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Myrov V, Siebenhühner F, Juvonen JJ, Arnulfo G, Palva S, Palva JM. Rhythmicity of neuronal oscillations delineates their cortical and spectral architecture. Commun Biol 2024; 7:405. [PMID: 38570628 PMCID: PMC10991572 DOI: 10.1038/s42003-024-06083-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 03/20/2024] [Indexed: 04/05/2024] Open
Abstract
Neuronal oscillations are commonly analyzed with power spectral methods that quantify signal amplitude, but not rhythmicity or 'oscillatoriness' per se. Here we introduce a new approach, the phase-autocorrelation function (pACF), for the direct quantification of rhythmicity. We applied pACF to human intracerebral stereoelectroencephalography (SEEG) and magnetoencephalography (MEG) data and uncovered a spectrally and anatomically fine-grained cortical architecture in the rhythmicity of single- and multi-frequency neuronal oscillations. Evidencing the functional significance of rhythmicity, we found it to be a prerequisite for long-range synchronization in resting-state networks and to be dynamically modulated during event-related processing. We also extended the pACF approach to measure 'burstiness' of oscillatory processes and characterized regions with stable and bursty oscillations. These findings show that rhythmicity is double-dissociable from amplitude and constitutes a functionally relevant and dynamic characteristic of neuronal oscillations.
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Affiliation(s)
- Vladislav Myrov
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland.
| | - Felix Siebenhühner
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki, Finland
| | - Joonas J Juvonen
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Gabriele Arnulfo
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy
| | - Satu Palva
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
| | - J Matias Palva
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
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Kim K, Nokia MS, Palva S. Distinct Hippocampal Oscillation Dynamics in Trace Eyeblink Conditioning Task for Retrieval and Consolidation of Associations. eNeuro 2024; 11:ENEURO.0030-23.2024. [PMID: 38627063 PMCID: PMC11046259 DOI: 10.1523/eneuro.0030-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/04/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
Trace eyeblink conditioning (TEBC) has been widely used to study associative learning in both animals and humans. In this paradigm, conditioned responses (CRs) to conditioned stimuli (CS) serve as a measure for retrieving learned associations between the CS and the unconditioned stimuli (US) within a trial. Memory consolidation, that is, learning over time, can be quantified as an increase in the proportion of CRs across training sessions. However, how hippocampal oscillations differentiate between successful memory retrieval within a session and consolidation across TEBC training sessions remains unknown. To address this question, we recorded local field potentials (LFPs) from the rat dorsal hippocampus during TEBC and investigated hippocampal oscillation dynamics associated with these two functions. We show that transient broadband responses to the CS were correlated with memory consolidation, as indexed by an increase in CRs across TEBC sessions. In contrast, induced alpha (8-10 Hz) and beta (16-20 Hz) band responses were correlated with the successful retrieval of the CS-US association within a session, as indexed by the difference in trials with and without CR.
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Affiliation(s)
- Kayeon Kim
- Neuroscience Center, Helsinki Institute of Life Sciences, University of Helsinki, Helsinki FI-00014, Finland
- Department of Neuroscience, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Miriam S Nokia
- Department of Psychology, University of Jyväskylä, Jyväskylä FI-40014, Finland
| | - Satu Palva
- Neuroscience Center, Helsinki Institute of Life Sciences, University of Helsinki, Helsinki FI-00014, Finland
- Centre for Cognitive Neuroscience, School of Psychology and Neuroscience, University of Glasgow, Glasgow G12 8QQ, Scotland
- Division of psychology, VISE, Faculty of Education and Psychology, University of Oulu, Oulu, Ostrobothnia FI-90014, Finland
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Peters A, Bruchmann M, Dellert T, Moeck R, Schlossmacher I, Straube T. Stimulus awareness is associated with secondary somatosensory cortex activation in an inattentional numbness paradigm. Sci Rep 2023; 13:22575. [PMID: 38114726 PMCID: PMC10730535 DOI: 10.1038/s41598-023-49857-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023] Open
Abstract
While inattentional blindness and deafness studies have revealed neural correlates of consciousness (NCC) without the confound of task relevance in the visual and auditory modality, comparable studies for the somatosensory modality are lacking. Here, we investigated NCC using functional magnetic resonance imaging (fMRI) in an inattentional numbness paradigm. Participants (N = 44) received weak electrical stimulation on the left hand while solving a demanding visual task. Half of the participants were informed that task-irrelevant weak tactile stimuli above the detection threshold would be applied during the experiment, while the other half expected stimuli below the detection threshold. Unexpected awareness assessments after the experiment revealed that altogether 10 participants did not consciously perceive the somatosensory stimuli during the visual task. Awareness was not significantly modulated by prior information. The fMRI data show that awareness of stimuli led to increased activation in the contralateral secondary somatosensory cortex. We found no significant effects of stimulus awareness in the primary somatosensory cortex or frontoparietal areas. Thus, our results support the hypothesis that somatosensory stimulus awareness is mainly based on activation in higher areas of the somatosensory cortex and does not require strong activation in extended anterior or posterior networks, which is usually seen when perceived stimuli are task-relevant.
