1
|
Whyte CJ, Redinbaugh MJ, Shine JM, Saalmann YB. Thalamic contributions to the state and contents of consciousness. Neuron 2024; 112:1611-1625. [PMID: 38754373 DOI: 10.1016/j.neuron.2024.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/11/2024] [Accepted: 04/17/2024] [Indexed: 05/18/2024]
Abstract
Consciousness can be conceptualized as varying along at least two dimensions: the global state of consciousness and the content of conscious experience. Here, we highlight the cellular and systems-level contributions of the thalamus to conscious state and then argue for thalamic contributions to conscious content, including the integrated, segregated, and continuous nature of our experience. We underscore vital, yet distinct roles for core- and matrix-type thalamic neurons. Through reciprocal interactions with deep-layer cortical neurons, matrix neurons support wakefulness and determine perceptual thresholds, whereas the cortical interactions of core neurons maintain content and enable perceptual constancy. We further propose that conscious integration, segregation, and continuity depend on the convergent nature of corticothalamic projections enabling dimensionality reduction, a thalamic reticular nucleus-mediated divisive normalization-like process, and sustained coherent activity in thalamocortical loops, respectively. Overall, we conclude that the thalamus plays a central topological role in brain structures controlling conscious experience.
Collapse
Affiliation(s)
- Christopher J Whyte
- Centre for Complex Systems, The University of Sydney, Sydney, NSW, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | | | - James M Shine
- Centre for Complex Systems, The University of Sydney, Sydney, NSW, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Yuri B Saalmann
- Department of Psychology, University of Wisconsin - Madison, Madison, WI, USA; Wisconsin National Primate Research Center, Madison, WI, USA
| |
Collapse
|
2
|
Rutkowski TM, Komendziński T, Otake-Matsuura M. Mild cognitive impairment prediction and cognitive score regression in the elderly using EEG topological data analysis and machine learning with awareness assessed in affective reminiscent paradigm. Front Aging Neurosci 2024; 15:1294139. [PMID: 38239487 PMCID: PMC10794306 DOI: 10.3389/fnagi.2023.1294139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/27/2023] [Indexed: 01/22/2024] Open
Abstract
Introduction The main objective of this study is to evaluate working memory and determine EEG biomarkers that can assist in the field of health neuroscience. Our ultimate goal is to utilize this approach to predict the early signs of mild cognitive impairment (MCI) in healthy elderly individuals, which could potentially lead to dementia. The advancements in health neuroscience research have revealed that affective reminiscence stimulation is an effective method for developing EEG-based neuro-biomarkers that can detect the signs of MCI. Methods We use topological data analysis (TDA) on multivariate EEG data to extract features that can be used for unsupervised clustering, subsequent machine learning-based classification, and cognitive score regression. We perform EEG experiments to evaluate conscious awareness in affective reminiscent photography settings. Results We use EEG and interior photography to distinguish between healthy cognitive aging and MCI. Our clustering UMAP and random forest application accurately predict MCI stage and MoCA scores. Discussion Our team has successfully implemented TDA feature extraction, MCI classification, and an initial regression of MoCA scores. However, our study has certain limitations due to a small sample size of only 23 participants and an unbalanced class distribution. To enhance the accuracy and validity of our results, future research should focus on expanding the sample size, ensuring gender balance, and extending the study to a cross-cultural context.
