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Thirion B, Aggarwal H, Ponce AF, Pinho AL, Thual A. Should one go for individual- or group-level brain parcellations? A deep-phenotyping benchmark. Brain Struct Funct 2024; 229:161-181. [PMID: 38012283 DOI: 10.1007/s00429-023-02723-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/11/2023] [Indexed: 11/29/2023]
Abstract
The analysis and understanding of brain characteristics often require considering region-level information rather than voxel-sampled data. Subject-specific parcellations have been put forward in recent years, as they can adapt to individual brain organization and thus offer more accurate individual summaries than standard atlases. However, the price to pay for adaptability is the lack of group-level consistency of the data representation. Here, we investigate whether the good representations brought by individualized models are merely an effect of circular analysis, in which individual brain features are better represented by subject-specific summaries, or whether this carries over to new individuals, i.e., whether one can actually adapt an existing parcellation to new individuals and still obtain good summaries in these individuals. For this, we adapt a dictionary-learning method to produce brain parcellations. We use it on a deep-phenotyping dataset to assess quantitatively the patterns of activity obtained under naturalistic and controlled-task-based settings. We show that the benefits of individual parcellations are substantial, but that they vary a lot across brain systems.
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Affiliation(s)
| | | | | | - Ana Luísa Pinho
- Department of Computer Science, Western University, London, ON, Canada
- Western Institute for Neuroscience, Western University, London, ON, Canada
| | - Alexis Thual
- Inria, CEA, Université Paris-Saclay, 91120, Palaiseau, France
- Inserm, Collège de France, Paris, France
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Colombo MA, Comanducci A, Casarotto S, Derchi CC, Annen J, Viganò A, Mazza A, Trimarchi PD, Boly M, Fecchio M, Bodart O, Navarro J, Laureys S, Gosseries O, Massimini M, Sarasso S, Rosanova M. Beyond alpha power: EEG spatial and spectral gradients robustly stratify disorders of consciousness. Cereb Cortex 2023:7091601. [PMID: 36977648 DOI: 10.1093/cercor/bhad031] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 03/30/2023] Open
Abstract
Neurophysiological markers can overcome the limitations of behavioural assessments of Disorders of Consciousness (DoC). EEG alpha power emerged as a promising marker for DoC, although long-standing literature reported alpha power being sustained during anesthetic-induced unconsciousness, and reduced during dreaming and hallucinations. We hypothesized that EEG power suppression caused by severe anoxia could explain this conflict. Accordingly, we split DoC patients (n = 87) in postanoxic and non-postanoxic cohorts. Alpha power was suppressed only in severe postanoxia but failed to discriminate un/consciousness in other aetiologies. Furthermore, it did not generalize to an independent reference dataset (n = 65) of neurotypical, neurological, and anesthesia conditions. We then investigated EEG spatio-spectral gradients, reflecting anteriorization and slowing, as alternative markers. In non-postanoxic DoC, these features, combined in a bivariate model, reliably stratified patients and indexed consciousness, even in unresponsive patients identified as conscious by an independent neural marker (the Perturbational Complexity Index). Crucially, this model optimally generalized to the reference dataset. Overall, alpha power does not index consciousness; rather, its suppression entails diffuse cortical damage, in postanoxic patients. As an alternative, EEG spatio-spectral gradients, reflecting distinct pathophysiological mechanisms, jointly provide a robust, parsimonious, and generalizable marker of consciousness, whose clinical application may guide rehabilitation efforts.
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Affiliation(s)
| | - Angela Comanducci
- IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome 00128, Italy
| | - Silvia Casarotto
- Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
- IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
| | | | - Jitka Annen
- Coma Science Group, GIGA-Consciousness, University of Liège and Centre du Cerveau2, University Hospital of Liège, Liège 4000, Belgium
| | | | - Alice Mazza
- IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
| | | | - Melanie Boly
- Department of Neurology and Department of Psychiatry, University of Wisconsin, Madison, WI 53705-2281, USA
| | - Matteo Fecchio
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Olivier Bodart
- Coma Science Group, GIGA-Consciousness, University of Liège and Centre du Cerveau2, University Hospital of Liège, Liège 4000, Belgium
| | - Jorge Navarro
- IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University of Liège and Centre du Cerveau2, University Hospital of Liège, Liège 4000, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège and Centre du Cerveau2, University Hospital of Liège, Liège 4000, Belgium
| | - Marcello Massimini
- Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
- IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
| | - Simone Sarasso
- Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
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