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Affiliation(s)
- Antje Peters
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany.
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149, Münster, Germany.
| | - Maximilian Bruchmann
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149, Münster, Germany
| | - Torge Dellert
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149, Münster, Germany
| | - Robert Moeck
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany
| | - Insa Schlossmacher
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149, Münster, Germany
| | - Thomas Straube
- Institute of Medical Psychology and Systems Neuroscience, University Hospital Münster, Von-Esmarch-Straße 52, 48149, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149, Münster, Germany
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Zarei AA, Jensen W, Faghani Jadidi A, Lontis R, Atashzar SF. Gamma-band Enhancement of Functional Brain Connectivity Following Transcutaneous Electrical Nerve Stimulation. J Neural Eng 2022; 19. [PMID: 35234662 DOI: 10.1088/1741-2552/ac59a1] [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: 11/30/2021] [Accepted: 03/01/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Transcutaneous electrical nerve stimulation (TENS) has been suggested as a possible non-invasive pain treatment. However, the underlying mechanism of the analgesic effect of TENS and how brain network functional connectivity is affected following the use of TENS is not yet fully understood. The purpose of this study was to investigate the effect of high-frequency TENS on the alternation of functional brain network connectivity and the corresponding topographical changes, besides perceived sensations. APPROACH Forty healthy subjects participated in this study. EEG data and sensory profiles were recorded before and up to an hour following high-frequency TENS (100 Hz) in sham and intervention groups. Brain source activity from EEG data was estimated using the LORETA algorithm. In order to generate the brain connectivity network, the Phase lag index was calculated for all pair-wise connections of eight selected brain areas over six different frequency bands (i.e., δ, θ, α, β, γ, and 0.5-90 Hz). MAIN RESULTS The results suggested that the functional connectivity between the primary somatosensory cortex (SI) and the anterior cingulate cortex (ACC), in addition to functional connectivity between S1 and the medial prefrontal cortex (mPFC), were significantly increased in the gamma-band, following the TENS intervention. Additionally, using graph theory, several significant changes were observed in global and local characteristics of functional brain connectivity in gamma-band. SIGNIFICANCE Our observations in this paper open a neuropsychological window of understanding the underlying mechanism of TENS and the corresponding changes in functional brain connectivity, simultaneously with alternation in sensory perception.
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Affiliation(s)
- Ali Asghar Zarei
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg Universitet, Fredrik Bajers Vej 7 D3, Aalborg, 9220, DENMARK
| | - Winnie Jensen
- Center for Sensory-Motor Interaction Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Aalborg, 9220, DENMARK
| | - Armita Faghani Jadidi
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg Universitet, Fredrik Bajers Vej 7 D3, Aalborg, 9220, DENMARK
| | - Romulus Lontis
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg Universitet, Fredrik Bajers Vej 7 D3, Aalborg, 9220, DENMARK
| | - S Farokh Atashzar
- Departments of Electrical and Computer Engineering, and Mechanical and Aerospace Engineering, New York University, 5 MetroTech Center #266D Brooklyn, NY 11201, New York, New York, NY 11201, UNITED STATES
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Salemi-Mokri-Boukani P, Karimian-Sani-Varjovi H, Safari MS. The promoting effect of vagus nerve stimulation on Lempel-Ziv complexity index of consciousness. Physiol Behav 2021; 240:113553. [PMID: 34375622 DOI: 10.1016/j.physbeh.2021.113553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 10/20/2022]
Abstract
Recent studies suggest that vagus nerve stimulation (VNS) promotes cognitive and behavioral restoration after traumatic brain injuries. As vagus nerve has wide effects over the brain and visceral organs, stimulation of the sensory/visceral afferents might have a therapeutic potential to modulate the level of consciousness. One of the most important challenges in studying consciousness is objective evaluation of the consciousness level. Brain complexity that can be measured through Lempel-Ziv complexity (LZC) index was used as a novel mathematical approach for objective measurement of consciousness. The main goal of our study was to examine the effects of VNS on LZC index of consciousness. In this study, we did VNS on the anesthetized rats, and simultaneously LFPs recording was performed in two different cortical areas of primary somatosensory (S1) or visual (V1) cortex. LZC and the amplitude of slow waves were computed during different periods of VNS. We found that the LZC index during VNS period was significantly higher in both of the cortical areas of S1 and V1. Slow-wave activity decreased during VNS in S1, while there was no significant change in V1. Our findings showed that VNS can augment the consciousness level, and LZC index is a more sensitive parameter for detecting the level of consciousness.