Collapse
Affiliation(s)
- Tomasz M. Rutkowski
- RIKEN Center for Advanced Intelligence Project, Tokyo, Japan
- Graduate School of Education, The University of Tokyo, Tokyo, Japan
- Department of Cognitive Science, Institute of Information and Communication Research, Nicolaus Copernicus University, Toruń, Poland
| | - Tomasz Komendziński
- Department of Cognitive Science, Institute of Information and Communication Research, Nicolaus Copernicus University, Toruń, Poland
| | | |
Collapse
|
3
|
Bao X, Lyu Y. VWM-based bias in conscious access can be extended to a new sandwich masking task and real-life stimuli. Atten Percept Psychophys 2023; 85:2123-2130. [PMID: 37226040 DOI: 10.3758/s13414-023-02726-0] [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] [Accepted: 05/02/2023] [Indexed: 05/26/2023]
Abstract
Previous studies using breaking continuous flash suppression observed that the content of visual working memory (VWM) influences the priority for accessing visual awareness. However, most studies have used simple stimuli, whereas real-life objects are typically more meaningful and contain more perceptual information than simple objects. In this study, we intermixed a delayed match-to-sample task to manipulate the content of VWM, and a breaking repeated masking suppression (b-RMS) task to investigate whether this memory-based effect in conscious access can be extended to a new sandwich masking task and real-life stimuli. The results revealed that memory-congruent objects broke RMS faster than incongruent objects for both simple and real-life objects. Specifically, for simple objects, color-matching targets broke RMS faster than color-mismatching targets, whereas state-matching targets broke RMS faster than state-mismatching targets for real-life objects. These results suggest that the faster detection of VWM-matching over VWM mismatching stimuli-which has been mostly studied using only one type of task (b-CFS) and stimulus (colored shapes)-extends to (1) yet another masking technique (b-RMS) and to (2) a novel stimulus type (real-life objects), providing evidence that memory-based biases in conscious access are a ubiquitous phenomenon.
Collapse
Affiliation(s)
- Xiaohua Bao
- Faculty of Psychology, Tianjin Normal University, Xiqing District, Tianjin, China
| | - Yong Lyu
- Faculty of Psychology, Tianjin Normal University, Xiqing District, Tianjin, China.
| |
Collapse
|
4
|
Earl B. Humans, fish, spiders and bees inherited working memory and attention from their last common ancestor. Front Psychol 2023; 13:937712. [PMID: 36814887 PMCID: PMC9939904 DOI: 10.3389/fpsyg.2022.937712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 11/11/2022] [Indexed: 02/08/2023] Open
Abstract
All brain processes that generate behaviour, apart from reflexes, operate with information that is in an "activated" state. This activated information, which is known as working memory (WM), is generated by the effect of attentional processes on incoming information or information previously stored in short-term or long-term memory (STM or LTM). Information in WM tends to remain the focus of attention; and WM, attention and STM together enable information to be available to mental processes and the behaviours that follow on from them. WM and attention underpin all flexible mental processes, such as solving problems, making choices, preparing for opportunities or threats that could be nearby, or simply finding the way home. Neither WM nor attention are necessarily conscious, and both may have evolved long before consciousness. WM and attention, with similar properties, are possessed by humans, archerfish, and other vertebrates; jumping spiders, honey bees, and other arthropods; and members of other clades, whose last common ancestor (LCA) is believed to have lived more than 600 million years ago. It has been reported that very similar genes control the development of vertebrate and arthropod brains, and were likely inherited from their LCA. Genes that control brain development are conserved because brains generate adaptive behaviour. However, the neural processes that generate behaviour operate with the activated information in WM, so WM and attention must have existed prior to the evolution of brains. It is proposed that WM and attention are widespread amongst animal species because they are phylogenetically conserved mechanisms that are essential to all mental processing, and were inherited from the LCA of vertebrates, arthropods, and some other animal clades.
Collapse
|
5
|
Abstract
The extent to which we are affected by perceptual input of which we are unaware is widely debated. By measuring neural responses to sensory stimulation, neuroscientific data could complement behavioral results with valuable evidence. Here we review neuroscientific findings of processing of high-level information, as well as interactions with attention and memory. Although the results are mixed, we find initial support for processing object categories and words, possibly to the semantic level, as well as emotional expressions. Robust neural evidence for face individuation and integration of sentences or scenes is lacking. Attention affects the processing of stimuli that are not consciously perceived, and such stimuli may exogenously but not endogenously capture attention when relevant, and be maintained in memory over time. Sources of inconsistency in the literature include variability in control for awareness as well as individual differences, calling for future studies that adopt stricter measures of awareness and probe multiple processes within subjects.
