. Various game-theoretical models support the hypothesis that concern for reputation may stabilize cooperation beyond kin, pairs or small groups. However, such models are not explicit about the underlying psychological mechanisms that support reputation-based cooperation. These models therefore cannot account for the apparent rarity of reputation-based cooperation in other species. Here, we identify the cognitive mechanisms that may support reputation-based cooperation in the absence of language. We argue that a large working memory enhances the ability to delay gratification, to understand others' mental states (which allows for perspective-taking and attribution of intentions) and to create and follow norms, which are key building blocks for increasingly complex reputation-based cooperation. We review the existing evidence for the appearance of these processes during human ontogeny as well as their presence in non-human apes and other vertebrates. Based on this review, we predict that most non-human species are cognitively constrained to show only simple forms of reputation-based cooperation. This article is part of the theme issue 'The language of cooperation: reputation and honest signalling'.
Collapse
Affiliation(s)
- Héctor M. Manrique
- Department of Psychology and Sociology, Universidad de Zaragoza, Campus Universitario de Teruel, Ciudad Escolar, s/n. 44003 Teruel, Spain
| | - Henriette Zeidler
- Department of Psychology, School of Life and Health Sciences, Aston University, Birmingham, UK
| | | | - Pat Barclay
- Psychology, University of Guelph, Guelph, Canada
| | - Michael Walker
- Department of Zoology and Physical Anthropology, Universidad de Murcia, Murcia, Spain
| | - Flóra Samu
- The Institute for Analytical Sociology, Linköping University, Linköping, Sweden
| | - Andrea Fariña
- Social, Economic, and Organizational Psychology, Leiden University, Leiden, The Netherlands
| | - Redouan Bshary
- Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Nichola Raihani
- Experimental Psychology, University College London, London, UK
| |
Collapse
|
6
|
Araujo APDC, de Lucena JD, Drieskens DC, Neves LR, Pugliane KC, Belchior HA, Castelo-Branco R, Barbosa FF. Rats recognize spatial and temporal attributes in a new object recognition memory task with multiple trials. J Neurosci Methods 2020; 348:108936. [PMID: 33022303 DOI: 10.1016/j.jneumeth.2020.108936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/05/2020] [Accepted: 09/03/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND Episodic-like memory tasks based on the spontaneous exploration of objects are commonly applied in one-trial protocols. However, multiple-trial designs are known to reduce animal numbers and data variance, providing faster accumulation of data. NEW METHOD In this study, we devised a new object recognition memory task for rats that carry out multiple trials per session. We developed three types of continual trial tasks: a longer protocol, a shorter protocol, and a protocol in which the experimental session was divided into two days. RESULTS In our design, rats expressed temporal and spatial memory, but not what-where-when content integration. We found that shorter protocols were more efficient to evaluate memory capabilities. COMPARISON WITH EXISTING METHODS To the best of our knowledge, it is the first object recognition task with multiple trials that simultaneously assess the temporal and spatial aspects of episodic-like memory. CONCLUSIONS We suggest that our task is suitable for the simultaneous measurements of brain functions related to spatial and temporal attributes in rats.
Collapse
Affiliation(s)
- Ana Paula de Castro Araujo
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Jalles Dantas de Lucena
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil; Faculdade de Santa Maria, Cajazeiras, PB, Brazil
| | - Davi Carvalho Drieskens
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil; Brain Institute, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Lívia Rodrigues Neves
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil; Brain Institute, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Karen Cristina Pugliane
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Hindiael Aeraf Belchior
- Faculdade de Ciências da Saúde do Trairí, Universidade federal do Rio Grande do norte, Santa Cruz, RN, Brazil
| | - Rochele Castelo-Branco
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Flávio Freitas Barbosa
- Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil.
| |
Collapse
|
7
|
Dere D, Zlomuzica A, Dere E. Channels to consciousness: a possible role of gap junctions in consciousness. Rev Neurosci 2020; 32:/j/revneuro.ahead-of-print/revneuro-2020-0012/revneuro-2020-0012.xml. [PMID: 32853172 DOI: 10.1515/revneuro-2020-0012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/26/2020] [Indexed: 12/20/2022]
Abstract
The neurophysiological basis of consciousness is still unknown and one of the most challenging questions in the field of neuroscience and related disciplines. We propose that consciousness is characterized by the maintenance of mental representations of internal and external stimuli for the execution of cognitive operations. Consciousness cannot exist without working memory, and it is likely that consciousness and working memory share the same neural substrates. Here, we present a novel psychological and neurophysiological framework that explains the role of consciousness for cognition, adaptive behavior, and everyday life. A hypothetical architecture of consciousness is presented that is organized as a system of operation and storage units named platforms that are controlled by a consciousness center (central executive/online platform). Platforms maintain mental representations or contents, are entrusted with different executive functions, and operate at different levels of consciousness. The model includes conscious-mode central executive/online and mental time travel platforms and semiconscious steady-state and preconscious standby platforms. Mental representations or contents are represented by neural circuits and their support cells (astrocytes, oligodendrocytes, etc.) and become conscious when neural circuits reverberate, that is, fire sequentially and continuously with relative synchronicity. Reverberatory activity in neural circuits may be initiated and maintained by pacemaker cells/neural circuit pulsars, enhanced electronic coupling via gap junctions, and unapposed hemichannel opening. The central executive/online platform controls which mental representations or contents should become conscious by recruiting pacemaker cells/neural network pulsars, the opening of hemichannels, and promoting enhanced neural circuit coupling via gap junctions.
Collapse
Affiliation(s)
- Dorothea Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
| | - Armin Zlomuzica
- Faculty of Psychology, Behavioral and Clinical Neuroscience, University of Bochum, Massenbergstraße 9-13, D-44787 Bochum, Germany
| | - Ekrem Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
| |
Collapse
|
8
|
Hirata S, Betsuyaku T, Fujita K, Nakano T, Ikegaya Y. Phylogeny and ontogeny of mental time. Neurosci Res 2020; 170:13-17. [PMID: 32681853 DOI: 10.1016/j.neures.2020.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 07/08/2020] [Accepted: 07/13/2020] [Indexed: 11/18/2022]
Abstract
Humans have mental time in our mind, apart from physical time that is a part of system that governs the physical world, and memory is our key cognitive ability for recognizing the passage of time. Recent studies have suggested that the memory system of several nonhuman animals may have an incidental nature, which is also a feature of episodic memory. In addition, apes, which are phylogenetically close to humans, have an ability to remember a single past event. In the case of humans, preverbal infants under the age of two are able to retain long-term memory of a single event and apply it to predict a future event. Thus, nonhuman animals and preverbal human infants both have their own specific mental time travel abilities, and there is a phylogenetic and ontogenic basis of full-fledged mental time travel that can be found in human adults.
Collapse
Affiliation(s)
- Satoshi Hirata
- Wildlife Research Center, Kyoto University, Kyoto 606-8203, Japan
| | - Toru Betsuyaku
- Graduate School of Letters, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuo Fujita
- Graduate School of Letters, Kyoto University, Kyoto 606-8501, Japan
| | - Tamami Nakano
- Graduate School of Frontier Biosciences, Osaka University, 565-0871, Japan
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, 565-0871, Japan.
| |
Collapse
|
9
|
Prefrontal working memory activity predicts episodic memory performance: A neuroimaging study. Behav Brain Res 2020; 379:112307. [DOI: 10.1016/j.bbr.2019.112307] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/09/2019] [Accepted: 10/15/2019] [Indexed: 01/06/2023]
|