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Affiliation(s)
- Paria Salemi-Mokri-Boukani
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Habib Karimian-Sani-Varjovi
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Brain Future Institute, Tehran, Iran
| | - Mir-Shahram Safari
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Brain Future Institute, Tehran, Iran.
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Uemura JI, Hoshino A, Igarashi G, Matsui Y, Chishima M, Hoshiyama M. Pre-stimulus alpha oscillation and post-stimulus cortical activity differ in localization between consciously perceived and missed near-threshold somatosensory stimuli. Eur J Neurosci 2021; 54:5518-5530. [PMID: 34251060 PMCID: PMC8456933 DOI: 10.1111/ejn.15388] [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: 03/18/2021] [Revised: 06/08/2021] [Accepted: 07/08/2021] [Indexed: 12/04/2022]
Abstract
Conscious perception of a near‐threshold (NT) stimulus is characterized by the pre‐ and post‐stimulus brain state. However, the power of pre‐stimulus neural oscillations and strength of post‐stimulus cortical activity that lead to conscious perception have rarely been examined in individual cortical areas. This is because most previous electro‐ and magnetoencephalography (EEG and MEG, respectively) studies involved scalp‐ and sensor‐level analyses. Therefore, we recorded MEG during a continuous NT somatosensory stimulus detection task and applied the reconstructed source data in order to identify cortical areas where the post‐stimulus cortical activity and pre‐stimulus alpha oscillation predict the conscious perception of NT somatosensory stimuli. We found that the somatosensory hierarchical processing areas, prefrontal areas and cortical areas belonging to the default mode network showed stronger cortical activity for consciously perceived trials in the post‐stimulus period, but the cortical activity in primary somatosensory area (SI) is independent of conscious perception during the early stage of NT stimulus processing. In addition, we revealed that the pre‐stimulus alpha oscillation only in SI is predictive of conscious perception. These findings suggest that the bottom‐up stream of somatosensory information flow following SI and pre‐stimulus alpha activity fluctuation in SI as a top‐down modulation are crucial constituents of conscious perception.
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Affiliation(s)
- Jun-Ichi Uemura
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Aiko Hoshino
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Go Igarashi
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Yusuke Matsui
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Makoto Chishima
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Minoru Hoshiyama
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan.,Brain and Mind Research Center, Nagoya University, Nagoya, Japan
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Neural correlates of conscious tactile perception: An analysis of BOLD activation patterns and graph metrics. Neuroimage 2020; 224:117384. [PMID: 32950689 DOI: 10.1016/j.neuroimage.2020.117384] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/10/2020] [Accepted: 09/12/2020] [Indexed: 11/23/2022] Open
Abstract
Theories of human consciousness substantially vary in the proposed spatial extent of brain activity associated with conscious perception as well as in the assumed functional alterations within the involved brain regions. Here, we investigate which local and global changes in brain activity accompany conscious somatosensory perception following electrical finger nerve stimulation, and whether there are whole-brain functional network alterations by means of graph metrics. Thirty-eight healthy participants performed a somatosensory detection task and reported their decision confidence during fMRI. For conscious tactile perception in contrast to undetected near-threshold trials (misses), we observed increased BOLD activity in the precuneus, the intraparietal sulcus, the insula, the nucleus accumbens, the inferior frontal gyrus and the contralateral secondary somatosensory cortex. For misses compared to correct rejections, bilateral secondary somatosensory cortices, supplementary motor cortex and insula showed greater activations. The analysis of whole-brain functional network topology for hits, misses and correct rejections, did not result in any significant differences in modularity, participation, clustering or path length, which was supported by Bayes factor statistics. In conclusion, for conscious somatosensory perception, our results are consistent with an involvement of (probably) domain-general brain areas (precuneus, insula, inferior frontal gyrus) in addition to somatosensory regions; our data do not support the notion of specific changes in graph metrics associated with conscious experience. For the employed somatosensory submodality of fine electrical current stimulation, this speaks for a global broadcasting of sensory content across the brain without substantial reconfiguration of the whole-brain functional network resulting in an integrative conscious experience.