Collapse
Affiliation(s)
- Liad Mudrik
- School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel;
| | - Leon Y Deouell
- Department of Psychology and The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel;
| |
Collapse
|
6
|
Gambarota F, Tsuchiya N, Pastore M, Di Polito N, Sessa P. Unconscious Visual Working Memory: A critical review and Bayesian meta-analysis. Neurosci Biobehav Rev 2022; 136:104618. [PMID: 35289273 DOI: 10.1016/j.neubiorev.2022.104618] [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: 11/04/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/16/2022]
Abstract
The relationship between consciousness and working memory (WM) has been recently debated both at the theoretical and methodological levels (Persuh et al., 2018; Velichkovsky, 2017). While there is behavioral and neural evidence that argues for the existence of unconscious WM, several methodological concerns have been raised, rendering this issue highly controversial. To address the robustness of the previous findings, here we adopt a meta-analytic approach to estimate the effect size and heterogeneity of the previously reported unconscious WM results, also including unpublished results. We used meta-regression to isolate relevant experimental variables, in particular, consciousness manipulation and the WM paradigm to identify the source of the heterogeneity in the reported effect size of the unconscious WM. Our meta-analysis supports the existence of the unconscious WM effect and critically reveals several experimental variables that contribute to relevant heterogeneity. Our analysis clarifies several theoretical and methodological issues. We recommend that future studies explicitly operationalize the definition of consciousness, standardize the methodology and systematically explore the role of critical variables for the unconscious WM effect.
Collapse
Affiliation(s)
- Filippo Gambarota
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy; Padova Neuroscience Center, University of Padova, Via Giuseppe Orus, 2, 35131 Padova, Italy.
| | - Naotsugu Tsuchiya
- Turner Institute for Brain and Mental Health & School of Psychological Sciences, Faculty of Medicine, Nursing, and Health Sciences, Monash University, Melbourne, Victoria, Australia; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita, Osaka 565-0871, Japan; Advanced Telecommunications Research Computational Neuroscience Laboratories, 2-2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0288, Japan.
| | - Massimiliano Pastore
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy.
| | - Nicola Di Polito
- Medical Neurosciences Program, Charité Universitätsmedizin, Charitépl 1, 10117, Berlin, Germany.
| | - Paola Sessa
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy; Padova Neuroscience Center, University of Padova, Via Giuseppe Orus, 2, 35131 Padova, Italy.
| |
Collapse
|
7
|
Schneider E, Züst MA, Wuethrich S, Schmidig F, Klöppel S, Wiest R, Ruch S, Henke K. Larger capacity for unconscious versus conscious episodic memory. Curr Biol 2021; 31:3551-3563.e9. [PMID: 34256016 DOI: 10.1016/j.cub.2021.06.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/29/2021] [Accepted: 06/03/2021] [Indexed: 11/28/2022]
Abstract
Episodic memory is the memory for experienced events. A peak competence of episodic memory is the mental combination of events to infer commonalities. Inferring commonalities may proceed with and without consciousness of events. Yet what distinguishes conscious from unconscious inference? This question inspired nine experiments that featured strongly and weakly masked cartoon clips presented for unconscious and conscious inference. Each clip featured a scene with a visually impenetrable hiding place. Five animals crossed the scene one-by-one consecutively. One animal trajectory represented one event. The animals moved through the hiding place, where they might linger or not. The participants' task was to observe the animals' entrances and exits to maintain a mental record of which animals hid simultaneously. We manipulated information load to explore capacity limits. Memory of inferences was tested immediately, 3.5 or 6 min following encoding. The participants retrieved inferences well when encoding was conscious. When encoding was unconscious, the participants needed to respond intuitively. Only habitually intuitive decision makers exhibited a significant delayed retrieval of inferences drawn unconsciously. Their unconscious retrieval performance did not drop significantly with increasing information load, while conscious retrieval performance dropped significantly. A working memory network, including hippocampus, was activated during both conscious and unconscious inference and correlated with retrieval success. An episodic retrieval network, including hippocampus, was activated during both conscious and unconscious retrieval of inferences and correlated with retrieval success. Only conscious encoding/retrieval recruited additional brain regions outside these networks. Hence, levels of consciousness influenced the memories' behavioral impact, memory capacity, and the neural representational code.
Collapse
Affiliation(s)
- Else Schneider
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland
| | - Marc Alain Züst
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland; University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bolligenstraße 111, 3000 Bern, Switzerland
| | - Sergej Wuethrich
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland
| | - Flavio Schmidig
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bolligenstraße 111, 3000 Bern, Switzerland
| | - Roland Wiest
- Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Freiburgstrasse 18, 3010 Bern, Switzerland
| | - Simon Ruch
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland
| | - Katharina Henke
- Institute of Psychology, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland.
| |
Collapse
|
8
|
Shea N, Frith CD. The Global Workspace Needs Metacognition. Trends Cogn Sci 2019; 23:560-571. [DOI: 10.1016/j.tics.2019.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/12/2019] [Accepted: 04/22/2019] [Indexed: 12/20/2022]
|
9
|
Trübutschek D, Marti S, Dehaene S. Temporal-order information can be maintained in non-conscious working memory. Sci Rep 2019; 9:6484. [PMID: 31019199 PMCID: PMC6482300 DOI: 10.1038/s41598-019-42942-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/05/2019] [Indexed: 11/09/2022] Open
Abstract
Classical theories hold conscious perception and working memory to be tightly interwoven. Recent work has challenged this assumption, demonstrating that information may be stored for several seconds without any subjective awareness. Does such non-conscious working memory possess the same functional properties as conscious working memory? Here, we probe whether non-conscious working memory can maintain multiple items and their temporal order. In a visual masking task with a delayed response, 38 participants were asked to retain the location and order of presentation of two sequentially flashed spatial positions, and retrieve both after a 2.5 second delay. Even when subjective visibility was nil, subjects' objective forced-choice performance exceeded chance level and, crucially, distinct retrieval of the first and second location was observed on both conscious and non-conscious trials. Non-conscious working memory may therefore store two items in proper temporal order. These findings can be explained by recent models of activity-silent working memory.
Collapse
Affiliation(s)
- Darinka Trübutschek
- Ecole des Neurosciences de Paris Ile-de-France, 15 rue de l'école de médecine, 75006, Paris, France.
- Sorbonne Université, UPMC Université Paris 06, 4 place Jussieu, 75005, Paris, France.
- Cognitive Neuroimaging Unit, CEA DSV/I2BM, INSERM, Université Paris-Sud, Université Paris-Saclay, NeuroSpin centre, 91191, Gif/Yvette, France.
| | - Sébastien Marti
- Cognitive Neuroimaging Unit, CEA DSV/I2BM, INSERM, Université Paris-Sud, Université Paris-Saclay, NeuroSpin centre, 91191, Gif/Yvette, France
| | - Stanislas Dehaene
- Cognitive Neuroimaging Unit, CEA DSV/I2BM, INSERM, Université Paris-Sud, Université Paris-Saclay, NeuroSpin centre, 91191, Gif/Yvette, France
- Collège de France, 11 Place Marcelin Berthelot, 75005, Paris, France
| |
Collapse
|
10
|
Liesefeld HR, Müller HJ. Current directions in visual working memory research: An introduction and emerging insights. Br J Psychol 2019; 110:193-206. [PMID: 30737770 DOI: 10.1111/bjop.12377] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 12/25/2022]
Abstract
Visual working memory (VWM) is a core construct in the cognitive (neuro-)sciences, assumed to serve as a hub for information exchange and thus supporting a multitude of cognitive functions related to processing visual information. Here, we give an introduction into key terms and paradigms and an overview of ongoing debates in the field, to which the articles collected in this Special Issue on 'Current Directions in Visual Working Memory Research' contribute. Our aim is to extract, from this overview, some 'emerging' theoretical insights concerning questions such as the optimal way to examine VWM, which types of mental representations contribute to performance on VWM tasks, and how VWM keeps features from the same object together and apart from features of concurrently maintained objects (the binding problem).