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NOJIMA I, OLIVIERO A, MIMA T. Transcranial static magnetic stimulation —From bench to bedside and beyond—. Neurosci Res 2020; 156:250-255. [DOI: 10.1016/j.neures.2019.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/04/2019] [Accepted: 11/25/2019] [Indexed: 12/26/2022]
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Al E, Iliopoulos F, Forschack N, Nierhaus T, Grund M, Motyka P, Gaebler M, Nikulin VV, Villringer A. Heart-brain interactions shape somatosensory perception and evoked potentials. Proc Natl Acad Sci U S A 2020; 117:10575-10584. [PMID: 32341167 PMCID: PMC7229654 DOI: 10.1073/pnas.1915629117] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Even though humans are mostly not aware of their heartbeats, several heartbeat-related effects have been reported to influence conscious perception. It is not clear whether these effects are distinct or related phenomena, or whether they are early sensory effects or late decisional processes. Combining electroencephalography and electrocardiography, along with signal detection theory analyses, we identify two distinct heartbeat-related influences on conscious perception differentially related to early vs. late somatosensory processing. First, an effect on early sensory processing was found for the heartbeat-evoked potential (HEP), a marker of cardiac interoception. The amplitude of the prestimulus HEP negatively correlated with localization and detection of somatosensory stimuli, reflecting a more conservative detection bias (criterion). Importantly, higher HEP amplitudes were followed by decreases in early (P50) as well as late (N140, P300) somatosensory-evoked potential (SEP) amplitudes. Second, stimulus timing along the cardiac cycle also affected perception. During systole, stimuli were detected and correctly localized less frequently, relating to a shift in perceptual sensitivity. This perceptual attenuation was accompanied by the suppression of only late SEP components (P300) and was stronger for individuals with a more stable heart rate. Both heart-related effects were independent of alpha oscillations' influence on somatosensory processing. We explain cardiac cycle timing effects in a predictive coding account and suggest that HEP-related effects might reflect spontaneous shifts between interoception and exteroception or modulations of general attentional resources. Thus, our results provide a general conceptual framework to explain how internal signals can be integrated into our conscious perception of the world.
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Affiliation(s)
- Esra Al
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany;
- MindBrainBody Institute, Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Fivos Iliopoulos
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- International Max Planck Research School on the Life Course, Max Planck Institute for Human Development, 14195 Berlin, Germany
| | - Norman Forschack
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- Experimental Psychology and Methods, Faculty of Life Sciences, University of Leipzig, 04109 Leipzig, Germany
| | - Till Nierhaus
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- Neurocomputation and Neuroimaging Unit, Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Martin Grund
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
| | - Paweł Motyka
- Faculty of Psychology, University of Warsaw, 00-927 Warsaw, Poland
| | - Michael Gaebler
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- MindBrainBody Institute, Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Vadim V Nikulin
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
- Institute of Cognitive Neuroscience, National Research University Higher School of Economics, 101000 Moscow, Russia
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany;
- MindBrainBody Institute, Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
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Influence of multiple hypothesis testing on reproducibility in neuroimaging research: A simulation study and Python-based software. J Neurosci Methods 2020; 337:108654. [PMID: 32114144 DOI: 10.1016/j.jneumeth.2020.108654] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/26/2020] [Accepted: 02/26/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Reproducibility of research findings has been recently questioned in many fields of science, including psychology and neurosciences. One factor influencing reproducibility is the simultaneous testing of multiple hypotheses, which entails false positive findings unless the analyzed p-values are carefully corrected. While this multiple testing problem is well known and studied, it continues to be both a theoretical and practical problem. NEW METHOD Here we assess reproducibility in simulated experiments in the context of multiple testing. We consider methods that control either the family-wise error rate (FWER) or false discovery rate (FDR), including techniques based on random field theory (RFT), cluster-mass based permutation testing, and adaptive FDR. Several classical methods are also considered. The performance of these methods is investigated under two different models. RESULTS We found that permutation testing is the most powerful method among the considered approaches to multiple testing, and that grouping hypotheses based on prior knowledge can improve power. We also found that emphasizing primary and follow-up studies equally produced most reproducible outcomes. COMPARISON WITH EXISTING METHOD(S) We have extended the use of two-group and separate-classes models for analyzing reproducibility and provide a new open-source software "MultiPy" for multiple hypothesis testing. CONCLUSIONS Our simulations suggest that performing strict corrections for multiple testing is not sufficient to improve reproducibility of neuroimaging experiments. The methods are freely available as a Python toolkit "MultiPy" and we aim this study to help in improving statistical data analysis practices and to assist in conducting power and reproducibility analyses for new experiments.
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Neuronal correlates of full and partial visual conscious perception. Conscious Cogn 2019; 78:102863. [PMID: 31887533 DOI: 10.1016/j.concog.2019.102863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 11/20/2022]
Abstract
Stimuli may induce only partial consciousness-an intermediate between null and full consciousness-where the presence but not identity of an object can be reported. The differences in the neuronal basis of full and partial consciousness are poorly understood. We investigated if evoked and oscillatory activity could dissociate full from partial conscious perception. We recorded human cortical activity with magnetoencephalography (MEG) during a visual perception task in which stimulus could be either partially or fully perceived. Partial consciousness was associated with an early increase in evoked activity and theta/low-alpha-band oscillations while full consciousness was also associated with late evoked activity and beta-band oscillations. Full from partial consciousness was dissociated by stronger evoked activity and late increase in theta oscillations that were localized to higher-order visual regions and posterior parietal and prefrontal cortices. Our results reveal both evoked activity and theta oscillations dissociate partial and full consciousness.
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12
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He B, Astolfi L, Valdés-Sosa PA, Marinazzo D, Palva SO, Bénar CG, Michel CM, Koenig T. Electrophysiological Brain Connectivity: Theory and Implementation. IEEE Trans Biomed Eng 2019; 66:10.1109/TBME.2019.2913928. [PMID: 31071012 PMCID: PMC6834897 DOI: 10.1109/tbme.2019.2913928] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We review the theory and algorithms of electrophysiological brain connectivity analysis. This tutorial is aimed at providing an introduction to brain functional connectivity from electrophysiological signals, including electroencephalography (EEG), magnetoencephalography (MEG), electrocorticography (ECoG), stereoelectroencephalography (SEEG). Various connectivity estimators are discussed, and algorithms introduced. Important issues for estimating and mapping brain functional connectivity with electrophysiology are discussed.
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Affiliation(s)
- Bin He
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, USA
| | - Laura Astolfi
- Department of Computer, Control and Management Engineering, University of Rome Sapienza, and with IRCCS Fondazione Santa Lucia, Rome, Italy
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10 Hz transcranial alternating current stimulation over posterior parietal cortex facilitates tactile temporal order judgment. Behav Brain Res 2019; 368:111899. [PMID: 30978408 DOI: 10.1016/j.bbr.2019.111899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 01/10/2023]
Abstract
The temporal order judgment (TOJ) task has been widely used to investigate spatial attentional bias and the sensitivity of temporal discrimination during the processing of bilateral tactile information. Previous studies have shown that TOJ is impaired in patients who are suffering from chronic pain, stroke, and Parkinson's disease. In addition, studies have indicated that the posterior parietal cortex (PPC) is involved in the TOJ task. However, the neural basis of the TOJ task has not been fully elucidated. To investigate the causal relationship between cortical oscillation and certain behaviors, transcranial alternating current stimulation (tACS) has been used. tACS can entrain an oscillation in the cortex to the applying frequency. In previous studies, increased alpha-band (around 10 Hz) oscillation in the PPC is associated with attentional inhibition of the contralateral side. Therefore, we hypothesized that 10 Hz tACS over PPC would inhibit tactile processing in the contralateral side, leading to ipsilateral spatial attentional bias and impaired temporal discrimination. However, we found that 10 Hz tACS over either side of the PPC facilitated temporal discrimination, with 10 Hz tACS over the right PPC leading to a rightward shift of attentional bias. These findings indicated that 10 Hz tACS over the PPC has a facilitative effect in the processing of bilateral tactile information, and may be useful for modulating or treating spatial bias or temporal discrimination during the integration of bilateral stimulation, at least in the somatosensory domain.
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Schröder P, Schmidt TT, Blankenburg F. Neural basis of somatosensory target detection independent of uncertainty, relevance, and reports. eLife 2019; 8:43410. [PMID: 30924769 PMCID: PMC6440741 DOI: 10.7554/elife.43410] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/19/2019] [Indexed: 01/04/2023] Open
Abstract
Research on somatosensory awareness has yielded highly diverse findings with putative neural correlates ranging from activity within somatosensory cortex to activation of widely distributed frontoparietal networks. Divergent results from previous studies may reside in cognitive processes that often coincide with stimulus awareness in experimental settings. To scrutinise the specific relevance of regions implied in the target detection network, we used functional magnetic resonance imaging (n = 27) on a novel somatosensory detection task that explicitly controls for stimulus uncertainty, behavioural relevance, overt reports, and motor responses. Using Bayesian Model Selection, we show that responses reflecting target detection are restricted to secondary somatosensory cortex, whereas activity in insular, cingulate, and motor regions is best explained in terms of stimulus uncertainty and overt reports. Our results emphasise the role of sensory-specific cortex for the emergence of perceptual awareness and dissect the contribution of the frontoparietal network to classical detection tasks.