Collapse
Affiliation(s)
- Heinrich René Liesefeld
- Department Psychologie, Ludwig-Maximilians-Universität, München, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, München, Germany
| | - Hermann J Müller
- Department Psychologie, Ludwig-Maximilians-Universität, München, Germany.,Department of Psychological Sciences, Birkbeck College, University of London, UK
| |
Collapse
|
11
|
Prevailing theories of consciousness are challenged by novel cross-modal associations acquired between subliminal stimuli. Cognition 2018; 175:169-185. [PMID: 29544152 DOI: 10.1016/j.cognition.2018.02.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 01/07/2018] [Accepted: 02/08/2018] [Indexed: 11/21/2022]
Abstract
While theories of consciousness differ substantially, the 'conscious access hypothesis', which aligns consciousness with the global accessibility of information across cortical regions, is present in many of the prevailing frameworks. This account holds that consciousness is necessary to integrate information arising from independent functions such as the specialist processing required by different senses. We directly tested this account by evaluating the potential for associative learning between novel pairs of subliminal stimuli presented in different sensory modalities. First, pairs of subliminal stimuli were presented and then their association assessed by examining the ability of the first stimulus to prime classification of the second. In Experiments 1-4 the stimuli were word-pairs consisting of a male name preceding either a creative or uncreative profession. Participants were subliminally exposed to two name-profession pairs where one name was paired with a creative profession and the other an uncreative profession. A supraliminal task followed requiring the timed classification of one of those two professions. The target profession was preceded by either the name with which it had been subliminally paired (concordant) or the alternate name (discordant). Experiment 1 presented stimuli auditorily, Experiment 2 visually, and Experiment 3 presented names auditorily and professions visually. All three experiments revealed the same inverse priming effect with concordant test pairs associated with significantly slower classification judgements. Experiment 4 sought to establish if learning would be more efficient with supraliminal stimuli and found evidence that a different strategy is adopted when stimuli are consciously perceived. Finally, Experiment 5 replicated the unconscious cross-modal association achieved in Experiment 3 utilising non-linguistic stimuli. The results demonstrate the acquisition of novel cross-modal associations between stimuli which are not consciously perceived and thus challenge the global access hypothesis and those theories embracing it.
Collapse
|
12
|
Persuh M, LaRock E, Berger J. Working Memory and Consciousness: The Current State of Play. Front Hum Neurosci 2018; 12:78. [PMID: 29551967 PMCID: PMC5840147 DOI: 10.3389/fnhum.2018.00078] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/12/2018] [Indexed: 12/24/2022] Open
Abstract
Working memory (WM), an important posit in cognitive science, allows one to temporarily store and manipulate information in the service of ongoing tasks. WM has been traditionally classified as an explicit memory system-that is, as operating on and maintaining only consciously perceived information. Recently, however, several studies have questioned this assumption, purporting to provide evidence for unconscious WM. In this article, we focus on visual working memory (VWM) and critically examine these studies as well as studies of unconscious perception that seem to provide indirect evidence for unconscious WM. Our analysis indicates that current evidence does not support an unconscious WM store, though we offer independent reasons to think that WM may operate on unconsciously perceived information.
Collapse
Affiliation(s)
- Marjan Persuh
- Department of Social Sciences, Human Services and Criminal Justice, Borough of Manhattan Community College, City University of New York, New York, NY, United States
| | - Eric LaRock
- Department of Philosophy, 751 Mathematics and Science Center, Oakland University, Rochester, MI, United States
| | - Jacob Berger
- Department of English and Philosophy, Idaho State University, Pocatello, ID, United States
| |
Collapse
|