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Affiliation(s)
- Pia Schröder
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, Berlin, Germany
| | - Timo Torsten Schmidt
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, Berlin, Germany
| | - Felix Blankenburg
- Neurocomputation and Neuroimaging Unit, Freie Universität Berlin, Berlin, Germany
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15
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Hirvonen J, Monto S, Wang SH, Palva JM, Palva S. Dynamic large-scale network synchronization from perception to action. Netw Neurosci 2018; 2:442-463. [PMID: 30320293 PMCID: PMC6175692 DOI: 10.1162/netn_a_00039] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/19/2017] [Indexed: 12/13/2022] Open
Abstract
Sensory-guided actions entail the processing of sensory information, generation of perceptual decisions, and the generation of appropriate actions. Neuronal activity underlying these processes is distributed into sensory, fronto-parietal, and motor brain areas, respectively. How the neuronal processing is coordinated across these brain areas to support functions from perception to action remains unknown. We investigated whether phase synchronization in large-scale networks coordinate these processes. We recorded human cortical activity with magnetoencephalography (MEG) during a task in which weak somatosensory stimuli remained unperceived or were perceived. We then assessed dynamic evolution of phase synchronization in large-scale networks from source-reconstructed MEG data by using advanced analysis approaches combined with graph theory. Here we show that perceiving and reporting of weak somatosensory stimuli is correlated with sustained strengthening of large-scale synchrony concurrently in delta/theta (3-7 Hz) and gamma (40-60 Hz) frequency bands. In a data-driven network localization, we found this synchronization to dynamically connect the task-relevant, that is, the fronto-parietal, sensory, and motor systems. The strength and temporal pattern of interareal synchronization were also correlated with the response times. These data thus show that key brain areas underlying perception, decision-making, and actions are transiently connected by large-scale dynamic phase synchronization in the delta/theta and gamma bands.
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Affiliation(s)
- Jonni Hirvonen
- Helsinki Institute for Life Sciences, Neuroscience Center, University of Helsinki, Finland
| | - Simo Monto
- Helsinki Institute for Life Sciences, Neuroscience Center, University of Helsinki, Finland
| | - Sheng H Wang
- Helsinki Institute for Life Sciences, Neuroscience Center, University of Helsinki, Finland
| | - J Matias Palva
- Helsinki Institute for Life Sciences, Neuroscience Center, University of Helsinki, Finland
| | - Satu Palva
- Helsinki Institute for Life Sciences, Neuroscience Center, University of Helsinki, Finland
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16
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Cortical dynamics underpinning the self-other distinction of touch: A TMS-EEG study. Neuroimage 2018; 178:475-484. [DOI: 10.1016/j.neuroimage.2018.05.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/09/2018] [Accepted: 05/31/2018] [Indexed: 01/10/2023] Open
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17
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Rajaei N, Aoki N, Takahashi HK, Miyaoka T, Kochiyama T, Ohka M, Sadato N, Kitada R. Brain networks underlying conscious tactile perception of textures as revealed using the velvet hand illusion. Hum Brain Mapp 2018; 39:4787-4801. [PMID: 30096223 DOI: 10.1002/hbm.24323] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/29/2018] [Accepted: 07/11/2018] [Indexed: 01/26/2023] Open
Abstract
Humans are adept at perceiving textures through touch. Previous neuroimaging studies have identified a distributed network of brain regions involved in the tactile perception of texture. However, it remains unclear how nodes in this network contribute to the tactile awareness of texture. To examine the hypothesis that such awareness involves the interaction of the primary somatosensory cortex with higher order cortices, we conducted a functional magnetic resonance imaging (fMRI) study utilizing the velvet hand illusion, in which an illusory velvet-like surface is perceived between the hands. Healthy participants were subjected to a strong illusion, a weak illusion, and tactile perception of real velvet. The strong illusion induced greater activation in the primary somatosensory cortex (S1) than the weak illusion, and increases in such activation were positively correlated with the strength of the illusion. Furthermore, both actual and illusory perception of velvet induced common activation in S1. Psychophysiological interaction (PPI) analysis revealed that the strength of the illusion modulated the functional connectivity of S1 with each of the following regions: the parietal operculum, superior parietal lobule, precentral gyrus, insula, and cerebellum. The present results indicate that S1 is associated with the conscious tactile perception of textures, which may be achieved via interactions with higher order somatosensory areas.
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Affiliation(s)
- Nader Rajaei
- Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, Japan.,Graduate School of Information Science, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Naoya Aoki
- Division of Cerebral Integration, National Institute for Physiological Sciences, Okazaki, Japan.,The Graduate University for Advanced Studies, Hayama, Japan
| | | | - Tetsu Miyaoka
- Shizuoka institute of Science and Technology, Fukuroi, Shizuoka, Japan
| | | | - Masahiro Ohka
- Graduate School of Information Science, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Norihiro Sadato
- Division of Cerebral Integration, National Institute for Physiological Sciences, Okazaki, Japan.,The Graduate University for Advanced Studies, Hayama, Japan
| | - Ryo Kitada
- Division of Psychology, School of Social Sciences, Nanyang Technological University, Singapore
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18
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Key B, Brown D. Designing Brains for Pain: Human to Mollusc. Front Physiol 2018; 9:1027. [PMID: 30127750 PMCID: PMC6088194 DOI: 10.3389/fphys.2018.01027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/11/2018] [Indexed: 12/16/2022] Open
Abstract
There is compelling evidence that the "what it feels like" subjective experience of sensory stimuli arises in the cerebral cortex in both humans as well as mammalian experimental animal models. Humans are alone in their ability to verbally communicate their experience of the external environment. In other species, sensory awareness is extrapolated on the basis of behavioral indicators. For instance, cephalopods have been claimed to be sentient on the basis of their complex behavior and anecdotal reports of human-like intelligence. We have interrogated the findings of avoidance learning behavioral paradigms and classical brain lesion studies and conclude that there is no evidence for cephalopods feeling pain. This analysis highlighted the questionable nature of anthropometric assumptions about sensory experience with increased phylogenetic distance from humans. We contend that understanding whether invertebrates such as molluscs are sentient should first begin with defining the computational processes and neural circuitries underpinning subjective awareness. Using fundamental design principles, we advance the notion that subjective awareness is dependent on observer neural networks (networks that in some sense introspect the neural processing generating neural representations of sensory stimuli). This introspective process allows the observer network to create an internal model that predicts the neural processing taking place in the network being surveyed. Predictions arising from the internal model form the basis of a rudimentary form of awareness. We develop an algorithm built on parallel observer networks that generates multiple levels of sensory awareness. A network of cortical regions in the human brain has the appropriate functional properties and neural interconnectivity that is consistent with the predicted circuitry of the algorithm generating pain awareness. By contrast, the cephalopod brain lacks the necessary neural circuitry to implement such an algorithm. In conclusion, we find no compelling behavioral, functional, or neuroanatomical evidence to indicate that cephalopods feel pain.
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Affiliation(s)
- Brian Key
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Deborah Brown
- School of Historical and Philosophical Inquiry, University of Queensland, Brisbane, QLD, Australia
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19
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Static Magnetic Field Stimulation over Parietal Cortex Enhances Somatosensory Detection in Humans. J Neurosci 2017; 37:3840-3847. [PMID: 28280254 DOI: 10.1523/jneurosci.2123-16.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 02/25/2017] [Accepted: 03/01/2017] [Indexed: 02/07/2023] Open
Abstract
The role of neuronal oscillations in human somatosensory perception is currently unclear. To address this, here we use noninvasive brain stimulation to artificially modulate cortical network dynamics in the context of neurophysiological and behavioral recordings. We demonstrate that transcranial static magnetic field stimulation (tSMS) over the somatosensory parietal cortex increases oscillatory power specifically in the alpha range, without significantly affecting bottom-up thalamocortical inputs indexed by the early cortical component of somatosensory evoked potentials. Critically, we next show that parietal tSMS enhances the detection of near-threshold somatosensory stimuli. Interestingly, this behavioral improvement reflects a decrease of habituation to somatosensation. Our data therefore provide causal evidence that somatosensory perception depends on parietal alpha activity.SIGNIFICANCE STATEMENT Artificially increasing alpha power by placing a powerful magnetic field over the somatosensory cortex overcomes the natural decline in detection probability of a repeated near-threshold sensory stimulus.
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20
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Neuroimaging somatosensory perception and masking. Neuropsychologia 2016; 94:44-51. [PMID: 27894900 DOI: 10.1016/j.neuropsychologia.2016.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 11/16/2016] [Accepted: 11/23/2016] [Indexed: 01/21/2023]
Abstract
The specific cortical and subcortical regions involved in conscious perception and masking are uncertain. This study sought to identify brain areas involved in conscious perception of somatosensory stimuli during a masking task using functional magnetic resonance (fMRI) to contrast perceived vs. non-perceived targets. Electrical trains were delivered to the right index finger for targets and to the left index finger for masks. Target intensities were adjusted to compensate for threshold drift. Sham target trials were given in ~10% of the trials, and target stimuli without masks were delivered in one of the five runs (68 trials/run). When healthy dextral adult volunteers (n=15) perceived right hand targets, greater left- than right-cerebral activations were seen with similar patterns across the parietal cortex, thalamus, insula, claustrum, and midbrain. When targets were not perceived, left/right cerebral activations were similar overall. Directly comparing perceived vs. non-perceived stimuli with similar intensities in the masking task revealed predominate activations contralateral to masks. In contrast, activations were greater contralateral to perceived targets if no masks were given or if masks were given but target stimulus intensities were greater for perceived than non-perceived targets. The novel aspects of this study include: 1) imaging of cortical and subcortical activations in healthy humans related to somatosensory perception during a masking task, 2) activations in the human thalamus and midbrain related to perception of stimuli compared to matched non-perceived stimuli, and 3) similar left/right cerebral activation patterns across cortical, thalamic and midbrain structures suggesting interactions across all three levels during conscious perception in humans.
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21
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Ewerdwalbesloh JA, Palva S, Rösler F, Khader PH. Neural correlates of maintaining generated images in visual working memory. Hum Brain Mapp 2016; 37:4349-4362. [PMID: 27411499 DOI: 10.1002/hbm.23313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 07/03/2016] [Accepted: 07/06/2016] [Indexed: 11/07/2022] Open
Abstract
How are images that have been assembled from their constituting elements maintained as a coherent representation in visual working memory (vWM)? Here, we compared two conditions of vWM maintenance that only differed in how vWM contents had been created. Participants maintained images that they either had to assemble from single features or that they had perceived as complete objects. Object complexity varied between two and four features. We analyzed electroencephalogram phase coupling as a measure of cortical connectivity in a time interval immediately before a probe stimulus appeared. We assumed that during this time both groups maintained essentially the same images, but that images constructed from their elements would require more neural coupling than images based on a complete percept. Increased coupling between frontal and parietal-to-occipital cortical sources was found for the maintenance of constructed in comparison to nonconstructed objects in the theta, alpha, beta, and gamma frequency bands. A similar pattern was found for an increase in vWM load (2 vs. 4 features) for nonconstructed objects. Under increased construction load (2 vs. 4 features for constructed images), the pattern was restricted to fronto-parietal couplings, suggesting that the fronto-parietal attention network is coping with the higher attentional demands involved in maintaining constructed images, but without increasing the communication with the occipital visual buffer in which the visual representations are assumed to be stored. We conclude from these findings that the maintenance of constructed images in vWM requires additional attentional processes to keep object elements together as a coherent representation. Hum Brain Mapp 37:4349-4362, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Satu Palva
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Frank Rösler
- Biological Psychology and Neuropsychology, Universität Hamburg, Hamburg, Germany
| | - Patrick H Khader
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
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22
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Tozzi A, Peters JF. Towards a fourth spatial dimension of brain activity. Cogn Neurodyn 2016; 10:189-99. [PMID: 27275375 DOI: 10.1007/s11571-016-9379-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/19/2016] [Accepted: 01/28/2016] [Indexed: 12/19/2022] Open
Abstract
Current advances in neurosciences deal with the functional architecture of the central nervous system, paving the way for general theories that improve our understanding of brain activity. From topology, a strong concept comes into play in understanding brain functions, namely, the 4D space of a "hypersphere's torus", undetectable by observers living in a 3D world. The torus may be compared with a video game with biplanes in aerial combat: when a biplane flies off one edge of gaming display, it does not crash but rather it comes back from the opposite edge of the screen. Our thoughts exhibit similar behaviour, i.e. the unique ability to connect past, present and future events in a single, coherent picture as if we were allowed to watch the three screens of past-present-future "glued" together in a mental kaleidoscope. Here we hypothesize that brain functions are embedded in a imperceptible fourth spatial dimension and propose a method to empirically assess its presence. Neuroimaging fMRI series can be evaluated, looking for the topological hallmark of the presence of a fourth dimension. Indeed, there is a typical feature which reveal the existence of a functional hypersphere: the simultaneous activation of areas opposite each other on the 3D cortical surface. Our suggestion-substantiated by recent findings-that brain activity takes place on a closed, donut-like trajectory helps to solve long-standing mysteries concerning our psychological activities, such as mind-wandering, memory retrieval, consciousness and dreaming state.
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Affiliation(s)
- Arturo Tozzi
- Center for Nonlinear Science, University of North Texas, 1155 Union Circle, #311427, Denton, TX 76203-5017 USA
| | - James F Peters
- Department of Electrical and Computer Engineering, University of Manitoba, 75A Chancellor's Circle, Winnipeg, MB R3T 5V6 Canada
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